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.

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.

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.

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.

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.

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 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.

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.

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.

Herbal remedies,vaccines and drugs for dengue fever:Emerging prevention and treatment strategies

Dengue fever is a disease that is caused by five dengue virus(DENV) serotypes. It is endemic in more than 128 countries. Millions of people are affected by this disease. But still, there is no specific treatment available till now to combat it. Some of the preventive measures using plant extracts showed certain promising ovicidal activity against Aedes aegypti. There are some vaccines as preventive measure and antiviral agents to cure the dengue fever, which are under clinical trials but their results have not been reported or approved yet. Dengvaxia is the only licensed vaccine to prevent dengue fever in some South American countries, but it is not approved by other regulatory authorities worldwide. Scientific research has been going on to find a permanent cure for dengue fever, but till now, no successful invention has been done. There are some general treatments for dengue patient by employing analgesics and fluid replacement; however, specific treatment is needed to overcome the lethal effect of dengue fever. Since this disease has affected millions of people and not much invention has been made in this field; therefore, advancement in dengue therapy is required for the safety and well-being of dengue patients. Herein we collectively describe the different chemotherapeutics agents, alternative methods like vaccines and antiviral agents to prevent and cure this lethal disease. Furthermore, the future perspective for the treatment of dengue is discussed in this review.

Dengue fever presenting as acute liver failure-a case report

Dengue fever(DF) and dengue haemorrhagic fever(DHF) are important mosquito-borne viral diseases of humans and recognized as important emerging infectious diseases in the tropics and subtopics.Compared to nine reporting countries in the 1950s,today the geographic distribution includes more than 100 countries worldwide.Dengue viral infections are known to present a diverse clinical spectrum,ranging from asymptomatic illness to fatal dengue shock syndrome. Mild hepatic dysfunction in dengue haemorrhagic fever is usual.However,its presentation as acute liver failure(ALF) is unusual.We report a patient with dengue shock syndrome who presented with acute liver failure and hepatic encephalopathy in a recent outbreak of dengue fever in Delhi,India.