Geographically and Temporally Weighted Regression in Assessing Dengue Fever Spread Factors in Yunnan Border Regions

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.

Climate-driven dengue fever outbreaks in Nepal:Trends,challenges,and strategies

Dengue fever(DF)has become a major public health concern in Nepal,with increasing outbreaks in recent years.Transmitted by Aedes mosquitoes,this climate-sensitive viral disease presents a significant challenge for healthcare providers and policymakers.Since 2004,Nepal has experienced a sharp increase in DF cases,peaking in 2022 with 54784 cases and 88 deaths.The surge,driven mainly by serotypes 1,2,and 3,is exacerbated by climate change,which prolongs mosquito breeding seasons due to warmer temperatures and increased rainfall.This trend has even impacted previously unaffected hilly regions.Effective dengue control strategies must focus on climate change adaptation,strengthening healthcare system reinforcement,raising public awareness,and enhancing vector control measures.Government initiatives,like the national dengue control program,play a critical role,but research and community engagement are also vital for prevention and early detection.Integrating climate resilience into public health efforts is essential to reducing the dengue burden in Nepal.

Pituitary apoplexy secondary to dengue fever-induced-thrombocytopenia:A case report and review of literature

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.

The Impacts of Mosquito Density and Meteorological Factors on Dengue Fever Epidemics in Guangzhou, China, 2006-2014: a Time-series Analysis

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.

Dengue Fever Epidemiological Status and Relationship with Meteorological Variables in Guangzhou, Southern China, 2007-2012

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%.

Frequency, Duration and Intensity of Dengue Fever Epidemic Risk in Townships in Pearl River Delta and Yunnan in China, 2013

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.

Modeling and predicting dengue fever cases in key regions of the Philippines using remote sensing data

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.

Assessment of Biochemical and Antioxidative Status in Patients Suffering from Dengue Fever

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.

Community social capital on fighting dengue fever in suburban Surabaya, Indonesia: A qualitative study

Purpose:Dengue hemorraghic fever(DHF)is a communicable disease that is difficult to manage,espe-cially in tropical countries.Social capital is believed to be able to improve the ability of entire com-munities to work together to solve a collective health problem.This study aimed to describe the existing social capital in a community and how it was used to fight DHF.Methods:Qualitative descriptive methods were used,and in-depth interviews were conducted with 13 participants.This study was conducted in the Sawahan sub-district,Surabaya,Indonesia,an endemic area that combats DHF every year.Findings:Results showed that social capital as a community feature provides the main cornerstone of collective action.The creation of social groups,intersectoral collaboration,mutual assistance in cleaning,and voluntary work were visible forms of social capital in the prevention and control of DHF.Support from strong leaders also had significant implications.Conclusions:This study showed that social capital was an important feature,which,if managed,used and accessed properly,would be able to provide ideas for solving community problems.

Ophthalmic complications related to dengue fever: a case report

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.

Liver Damage during Dengue Fever in Ouagadougou

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.

Transient polycythemia during diabetic ketoacidosis triggered by dengue fever in a middle-aged woman

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.

Dengue fever may mislead the surgeons when it presents as an acute abdomen

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.

Outbreak of Dengue Fever in Central China,2013

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.

Dengue fever leading to acute dengue hemorrhagic leukoencephalitis:A case report

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.

Dengue hemorrhagic fever with rectus sheath hematoma:A case report

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.

Impact of climate change on dengue fever epidemics in South and Southeast Asian settings:A modelling study

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.

Stochastic Model of Dengue: Analysing the Probability of Extinction and LLN

In this article, we develop and analyze a continuous-time Markov chain (CTMC) model to study the resurgence of dengue. We also explore the large population asymptotic behavior of probabilistic model of dengue using the law of large numbers (LLN). Initially, we calculate and estimate the probabilities of dengue extinction and major outbreak occurrence using multi-type Galton-Watson branching processes. Subsequently, we apply the LLN to examine the convergence of the stochastic model towards the deterministic model. Finally, theoretical numerical simulations are conducted exploration to validate our findings. Under identical conditions, our numerical results demonstrate that dengue could vanish in the stochastic model while persisting in the deterministic model. The highlighting of the law of large numbers through numerical simulations indicates from what population size a deterministic model should be considered preferable.

Resurgence of dengue in the Philippines

The coronavirus disease 2019(COVID-19)pandemic has significantly influenced the epidemiological landscape of various infectious diseases such as dengue.Dengue is an endemic disease in the Philippines,which showed a significant de-cline in the number of cases beginning in March 2020 due to the stringent public health measures implemented to curb COVID-19 cases.However,the easing of these restrictions subsequently led to a resurgence in dengue cases,as reported by the World Health Organization,with a notable increase compared to previous years.As the country navigates towards a post-pandemic phase,addressing the resurgence of dengue requires sustained efforts in vector control,surveillance,and healthcare preparedness.This article underscores the critical need for collab-orative efforts among stakeholders to mitigate the resurgence of dengue while managing the ongoing recovery from the COVID-19 pandemic.

Dengue induced acute liver failure:A meta summary of case reports

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.