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1.
Article in English | MEDLINE | ID: mdl-33808795

ABSTRACT

Severe dengue outbreaks (DOs) affect the majority of Asian and Latin American countries. Whether all DOs always occurred in sub-tropical and tropical areas (STTA) has not been verified. We downloaded abstracts by searching keywords "dengue (MeSH Major Topic)" from Pubmed Central since 1950, including three collections: country names in abstracts (CNA), no abstracts (WA), and no country names in abstracts (Non-CNA). Visualizations were created to present the DOs across countries/areas in STTA. The percentages of mentioned country names and authors' countries in STTA were computed on the CNA and Non-CNA bases. The social network analysis was applied to highlight the most cited articles and countries. We found that (1) three collections are 3427 (25.48%), 3137 (23.33%), and 6884 (51.19%) in CNA, WA, and Non-CNA, respectively; (2) the percentages of 94.3% and 79.9% were found in the CNA and Non-CNA groups; (3) the most mentioned country in abstracts were India, Thailand, and Brazil; (4) most authors in the Non-CNA collections were from the United States, Brazil, and China; (5) the most cited article (PMID = 23563266) authored by Bhatt et al. had 2604 citations since 2013. Our findings provide in-depth insights into the DO knowledge. The research approaches are recommended for authors in research on other infectious diseases in the future, not just limited to the DO topic.


Subject(s)
Dengue , Tropical Climate , Bibliometrics , Brazil , China/epidemiology , Dengue/epidemiology , Disease Outbreaks , Humans , India , Thailand , United States
2.
Article in English | MEDLINE | ID: mdl-33799640

ABSTRACT

New spatial characteristics of dengue fever in mainland China during 2019 were analyzed. There was a dengue fever outbreak in mainland China in 2019, with 15,187 indigenous cases in 13 provinces, 1281 domestic imported cases from 12 provinces and 5778 overseas imported cases from 47 countries, more than the previous cases during the period 2005-2018, except for in 2014. Indigenous cases occurred in Sichuan, Hubei and Chongqing in 2019. There have been big changes in the spatial distribution and proportion of dengue cases. Indigenous cases were not only located in the southwestern border and southeastern coastal provinces of Yunnan, Guangdong, Guangxi and Fujian but also in the central provinces of Jiangxi and Chongqing. Domestic imported cases were not only from Guangdong, but also from Yunnan. There were five new sources of importation of cases. Overseas imported cases were mainly from Cambodia and Myanmar in 2019. Understanding the new spatial characteristics of dengue fever in China helps to formulate targeted, strategic plans and implement effective public health prevention and control measures.


Subject(s)
Dengue , Cambodia , China/epidemiology , Dengue/epidemiology , Humans , Incidence , Myanmar
3.
Cad Saude Publica ; 37(4): e00079620, 2021.
Article in English | MEDLINE | ID: mdl-33886707

ABSTRACT

Around 14% of world dengue virus (DENV) cases occur in the Americas, most of them in Brazil. While socioeconomic, environmental, and behavioral correlates have been analyzed thoroughly, the role played by population mobility on DENV epidemics, especially at the local level, remains scarce. This study assesses whether the daily pattern of population mobility is associated with DENV incidence in Campinas, a Brazilian major city with over 1.2 million inhabitants in São Paulo State. DENV notifications from 2007 to 2015 were geocoded at street level (n = 114,884) and combined with sociodemographic and environmental data from the 2010 population census. Population mobility was extracted from the Origin-Destination Survey (ODS), carried out in 2011, and daily precipitation was obtained from satellite imagery. Multivariate zero-inflated negative binomial regression models were applied. High population mobility presented a relevant positive effect on higher risk for DENV incidence. High income and residence in apartments were found to be protective characteristics against the disease, while unpaved streets, number of strategic points (such as scrapyards and tire repair shops), and precipitation were consistently risk factors.


Subject(s)
Dengue Virus , Dengue , Epidemics , Brazil/epidemiology , Cities/epidemiology , Dengue/epidemiology , Humans
4.
Arch. argent. pediatr ; 119(2): 131-138, abril 2021. ilus
Article in Spanish | LILACS, BINACIS | ID: biblio-1152134

ABSTRACT

A 11 años del primer brote de dengue en Buenos Aires, el 20 de marzo de 2020, mientras se iniciaba la cuarentena obligatoria por COVID-19, dengue pasó a ser la causa más común de consulta por fiebre. La nueva ola de casos de dengue ya se encontraba entre las predicciones de la Organización Panamericana de la Salud en función del aumento en la región de las Américas que se venía presentando desde el año anterior. La llegada del SARS-CoV-2 a principios de marzo, sumada al brote de dengue que ya estaba en curso, resultó en un nuevo desafío para el sistema de salud, mientras comenzaba un paradigma con planes de adaptación a la nueva infección pandémica en el país. La superposición de infecciones con potencial epidémico, como dengue, recuerda la importancia de no desatender otras enfermedades endémicas, emergentes y reemergentes a la sombra del nuevo fenómeno epidemiológico


Eleven years after the first dengue outbreak in Buenos Aires, on March 20, 2020, while the mandatory quarantine for COVID-19 began dengue became the most common cause of fever consultation. The new wave of dengue cases was already among the predictions of the Pan American Health Organization based on the increase in the region of the Americas that had been occurring since the previous year. The arrival of SARS-CoV-2 at the beginning of March, added to the dengue outbreak that was already underway, made a new challenge for the health system while a new paradigm was initiated with adaptation plans to the new pandemic infection in the country. The overlapping of infections with epidemic potential such as dengue recalls the importance of not neglecting other endemic, emerging and re-emerging diseases in the shadow of the new epidemiological phenomenon.


Subject(s)
Humans , Dengue/epidemiology , Pediatrics , Arboviruses , Argentina/epidemiology , Coronavirus Infections , Aedes , Coinfection
5.
Medicine (Baltimore) ; 100(14): e25311, 2021 Apr 09.
Article in English | MEDLINE | ID: mdl-33832104

ABSTRACT

ABSTRACT: The 2015 dengue outbreak in southern Taiwan turned into a public health emergency, resulting in a large-scale mobilization of personnel from the emergency department (ED) services operating in and near full capacity to assist with the outbreak. This study aimed to assess a rapid independent clinic-based service (RCS), which was set up and designed to relieve the overcrowding of the regular ambulatory and emergency services during an epidemic of dengue.This is a retrospective cross-sectional study.National Cheng Kung University Hospital, Tainan, Taiwan.Patients with positive test results were enrolled and reviewed to evaluate the efficacy of RCS implementation between August and October 2015. The case-treatment rates stratified by length of stay (LOS) were used to examine the performance of the RCS that was set up outside the ED and designed to relieve the overcrowding of the regular ambulatory and emergency services.Patients with dengue-like illnesses may arrive at the hospital and require optimal ED triage and management thereafter. Although the outbreak resulted in a shortage of spare space in the ED, a proper response from the hospital administration would ameliorate the work overload of the staff and would not decrease the quality of care for critical patients.An early and restrictive intensive intervention was beneficial to health care facilities during a dengue outbreak. Further planning and training of the RCS could be crucial for hospital preparedness for infectious disease outbreaks.


Subject(s)
Ambulatory Care Facilities/organization & administration , Dengue/epidemiology , Emergency Service, Hospital/organization & administration , Blood Culture , Cross-Sectional Studies , Dengue/diagnosis , Dengue/drug therapy , Diagnostic Imaging , Disease Outbreaks , Hospital Bed Capacity , Hospitals, Teaching , Humans , Length of Stay/statistics & numerical data , Real-Time Polymerase Chain Reaction , Retrospective Studies , Taiwan/epidemiology , Tertiary Care Centers , Time Factors , Triage/organization & administration
6.
Rev Bras Epidemiol ; 24: e210020, 2021.
Article in English | MEDLINE | ID: mdl-33825776

ABSTRACT

OBJECTIVE: To describe the entry of Dengue virus (DENV) serotypes in Brazil and its federative units. METHODS: A systematic review of studies published between 1980 and 2018 in databases and in the gray literature was performed using descriptors related to the years of entry of the DENV serotypes. Additionally, experts and official sources of information (Brazilian Ministry of Health) were consulted. RESULTS: From 100 publications selected for the systematic review, 26 addressed the entry of DENV serotypes in the North region of the country, 33 in the Northeast, 24 in the Southeast, 14 in the Central-West, and five in the South. DENV-1 and DENV-4 were introduced in the North region in 1981. DENV-2 was introduced in the Southeast in 1990. DENV-3 was introduced in the North in 1999. CONCLUSION: The rapid expansion of dengue throughout the Brazilian territory was verified from the second half of the 1980s, with the gradual entry of the four serotypes, which resulted in the emergence of epidemics of arbovirus, which are currently verified in the country. Considering the epidemiology of the disease, more information should be disseminated and published in the wide-ranging scientific literature for a better understanding of the spread and circulation of DENV serotypes.


Subject(s)
Dengue Virus , Dengue , Brazil/epidemiology , Dengue/epidemiology , Dengue Virus/genetics , Geography , Humans , Serogroup
7.
Zhonghua Gan Zang Bing Za Zhi ; 29(3): 265-270, 2021 Mar 20.
Article in Chinese | MEDLINE | ID: mdl-33902195

ABSTRACT

Objective: To investigate the correlation between serum ferritin (SF) level and liver damage in the acute stage of dengue fever. Methods: A retrospective study was conducted to analyze 171 cases diagnosed with dengue fever as dengue fever group and 130 healthy patients as control group in Hangzhou 3A grade hospital from July to December 2017. Clinical data, SF and liver function related indicators were collected from both groups: alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL) to analyze the correlation between liver damage and SF in patients with dengue fever. Results: ALT, AST, and SF levels were significantly higher in the dengue fever group than those in the healthy control group (Z = 11.553, 15.054 and 15.163, P < 0.001). SF levels were higher in the dengue fever combined with liver damage group than those without the liver damage group (z = 6.930, P < 0.001). However, there was no statistically significant differences in age, gender, peak body temperature, and history of liver disease (P > 0.05). In addition, Spearman's correlation analysis showed that SF was positively correlated with ALT, AST, and TBIL (r = 0.464, 0.531 and 0.315, P < 0.001). Among dengue patients with different SF levels, there were significant difference in ALT, AST levels and incidence of liver damage (H = 14.240 and 17.584, χ(2) = 49.547, P < 0.001). Patients with higher SF levels had higher ALT, AST levels and incidence of liver damage. Binary logistic regression analysis showed that hyperferritinemia (SF≥500 ng/ml) was the risk factor for dengue fever combined with liver damage (OR = 8.120, P < 0.001). Furthermore, ROC curve analysis showed that the AUC for SF to judge dengue fever combined liver damage was 0.846 (95% CI: 0.785-0.908), and the sensitivity and specificity when the SF cut-off value was 1 506 ng/ml were 74.8% and 83.3%. Conclusion: There is a certain correlation between the SF level and the degree of liver damage in acute stage of dengue fever patients, and hyperferritinemia is a risk factor for dengue fever combined with liver damage.


Subject(s)
Dengue , Liver Diseases , Alanine Transaminase , Aspartate Aminotransferases , Dengue/complications , Dengue/epidemiology , Ferritins , Humans , Liver , Retrospective Studies
8.
Nat Commun ; 12(1): 2296, 2021 04 16.
Article in English | MEDLINE | ID: mdl-33863880

ABSTRACT

Brazil experienced a large dengue virus (DENV) epidemic in 2019, highlighting a continuous struggle with effective control and public health preparedness. Using Oxford Nanopore sequencing, we led field and classroom initiatives for the monitoring of DENV in Brazil, generating 227 novel genome sequences of DENV1-2 from 85 municipalities (2015-2019). This equated to an over 50% increase in the number of DENV genomes from Brazil available in public databases. Using both phylogenetic and epidemiological models we retrospectively reconstructed the recent transmission history of DENV1-2. Phylogenetic analysis revealed complex patterns of transmission, with both lineage co-circulation and replacement. We identified two lineages within the DENV2 BR-4 clade, for which we estimated the effective reproduction number and pattern of seasonality. Overall, the surveillance outputs and training initiative described here serve as a proof-of-concept for the utility of real-time portable sequencing for research and local capacity building in the genomic surveillance of emerging viruses.


Subject(s)
Dengue Virus/genetics , Dengue/epidemiology , Epidemics/prevention & control , Epidemiological Monitoring , Brazil/epidemiology , Dengue/prevention & control , Dengue/transmission , Dengue/virology , Dengue Virus/isolation & purification , Feasibility Studies , Genetic Variation , Genome, Viral/genetics , Humans , Mobile Health Units , Molecular Epidemiology , Molecular Typing , Phylogeny , Proof of Concept Study , RNA, Viral/genetics , RNA, Viral/isolation & purification , Real-Time Polymerase Chain Reaction , Retrospective Studies , Whole Genome Sequencing
9.
An Acad Bras Cienc ; 93(3): e20200670, 2021.
Article in English | MEDLINE | ID: mdl-33681889

ABSTRACT

Arboviral diseases are disseminated all over the world. In Brazil, they remain neglected, alerting public authorities to possible outbreaks. Over here, we report the epidemiological indicators of Dengue from 2010 to 2015, Zika between 2015 and 2016, and Chikungunya from 2014 to 2016, within 19 municipalities of Southwestern Region of Bahia, Brazil. The data were collected from Brazilian national public information systems (SISFAD, SINAN, and IBGE) and by Endemic Control Agents. The analysis consisted of a description of vector characteristics, Home Infestation Index and characterization of human reported cases. The years 2011 and 2013 were recorded as having the highest frequencies of positive properties for the presence of the arboviruse vectors. Most municipalities presented high annual values of Home Infestation Index indicating an alert situation (62.28%). In the evaluated period, there were (i) 9,196 cases of Dengue, (ii) 636 cases of Zika and (iii) 224 cases of Chikungunya reported. This is the first report of the epidemiological characteristics of these arboviruses in the 19 municipalities of Bahia. It is believed that the data collected may contribute to public health policies aimed at controlling future epidemics of these arboviruses.


Subject(s)
Arboviruses , Chikungunya Fever , Dengue , Zika Virus Infection , Zika Virus , Brazil/epidemiology , Chikungunya Fever/epidemiology , Dengue/epidemiology , Humans , Zika Virus Infection/epidemiology
10.
Int J Mol Sci ; 22(4)2021 Feb 16.
Article in English | MEDLINE | ID: mdl-33669407

ABSTRACT

La Reunion island in the South West Indian Ocean is now endemic for dengue following the introduction of dengue virus serotype 2 (DENV-2) cosmopolitan-I genotype in 2017. DENV-2 infection causes a wide spectrum of clinical manifestations ranging from flu-like disease to severe dengue. The nonstructural glycoprotein 1 (NS1) has been identified as playing a key role in dengue disease severity. The intracellular NS1 exists as a homodimer, whereas a fraction is driven towards the plasma membrane or released as a soluble hexameric protein. Here, we characterized the NS1 glycoproteins from clinical isolates DES-14 and RUN-18 that were collected during the DENV-2 epidemics in Tanzania in 2014 and La Reunion island in 2018, respectively. In relation to hepatotropism of the DENV, expression of recombinant DES-14 NS1 and RUN-18 NS1 glycoproteins was compared in human hepatoma Huh7 cells. We observed that RUN-18 NS1 was poorly stable in Huh7 cells compared to DES-14 NS1. The instability of RUN-18 NS1 leading to a low level of NS1 secretion mostly relates to lysine residues on positions 272 and 324. Our data raise the issue of the consequences of a defect in NS1 stability in human hepatocytes in relation to the major role of NS1 in the pathogenesis of the DENV-2 infection.


Subject(s)
Dengue Virus/metabolism , Dengue/epidemiology , Dengue/metabolism , Epidemics , Genotype , Lysine/chemistry , Viral Nonstructural Proteins/chemistry , Amino Acid Substitution , Antigens, Viral/chemistry , Antigens, Viral/genetics , Cell Line, Tumor , Dengue/virology , HEK293 Cells , Hepatocytes/metabolism , Hepatocytes/virology , Humans , Protein Multimerization , Protein Stability , Recombinant Proteins/chemistry , Reunion/epidemiology , Serogroup , Tanzania/epidemiology , Transfection , Viral Nonstructural Proteins/genetics
11.
BMC Infect Dis ; 21(1): 265, 2021 Mar 17.
Article in English | MEDLINE | ID: mdl-33731022

ABSTRACT

BACKGROUND: Increasing arbovirus infections have been a global burden in recent decades. Many countries have experienced the periodic emergence of arbovirus diseases. However, information on the prevalence of arboviruses is largely unknown or infrequently updated because of the lack of surveillance studies, especially in Africa. METHODS: A surveillance study was conducted in Gabon, Central Africa, on arboviruses, which are a major public health concern in Africa, including: West Nile virus (WNV), dengue virus (DENV), Zika virus (ZIKV), yellow fever virus (YFV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). Serological and molecular assays were performed to investigate past infection history and the current status of infection, using serum samples collected from healthy individuals and febrile patients, respectively. RESULTS: The overall seroprevalence during 2014-2017 was estimated to be 25.3% for WNV, 20.4% for DENV, 40.3% for ZIKV, 60.7% for YFV, 61.2% for CHIKV, and 14.3% for RVFV. No significant differences were found in the seroprevalence of any of the viruses between the male and female populations. However, a focus on the mean age in each arbovirus-seropositive individual showed a significantly younger age in WNV- and DENV-seropositive individuals than in CHIKV-seropositive individuals, indicating that WNV and DENV caused a relatively recent epidemic in the region, whereas CHIKV had actively circulated before. Of note, this indication was supported by the detection of both WNV and DENV genomes in serum samples collected from febrile patients after 2016. CONCLUSIONS: This study revealed the recent re-emergence of WNV and DENV in Gabon as well as the latest seroprevalence state of the major arboviruses, which indicated the different potential risks of virus infections and virus-specific circulation patterns. This information will be helpful for public health organizations and will enable a rapid response towards these arbovirus infections, thereby preventing future spread in the country.


Subject(s)
Arboviruses/isolation & purification , Dengue/epidemiology , Zika Virus Infection/epidemiology , Adolescent , Animals , Arbovirus Infections/diagnosis , Arbovirus Infections/epidemiology , Arboviruses/classification , Child , Child, Preschool , Communicable Diseases, Emerging , Dengue/diagnosis , Female , Fever/epidemiology , Fever/virology , Gabon/epidemiology , Humans , Infant , Male , Public Health , Seroepidemiologic Studies , Zika Virus Infection/diagnosis
12.
Rev Soc Bras Med Trop ; 54: e0055-2020, 2021.
Article in English | MEDLINE | ID: mdl-33759914

ABSTRACT

INTRODUCTION: Mayaro virus (MAYV) was found in Pará state, Brazil, in 1955. Since then, sporadic outbreaks have occurred in different regions of the country. METHODS: Serum sample were collected from 49 individuals in 2016 and were initially tested for dengue virus (DENV) by real-time (RT) polymerase chain reaction (PCR). DENV-negative samples were tested for MAYV and Oropouche virus (OROV) by multiplexed RT quantitative PCR. RESULTS: All samples were negative for DENV and OROV, but MAYV was detected in four samples. CONCLUSIONS: Differential diagnoses of acute febrile syndrome are required, especially in regions where several arboviruses with similar clinical manifestations are endemic.


Subject(s)
Alphavirus , Arboviruses , Dengue , Alphavirus/genetics , Arboviruses/genetics , Brazil/epidemiology , Dengue/diagnosis , Dengue/epidemiology , Disease Outbreaks , Humans , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction
13.
Article in English | MEDLINE | ID: mdl-33787737

ABSTRACT

Dengue virus, the etiological agent of dengue fever (DF) occurs in four genetically distinct serotypes (DENV1-4), being transmitted by female Aedes mosquitoes. DF incidence is increasing in Brazil, following vector dispersal, proliferation and DENV serotypes introduction, co-circulation and substitution. Medium- and small-sized cities in Sao Paulo State, such as Marilia (Midwest region), have been affected by huge epidemics. To understand the evolution of DENV epidemics in medium-sized cities, in this study a historical data on DENV incidence (2000-2015) in Marilia, was evaluated. Previous studies disclosed regional and specific DF outcomes associated with 2007 outbreak in that city, when co-circulating DENV1 and DENV3 presented different hematological profiles. In this study, characteristics of 2007 DENV epidemics were compared to the epidemiological, hematological and demographic outlines of the major outbreak of DENV1 in Marilia in 2015. DENV1 genetic diversity was assessed through capsid and pre-membrane junction encoding gene (CprM) sequencing. The results revealed circulation of DENV1 serotype from 2007 to 2015, with epidemics occurring every three-years until 2013 and then, increasing yearly. There were significant differences in hematological profiles of DENV1 patients between 2015 and 2007. CprM showed DENV1 genetic variability in 2015, contrasting with the unique sequence pattern in 2007. These results reinforce the regional and temporal characteristics of DENV epidemics that need local public health research to improve care for people and to limit the spread of new serotypes/genotypes to uninfected areas.


Subject(s)
Dengue Virus/genetics , Dengue/epidemiology , Disease Outbreaks , Adolescent , Adult , Aged , Animals , Brazil/epidemiology , Child , Dengue/transmission , Dengue Virus/classification , Dengue Virus/isolation & purification , Female , Humans , Immunoglobulin M/blood , Male , Middle Aged , Mosquito Vectors , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Serogroup , Serotyping , Young Adult
14.
PLoS Negl Trop Dis ; 15(3): e0009259, 2021 03.
Article in English | MEDLINE | ID: mdl-33705409

ABSTRACT

Dengue, Zika and chikungunya are diseases of global health significance caused by arboviruses and transmitted by the mosquito Aedes aegypti, which is of worldwide circulation. The arrival of the Zika and chikungunya viruses to South America increased the complexity of transmission and morbidity caused by these viruses co-circulating in the same vector mosquito species. Here we present an integrated analysis of the reported arbovirus cases between 2007 and 2017 and local climate and socio-economic profiles of three distinct Colombian municipalities (Bello, Cúcuta and Moniquirá). These locations were confirmed as three different ecosystems given their contrasted geographic, climatic and socio-economic profiles. Correlational analyses were conducted with both generalised linear models and generalised additive models for the geographical data. Average temperature, minimum temperature and wind speed were strongly correlated with disease incidence. The transmission of Zika during the 2016 epidemic appeared to decrease circulation of dengue in Cúcuta, an area of sustained high incidence of dengue. Socio-economic factors such as barriers to health and childhood services, inadequate sanitation and poor water supply suggested an unfavourable impact on the transmission of dengue, Zika and chikungunya in all three ecosystems. Socio-demographic influencers were also discussed including the influx of people to Cúcuta, fleeing political and economic instability from neighbouring Venezuela. Aedes aegypti is expanding its range and increasing the global threat of these diseases. It is therefore vital that we learn from the epidemiology of these arboviruses and translate it into an actionable local knowledge base. This is even more acute given the recent historical high of dengue cases in the Americas in 2019, preceding the COVID-19 pandemic, which is itself hampering mosquito control efforts.


Subject(s)
Chikungunya Fever/epidemiology , Dengue/epidemiology , Zika Virus Infection/epidemiology , Aedes/physiology , Aedes/virology , Animals , Chikungunya Fever/economics , Chikungunya Fever/virology , Chikungunya virus/physiology , Climate , Colombia/epidemiology , Dengue/economics , Dengue/virology , Dengue Virus/physiology , Ecosystem , Humans , Mosquito Vectors/physiology , Mosquito Vectors/virology , South America , Temperature , Zika Virus/physiology , Zika Virus Infection/economics , Zika Virus Infection/virology
15.
Arch Argent Pediatr ; 119(2): 131-138, 2021 04.
Article in Spanish | MEDLINE | ID: mdl-33749212

ABSTRACT

Eleven years after the first dengue outbreak in Buenos Aires, on March 20, 2020, while the mandatory quarantine for COVID-19 began dengue became the most common cause of fever consultation. The new wave of dengue cases was already among the predictions of the Pan American Health Organization based on the increase in the region of the Americas that had been occurring since the previous year. The arrival of SARS-CoV-2 at the beginning of March, added to the dengue outbreak that was already underway, made a new challenge for the health system while a new paradigm was initiated with adaptation plans to the new pandemic infection in the country. The overlapping of infections with epidemic potential such as dengue recalls the importance of not neglecting other endemic, emerging and re-emerging diseases in the shadow of the new epidemiological phenomenon.


Subject(s)
/epidemiology , Dengue/epidemiology , Argentina/epidemiology , Dengue/diagnosis , Dengue/prevention & control , Disease Outbreaks , Health Policy , Humans , Pandemics , Quarantine
16.
Nat Commun ; 12(1): 1810, 2021 03 22.
Article in English | MEDLINE | ID: mdl-33753725

ABSTRACT

For most pathogens, transmission is driven by interactions between the behaviours of infectious individuals, the behaviours of the wider population, the local environment, and immunity. Phylogeographic approaches are currently unable to disentangle the relative effects of these competing factors. We develop a spatiotemporally structured phylogenetic framework that addresses these limitations by considering individual transmission events, reconstructed across spatial scales. We apply it to geocoded dengue virus sequences from Thailand (N = 726 over 18 years). We find infected individuals spend 96% of their time in their home community compared to 76% for the susceptible population (mainly children) and 42% for adults. Dynamic pockets of local immunity make transmission more likely in places with high heterotypic immunity and less likely where high homotypic immunity exists. Age-dependent mixing of individuals and vector distributions are not important in determining spread. This approach provides previously unknown insights into one of the most complex disease systems known and will be applicable to other pathogens.


Subject(s)
Algorithms , Dengue Virus/genetics , Dengue/transmission , Models, Theoretical , Adult , Aedes/virology , Animals , Child , Dengue/epidemiology , Dengue/virology , Dengue Virus/classification , Dengue Virus/physiology , Genome, Viral/genetics , Host-Pathogen Interactions , Humans , Mosquito Vectors/virology , Phylogeny , Phylogeography/methods , Phylogeography/statistics & numerical data , Population Dynamics , Thailand/epidemiology
17.
Rev Soc Bras Med Trop ; 54: e08372020, 2021.
Article in English | MEDLINE | ID: mdl-33656154

ABSTRACT

INTRODUCTION: This study evaluated the epidemiological implications of arbovirus infections and coronavirus disease (COVID-19) co-occurrences in Espírito Santo, Brazil. METHODS: This ecological study of dengue, chikungunya, zika, and COVID-19 was performed from January 1 to July 31, 2020. RESULTS: Espírito Santo registered 44,614, 8,092, 3,138, and 91,483 cases of dengue, chikungunya, zika, and COVID-19, respectively (January-July, 2020). In the 27 and four municipalities with a high incidence of dengue and chikungunya, respectively, the incidence of COVID-19 was 647.0-3,721.7 and 1,787.2-3,403.0 cases per 100,000 inhabitants, respectively. CONCLUSIONS: Espírito Santo experienced an overlap of epidemics, especially in urban areas.


Subject(s)
Chikungunya Fever , Coronavirus , Dengue , Epidemics , Zika Virus Infection , Zika Virus , Brazil/epidemiology , Chikungunya Fever/epidemiology , Dengue/epidemiology , Humans , Zika Virus Infection/complications , Zika Virus Infection/epidemiology
18.
Epidemiol Infect ; 149: e58, 2021 02 15.
Article in English | MEDLINE | ID: mdl-33583455

ABSTRACT

The role of anthropometric status on dengue is uncertain. We investigated the relations between anthropometric characteristics (height, body mass index and waist circumference (WC)) and two dengue outcomes, seropositivity and hospitalisation, in a cross-sectional study of 2038 children (aged 2-15 years) and 408 adults (aged 18-72 years) from Bucaramanga, Colombia. Anthropometric variables were standardised by age and sex in children. Seropositivity was determined through immunoglobulin G antibodies; past hospitalisation for dengue was self-reported. We modelled the prevalence of each outcome by levels of anthropometric exposures using generalised estimating equations with restricted cubic splines. In children, dengue seropositivity was 60.8%; 9.9% of seropositive children reported prior hospitalisation for dengue. WC was positively associated with seropositivity in girls (90th vs. 10th percentile adjusted prevalence ratio (APR) = 1.19; 95% confidence interval (CI) 1.03-1.36). Among adults, dengue seropositivity was 95.1%; 8.1% of seropositive adults reported past hospitalisation. Height was inversely associated with seropositivity (APR = 0.90; 95% CI 0.83-0.99) and with hospitalisation history (APR = 0.19; 95% CI 0.04-0.79). WC was inversely associated with seropositivity (APR = 0.89; 95% CI 0.81-0.98). We conclude that anthropometry correlates with a history of dengue, but could not determine causation. Prospective studies are warranted to enhance causal inference on these questions.


Subject(s)
Dengue/epidemiology , Hospitalization/statistics & numerical data , Seroepidemiologic Studies , Adolescent , Adult , Aged , Child , Child, Preschool , Colombia , Female , Humans , Male , Middle Aged , Risk Factors , Young Adult
19.
Environ Res ; 195: 110849, 2021 04.
Article in English | MEDLINE | ID: mdl-33561446

ABSTRACT

BACKGROUND: The mosquitoes Aedes aegypti and Ae. albopictus are the primary vectors of dengue virus, and their geographic distributions are predicted to expand further with economic development, and in response to climate change. We aimed to estimate the impact of future climate change on dengue transmission through the development of a Suitable Conditions Index (SCI), based on climatic variables known to support vectorial capacity. We calculated the SCI based on various climate change scenarios for six countries in the Asia-Pacific region (Australia, China, Indonesia, The Philippines, Thailand and Vietnam). METHODS: Monthly raster climate data (temperature and precipitation) were collected for the period January 2005 to December 2018 along with projected climate estimates for the years 2030, 2050 and 2070 using Representative Concentration Pathway (RCP) 4·5, 6·0 and 8·5 emissions scenarios. We defined suitable temperature ranges for dengue transmission of between 17·05-34·61 °C for Ae. aegypti and 15·84-31·51 °C for Ae. albopictus and then developed a historical and predicted SCI based on weather variability to measure the expected geographic limits of dengue vectorial capacity. Historical and projected SCI values were compared through difference maps for the six countries. FINDINGS: Comparing different emission scenarios across all countries, we found that most South East Asian countries showed either a stable pattern of high suitability, or a potential decline in suitability for both vectors from 2030 to 2070, with a declining pattern particularly evident for Ae. albopictus. Temperate areas of both China and Australia showed a less stable pattern, with both moderate increases and decreases in suitability for each vector in different regions between 2030 and 2070. INTERPRETATION: The SCI will be a useful index for forecasting potential dengue risk distributions in response to climate change, and independently of the effects of human activity. When considered alongside additional correlates of infection such as human population density and socioeconomic development indicators, the SCI could be used to develop an early warning system for dengue transmission.


Subject(s)
Aedes , Dengue , Animals , Australia , China , Climate Change , Dengue/epidemiology , Humans , Indonesia/epidemiology , Mosquito Vectors , Thailand , Vietnam
20.
Sci Total Environ ; 775: 145117, 2021 Jun 25.
Article in English | MEDLINE | ID: mdl-33618312

ABSTRACT

BACKGROUND: Global incidence of dengue has surged rapidly over the past decade. Each year, an estimated 390 million infections occur worldwide, with Asia-Pacific countries bearing about three-quarters of the global dengue disease burden. Global warming may influence the pattern of dengue transmission. While previous studies have shown that extremely high temperatures can impede the development of the Aedes mosquito, the effect of such extreme heat over a sustained period, also known as heatwaves, has not been investigated in a tropical climate setting. AIM: We examined the short-term relationships between maximum ambient temperature and heatwaves and reported dengue infections in Singapore, via ecological time series analysis, using data from 2009 to 2018. METHODS: We studied the effect of two measures of extreme heat - (i) heatwaves and (ii) maximum ambient temperature. We used a negative binomial regression, coupled with a distributed lag nonlinear model, to examine the immediate and lagged associations of extreme temperature on dengue infections, on a weekly timescale. We adjusted for long-term trend, seasonality, rainfall and absolute humidity, public holidays and autocorrelation. RESULTS: We observed an overall inhibitive effect of heatwaves on the risk of dengue infections, and a parabolic relationship between maximum temperature and dengue infections. A 1 °C increase in maximum temperature from 31 °C was associated with a 13.1% (Relative Risk (RR): 0.868, 95% CI: 0.798, 0.946) reduction in the cumulative risk of dengue infections over six weeks. Weeks with 3 heatwave days were associated with a 28.3% (RR: 0.717, 95% CI: 0.608, 0.845) overall reduction compared to weeks with no heatwave days. Adopting different heatwaves specifications did not substantially alter our estimates. CONCLUSION: Extreme heat was associated with decreased dengue incidence. Findings from this study highlight the importance of understanding the temperature dependency of vector-borne diseases in resource planning for an anticipated climate change scenario.


Subject(s)
Dengue , Mosquito Vectors , Animals , Asia , Cities , Dengue/epidemiology , Hot Temperature , Singapore/epidemiology , Temperature
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