Objective This study employs the Geographically and Temporally Weighted Regression(GTWR)model to assess the impact of meteorological elements and imported cases on dengue fever outbreaks,emphasizing the spatial-tempor...Objective This study employs the Geographically and Temporally Weighted Regression(GTWR)model to assess the impact of meteorological elements and imported cases on dengue fever outbreaks,emphasizing the spatial-temporal variability of these factors in border regions.Methods We conducted a descriptive analysis of dengue fever’s temporal-spatial distribution in Yunnan border areas.Utilizing annual data from 2013 to 2019,with each county in the Yunnan border serving as a spatial unit,we constructed a GTWR model to investigate the determinants of dengue fever and their spatio-temporal heterogeneity in this region.Results The GTWR model,proving more effective than Ordinary Least Squares(OLS)analysis,identified significant spatial and temporal heterogeneity in factors influencing dengue fever’s spread along the Yunnan border.Notably,the GTWR model revealed a substantial variation in the relationship between indigenous dengue fever incidence,meteorological variables,and imported cases across different counties.Conclusion In the Yunnan border areas,local dengue incidence is affected by temperature,humidity,precipitation,wind speed,and imported cases,with these factors’influence exhibiting notable spatial and temporal variation.展开更多
Rationale:Pituitary apoplexy(PA)is a rare endocrine emergency that requires prompt diagnosis and management.Dengue fever-induced-thrombocytopenia may rarely predispose to PA.Patient’s Concern:A 58-year-old male patie...Rationale:Pituitary apoplexy(PA)is a rare endocrine emergency that requires prompt diagnosis and management.Dengue fever-induced-thrombocytopenia may rarely predispose to PA.Patient’s Concern:A 58-year-old male patient having known pituitary macroadenoma presented to the emergency department with fever,a sudden onset severe headache,and altered sensorium.Diagnosis:Pituitary apoplexy caused by dengue fever-induced-thrombocytopenia.Interventions:Conservative management with fluids,mannitol,dexamethasone and symptomatic treatment.Outcomes:The patient responded well to the treatment and was discharged uneventfully.Lessons:Although dengue hemorrhagic fever is a rare cause of pituitary apoplexy,it should be considered if a patient presents with headache and altered sensorium,and prompt initiation of treatment is crucial to prevent fatality and neuro-ophthalmic deficits.展开更多
Objective To explore the associations between the monthly number of dengue fever(DF) cases and possible risk factors in Guangzhou, a subtropical city of China. Methods The monthly number of DF cases, Breteau Index ...Objective To explore the associations between the monthly number of dengue fever(DF) cases and possible risk factors in Guangzhou, a subtropical city of China. Methods The monthly number of DF cases, Breteau Index (BI), and meteorological measures during 2006-2014 recorded in Guangzhou, China, were assessed. A negative binomial regression model was used to evaluate the relationships between BI, meteorological factors, and the monthly number of DF cases. Results A total of 39,697 DF cases were detected in Guangzhou during the study period. DF incidence presented an obvious seasonal pattern, with most cases occurring from June to November. The current month's BI, average temperature (Tare), previous month's minimum temperature (Train), and Tare were positively associated with DF incidence. A threshold of 18.25℃ was found in the relationship between the current month's Tmin and DF incidence. Conclusion Mosquito density, Tove, and Tmin play a critical role in DF transmission in Guangzhou. These findings could be useful in the development of a DF early warning system and assist in effective control and prevention strategies in the DF epidemic.展开更多
Ecological methodology plus negative binomial regression were used to identify dengue fever (DF) epidemiological status and its relationship with meteorological variables. From 2007 to 2012, annual incidence rate of...Ecological methodology plus negative binomial regression were used to identify dengue fever (DF) epidemiological status and its relationship with meteorological variables. From 2007 to 2012, annual incidence rate of DF in Guangzhou was 0.33, 0.11, 0.15, 0.64, 0.45, and 1.34 (per 100 000) respectively, showing an increasing trend. Each 1℃ rise of temperature corresponded to an increase of 10.23% (95% CI 7.68% to 12.83%) in the monthly number of DF cases, whereas l hPa rise of atmospheric pressure corresponded to a decrease in the number of cases by 5.14% (95% CI: 7.10%-3.14%). Likewise, each one meter per second rise in wind velocity led to an increase by 43.80% or 107.53%, and one percent rise of relative humidity led to an increase by 2.04% or 2.19%.展开更多
Dengue fever (DF), one of the neglected tropical diseases also known as breakbone fever, is a mosquito-borne disease common in the tropics and subtropics. Dengue fever is transmitted primarily by A.aegypti, resultin...Dengue fever (DF), one of the neglected tropical diseases also known as breakbone fever, is a mosquito-borne disease common in the tropics and subtropics. Dengue fever is transmitted primarily by A.aegypti, resulting in infection with any of four distinct but closely related virus serotypes. The majority of infected people experience a self-limiting clinical course. A small proportion of cases develop into life-threatening Dengue Hemorrhagic Fever or Dengue Shock Syndrome.展开更多
Objective: To correlate climatic and environmental factors such as land surface temperature, rainfall, humidity and normalized difference vegetation index with the incidence of dengue to develop prediction models for ...Objective: To correlate climatic and environmental factors such as land surface temperature, rainfall, humidity and normalized difference vegetation index with the incidence of dengue to develop prediction models for the Philippines using remote-sensing data.Methods: Timeseries analysis was performed using dengue cases in four regions of the Philippines and monthly climatic variables extracted from Global Satellite Mapping of Precipitation for rainfall, and MODIS for the land surface temperature and normalized difference vegetation index from 2008-2015.Consistent dataset during the period of study was utilized in Autoregressive Integrated Moving Average models to predict dengue incidence in the four regions being studied.Results: The best-fitting models were selected to characterize the relationship between dengue incidence and climate variables.The predicted cases of dengue for January to December 2015 period fitted well with the actual dengue cases of the same timeframe.It also showed significantly good linear regression with a square of correlation of 0.869 5 for the four regions combined.Conclusion: Climatic and environmental variables are positively associated with dengue incidence and suit best as predictor factors using Autoregressive Integrated Moving Average models.This finding could be a meaningful tool in developing an early warning model based on weather forecasts to deliver effective public health prevention and mitigation programs.展开更多
Summary:A multi-centred study was designed to collect dengue epidemiologic data from government and registered private hospitals/clinics and maintained archive of frozen specimens in bio-bank to be used for future de...Summary:A multi-centred study was designed to collect dengue epidemiologic data from government and registered private hospitals/clinics and maintained archive of frozen specimens in bio-bank to be used for future dengue epidemic control program, and assess the epidemiology of dengue fever(DF) by evaluating biochemical and oxidative status of patients. ELISA Ig M antibodies test was done to confirm DF. From August 2010 to December 2011, 101 confirmed blood samples of DF patients referred to pathology lab of Jinnah Hospital Lahore were subjected to the epidemiologic assessment by evaluating the biochemical and physiological indices and alterations of circulating antioxidants. Clinical features of DF patients and effect of fever on blood components and serum proteins of liver were recorded. The hospital stay in DF, dengue hemorrhagic fever(DHF) and dengue shock syndrome(DSS) showed significant difference. Significant increases in serum alanine amino transferase(ALT)(P=0.000), aspartate amino transferase(AST)(P=0.000), alkaline phosphatase(ALP)(P=0.000), malondialdehyde(MDA) along with significant decreases in total protein(TP)(P=0.000), reduced glutathione(GSH)(P=0.000), superoxide dismutase(SOD), catalase(CAT)(P=0.000), and sialic acid contents(P=0.016) were observed. A positive correlation existed between bound sialic acid levels, liver enzymes and circulating antioxidants(r=0.656, P=0.016). In the present study, alterations of circulating antioxidants in DF suggest that DF might be a metabolic response to an acute, self-limiting tropical viral infection, and a consequence of the viral inflammatory process.展开更多
Two patients aged of 30 and 22(female in cases 1,and male in case 2) both complained of unilateral blurring of vision and scotoma within a week of being diagnosed with dengue fever.No other abnormal findings were foun...Two patients aged of 30 and 22(female in cases 1,and male in case 2) both complained of unilateral blurring of vision and scotoma within a week of being diagnosed with dengue fever.No other abnormal findings were found in their anterior segment.Retinal examination revealed blurring of the optic disc margin and several white spots in the posterior in both cases.Optical coherence tomography(OCT)imagery revealed that the white spots were only located in the retinal outer layers.Macular cystic foveolitis were also found in case 1 and diffused macular edema in case 2.In case 1,visual and retinal recovery were seen to resolve spontaneously.In case 2,patient had complete visual recovery two months after onset of the disease after being treated with steroids but central scotomata has continued to persist.展开更多
Dengue fever is widespread in all tropical and subtropical areas of the world and is the main public health problem posed by arboviroses. In Burkina Faso, an outbreak of dengue serotype “DENV-2”, which is responsibl...Dengue fever is widespread in all tropical and subtropical areas of the world and is the main public health problem posed by arboviroses. In Burkina Faso, an outbreak of dengue serotype “DENV-2”, which is responsible for severe forms of dengue, has been reported. In this study, we will discuss liver damage during this disease. The aim of this study was to describe the sociodemographic, diagnostic, therapeutic and evolutionary aspects of dengue patients with hepatic cytolysis. Patients and Methods: This was a prospective cross-sectional study of dengue disease in 2 facilities in the city of Ouagadougou. The study was spread over a period of 3 months from August to November 2019. The study population consisted of all patients hospitalised for dengue with a positive AgNS1 and/or IgM rapid diagnostic test (RDT) and presenting signs of liver damage. Results: During our study period we recruited 134 patients with dengue fever of which 93 or 69.4% had at least one elevated transaminase. The sex ratio was 1.90 and the average age was 35 years. Symptoms of liver damage were rare with right hypochondrial pain in 4.30% of cases and jaundice in 1.07% of cases. Dengue haemorrhagic fever was found in 5 patients. IgG was negative in 77.42%. The majority of patients (44% or 47.31%) had at least one transaminase value elevated to the upper limit of normal (ULN);and a minority, 14 patients or 15.06%, had transaminases above 10 ULN. A small proportion of patients had hepatocellular failure 26.92% with a lowered prothrombin level. Ninety-four per cent (94.62%) of the patients received analgesics. Level 1 analgesic (paracetamol) was the most widely administered, particularly in 76 patients (86.36%). More than half of the patients (57.14%) had a length of stay of less than or equal to 3 days and the outcome was favourable in 91.40%. Conclusion: Dengue virus causes alterations in the liver parenchyma. The degree of liver damage is variable. As clinical symptoms are almost non-existent, the measurement of transaminases remains important.展开更多
Either dengue fever or diabetic ketoacidosis can cause the high hemoglobin concentration due to intravascular volume loss.When both entities were found together as in our case,the hemoglobin concentration could access...Either dengue fever or diabetic ketoacidosis can cause the high hemoglobin concentration due to intravascular volume loss.When both entities were found together as in our case,the hemoglobin concentration could access the strikingly high level until either of them could not contribute it.She was a Thai woman with 46 years of age presenting with fever,fatigue and severe sore throat for a few days.The physical examination showed she had mild dyspnea and oral thrush,the temperature was 36.4 degree Celsius,and her pulse rate was 102/min.Her blood tests showed:Hb 18.3 g%,WBC 9,850/mm^(3),atypical lymphocyte 10%,platelet 16,000/mm^(3),MCV 89.2 fl,Dengue NS1 antigen-positive,dengue IgG-positive,IgM-weakly positive,KOH preparation of curd from buccal mucosa-positive for budding yeasts and pseudo-hyphae,blood sugar 442 mg%,triglyceride 578 mg%,Na 122.8 mEq/L,K 6.28 mEq/L,Cl 90.6 mEq/L,CO_(2)9.2 mEq/L,blood ketone 53.6 mmol/L,lactate 4.5 mmol/L,pH 7.257,pCO_(2)27.4 mmHg,HCO_(3)11.9 mmo/L,BUN 22.9 mg%,creatinine 0.64 mg%,AST 375 U/L,ALT 224 U/L,alkaline phosphatase 151 U/L.She was diagnosed as having diabetes with diabetic ketoacidosis,dengue fever and polycythemia.She was immediately treated with intravenous fluid therapy to correct the metabolic acidosis,electrolyte imbalance and dehydration,insulin for hyperglycemia,clotrimazole for oral thrush and platelet transfusion.Her high hemoglobin level was dramatically lowered until became normal within one day of therapy whereas she also recovered from DKA although the platelet was progressively lowered every day.It suggested that transient polycythemia was solely contributed by DKA that was triggered by dengue fever hence DKA from dengue fever should be added in the list of unusual causes of transient polycythemia.展开更多
Objective: To review the management experience of a consecutive series of patients presenting as acute surgical abdomen whom were ultimately diagnosed to have DF(Dengue fever)/ DHF(Dengue heamorrhagic fever),Methods: ...Objective: To review the management experience of a consecutive series of patients presenting as acute surgical abdomen whom were ultimately diagnosed to have DF(Dengue fever)/ DHF(Dengue heamorrhagic fever),Methods: Clinical data of all cases of apparent acute abdomen(AA) which were later confirmed as having DF/DHF reviewed by two surgical units from December 2012 to December 2013 were analyzed,Initially confirmed patients with DF/DHF who developed abdominal symptoms were not considered,Results: Out of the seventeen cases(7 males,age range 10-71 years) presented with fever and AA; appendicitis,cholecystitis,pancreatitis and non-specific peritonitis were suspected initially in 8,5,1 and 3 cases,respectively,Neutropenia or thrombocytopenia signifying DF/DHF occurred only in 11 patients at first evaluation thus six remained as surgical candidates beyond 24 h,One patient underwent appendicectomy with a prolonged hospital stay,DF was confirmed by serology in all patients,latest by fourth day of admission,One required blood product transfusion,4 needed critical care treatment and there was 1 death,Conclusions: DF/DHF misleads the clinicians when it presents as AA,Initial heamatological and ultrasonographic findings may be equivocal creating a diagnostic and management dilemma,Vigilant clinical suspicion and early dengue serological assessment is advisable in equivocal cases of AAs with fever in dengue endemic areas,to confirm/exclude the infection in order to avoid unnecessary surgical morbidity in the presence of DF.展开更多
In 2013,the first dengue fever(DF) outbreak in central China was reported in the central of Henan province,northern temperate regions,although they have been sequentially recorded in Southern China.106 suspected DF ...In 2013,the first dengue fever(DF) outbreak in central China was reported in the central of Henan province,northern temperate regions,although they have been sequentially recorded in Southern China.106 suspected DF cases were reported and 73 patients were confirmed dengue virus type 3(DEN-3) infections.62/392(15.8%) local health persons showed DEN antibodies positive.To this day Henan is the northernmost province in China which has been reported about outbreak of DF and what is important is that it warns us the endemic range of DF has been expanded geographically in China.展开更多
Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and den...Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and dengue shock syndrome.Patient’s concerns:A 20-year-old male presented with a 2-day history of fever,multiple episodes of vomiting,and altered sensorium.Diagnosis:Dengue fever leading to acute hemorrhagic leukoencephalitis.Interventions:Multiple transfusions of single donor platelets,intravenous methylprednisolone,intravenous immunoglobulin,anti-seizure prophylaxis,and broad-spectrum antibiotics.Outcomes:Repeat brain magnetic resonance imaging showed resolution of lesions.The patient was subsequently discharged from the hospital in a healthy state.Lessons:This report helps us to gain a better understanding of the patient’s presentation,which will help to improve the timely recognition and prevention of this rare devastating presentation.展开更多
Rationale:Acute pain is a medical emergency that requires prompt abdominal evaluation and management.Dengue,a mosquito-borne arboviral infection,can lead to complications such as acute abdominal pain.Patient concerns:...Rationale:Acute pain is a medical emergency that requires prompt abdominal evaluation and management.Dengue,a mosquito-borne arboviral infection,can lead to complications such as acute abdominal pain.Patient concerns:A 72-year-old hypertensive female presented with high-grade intermittent fever with chills and rigors for four days.She was diagnosed with dengue fever(NS1Ag-reactive)the day before admission.A contrast-enhanced computed tomography of the abdomen showed a hematoma along the rectus sheath which was managed conservatively as per surgical opinion.Diagnosis:Dengue hemorrhagic fever with rectus sheath hematoma.Interventions:Blood transfusion and fluid therapy.Outcomes:Ten days after discharge,the patient reproted no pain in the right iliac fossa and the size of the hematoma was significantly reduced.Lessons:Although it is rarely seen as a cause of acute abdomen,complaints of adnominal pain should never be ignored in critical or convalescent phase of dengue fever.Radiological investigations should be promptly conducted as hematoma is often difficult to be diagnosed clinically.Delay in diagnosis of rectus sheath hematoma can be fatal.展开更多
The potential for dengue fever epidemic due to climate change remains uncertain in tropical areas.This study aims to assess the impact of climate change on dengue fever transmission in four South and Southeast Asian s...The potential for dengue fever epidemic due to climate change remains uncertain in tropical areas.This study aims to assess the impact of climate change on dengue fever transmission in four South and Southeast Asian settings.We collected weekly data of dengue fever incidence,daily mean temperature and rainfall from 2012 to 2020 in Singapore,Colombo,Selangor,and Chiang Mai.Projections for temperature and rainfall were drawn for three Shared Socioeconomic Pathways(SSP126,SSP245,and SSP585)scenarios.Using a disease transmission model,we projected the dengue fever epidemics until 2090s and determined the changes in annual peak incidence,peak time,epidemic size,and outbreak duration.A total of 684,639 dengue fever cases were reported in the four locations between 2012 and 2020.The projected change in dengue fever transmission would be most significant under the SSP585 scenario.In comparison to the 2030s,the peak incidence would rise by 1.29 times in Singapore,2.25 times in Colombo,1.36 times in Selangor,and>10 times in Chiang Mai in the 2090s under SSP585.Additionally,the peak time was projected to be earlier in Singapore,Colombo,and Selangor,but be later in Chiang Mai under the SSP585 scenario.Even in a milder emission scenario of SSP126,the epidemic size was projected to increase by 5.94%,10.81%,12.95%,and 69.60%from the 2030se2090s in Singapore,Colombo,Selangor,and Chiang Mai,respectively.The outbreak durations in the four settings were projected to be prolonged over this century under SSP126 and SSP245,while a slight decrease is expected in 2090s under SSP585.The results indicate that climate change is expected to increase the risk of dengue fever transmission in tropical areas of South and Southeast Asia.Limiting greenhouse gas emissions could be crucial in reducing the transmission of dengue fever in the future.展开更多
BACKGROUND Dengue fever is the most common cause of viral hemorrhagic fever,with more than 400 million cases being reported annually,worldwide.Even though hepatic involvement is common,acute liver failure(ALF)is a rar...BACKGROUND Dengue fever is the most common cause of viral hemorrhagic fever,with more than 400 million cases being reported annually,worldwide.Even though hepatic involvement is common,acute liver failure(ALF)is a rare complication of dengue fever.AIM To analyze the demographic profile,symptomology,hospital course and outcomes of patients presenting with ALF secondary to dengue infection by reviewing the published case reports.METHODS A systematic search was performed from multiple databases including PubMed,Reference Citation Analysis,Science Direct,and Google Scholar.The search terms used were"dengue"OR"severe dengue"OR"dengue shock syndrome"OR"dengue haemorrhagic syndrome"OR"dengue fever"AND"acute liver failure"OR"hepatic failure"OR"liver injury".The inclusion criteria were:(1)Case reports or case series with individual patient details;(2)Reported acute liver failure secondary to dengue infection;and(3)Published in English language and on adult humans.The data were extracted for patient demographics,clinical sympto-matology,clinical interventions,hospital and intensive care unit course,need for organ support and clinical outcomes.RESULTS Data from 19 case reports fulfilling the predefined inclusion criteria were included.The median age of patients was 38 years(inter quartile range:Q3-Q126.5 years)with a female preponderance(52.6%).The median days from diagnosis of dengue to development of ALF was 4.5 d.The increase in aspartate aminotransferase was higher than that in alanine aminotransferase(median 4625 U/L vs 3100 U/L).All the patients had one or more organ failure,with neurological failure present in 73.7%cases.42.1%patients required vasopressor support and hepatic enceph-alopathy was the most reported complication in 13(68.4%)cases.Most of the patients were managed conser-vatively and 2 patients were taken up for liver transplantation.Only 1 death was reported(5.3%).CONCLUSION Dengue infection may rarely lead to ALF.These patients may frequently require intensive care and organ support.Even though most of these patients may improve with supportive care,liver transplantation may be a therapeutic option in refractory cases.展开更多
Background:Dengue cases have been reported each year for the past 25 years in Guangdong Province,China with a recorded historical peak in 2014.This study aims to describe the epidemiological characteristics of this la...Background:Dengue cases have been reported each year for the past 25 years in Guangdong Province,China with a recorded historical peak in 2014.This study aims to describe the epidemiological characteristics of this large outbreak in order to better understand its epidemic factors and to inform control strategies.Methods:Data for clinically diagnosed and laboratory-confirmed dengue fever cases in 2014 were extracted from the China Notifiable Infectious Disease Reporting System.We analyzed the incidence and characteristics of imported and indigenous cases in terms of population,temporal and spatial distributions.Results:A total of 45224 dengue fever cases and 6 deaths were notified in Guangdong Province in 2014,with an incidence of 47.3 per 100000 people.The elderly(65+years)represented 11.7%of total indigenous cases with the highest incidence(72.3 per 100000).Household workers and the unemployed accounted for 23.1%of indigenous cases.The majority of indigenous cases occurred in the 37th to 44th week of 2014(September and October)and almost all(20 of 21)prefecture-level cities in Guangdong were affected.Compared to the non-Pearl River Delta Region,the Pearl River Delta Region accounted for the majority of dengue cases and reported cases earlier in 2014.Dengue virus serotypes 1(DENV-1),2(DENV-2)and 3(DENV-3)were detected and DENV-1 was predominant(88.4%).Conclusions:Dengue fever is a serious public health problem and is emerging as a continuous threat in Guangdong Province.There is an urgent need to enhance dengue surveillance and control,especially for the high-risk populations in high-risk areas.展开更多
Background Overseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China.To better prevent and control such local outbreaks,the epidemiological characteristics and t...Background Overseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China.To better prevent and control such local outbreaks,the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provincial-level administrative divisions(PLADs)where dengue fever is outbreak in the mainland of China were explored.Methods Using the Chinese National Notifiable Infectious Disease Reporting Information System(CNNDS),we identified overseas imported dengue fever cases in dengue fever outbreak areas in the mainland of China from 2005 to 2019 to draw the epidemic curve and population characteristic distribution of overseas imported cases in each PLAD.Based on spatial autocorrelation analysis of ArcGIS 10.5 and temporal-spatial scanning analysis of SaTScan 9.5,we analyzed the temporal-spatial distribution of overseas imported dengue fever in dengue fever outbreak areas in the mainland of China.Results A total of 11,407 imported cases,mainly from Southeast Asia,were recorded from 2005 to 2019 in these 13 PLADs.Of which 62.1%were imported into Yunnan and Guangdong Provinces.Among the imported cases,there were more males than females,mainly from the 21–50 age group.The hot spots were concentrated in parts of Yunnan,Guangdong and Fujian Provinces.We found the cluster of infected areas were expanding northward.Conclusions Based on the analysis of overseas imported dengue cases in 13 PLADs of the mainland of China from 2005 to 2019,we obtained the epidemiological characteristics and spatial distribution of imported dengue cases.Border controls need to pay attention to key population sectors,such as 21–50 years old men and education of key populations on dengue prevention.There is a need to improve the awareness of the prevention and control of imported cases in border areas.At the same time,northern regions cannot relax their vigilance.展开更多
Dengue virus is an arthropod-borne pathogen that is transmitted to humans primarily by Aedes spp.mosquitos,causing the acute infectious disease,dengue fever(DF).Until 2019,no dengue outbreak had been reported in Haina...Dengue virus is an arthropod-borne pathogen that is transmitted to humans primarily by Aedes spp.mosquitos,causing the acute infectious disease,dengue fever(DF).Until 2019,no dengue outbreak had been reported in Hainan Province for over 20 years.However,in early September of 2019,an increasing number of infected cases appeared and the DF outbreak lasted for over one month in Haikou City,Hainan Province.In our study,we collected 97 plasma samples from DF patients at three hospitals,as well as 1585 mosquito larvae samples from puddles in different areas of Haikou.There were 49(50.5%)plasma samples found to be strongly positive and 9(9.3%)plasma samples were weakly positive against the NS1 antigen.We discovered DENV both in the patient's plasma samples and mosquito larvae samples,and isolated the virus from C6/36 cells inoculated with the acute phase serum of patients.Phylogenetic analysis revealed that the new strains were the most closely related to the epidemic strain in the southern regions of China,belonging to lineageⅣ,genotypeⅠ,DENV-1.Compared to the seven closest strains from neighboring countries and provinces,a total of 18 amino acid mutations occurred in the coding sequences(CDS)of the new isolated strain,DENV1 HMU-HKU-2.Our data shows that dengue virus is re-emerged in Hainan,and pose new threats for public health.Thus regular molecular epidemiological surveillance is necessary for control and prevention of DENV transmission.展开更多
Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pa...Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pakistan in order to assess the transmissibility of the disease.We obtain estimates of the basic reproduction number R0 from epidemic data using different methodologies applied to different epidemic models in order to evaluate the robustness of our estimate.Results:We first estimate model parameters by fitting a deterministic ODE vector-host model for the transmission dynamics of single-strain dengue to the epidemic data,using both a basic ordinary least squares(OLS)as well as a generalized least squares(GLS)scheme.Moreover,we perform the same analysis for a direct-transmission ODE model,thereby allowing us to compare our results across different models.In addition,we formulate a direct-transmission stochastic model for the transmission dynamics of dengue and obtain parameter estimates for the stochastic model using Markov chain Monte Carlo(MCMC)methods.In each of the cases we have considered,the estimate for the basic reproduction number R0 is initially greater than unity leading to an epidemic outbreak.However,control measures implemented several weeks after the initial outbreak successfully reduce R0 to less than unity,thus resulting in disease elimination.Furthermore,it is observed that there is strong agreement in our estimates for the pre-control value of R0,both across different methodologies as well across different models.However,there are also significant differences between our estimates for the post-control value of the basic reproduction number across the two different models.Conclusion:In conclusion,we have obtained robust estimates for the value of the basic reproduction number R0 associated with the 2011 dengue fever epidemic before the implementation of public health control measures.Furthermore,we have shown that there is close agreement between our estimates for the post-control value of R0 across the different methodologies.Nevertheless,there are also significant differences between the estimates for the post-control value of R0 across the two different models.展开更多
基金supported by National Science and Technology Infrastructure Platform National Population and Health Science Data Sharing Service Platform Public Health Science Data Center[NCMI-ZB01N-201905]。
文摘Objective This study employs the Geographically and Temporally Weighted Regression(GTWR)model to assess the impact of meteorological elements and imported cases on dengue fever outbreaks,emphasizing the spatial-temporal variability of these factors in border regions.Methods We conducted a descriptive analysis of dengue fever’s temporal-spatial distribution in Yunnan border areas.Utilizing annual data from 2013 to 2019,with each county in the Yunnan border serving as a spatial unit,we constructed a GTWR model to investigate the determinants of dengue fever and their spatio-temporal heterogeneity in this region.Results The GTWR model,proving more effective than Ordinary Least Squares(OLS)analysis,identified significant spatial and temporal heterogeneity in factors influencing dengue fever’s spread along the Yunnan border.Notably,the GTWR model revealed a substantial variation in the relationship between indigenous dengue fever incidence,meteorological variables,and imported cases across different counties.Conclusion In the Yunnan border areas,local dengue incidence is affected by temperature,humidity,precipitation,wind speed,and imported cases,with these factors’influence exhibiting notable spatial and temporal variation.
文摘Rationale:Pituitary apoplexy(PA)is a rare endocrine emergency that requires prompt diagnosis and management.Dengue fever-induced-thrombocytopenia may rarely predispose to PA.Patient’s Concern:A 58-year-old male patient having known pituitary macroadenoma presented to the emergency department with fever,a sudden onset severe headache,and altered sensorium.Diagnosis:Pituitary apoplexy caused by dengue fever-induced-thrombocytopenia.Interventions:Conservative management with fluids,mannitol,dexamethasone and symptomatic treatment.Outcomes:The patient responded well to the treatment and was discharged uneventfully.Lessons:Although dengue hemorrhagic fever is a rare cause of pituitary apoplexy,it should be considered if a patient presents with headache and altered sensorium,and prompt initiation of treatment is crucial to prevent fatality and neuro-ophthalmic deficits.
基金supported by grants from the National Institutes of Health,USA(R01 AI083202,D43 TW009527)National Nature Science Foundation of China(81273139)+1 种基金the Project for Key Medicine Discipline Construction of Guangzhou Municipality(2013-2015-07)Technology Planning Project of Guangdong Province,China(2013B021800041)
文摘Objective To explore the associations between the monthly number of dengue fever(DF) cases and possible risk factors in Guangzhou, a subtropical city of China. Methods The monthly number of DF cases, Breteau Index (BI), and meteorological measures during 2006-2014 recorded in Guangzhou, China, were assessed. A negative binomial regression model was used to evaluate the relationships between BI, meteorological factors, and the monthly number of DF cases. Results A total of 39,697 DF cases were detected in Guangzhou during the study period. DF incidence presented an obvious seasonal pattern, with most cases occurring from June to November. The current month's BI, average temperature (Tare), previous month's minimum temperature (Train), and Tare were positively associated with DF incidence. A threshold of 18.25℃ was found in the relationship between the current month's Tmin and DF incidence. Conclusion Mosquito density, Tove, and Tmin play a critical role in DF transmission in Guangzhou. These findings could be useful in the development of a DF early warning system and assist in effective control and prevention strategies in the DF epidemic.
基金supported by the Research Fund from Health Bureau of Guangzhou(201102A212006)Science and Technology Bureau of Guangzhou(2012Y2-00020)Medical Sciences Program of Guangdong(A2011507)
文摘Ecological methodology plus negative binomial regression were used to identify dengue fever (DF) epidemiological status and its relationship with meteorological variables. From 2007 to 2012, annual incidence rate of DF in Guangzhou was 0.33, 0.11, 0.15, 0.64, 0.45, and 1.34 (per 100 000) respectively, showing an increasing trend. Each 1℃ rise of temperature corresponded to an increase of 10.23% (95% CI 7.68% to 12.83%) in the monthly number of DF cases, whereas l hPa rise of atmospheric pressure corresponded to a decrease in the number of cases by 5.14% (95% CI: 7.10%-3.14%). Likewise, each one meter per second rise in wind velocity led to an increase by 43.80% or 107.53%, and one percent rise of relative humidity led to an increase by 2.04% or 2.19%.
基金Supported by Ministry of Science and Technology of the People's Republic of China(Grant number:2012CB955504&2012ZX10004201-011)
文摘Dengue fever (DF), one of the neglected tropical diseases also known as breakbone fever, is a mosquito-borne disease common in the tropics and subtropics. Dengue fever is transmitted primarily by A.aegypti, resulting in infection with any of four distinct but closely related virus serotypes. The majority of infected people experience a self-limiting clinical course. A small proportion of cases develop into life-threatening Dengue Hemorrhagic Fever or Dengue Shock Syndrome.
基金funded by the Asia Pacific Network for Global Change Research(APN)-CAF2016-RR11-CMY-Pham
文摘Objective: To correlate climatic and environmental factors such as land surface temperature, rainfall, humidity and normalized difference vegetation index with the incidence of dengue to develop prediction models for the Philippines using remote-sensing data.Methods: Timeseries analysis was performed using dengue cases in four regions of the Philippines and monthly climatic variables extracted from Global Satellite Mapping of Precipitation for rainfall, and MODIS for the land surface temperature and normalized difference vegetation index from 2008-2015.Consistent dataset during the period of study was utilized in Autoregressive Integrated Moving Average models to predict dengue incidence in the four regions being studied.Results: The best-fitting models were selected to characterize the relationship between dengue incidence and climate variables.The predicted cases of dengue for January to December 2015 period fitted well with the actual dengue cases of the same timeframe.It also showed significantly good linear regression with a square of correlation of 0.869 5 for the four regions combined.Conclusion: Climatic and environmental variables are positively associated with dengue incidence and suit best as predictor factors using Autoregressive Integrated Moving Average models.This finding could be a meaningful tool in developing an early warning model based on weather forecasts to deliver effective public health prevention and mitigation programs.
基金funded and supported by the Institute of Molecular Biology and Biotechnology,University of Lahore,PakistanDean Scientific Research of King Abdul Aziz University(Award No.Hi Ci-1434-117-2)Jeddah and King Abdullah City for support of Science and Technology(Award Nos.10-BIO1258-03,10-BIO1073-03,08-MED120-03)Riyadh,Saudi Arabia
文摘Summary:A multi-centred study was designed to collect dengue epidemiologic data from government and registered private hospitals/clinics and maintained archive of frozen specimens in bio-bank to be used for future dengue epidemic control program, and assess the epidemiology of dengue fever(DF) by evaluating biochemical and oxidative status of patients. ELISA Ig M antibodies test was done to confirm DF. From August 2010 to December 2011, 101 confirmed blood samples of DF patients referred to pathology lab of Jinnah Hospital Lahore were subjected to the epidemiologic assessment by evaluating the biochemical and physiological indices and alterations of circulating antioxidants. Clinical features of DF patients and effect of fever on blood components and serum proteins of liver were recorded. The hospital stay in DF, dengue hemorrhagic fever(DHF) and dengue shock syndrome(DSS) showed significant difference. Significant increases in serum alanine amino transferase(ALT)(P=0.000), aspartate amino transferase(AST)(P=0.000), alkaline phosphatase(ALP)(P=0.000), malondialdehyde(MDA) along with significant decreases in total protein(TP)(P=0.000), reduced glutathione(GSH)(P=0.000), superoxide dismutase(SOD), catalase(CAT)(P=0.000), and sialic acid contents(P=0.016) were observed. A positive correlation existed between bound sialic acid levels, liver enzymes and circulating antioxidants(r=0.656, P=0.016). In the present study, alterations of circulating antioxidants in DF suggest that DF might be a metabolic response to an acute, self-limiting tropical viral infection, and a consequence of the viral inflammatory process.
基金supported by Guangzhou Medicine and Health Care Technology Projects,Guangdong Province,China(No.20141A011100)
文摘Two patients aged of 30 and 22(female in cases 1,and male in case 2) both complained of unilateral blurring of vision and scotoma within a week of being diagnosed with dengue fever.No other abnormal findings were found in their anterior segment.Retinal examination revealed blurring of the optic disc margin and several white spots in the posterior in both cases.Optical coherence tomography(OCT)imagery revealed that the white spots were only located in the retinal outer layers.Macular cystic foveolitis were also found in case 1 and diffused macular edema in case 2.In case 1,visual and retinal recovery were seen to resolve spontaneously.In case 2,patient had complete visual recovery two months after onset of the disease after being treated with steroids but central scotomata has continued to persist.
文摘Dengue fever is widespread in all tropical and subtropical areas of the world and is the main public health problem posed by arboviroses. In Burkina Faso, an outbreak of dengue serotype “DENV-2”, which is responsible for severe forms of dengue, has been reported. In this study, we will discuss liver damage during this disease. The aim of this study was to describe the sociodemographic, diagnostic, therapeutic and evolutionary aspects of dengue patients with hepatic cytolysis. Patients and Methods: This was a prospective cross-sectional study of dengue disease in 2 facilities in the city of Ouagadougou. The study was spread over a period of 3 months from August to November 2019. The study population consisted of all patients hospitalised for dengue with a positive AgNS1 and/or IgM rapid diagnostic test (RDT) and presenting signs of liver damage. Results: During our study period we recruited 134 patients with dengue fever of which 93 or 69.4% had at least one elevated transaminase. The sex ratio was 1.90 and the average age was 35 years. Symptoms of liver damage were rare with right hypochondrial pain in 4.30% of cases and jaundice in 1.07% of cases. Dengue haemorrhagic fever was found in 5 patients. IgG was negative in 77.42%. The majority of patients (44% or 47.31%) had at least one transaminase value elevated to the upper limit of normal (ULN);and a minority, 14 patients or 15.06%, had transaminases above 10 ULN. A small proportion of patients had hepatocellular failure 26.92% with a lowered prothrombin level. Ninety-four per cent (94.62%) of the patients received analgesics. Level 1 analgesic (paracetamol) was the most widely administered, particularly in 76 patients (86.36%). More than half of the patients (57.14%) had a length of stay of less than or equal to 3 days and the outcome was favourable in 91.40%. Conclusion: Dengue virus causes alterations in the liver parenchyma. The degree of liver damage is variable. As clinical symptoms are almost non-existent, the measurement of transaminases remains important.
文摘Either dengue fever or diabetic ketoacidosis can cause the high hemoglobin concentration due to intravascular volume loss.When both entities were found together as in our case,the hemoglobin concentration could access the strikingly high level until either of them could not contribute it.She was a Thai woman with 46 years of age presenting with fever,fatigue and severe sore throat for a few days.The physical examination showed she had mild dyspnea and oral thrush,the temperature was 36.4 degree Celsius,and her pulse rate was 102/min.Her blood tests showed:Hb 18.3 g%,WBC 9,850/mm^(3),atypical lymphocyte 10%,platelet 16,000/mm^(3),MCV 89.2 fl,Dengue NS1 antigen-positive,dengue IgG-positive,IgM-weakly positive,KOH preparation of curd from buccal mucosa-positive for budding yeasts and pseudo-hyphae,blood sugar 442 mg%,triglyceride 578 mg%,Na 122.8 mEq/L,K 6.28 mEq/L,Cl 90.6 mEq/L,CO_(2)9.2 mEq/L,blood ketone 53.6 mmol/L,lactate 4.5 mmol/L,pH 7.257,pCO_(2)27.4 mmHg,HCO_(3)11.9 mmo/L,BUN 22.9 mg%,creatinine 0.64 mg%,AST 375 U/L,ALT 224 U/L,alkaline phosphatase 151 U/L.She was diagnosed as having diabetes with diabetic ketoacidosis,dengue fever and polycythemia.She was immediately treated with intravenous fluid therapy to correct the metabolic acidosis,electrolyte imbalance and dehydration,insulin for hyperglycemia,clotrimazole for oral thrush and platelet transfusion.Her high hemoglobin level was dramatically lowered until became normal within one day of therapy whereas she also recovered from DKA although the platelet was progressively lowered every day.It suggested that transient polycythemia was solely contributed by DKA that was triggered by dengue fever hence DKA from dengue fever should be added in the list of unusual causes of transient polycythemia.
文摘Objective: To review the management experience of a consecutive series of patients presenting as acute surgical abdomen whom were ultimately diagnosed to have DF(Dengue fever)/ DHF(Dengue heamorrhagic fever),Methods: Clinical data of all cases of apparent acute abdomen(AA) which were later confirmed as having DF/DHF reviewed by two surgical units from December 2012 to December 2013 were analyzed,Initially confirmed patients with DF/DHF who developed abdominal symptoms were not considered,Results: Out of the seventeen cases(7 males,age range 10-71 years) presented with fever and AA; appendicitis,cholecystitis,pancreatitis and non-specific peritonitis were suspected initially in 8,5,1 and 3 cases,respectively,Neutropenia or thrombocytopenia signifying DF/DHF occurred only in 11 patients at first evaluation thus six remained as surgical candidates beyond 24 h,One patient underwent appendicectomy with a prolonged hospital stay,DF was confirmed by serology in all patients,latest by fourth day of admission,One required blood product transfusion,4 needed critical care treatment and there was 1 death,Conclusions: DF/DHF misleads the clinicians when it presents as AA,Initial heamatological and ultrasonographic findings may be equivocal creating a diagnostic and management dilemma,Vigilant clinical suspicion and early dengue serological assessment is advisable in equivocal cases of AAs with fever in dengue endemic areas,to confirm/exclude the infection in order to avoid unnecessary surgical morbidity in the presence of DF.
基金sponsored by Henan Province Health Department and China's Ministry of Health Co-build Project(201201003)Henan Department of Science and Technology Project(122400450357)
文摘In 2013,the first dengue fever(DF) outbreak in central China was reported in the central of Henan province,northern temperate regions,although they have been sequentially recorded in Southern China.106 suspected DF cases were reported and 73 patients were confirmed dengue virus type 3(DEN-3) infections.62/392(15.8%) local health persons showed DEN antibodies positive.To this day Henan is the northernmost province in China which has been reported about outbreak of DF and what is important is that it warns us the endemic range of DF has been expanded geographically in China.
文摘Rationale:Dengue fever is a prevalent tropical infectious disease that has a broad panorama of presentations from mild febrile illness to life-threatening manifestations in the form of dengue hemorrhagic fever and dengue shock syndrome.Patient’s concerns:A 20-year-old male presented with a 2-day history of fever,multiple episodes of vomiting,and altered sensorium.Diagnosis:Dengue fever leading to acute hemorrhagic leukoencephalitis.Interventions:Multiple transfusions of single donor platelets,intravenous methylprednisolone,intravenous immunoglobulin,anti-seizure prophylaxis,and broad-spectrum antibiotics.Outcomes:Repeat brain magnetic resonance imaging showed resolution of lesions.The patient was subsequently discharged from the hospital in a healthy state.Lessons:This report helps us to gain a better understanding of the patient’s presentation,which will help to improve the timely recognition and prevention of this rare devastating presentation.
文摘Rationale:Acute pain is a medical emergency that requires prompt abdominal evaluation and management.Dengue,a mosquito-borne arboviral infection,can lead to complications such as acute abdominal pain.Patient concerns:A 72-year-old hypertensive female presented with high-grade intermittent fever with chills and rigors for four days.She was diagnosed with dengue fever(NS1Ag-reactive)the day before admission.A contrast-enhanced computed tomography of the abdomen showed a hematoma along the rectus sheath which was managed conservatively as per surgical opinion.Diagnosis:Dengue hemorrhagic fever with rectus sheath hematoma.Interventions:Blood transfusion and fluid therapy.Outcomes:Ten days after discharge,the patient reproted no pain in the right iliac fossa and the size of the hematoma was significantly reduced.Lessons:Although it is rarely seen as a cause of acute abdomen,complaints of adnominal pain should never be ignored in critical or convalescent phase of dengue fever.Radiological investigations should be promptly conducted as hematoma is often difficult to be diagnosed clinically.Delay in diagnosis of rectus sheath hematoma can be fatal.
基金supported by the National Natural Science Foundation of China(grant numbers 71974165)partially supported by Health and Medical Research Fund(grant numbers INF-CUHK-1).
文摘The potential for dengue fever epidemic due to climate change remains uncertain in tropical areas.This study aims to assess the impact of climate change on dengue fever transmission in four South and Southeast Asian settings.We collected weekly data of dengue fever incidence,daily mean temperature and rainfall from 2012 to 2020 in Singapore,Colombo,Selangor,and Chiang Mai.Projections for temperature and rainfall were drawn for three Shared Socioeconomic Pathways(SSP126,SSP245,and SSP585)scenarios.Using a disease transmission model,we projected the dengue fever epidemics until 2090s and determined the changes in annual peak incidence,peak time,epidemic size,and outbreak duration.A total of 684,639 dengue fever cases were reported in the four locations between 2012 and 2020.The projected change in dengue fever transmission would be most significant under the SSP585 scenario.In comparison to the 2030s,the peak incidence would rise by 1.29 times in Singapore,2.25 times in Colombo,1.36 times in Selangor,and>10 times in Chiang Mai in the 2090s under SSP585.Additionally,the peak time was projected to be earlier in Singapore,Colombo,and Selangor,but be later in Chiang Mai under the SSP585 scenario.Even in a milder emission scenario of SSP126,the epidemic size was projected to increase by 5.94%,10.81%,12.95%,and 69.60%from the 2030se2090s in Singapore,Colombo,Selangor,and Chiang Mai,respectively.The outbreak durations in the four settings were projected to be prolonged over this century under SSP126 and SSP245,while a slight decrease is expected in 2090s under SSP585.The results indicate that climate change is expected to increase the risk of dengue fever transmission in tropical areas of South and Southeast Asia.Limiting greenhouse gas emissions could be crucial in reducing the transmission of dengue fever in the future.
文摘BACKGROUND Dengue fever is the most common cause of viral hemorrhagic fever,with more than 400 million cases being reported annually,worldwide.Even though hepatic involvement is common,acute liver failure(ALF)is a rare complication of dengue fever.AIM To analyze the demographic profile,symptomology,hospital course and outcomes of patients presenting with ALF secondary to dengue infection by reviewing the published case reports.METHODS A systematic search was performed from multiple databases including PubMed,Reference Citation Analysis,Science Direct,and Google Scholar.The search terms used were"dengue"OR"severe dengue"OR"dengue shock syndrome"OR"dengue haemorrhagic syndrome"OR"dengue fever"AND"acute liver failure"OR"hepatic failure"OR"liver injury".The inclusion criteria were:(1)Case reports or case series with individual patient details;(2)Reported acute liver failure secondary to dengue infection;and(3)Published in English language and on adult humans.The data were extracted for patient demographics,clinical sympto-matology,clinical interventions,hospital and intensive care unit course,need for organ support and clinical outcomes.RESULTS Data from 19 case reports fulfilling the predefined inclusion criteria were included.The median age of patients was 38 years(inter quartile range:Q3-Q126.5 years)with a female preponderance(52.6%).The median days from diagnosis of dengue to development of ALF was 4.5 d.The increase in aspartate aminotransferase was higher than that in alanine aminotransferase(median 4625 U/L vs 3100 U/L).All the patients had one or more organ failure,with neurological failure present in 73.7%cases.42.1%patients required vasopressor support and hepatic enceph-alopathy was the most reported complication in 13(68.4%)cases.Most of the patients were managed conser-vatively and 2 patients were taken up for liver transplantation.Only 1 death was reported(5.3%).CONCLUSION Dengue infection may rarely lead to ALF.These patients may frequently require intensive care and organ support.Even though most of these patients may improve with supportive care,liver transplantation may be a therapeutic option in refractory cases.
基金supported by Guangdong Provincial Science and Technology Project Fundings(NO.2013A020229005,NO.2014A040401041,NO.2015A020213004).
文摘Background:Dengue cases have been reported each year for the past 25 years in Guangdong Province,China with a recorded historical peak in 2014.This study aims to describe the epidemiological characteristics of this large outbreak in order to better understand its epidemic factors and to inform control strategies.Methods:Data for clinically diagnosed and laboratory-confirmed dengue fever cases in 2014 were extracted from the China Notifiable Infectious Disease Reporting System.We analyzed the incidence and characteristics of imported and indigenous cases in terms of population,temporal and spatial distributions.Results:A total of 45224 dengue fever cases and 6 deaths were notified in Guangdong Province in 2014,with an incidence of 47.3 per 100000 people.The elderly(65+years)represented 11.7%of total indigenous cases with the highest incidence(72.3 per 100000).Household workers and the unemployed accounted for 23.1%of indigenous cases.The majority of indigenous cases occurred in the 37th to 44th week of 2014(September and October)and almost all(20 of 21)prefecture-level cities in Guangdong were affected.Compared to the non-Pearl River Delta Region,the Pearl River Delta Region accounted for the majority of dengue cases and reported cases earlier in 2014.Dengue virus serotypes 1(DENV-1),2(DENV-2)and 3(DENV-3)were detected and DENV-1 was predominant(88.4%).Conclusions:Dengue fever is a serious public health problem and is emerging as a continuous threat in Guangdong Province.There is an urgent need to enhance dengue surveillance and control,especially for the high-risk populations in high-risk areas.
文摘Background Overseas imported dengue fever is an important factor in local outbreaks of this disease in the mainland of China.To better prevent and control such local outbreaks,the epidemiological characteristics and temporal-spatial distribution of overseas imported dengue fever cases in provincial-level administrative divisions(PLADs)where dengue fever is outbreak in the mainland of China were explored.Methods Using the Chinese National Notifiable Infectious Disease Reporting Information System(CNNDS),we identified overseas imported dengue fever cases in dengue fever outbreak areas in the mainland of China from 2005 to 2019 to draw the epidemic curve and population characteristic distribution of overseas imported cases in each PLAD.Based on spatial autocorrelation analysis of ArcGIS 10.5 and temporal-spatial scanning analysis of SaTScan 9.5,we analyzed the temporal-spatial distribution of overseas imported dengue fever in dengue fever outbreak areas in the mainland of China.Results A total of 11,407 imported cases,mainly from Southeast Asia,were recorded from 2005 to 2019 in these 13 PLADs.Of which 62.1%were imported into Yunnan and Guangdong Provinces.Among the imported cases,there were more males than females,mainly from the 21–50 age group.The hot spots were concentrated in parts of Yunnan,Guangdong and Fujian Provinces.We found the cluster of infected areas were expanding northward.Conclusions Based on the analysis of overseas imported dengue cases in 13 PLADs of the mainland of China from 2005 to 2019,we obtained the epidemiological characteristics and spatial distribution of imported dengue cases.Border controls need to pay attention to key population sectors,such as 21–50 years old men and education of key populations on dengue prevention.There is a need to improve the awareness of the prevention and control of imported cases in border areas.At the same time,northern regions cannot relax their vigilance.
基金This work was supported by the Hainan Provincial Natural Science Foundation of China(Grant No.2019RC218)the National Natural Science Foundation of China(grant No.81860367,31460017)+5 种基金the Scientific Research Foundation of the Higher Education Institutions of Hainan Province,China(Grant No.Hnky2020-33)the Hainan Medical University novel coronavirus pneumonia project(Grant No.XGZX2020005)the Hainan Provincial Natural Science Foundation of China(Grant No.819QN360)State Key Laboratory of Virology 2018 Open Fund Project(2018IOV002)the National S&T Major Project"China Mega-Project for Infectious Disease"(Grant No.2018ZX10711001)the CAMS Innovation Fund for Medical Sciences(Grant No.2017-I2M-3-017).
文摘Dengue virus is an arthropod-borne pathogen that is transmitted to humans primarily by Aedes spp.mosquitos,causing the acute infectious disease,dengue fever(DF).Until 2019,no dengue outbreak had been reported in Hainan Province for over 20 years.However,in early September of 2019,an increasing number of infected cases appeared and the DF outbreak lasted for over one month in Haikou City,Hainan Province.In our study,we collected 97 plasma samples from DF patients at three hospitals,as well as 1585 mosquito larvae samples from puddles in different areas of Haikou.There were 49(50.5%)plasma samples found to be strongly positive and 9(9.3%)plasma samples were weakly positive against the NS1 antigen.We discovered DENV both in the patient's plasma samples and mosquito larvae samples,and isolated the virus from C6/36 cells inoculated with the acute phase serum of patients.Phylogenetic analysis revealed that the new strains were the most closely related to the epidemic strain in the southern regions of China,belonging to lineageⅣ,genotypeⅠ,DENV-1.Compared to the seven closest strains from neighboring countries and provinces,a total of 18 amino acid mutations occurred in the coding sequences(CDS)of the new isolated strain,DENV1 HMU-HKU-2.Our data shows that dengue virus is re-emerged in Hainan,and pose new threats for public health.Thus regular molecular epidemiological surveillance is necessary for control and prevention of DENV transmission.
文摘Background:Dengue,an infectious tropical disease,has recently emerged as one of the most important mosquito-borne viral diseases in the world.We perform a retrospective analysis of the 2011 dengue fever epidemic in Pakistan in order to assess the transmissibility of the disease.We obtain estimates of the basic reproduction number R0 from epidemic data using different methodologies applied to different epidemic models in order to evaluate the robustness of our estimate.Results:We first estimate model parameters by fitting a deterministic ODE vector-host model for the transmission dynamics of single-strain dengue to the epidemic data,using both a basic ordinary least squares(OLS)as well as a generalized least squares(GLS)scheme.Moreover,we perform the same analysis for a direct-transmission ODE model,thereby allowing us to compare our results across different models.In addition,we formulate a direct-transmission stochastic model for the transmission dynamics of dengue and obtain parameter estimates for the stochastic model using Markov chain Monte Carlo(MCMC)methods.In each of the cases we have considered,the estimate for the basic reproduction number R0 is initially greater than unity leading to an epidemic outbreak.However,control measures implemented several weeks after the initial outbreak successfully reduce R0 to less than unity,thus resulting in disease elimination.Furthermore,it is observed that there is strong agreement in our estimates for the pre-control value of R0,both across different methodologies as well across different models.However,there are also significant differences between our estimates for the post-control value of the basic reproduction number across the two different models.Conclusion:In conclusion,we have obtained robust estimates for the value of the basic reproduction number R0 associated with the 2011 dengue fever epidemic before the implementation of public health control measures.Furthermore,we have shown that there is close agreement between our estimates for the post-control value of R0 across the different methodologies.Nevertheless,there are also significant differences between the estimates for the post-control value of R0 across the two different models.