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1.
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
2.
Public Health ; 192: 21-29, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33607517

ABSTRACT

OBJECTIVES: The primary aim of this study was to evaluate the temporal correlation between Wikitrends and conventional surveillance data generated for Chikungunya, Dengue, Zika, and West Nile Virus infection reported by bulletin of Italian National Institute of Health (Istituto Superiore di Sanità in italian, ISS). STUDY DESIGN: A cross-sectional study design was used. METHODS: The reported cases of Dengue and Chikungunya were selected from July 2015 to December 2019. For West Nile Virus, the bulletins are issued in the period June-November (6 months) of the years 2015-2019, and for Zika virus, the data reported in the ISS bulletin start from January 2016. From Wikipedia Trends, we extracted the number of monthly views by users from the July 2015 to December 2019 of the pages Chikungunya, Dengue, Zika virus, and West Nile Virus. RESULTS: A correlation was observed between the bulletin of ISS and Wikipedia Wikitrends, the correlation was strong for Chikungunya and West Nile Virus (r = 0.9605; r = 0.9556, respectively), and highly statistically significant with P-values <0.001. The correlation was moderate for Dengue and Zika virus (r = 0.6053; r = 0.5888, respectively), but highly statistically significant with P-values <0.001. CONCLUSIONS: Classical surveillance system should be integrated with the tools of digital epidemiology that have potential role in public health for the dynamic information and provide near real-time indicators of the spread of infectious disease.


Subject(s)
Arboviruses , Chikungunya Fever/epidemiology , Culicidae/virology , Dengue/epidemiology , Internet , West Nile Fever/epidemiology , Zika Virus Infection/epidemiology , Animals , Arboviruses/classification , Arboviruses/isolation & purification , Chikungunya virus , Cross-Sectional Studies , Dengue/virology , Dengue Virus , Epidemiological Monitoring , Humans , Italy/epidemiology , Male , Public Health , West Nile virus , Zika Virus
3.
Viruses ; 13(1)2021 Jan 14.
Article in English | MEDLINE | ID: mdl-33466915

ABSTRACT

Mosquito-borne arthropod-borne viruses (arboviruses) such as the dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) are important human pathogens that are responsible for significant global morbidity and mortality. The recent emergence and re-emergence of mosquito-borne viral diseases (MBVDs) highlight the urgent need for safe and effective vaccines, therapeutics, and vector-control approaches to prevent MBVD outbreaks. In nature, arboviruses circulate between vertebrate hosts and arthropod vectors; therefore, disrupting the virus lifecycle in mosquitoes is a major approach for combating MBVDs. Several strategies were proposed to render mosquitoes that are refractory to arboviral infection, for example, those involving the generation of genetically modified mosquitoes or infection with the symbiotic bacterium Wolbachia. Due to the recent development of high-throughput screening methods, an increasing number of drugs with inhibitory effects on mosquito-borne arboviruses in mammalian cells were identified. These antivirals are useful resources that can impede the circulation of arboviruses between arthropods and humans by either rendering viruses more vulnerable in humans or suppressing viral infection by reducing the expression of host factors in mosquitoes. In this review, we summarize recent advances in small-molecule antiarboviral drugs in mammalian and mosquito cells, and discuss how to use these antivirals to block the transmission of MBVDs.


Subject(s)
Aedes/virology , Antiviral Agents/pharmacology , Arbovirus Infections/transmission , Arbovirus Infections/virology , Arboviruses/drug effects , Mosquito Vectors/virology , Aedes/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Arbovirus Infections/drug therapy , Arboviruses/classification , Cells, Cultured , Drug Discovery/methods , Drug Evaluation, Preclinical , Humans , Mosquito Control/methods , Vector Borne Diseases/drug therapy , Vector Borne Diseases/transmission , Vector Borne Diseases/virology , Virus Replication/drug effects
4.
PLoS One ; 15(7): e0234959, 2020.
Article in English | MEDLINE | ID: mdl-32663230

ABSTRACT

The economic and social impacts due to diseases transmitted by mosquitoes in the latest years have been significant. Currently, no specific treatment or commercial vaccine exists for the control and prevention of arboviruses, thereby making entomological characterization fundamental in combating diseases such as dengue, chikungunya, and Zika. The morphological identification of mosquitos includes a visual exam of the samples. It is time consuming and requires adequately trained professionals. Accordingly, the development of a new automated method for realizing mosquito-perception and -classification is becoming increasingly essential. Therefore, in this study, a computational model based on a convolutional neural network (CNN) was developed to extract features from the images of mosquitoes and then classify the species Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus. In addition, the model was trained to detect the mosquitoes of the genus Aedes. To train CNNs to perform the automatic morphological classification of mosquitoes, a dataset, which included 7,561 images of the target mosquitoes and 1,187 images of other insects, was acquired. Various neural networks, such as Xception and DenseNet, were used for developing the automatic-classification model based on images. A structured optimization process of random search and grid search was developed to select the hyperparameters set and increase the accuracy of the model. In addition, strategies to eliminate overfitting were implemented to increase the generalization of the model. The optimized model, during the test phase, obtained the balanced accuracy (BA) of 93.5% in classifying the target mosquitoes and other insects and the BA of 97.3% in detecting the mosquitoes of the genus Aedes in comparison to Culex. The results provide fundamental information for performing the automatic morphological classification of mosquito species. Using a CNN-embedded entomological tool is a valuable and accessible resource for health workers and non-taxonomists for identifying insects that can transmit infectious diseases.


Subject(s)
Arboviruses/classification , Culicidae/classification , Image Processing, Computer-Assisted/methods , Aedes/virology , Animals , Automation, Laboratory/methods , Chikungunya Fever/transmission , Chikungunya virus/genetics , Culex/virology , Culicidae/genetics , Dengue/transmission , Dengue Virus/genetics , Female , Male , Mosquito Vectors/virology , Zika Virus/genetics , Zika Virus Infection/transmission
5.
PLoS One ; 15(7): e0235322, 2020.
Article in English | MEDLINE | ID: mdl-32609784

ABSTRACT

INTRODUCTION: The re-emergence of vector borne diseases affecting millions of people in recent years has drawn attention to arboviruses globally. Here, we report on the sero-prevalence of chikungunya virus (CHIKV), dengue virus (DENV), mayaro virus (MAYV) and zika virus (ZIKV) in a swamp community in Zambia. METHODS: We collected blood and saliva samples from residents of Lukanga swamps in 2016 during a mass-cholera vaccination campaign. Over 10,000 residents were vaccinated with two doses of Shanchol™ during this period. The biological samples were collected prior to vaccination (baseline) and at specified time points after vaccination. We tested a total of 214 baseline stored serum samples for IgG antibodies against NS1 of DENV and ZIKV and E2 of CHIKV and MAYV on ELISA. We defined sero-prevalence as the proportion of participants with optical density (OD) values above a defined cut-off value, determined using a finite mixture model. RESULTS: Of the 214 participants, 79 (36.9%; 95% CI 30.5-43.8) were sero-positive for Chikungunya; 23 (10.8%; 95% CI 6.9-15.7) for Zika, 36 (16.8%; 95% CI 12.1-22.5) for Dengue and 42 (19.6%; 95% CI 14.5-25.6) for Mayaro. Older participants were more likely to have Zika virus whilst those involved with fishing activities were at greater risk of contracting Chikungunya virus. Among all the antigens tested, we also found that Chikungunya saliva antibody titres correlated with baseline serum titres (Spearman's correlation coefficient = 0.222; p = 0.03). CONCLUSION: Arbovirus transmission is occurring in Zambia. This requires proper screening tools as well as surveillance data to accurately report on disease burden in Zambia.


Subject(s)
Arbovirus Infections/epidemiology , Arbovirus Infections/virology , Arboviruses/classification , Arboviruses/isolation & purification , Adult , Coinfection/epidemiology , Female , Humans , Male , Middle Aged , Prevalence , Serogroup , Wetlands , Young Adult , Zambia/epidemiology
6.
PLoS One ; 15(6): e0233669, 2020.
Article in English | MEDLINE | ID: mdl-32502226

ABSTRACT

Only few data exist in Cambodia on mosquito diversity and their potential role as vectors. Many arboviruses, such as dengue and Japanese encephalitis, are endemic and mostly affect children in the country. This research sets out to evaluate vector relative abundance and diversity in primary schools in Cambodia in an attempt to explain the apparent burden of dengue fever, severe dengue (DEN), Japanese encephalitis (JE), other arboviral diseases and malaria among children, 15 years and under, attending selected primary schools through vector surveys. Entomological surveys were implemented in primary schools in two provinces of Cambodia to assess the potential risk of exposure of schoolchildren to mosquito vector species. Light traps and BG traps were used to collect adult mosquitoes in 24 schools during the rainy and dry seasons of 2017 and 2018 in Kampong Cham and Tboung Khmum provinces. A total of 61 species were described, including Aedes, Culex and Anopheles species. The relative abundance and biodiversity of mosquito species were dependent on the month and school. Of the 37,725 mosquitoes caught during the study, three species accounted for three-quarters of the relative abundance: Culex vishnui, Anopheles indefinitus and Culex quinquefasciatus. More importantly, nearly 90% of the mosquitoes caught in the schools were identified as potential vectors of pathogens including Japanese encephalitis, dengue, and malaria parasites. Our results showed that schools in Cambodia represent a risk for vector-borne disease transmission and highlight the importance of implementing vector control in schools in Cambodia to decrease the risk of transmission.


Subject(s)
Arbovirus Infections/transmission , Arboviruses/isolation & purification , Mosquito Vectors , Adolescent , Arbovirus Infections/epidemiology , Arboviruses/classification , Biodiversity , Cambodia/epidemiology , Child , Child, Preschool , Dengue/epidemiology , Dengue/transmission , Dengue/virology , Encephalitis, Japanese/epidemiology , Encephalitis, Japanese/transmission , Encephalitis, Japanese/virology , Humans , Malaria/epidemiology , Malaria/transmission , Malaria/virology
7.
PLoS Negl Trop Dis ; 14(2): e0008066, 2020 02.
Article in English | MEDLINE | ID: mdl-32092063

ABSTRACT

BACKGROUND: In the northeast United States (U.S.), mosquitoes transmit a number of arboviruses, including eastern equine encephalitis, Jamestown Canyon, and West Nile that pose an annual threat to human and animal health. Local transmission of each arbovirus may be driven by the involvement of multiple mosquito species; however, the specificity of these vector-virus associations has not been fully quantified. METHODOLOGY: We used long-term surveillance data consistently collected over 18 years to evaluate mosquito and arbovirus community composition in the State of Connecticut (CT) based on land cover classifications and mosquito species-specific natural histories using community ecology approaches available in the R package VEGAN. We then used binomial-error generalized linear mixed effects models to quantify species-specific trends in arbovirus detections. PRIMARY RESULTS: The composition of mosquito communities throughout CT varied more among sites than among years, with variation in mosquito community composition among sites explained mostly by a forested-to-developed-land-cover gradient. Arboviral communities varied equally among sites and years, and only developed and forested wetland land cover classifications were associated with the composition of arbovirus detections among sites. Overall, the avian host arboviruses, mainly West Nile and eastern equine encephalitis, displayed the most specific associations among mosquito species and sites, while in contrast, the mammalian host arboviruses (including Cache Valley, Jamestown Canyon, and Potosi) associated with a more diverse mix of mosquito species and were widely distributed throughout CT. CONCLUSIONS: We find that avian arboviruses act as vector specialists infecting a few key mosquito species that associate with discrete habitats, while mammalian arboviruses are largely vector generalists infecting a wide diversity of mosquito species and habitats in the region. These distinctions have important implications for the design and implementation of mosquito and arbovirus surveillance programs as well as mosquito control efforts.


Subject(s)
Arboviruses/physiology , Culicidae/virology , Animals , Arboviruses/classification , Connecticut , Female , Host-Pathogen Interactions , Humans , Mosquito Vectors/virology , Retrospective Studies
8.
PLoS One ; 15(1): e0227998, 2020.
Article in English | MEDLINE | ID: mdl-32004323

ABSTRACT

Arboviruses cause diseases of significant global health concerns. Interactions between mosquitoes and their microbiota as well as the important role of this interaction in the mosquito's capacity to harbor and transmit pathogens have emerged as important fields of research. Aedes aegypti is one of the most abundant mosquitoes in many geographic locations, a vector capable of transmitting a number of arboviruses such as dengue and Zika. Currently, there are few studies on the metavirome of this mosquito particularly in the Americas. This study analyzes the metavirome of A. aegypti from Grenada, a Caribbean nation with tropical weather, abundant A. aegypti, and both endemic and arboviral pathogens transmitted by this mosquito. Between January and December 2018, 1152 mosquitoes were collected from six semi-rural locations near houses in St. George Parish, Grenada, by weekly trapping using BG-Sentinel traps. From these, 300 A. aegypti were selected for analysis. The metavirome was analyzed using the Illumina HiSeq 1500 for deep sequencing. The generation sequencing library construction protocol used was NuGEN Universal RNA with an average read length of 125 bp. Reads were mapped to the A. aegypti assembly. Non-mosquito reads were analyzed using the tools FastViromeExplorer. The NCBI total virus, RNA virus, and eukaryotic virus databases were used as references. The metagenomic comparison analysis showed that the most abundant virus-related reads among all databases and assemblies was Phasi Charoen-like virus. The Phasi Charoen-like virus results are in agreement to other studies in America, Asia and Australia. Further studies using wild-caught mosquitoes is needed to assess the impact of this insect-specific virus on the A. aegypti lifecycle and vector capacity.


Subject(s)
Aedes/virology , Arboviruses , Genome, Viral/genetics , Insect Viruses , Metagenome , Animals , Arboviruses/classification , Arboviruses/genetics , Grenada , Insect Viruses/classification , Insect Viruses/genetics , Mosquito Vectors/virology
9.
Transbound Emerg Dis ; 67(1): 11-17, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31420970

ABSTRACT

Sloths are genetically and physiologically divergent mammals. Phleboviruses are major arthropod-borne viruses (arboviruses) causing disease in humans and other animals globally. Sloths host arboviruses, but virus detections are scarce. A phlebovirus termed Anhanga virus (ANHV) was isolated from a Brazilian Linnaeus's two-toed sloth (Choloepus didactylus) in 1962. Here, we investigated the presence of phleboviruses in sera sampled in 2014 from 74 Hoffmann's two-toed (Choloepus hoffmanni, n = 65) and three-toed (Bradypus variegatus, n = 9) sloths in Costa Rica by broadly reactive RT-PCR. A clinically healthy adult Hoffmann's two-toed sloth was infected with a phlebovirus. Viral load in this animal was high at 8.5 × 107  RNA copies/ml. The full coding sequence of the virus was determined by deep sequencing. Phylogenetic analyses and sequence distance comparisons revealed that the new sloth virus, likely representing a new phlebovirus species, provisionally named Penshurt virus (PEHV), was most closely related to ANHV, with amino acid identities of 93.1%, 84.6%, 94.7% and 89.0% in the translated L, M, N and NSs genes, respectively. Significantly more non-synonymous mutations relative to ANHV occurred in the M gene encoding the viral glycoproteins and in the NSs gene encoding a putative interferon antagonist compared to L and N genes. This was compatible with viral adaptation to different sloth species and with micro-evolutionary processes associated with immune evasion during the genealogy of sloth-associated phleboviruses. However, gene-wide mean dN/dS ratios were low at 0.02-0.15 and no sites showed significant evidence for positive selection, pointing to comparable selection pressures within sloth-associated viruses and genetically related phleboviruses infecting hosts other than sloths. The detection of a new phlebovirus closely-related to ANHV, in sloths from Costa Rica fifty years after and more than 3,000 km away from the isolation of ANHV confirmed the host associations of ANHV-related phleboviruses with the two extant species of two-toed sloths.


Subject(s)
Arbovirus Infections/veterinary , Arboviruses/classification , Phlebovirus/classification , Sloths/virology , Vector Borne Diseases/veterinary , Animals , Arbovirus Infections/virology , Arboviruses/genetics , Arboviruses/isolation & purification , Brazil , Costa Rica , Geography , High-Throughput Nucleotide Sequencing/veterinary , Phlebovirus/genetics , Phlebovirus/isolation & purification , Phylogeny , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Vector Borne Diseases/virology , Viral Load/veterinary
10.
Viruses ; 11(11)2019 11 01.
Article in English | MEDLINE | ID: mdl-31683823

ABSTRACT

We reviewed the literature on the role of temperature in transmission of zoonotic arboviruses. Vector competence is affected by both direct and indirect effects of temperature, and generally increases with increasing temperature, but results may vary by vector species, population, and viral strain. Temperature additionally has a significant influence on life history traits of vectors at both immature and adult life stages, and for important behaviors such as blood-feeding and mating. Similar to vector competence, temperature effects on life history traits can vary by species and population. Vector, host, and viral distributions are all affected by temperature, and are generally expected to change with increased temperatures predicted under climate change. Arboviruses are generally expected to shift poleward and to higher elevations under climate change, yet significant variability on fine geographic scales is likely. Temperature effects are generally unimodal, with increases in abundance up to an optimum, and then decreases at high temperatures. Improved vector distribution information could facilitate future distribution modeling. A wide variety of approaches have been used to model viral distributions, although most research has focused on the West Nile virus. Direct temperature effects are frequently observed, as are indirect effects, such as through droughts, where temperature interacts with rainfall. Thermal biology approaches hold much promise for syntheses across viruses, vectors, and hosts, yet future studies must consider the specificity of interactions and the dynamic nature of evolving biological systems.


Subject(s)
Arboviruses/physiology , Disease Vectors , Temperature , Vector Borne Diseases/transmission , Animals , Arboviruses/classification , Climate Change , Disease Vectors/classification , Ecosystem , Mosquito Vectors/physiology , Mosquito Vectors/virology , Species Specificity , West Nile virus/physiology
11.
Viruses ; 11(11)2019 11 05.
Article in English | MEDLINE | ID: mdl-31694175

ABSTRACT

Metagenomic studies of mosquitoes have revealed that their virome is far more diverse and includes many more viruses than just the pathogenic arboviruses vectored by mosquitoes. In this study, the virome of 953 female mosquitoes collected in the summer of 2017, representing six mosquito species from two geographic locations in Mid-Eastern Sweden, were characterized. In addition, the near-complete genome of nine RNA viruses were characterized and phylogenetically analysed. These viruses showed association to the viral orders Bunyavirales, Picornavirales, Articulavirales, and Tymovirales, and to the realm Ribovira. Hence, through this study, we expand the knowledge of the virome composition of different mosquito species in Sweden. In addition, by providing viral reference genomes from wider geographic regions and different mosquito species, future in silico recognition and assembly of viral genomes in metagenomic datasets will be facilitated.


Subject(s)
Culicidae/virology , Genome, Viral/genetics , RNA Viruses/genetics , Animals , Arboviruses/classification , Arboviruses/genetics , Arboviruses/isolation & purification , Culicidae/classification , Female , Host Specificity , Metagenomics , Phylogeny , RNA Viruses/classification , RNA Viruses/isolation & purification , Sweden
12.
Parasit Vectors ; 12(1): 463, 2019 Oct 02.
Article in English | MEDLINE | ID: mdl-31578140

ABSTRACT

Arboviruses infecting people primarily exist in urban transmission cycles involving urban mosquitoes in densely populated tropical regions. For dengue, chikungunya, Zika and yellow fever viruses, sylvatic (forest) transmission cycles also exist in some regions and involve non-human primates and forest-dwelling mosquitoes. Here we review the investigation methods and available data on sylvatic cycles involving non-human primates and dengue, chikungunya, Zika and yellow fever viruses in Africa, dengue viruses in Asia and yellow fever virus in the Americas. We also present current putative data that Mayaro, o'nyong'nyong, Oropouche, Spondweni and Lumbo viruses exist in sylvatic cycles.


Subject(s)
Arbovirus Infections/veterinary , Arboviruses/isolation & purification , Primate Diseases/virology , Africa , Americas , Animals , Arbovirus Infections/virology , Arboviruses/classification , Asia , Disease Transmission, Infectious , Humans
13.
Pathog Glob Health ; 113(5): 209-228, 2019 07.
Article in English | MEDLINE | ID: mdl-31664886

ABSTRACT

Mosquito-borne diseases, including arbovirus-related diseases, make up a large proportion of infectious disease cases worldwide, causing a serious global public health burden with over 700,000 deaths annually. Mosquito-borne arbovirus outbreaks can range from global to regional. In the East African Community (EAC) region, these viruses have caused a series of emerging and reemerging infectious disease outbreaks. Member states in the EAC share a lot in common including regional trade and transport, some of the factors highlighted to be the cause of mosquito-borne arbovirus disease outbreaks worldwide. In this review, characteristics of 24 mosquito-borne arboviruses indigenous to the EAC are reviewed, including lesser or poorly understood viruses, like Batai virus (BATV) and Ndumu virus (NDUV), which may escape their origins under perfect conditions to establish a foothold in new geographical locations. Factors that may influence the future spread of these viruses within the EAC are addressed. With the continued development observed in the EAC, strategies should be developed by the Community in improving mosquito and mosquito-borne arbovirus surveillance to prevent future outbreaks.


Subject(s)
Alphavirus Infections/epidemiology , Arboviruses/classification , Arboviruses/isolation & purification , Mosquito Vectors/virology , Africa, Eastern/epidemiology , Alphavirus Infections/transmission , Animals , Disease Outbreaks , Disease Transmission, Infectious , Humans , Mosquito Vectors/growth & development
14.
An Acad Bras Cienc ; 91(suppl 3): e20190407, 2019 Aug 26.
Article in English | MEDLINE | ID: mdl-31460596

ABSTRACT

We review the potential of Amazon forest as a source for circulation and maintenance of native arboviruses as well its capacity to host exotic arboviruses introduced in Brazil during their process of adapting to the Amazon environment. After a brief introduction about arboviruses isolated in Amazon region and description of the main arboviruses pathogenic to humans, we highlight the history of the last two exotic viruses introduced in Brazil - Chikungunya virus (CHIKV) and Zika virus (ZIKV) - and their consequences to the public health. Finally, we discuss and hypothesize what will happen with them after the outbreak. We look to the past to predict the future.


Subject(s)
Arboviruses/classification , Communicable Diseases, Emerging/virology , Animals , Brazil , Chikungunya virus , Dengue Virus , Humans , Orthobunyavirus , Yellow fever virus , Zika Virus
15.
BMC Res Notes ; 12(1): 332, 2019 Jun 11.
Article in English | MEDLINE | ID: mdl-31186058

ABSTRACT

OBJECTIVE: Arboviruses, Dengue and Chikungunya have become major international public health concerns due to their epidemics and introduction in new areas. In Ghana, little is known is about Dengue and Chikungunya viruses though the country has been listed as part of the 34 countries in which the viruses are endemic. This has been attributed partly to the lack of diagnostic tools for these viruses in several health facilities and institutions across the country. The purpose of this study was to detect and characterize these viral pathogens among febrile patients in Accra Ghana. RESULTS: This hospital-based cross-sectional study enrolled 260 suspected Dengue and/or Chikungunya febrile patients who submitted their clinical specimens of serum. Out of the total number tested with both molecular and serological tools, Chikungunya and Dengue specific total antibodies were detected from 72 (27.69%) and 180 (69.23%) respectively. None of the participants tested positive for Dengue and Chikungunya by reverse transcription-polymerase chain reaction (RT-PCR) and with the Dengue-specific NS1 antigen strip kits. Our findings suggested that Dengue and Chikungunya viruses may be circulating but are being missed among febrile patients. Differential diagnosis work-up in febrile patients should be made to include Dengue and Chikungunya infections.


Subject(s)
Chikungunya Fever/epidemiology , Coinfection/epidemiology , Cross Infection/epidemiology , Dengue/epidemiology , Adolescent , Adult , Aged , Antibodies, Viral/blood , Antibodies, Viral/immunology , Arboviruses/classification , Arboviruses/immunology , Arboviruses/physiology , Chikungunya Fever/diagnosis , Chikungunya Fever/virology , Chikungunya virus/immunology , Chikungunya virus/physiology , Child , Child, Preschool , Coinfection/diagnosis , Coinfection/virology , Cross Infection/diagnosis , Cross Infection/virology , Cross-Sectional Studies , Dengue/diagnosis , Dengue/virology , Dengue Virus/immunology , Dengue Virus/physiology , Female , Ghana/epidemiology , Humans , Male , Middle Aged , Young Adult
16.
J Clin Virol ; 116: 49-57, 2019 07.
Article in English | MEDLINE | ID: mdl-31103802

ABSTRACT

Dengue, Zika, Chikungunya and yellow fever viruses are arboviruses transmitted by the mosquito Aedes aegypti. These viruses exhibit marked neurotropism but have rarely been studied. Here, we conduct an integrative review of the neurological manifestations caused by these arboviruses in the pediatric population. Data on patients under 18 years of age were extracted from literature databases. The most frequently reported neurological manifestations were encephalitis, meningitis, seizures, hypotonia, paresis, and behavioral changes. This review highlights the importance of accurately diagnosing these arboviral infections in children and adolescents with neurological manifestations.


Subject(s)
Arbovirus Infections/pathology , Arbovirus Infections/physiopathology , Arboviruses/pathogenicity , Nervous System Diseases/pathology , Nervous System Diseases/physiopathology , Adolescent , Americas/epidemiology , Arbovirus Infections/diagnosis , Arbovirus Infections/virology , Arboviruses/classification , Child , Child, Preschool , Humans , Nervous System Diseases/diagnosis , Nervous System Diseases/virology
17.
Parasit Vectors ; 12(1): 265, 2019 May 27.
Article in English | MEDLINE | ID: mdl-31133059

ABSTRACT

Arboviruses represent a significant burden to public health and local economies due to their ability to cause unpredictable and widespread epidemics. To maximize early detection of arbovirus emergence in non-endemic areas, surveillance efforts should target areas where circulation is most likely. However, identifying such hotspots of potential emergence is a major challenge. The ecological conditions leading to arbovirus outbreaks are shaped by complex interactions between the virus, its vertebrate hosts, arthropod vector, and abiotic environment that are often poorly understood. Here, we systematically review the ecological risk factors associated with the circulation of six arboviruses that are of considerable concern to northwestern Europe. These include three mosquito-borne viruses (Japanese encephalitis virus, West Nile virus, Rift Valley fever virus) and three tick-borne viruses (Crimean-Congo hemorrhagic fever virus, tick-borne encephalitis virus, and louping-ill virus). We consider both intrinsic (e.g. vector and reservoir host competence) and extrinsic (e.g. temperature, precipitation, host densities, land use) risk factors, identify current knowledge gaps, and discuss future directions. Our systematic review provides baseline information for the identification of regions and habitats that have suitable ecological conditions for endemic circulation, and therefore may be used to target early warning surveillance programs aimed at detecting multi-virus and/or arbovirus emergence.


Subject(s)
Arbovirus Infections/epidemiology , Arboviruses/isolation & purification , Mosquito Vectors/virology , Animals , Arboviruses/classification , Arthropod Vectors/virology , Disease Vectors , Encephalitis Virus, Japanese/isolation & purification , Europe , Humans , Rift Valley fever virus/isolation & purification , Risk Factors , West Nile virus/isolation & purification
18.
Viruses ; 11(5)2019 05 25.
Article in English | MEDLINE | ID: mdl-31130629

ABSTRACT

Since the beginning of modern virology in the 1950s, transmission electron microscopy (TEM) has been an important and widely used technique for discovery, identification and characterization of new viruses. Using TEM, viruses can be differentiated by their ultrastructure: shape, size, intracellular location and for some viruses, by the ultrastructural cytopathic effects and/or specific structures forming in the host cell during their replication. Ultrastructural characteristics are usually sufficient for the identification of a virus to the family level. In this review, we summarize 25 years of experience in identification of novel viruses from the collection of the World Reference Center for Emerging Viruses and Arboviruses (WRCEVA).


Subject(s)
Arbovirus Infections/virology , Arboviruses/ultrastructure , Communicable Diseases, Emerging/virology , Animals , Arboviruses/classification , Chlorocebus aethiops , Humans , Microscopy, Electron , Microscopy, Electron, Transmission , Vero Cells
19.
Parasit Vectors ; 12(1): 198, 2019 May 03.
Article in English | MEDLINE | ID: mdl-31053094

ABSTRACT

BACKGROUND: More than 70 arboviruses have been identified in Australia and the transmission cycles of most are poorly understood. While there is an extensive list of arthropods from which these viruses have been recovered, far less is known about the non-human hosts that may be involved in the transmission cycles of these viruses and the relative roles of different mosquito species in cycles of transmission involving different hosts. Some of the highest rates of human infection with zoonotic arboviruses, such as Ross River (RRV) and Barmah Forest (BFV) viruses, occur in coastal regions of north-eastern Australia. METHODS: Engorged mosquitoes collected as a part of routine surveillance using CO2-baited light traps in the Rockhampton Region and the adjoining Shire of Livingstone in central Queensland, north-eastern Australia, were analysed for the source of their blood meal. A 457 or 623 nucleotide region of the cytochrome b gene in the blood was amplified by PCR and the amplicons sequenced. The origin of the blood was identified by comparing the sequences obtained with those in GenBank®. RESULTS: The most common hosts for the mosquitoes sampled were domestic cattle (26/54) and wild birds (14/54). Humans (2/54) were an infrequent host for this range of mosquitoes that are known to transmit arboviruses causing human disease, and in an area where infections with human pathogens like RRV and BFV are commonly recorded. The blood meals identified in the most abundant vector analysed, Culex annulirostris, were from 10 different vertebrate hosts. The notable detection of chimpanzee blood in two mosquitoes, presumably obtained from a nearby zoo, extends the known range of hosts for this species. Culex quinquefasciatus and Cx. sitiens fed almost exclusively on a variety of bird species. CONCLUSIONS: While human-mosquito-human transmission of arboviruses like RRV can occur, this study highlights the potential importance of zoonotic cycles of transmission, including avian species, of arboviruses that are indigenous to Australia. Further studies on larger samples of blood-engorged mosquitoes are required to validate the trends observed herein. Moreover, serological and virological evidence that the hosts on which the mosquitoes are feeding are being infected with arboviruses of interest are required.


Subject(s)
Bites and Stings/blood , Bites and Stings/veterinary , Culicidae/physiology , Host Specificity , Mosquito Vectors/physiology , Animals , Arboviruses/classification , Arboviruses/genetics , Arboviruses/isolation & purification , Australia , Birds , Bites and Stings/parasitology , Cattle , Culicidae/classification , Culicidae/virology , Feeding Behavior , Female , Humans , Male , Mosquito Vectors/classification , Mosquito Vectors/virology , Pan troglodytes
20.
Parasit Vectors ; 12(1): 153, 2019 Apr 03.
Article in English | MEDLINE | ID: mdl-30944019

ABSTRACT

BACKGROUND: In the last 50 years, the United Arab Emirates (UAE) has experienced rapid population growth and urbanization. Urbanization is known to influence biodiversity, and there appears to be a link between the emergence of arboviruses and urban growth. Very little is known about the UAE mosquito species richness and dominant vectors. We performed a mosquito survey comparing peri-urban sites in Dubai and Al Ain to a protected, natural site in Fujairah emirate. We measured mosquito biodiversity and species composition, and screened mosquito pools for common arboviruses to measure arbovirus activity in the region. RESULTS: We report ten species of mosquitoes from the UAE, with highest species diversity in the natural site, a protected wadi near the eastern coast. The predominant mosquito was Culex perexiguus, and was associated with peri-urban habitats. The site with lowest mosquito species diversity but relatively high species richness was the peri-urban site of Al Ain Zoo, where we identified Bagaza virus and Barkedji virus, two flaviviruses, in pools of Cx. perexiguus. CONCLUSIONS: Decreased mosquito biodiversity was associated with increased levels of urbanization. The predominance of two species at peri-urban sites was related to the availability of their larval habitats. Arboviruses were associated with the presence of a single predominant mosquito species, Cx. perexiguus.


Subject(s)
Arboviruses/isolation & purification , Culicidae , Animals , Arboviruses/classification , Biodiversity , Culicidae/classification , Culicidae/virology , Female , Male , Mosquito Vectors/virology , United Arab Emirates , Urbanization
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