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.

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.

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.

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.

Frequent Import and Multiple Sources of Dengue Fever have Changed the Epidemic Situation of the Disease in Fujian Province,China

Objective The aim of this study was to update the epidemic situation of dengue fever(DF) and provide new insights for the consideration of disease control in Fujian province,China.Methods Details about DF cases in Fujian reported during 2004–2017 were collected and analyzed.The envelope(E) genes of isolates of dengue virus(DENV) were sequenced for phylogenetic analysis.Results The number of imported DF cases had increased dramatically since 2013,and the source regions expanded from Southeast Asia to South Asia,America,Oceania,and Africa,as well as the surrounding provinces.This resulted in local outbreaks and indigenous cases of DF that occurred more frequently,with 10 of 13 local outbreaks and 85.9%(1,252/1,458) of indigenous cases reported in2013–2017.Compared with only two coastal cities before 2013,four coastal and one inland city in 2013–2017 experienced the local DF outbreaks.The phylogenetic analysis of E genes confirmed that the import of DENV,not only from abroad but also from the surrounding provinces,played an important role in dissemination and local outbreaks of DF in Fujian.Conclusions The frequent import of DF cases from not only abroad but also the surrounding provinces resulted in increased incidence,frequent local outbreaks,and expansion of distribution in Fujian in recent years.There is a need for urgent measures to improve disease control in this province.

Clinico-epidemiological features of dengue fever in Saudi Arabia

Objective:To highlight some clinical and epidemiological features of dengue fever.Methods: All patients who were admitted to hospitals in Holly Mecca City,Saudi Arabia and were confirmed as dengue fever(DF) or dengue hemorrhagic fever(DHF) were included in this study. The data were collected from patient files and through direct interview with patients or their relatives.Cases were followed through their hospital stay.Routine laboratory investigations were done and diagnosis was confirmed by PCR.Results:Most of cases admitted in stable condition(94.37%) and only one case(1.41%) died.Dengue-1 and 3 types were the prevalent dengue viruses and cases in age group 16-44 were the most frequent(70.40%).The most common symptoms was fever reported from all cases followed by headache(74.60%),myalgia and anorexia(67.60%),back pain(59.20%) and chills(54.90%).DF represented(60.57%) of the cases while DHF represented(39.43%).About half of cases had underground water tanks for human use,5.60%had over house roof water tanks and 43.70%had both types,16.90% of these tanks were uncovered.Approximately 70.00%of cases reported presence of small collection of water nearby houses and 46.80%reported the presence of mosquitoes within their houses.Conclusions:Most dengue fever cases might be endogenous in origin due to prevalence of mosquitoes and their breeding places within the houses and in nearby localities.Control of mosquitoes and their breeding places will contribute to prevention of dengue fever.

Dengue fever treatment with Carica papaya leaves extracts

The main objective of the current study is to investigate the potential of Carica papaya leaves extracts against Dengue fever in 45 year old patient bitten by carrier mosquitoes.For the treatment of Dengue fever the extract was prepared in water.25 mL of aqueous extract of C.papaya leaves was administered to patient infected with Dengue fever twice daily i.e.morning and evening for five consecutive days.Before the extract administration the blood samples from patient were analyzed.Platelets count(PLT),White Blood Cells(WBC) and Neutrophils(NEUT) decreased from 176×10~3/μ L,8.10×10~3/μ L,84.0%to 55×10~3/μ L,3.7×10~3/μL and 46.0%.Subsequently,the blood samples were rechecked after the administration of leaves extract.It was observed that the PLT count increased from 55×10~3/μ L to 168×10~3/μ L,WBC from 3.7×10~3/μ L to 7.7×10~3/μ L and NEUT from 46.0%to 78.3%.From the patient feelings and blood reports it showed that Carica papaya leaves aqueous extract exhibited potential activity against Dengue fever.Furthermore,the different parts of this valuable specie can be further used as a strong natural candidate against viral diseases.

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 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.

Potential impacts of climate change on dengue fever distribution using RCP scenarios in China

This study projected dengue distribution risk map using representative concentration pathways(RCP2.6,RCP4.5,RCP6.0,RCP8.5)in China in 2020s,2030s,2050s and 2100s.Based on the biological characteristics of Aedes albopictus and the dengue epidemic process,dengue transmission biological model was developed to project the risk epidemic areas.Observational temperature data in 1981-2016 at 740 stations and grid data of 0.5°×0.5°(15°-55.5°N,70°-140.5E)under selected RCPs in 2020s,2030s,2050s and 2100s were used.Relative to 142 counties and 168 million people living in the projected high risk area of dengue in the climate condition of 1981-2016,dengue high risk areas in China would expand under same RCP scenarios in the 21st century with time past except RCP2.6 with a turning down point in 2050s.Especially under RCP8.5 which global mean temperature would increase by 4.9 C till 2100s,the high risk area and population for dengue transmission would expand additional 34 counties(20 million)in 2020s,114 counties(60 million)in 2030s,208 counties(160 million)in 2050 and 456 counties(490 million)in 2100s respectively than those of 1981-2016.For RCP8.5 in 2100s,the population and expanded high risk areas would increase 4.2-fold and 2.9-fold than the 1981-2016 mean.The newly added high risk areas should prepare for controlling and preventing dengue in different period according to projected dengue risk map.

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%.

Imported cases of dengue fever in Russia during 2010-2013

Objective:To confirm dengue infection among Russian tourists returned from Southeast and Mexico in 2010-2013 with clinical signs of infection.Methods:Blood and serum samples from patients were collected.NSI antigen and human IgM/IgG antibodies to dengue virus were identified using commercial tests manufactured by "Standard Diagnostics,INC.",Korea.ELISA test was used for the quantitative analyses of human IgM/IgG antibodies to dengue virus( "Orgenics Ltd.",Israel).Viral RNA was delected using commercial real-lime PCR lesls manufactured by "Genome Diagnostics Pvt.Ltd.",India and "Vector",Russia.Genotypes of revealed dengue viruses were determined employing nucleotide sequencing and phylogenetic analysis of 5'-UTR of the viral genome.Results:A total of 98 collected blood samples were analyzed.Fifty samples were positive for at least one of four markers of dengue infection.IgM to dengue virus were revealed in 38 samples,in 25 samples IgM were combined with IgG.NSI antigen was detected in43 samples.22 serum samples were positive for dengue virus RNA.The majority of samples(12patients) from tourists returned from Thailand were positive for genotype 1 of dengue virus,2nd and 4lh genotype were identified each in 1 patient.Conclusions:Due to laboratory confirmed cases of imported dengue fever in Russia,the differential diagnosis of dengue is strictly recommended for tourists returning from endemic areas.

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.

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.

Dengue hemorrhagic fever and the liver

Dengue hemorrhagic fever(DHF)is one of the most rapidly emerging infections of tropical and subtropical regions worldwide.It affects more rural and urban areas due to many factors,including climate change.Although most people with dengue viral infection are asymptomatic,approximately 25%experience a selflimited febrile illness with mild to moderate biochemical abnormalities.Severe dengue diseases develop in a small proportion of these patients,and the common organ involvement is the liver.The hepatocellular injury was found in 60%-90%of DHF patients manifested as hepatomegaly,jaundice,elevated aminotransferase enzymes,and critical condition as an acute liver failure(ALF).Even the incidence of ALF in DHF is very low(0.31%-1.1%),but it is associated with a relatively high mortality rate(20%-68.3%).The pathophysiology of liver injury in DHF included the direct cytopathic effect of the DENV causing hepatocytes apoptosis,immunemediated hepatocyte injury induced hepatitis,and cytokine storm.Hepatic hypoperfusion is another contributing factor in dengue shock syndrome.The reduction of morbidity and mortality in DHF with liver involvement is dependent on the early detection of warning signs before the development of ALF.

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.

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.

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.

Femoral compressive neuropathy from iliopsoas haematoma complicating dengue hemorrhagic fever

Dengue fever is a debilitating mosquito-borne disease caused by dengue virus.We reported a case of femoral compression neuropathy due to iliopsoas hematoma complicating dengue hemorrhagic fever.Iliopsoas muscle hematoma can cause femoral neuropathy with resultant pain and paralysis.Such manifestations are not well documented in the literature.The pathogenesis of hematoma and compressive neuropathy with its appropriate management is discussed.