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Scientific Reports Jan 2023The increasing trend of mosquito-borne pathogens demands more accurate global estimations of infection and transmission risks between mosquitoes. Here, we systematically...
The increasing trend of mosquito-borne pathogens demands more accurate global estimations of infection and transmission risks between mosquitoes. Here, we systematically review field and laboratory studies to assess the natural field infection and experimental laboratory transmission risk in Culex mosquitoes. We studied four worldwide flaviviruses: West Nile, Usutu, Japanese encephalitis, and St. Louis encephalitis, belonging to the Japanese encephalitis Serocomplex (JES). The PRISMA statement was carried out for both approaches. The Transmission-Infection Risk of the diverse mosquito species for the different viruses was estimated through seven variables. We considered 130 and 95 articles for field and experimental approach, respectively. We identified 30 species naturally infected, and 23 species capable to transmit some of the four flaviviruses. For the JES, the highest Transmission-Infection Risk estimate was recorded in Culex quinquefasciatus (North America). The maximum Infection-Transmission Risk values for West Nile was Culex restuans, for Usutu it was Culex pipiens (Europe), for St. Louis encephalitis Culex quinquefasciatus (North America), and for Japanese encephalitis Culex gelidus (Oceania). We conclude that on a worldwide scale, a combination of field and experimental data offers a better way of understanding natural infection and transmission risks between mosquito populations.
Topics: Animals; Encephalitis Viruses, Japanese; Mosquito Vectors; West Nile virus; West Nile Fever; Encephalitis, St. Louis; Encephalitis, Japanese; Flavivirus; Culicidae; Culex
PubMed: 36609450
DOI: 10.1038/s41598-022-27236-1 -
Viruses Dec 2022West Nile virus (WNV) is a virus of the Japanese encephalitis antigenic complex and belongs to the family Flaviviridae of the genus flavivirus. The virus can cause...
West Nile virus (WNV) is a virus of the Japanese encephalitis antigenic complex and belongs to the family Flaviviridae of the genus flavivirus. The virus can cause infection in humans which in most cases is asymptomatic, however symptomatic cases exist and the disease can be severe causing encephalitis and meningoencephalitis. The virus is maintained in an enzootic cycle involving mosquitoes and birds, humans and other mammals such as horses can be accidental hosts. A mosquito-based arbovirus surveillance system and the sentinel syndromic surveillance network (4S) have been in place since 1988 and 2015 respectively, to better understand the transmission dynamics of arboviruses including WNV in Senegal. Arthropod and human samples have been collected from the field and analysed at Institut Pasteur de Dakar using different methods including RT-PCR, ELISA, plaque reduction neutralization test and viral isolation. RT-PCR positive samples have been analysed by Next Generation Sequencing. From 2012 to 2021, 7912 samples have been analysed and WNV positive cases have been detected, 20 human cases (19 IgM and 1 RT-PCR positive cases) and 41 mosquito pools. Phylogenetic analyzes of the sequences of complete genomes obtained showed the circulation of lineage 1a, with all these recent strains from Senegal identical to each other and very close to strains isolated from horse in France in 2015, Italy and Spain. Our data showed lineage 1a endemicity in Senegal as previously described, with circulation of WNV in humans and mosquitoes. Phylogenetic analyzes carried out with the genome sequences obtained also revealed exchanges of WNV strains between Europe and Senegal which could be possible via migratory birds. The surveillance systems that have enabled the detection of WNV in humans and arthropods should be extended to animals in a one-health approach to better prepare for global health threats.
Topics: Humans; Animals; Horses; West Nile virus; Culicidae; West Nile Fever; Phylogeny; Senegal; Birds; Europe; Arboviruses; Mammals
PubMed: 36560724
DOI: 10.3390/v14122720 -
PLoS Neglected Tropical Diseases Apr 2010The major arboviral diseases in mainland China include Japanese encephalitis, dengue fever, Crimean-Congo hemorrhagic fever (also known as Xinjiang hemorrhagic fever),... (Review)
Review
The major arboviral diseases in mainland China include Japanese encephalitis, dengue fever, Crimean-Congo hemorrhagic fever (also known as Xinjiang hemorrhagic fever), and tick-borne encephalitis. These and other newly found arbovirus infections due to Banna virus and Tahyna virus contribute to a large and relatively neglected disease burden in China. Here we briefly review the literature regarding these arboviral infections in mainland China with emphasis on their epidemiology, primary vectors, phylogenetic associations, and the prevention programs associated with these agents in China.
Topics: Arboviruses; China; Dengue; Encephalitis, Japanese; Encephalitis, Tick-Borne; Hemorrhagic Fever, Crimean; Humans; Molecular Epidemiology; Phylogeny
PubMed: 20436960
DOI: 10.1371/journal.pntd.0000624 -
Arquivos de Neuro-psiquiatria Nov 2021The year of 2021 marks 90 year since the death of the neuroscientist Constantin von Economo, whose research in various areas was extremely relevant for the field of...
The year of 2021 marks 90 year since the death of the neuroscientist Constantin von Economo, whose research in various areas was extremely relevant for the field of neurology. He described lethargic epidemic encephalitis, published an atlas of the cytoarchitecture of the human cerebral cortex, and conducted multiple studies in neuroanatomy, neurophysiology, and clinical neurology. Von Economo's genius extended into other nonmedical fields such as aeronautics, and he had renowned artistic skills.
Topics: Anniversaries and Special Events; Encephalitis, Arbovirus; History, 20th Century; Humans; Male; Neuroanatomy; Neurology; Neurophysiology
PubMed: 34816996
DOI: 10.1590/0004-282X-ANP-2021-0098 -
Vector Borne and Zoonotic Diseases... Jul 2017Powassan virus (POWV, Flaviviridae) is the only North American member of the tick-borne encephalitis serogroup of flaviviruses. It is transmitted to small- and... (Review)
Review
Powassan virus (POWV, Flaviviridae) is the only North American member of the tick-borne encephalitis serogroup of flaviviruses. It is transmitted to small- and medium-sized mammals by Ixodes scapularis, Ixodes cookei, and several other Ixodes tick species. Humans become infected with POWV during spillover transmission from the natural transmission cycles. In humans, POWV is the causative agent of a severe neuroinvasive illness with 50% of survivors displaying long-term neurological sequelae. POWV was recognized as a human pathogen in 1958 when a young boy died of severe encephalitis in Powassan, Ontario, and POWV was isolated from the brain autopsy of this case. Two distinct genetic lineages of POWV are now recognized: POWV (lineage I) and deer tick virus (lineage II). Since the index case in 1958, over 100 human cases of POWV have been reported, with an apparent rise in disease incidence in the past 16 years. This recent increase in cases may represent a true emergence of POWV in regions where the tick vector species are prevalent, or it could represent an increase in POWV surveillance and diagnosis. In the past 5 years, both basic and applied research for POWV disease has intensified, including phylogenetic studies, field surveillance, case studies, and animal model development. This review provides an overview of POWV, including the epidemiology, transmission, clinical disease, and diagnosis of POWV infection. Recent research developments and future priorities with regard to the disease are emphasized.
Topics: Communicable Diseases, Emerging; Encephalitis Viruses, Tick-Borne; Encephalitis, Tick-Borne; Humans; North America; Tick-Borne Diseases
PubMed: 28498740
DOI: 10.1089/vbz.2017.2110 -
Clinical Infectious Diseases : An... Mar 2023With increasing use of rituximab and other B-cell depleting monoclonal antibodies for multiple indications, infectious complications are being recognized. We summarize... (Review)
Review
With increasing use of rituximab and other B-cell depleting monoclonal antibodies for multiple indications, infectious complications are being recognized. We summarize clinical findings of patients on rituximab with arboviral diseases identified through literature review or consultation with the Centers for Disease Control and Prevention. We identified 21 patients on recent rituximab therapy who were diagnosed with an arboviral disease caused by West Nile, tick-borne encephalitis, eastern equine encephalitis, Cache Valley, Jamestown Canyon, and Powassan viruses. All reported patients had neuroinvasive disease. The diagnosis of arboviral infection required molecular testing in 20 (95%) patients. Median illness duration was 36 days (range, 12 days to 1 year), and 15/19 (79%) patients died from their illness. Patients on rituximab with arboviral disease can have a severe or prolonged course with an absence of serologic response. Patients should be counseled about mosquito and tick bite prevention when receiving rituximab and other B-cell depleting therapies.
Topics: Animals; Rituximab; West Nile Fever; Disease Outbreaks; Arbovirus Infections; Encephalitis, Tick-Borne
PubMed: 36103602
DOI: 10.1093/cid/ciac766 -
Journal of the American Mosquito... Mar 2022To mitigate the effects of West Nile virus (WNV) and eastern equine encephalitis virus (EEEV), the state of Florida conducts a serosurveillance program that uses...
To mitigate the effects of West Nile virus (WNV) and eastern equine encephalitis virus (EEEV), the state of Florida conducts a serosurveillance program that uses sentinel chickens operated by mosquito control programs at numerous locations throughout the state. Coop locations were initially established to detect St. Louis encephalitis virus (SLEV), and coop placement was determined based on the location of human SLEV infections that occurred between 1959 and 1977. Since the introduction of WNV into Florida in 2001, WNV has surpassed SLEV as the primary arbovirus in Florida. Identifying high probability locations for WNV and EEEV transmission and relocating coops to areas of higher arbovirus activity would improve the sensitivity of the sentinel chicken surveillance program. Using 2 existing models, this study conducted an overlay analysis to identify areas with high probability habitats for both WNV and EEEV activity. This analysis identified approximately 7,800 km2 (about 4.5% of the state) as high probability habitat for supporting both WNV and EEEV transmission. Mosquito control programs can use the map resulting from this analysis to improve their sentinel chicken surveillance programs, increase the probability of virus detection, reduce operational costs, and allow for a faster, targeted response to virus detection.
Topics: Animals; Arboviruses; Chickens; Ecosystem; Encephalitis Virus, Eastern Equine; Encephalitis Virus, St. Louis; Florida; Horses; Probability; West Nile Fever; West Nile virus
PubMed: 35276726
DOI: 10.2987/21-7049 -
Brazilian Journal of Microbiology :... Mar 2022Several arboviruses causing human disease have been reported in Brazil. In nature, arboviruses maintain a lifecycle involving vertebrates and vectors, which may...
INTRODUCTION
Several arboviruses causing human disease have been reported in Brazil. In nature, arboviruses maintain a lifecycle involving vertebrates and vectors, which may contribute for periodical reemergence of those of public health concern in tropical regions, as Mato Grosso State (MT). In this study, we searched for arboviruses in mosquito body pools sampled during the rainy season of 2018 in 21 bird watching points of Cuiabá and Varzea Grande, South Central MT.
METHODS
In total, 2873 (57%) males and 2167 (43%) females belonging to six urban and sylvatic mosquito genera allocated to 398 pools were subjected to RNA extraction and RT-PCR for arboviruses. Positive pools were subjected to virus isolation in C6/36 cells.
RESULTS
A total of 102/398 pools, 66/233 (29.6%) of females, and 36/165 (21.8%) of males, mostly sampled in May (31/102), were positive for arboviruses. Chikungunya virus (CHIKV) was distributed in 19 points, Zika virus (ZIKV) was found in 14 points, Mayaro virus (MAYV) in 10 points, and East Equine encephalitis virus (EEEV) in three points. Culex quinquefasciatus pools (39/89 of females and 24/99 of males) were positive for CHIKV, ZIKV, and MAYV; Aedes (Stg) aegypti pools (11/46 of females and 12/33 of males) for CHIKV, ZIKV, MAYV, and EEEV; Aedes albopictus female pools (8/29) for CHIKV, ZIKV, and EEEV; and Psorophora albigenu (2/12) and Psorophora ferox female pools (4/16) for CHIKV.
CONCLUSIONS
Arbovirus molecular detection in mosquito populations varies considerable between geographical regions and epidemics, influenced by genetic characteristics and microbiome interference on virus replication. Although infected females are responsible for the transmission to vertebrates during bloodfeeding, male infection by CHIKV, ZIKV, and MAYV resultant from vertical route could lead to interepidemic maintenance of these arboviruses in their natural reservoirs.
Topics: Aedes; Animals; Brazil; Chikungunya Fever; Chikungunya virus; Encephalomyelitis, Equine; Female; Humans; Male; Mosquito Vectors; Seasons; Zika Virus; Zika Virus Infection
PubMed: 34787837
DOI: 10.1007/s42770-021-00646-5 -
Microbes and Infection Apr 2011Japanese encephalitis virus (JEV) is an arbovirus belonging to the family Flaviviridae. It is maintained in a zoonotic cycle involving pigs, ardeid birds and Culex... (Review)
Review
Japanese encephalitis virus (JEV) is an arbovirus belonging to the family Flaviviridae. It is maintained in a zoonotic cycle involving pigs, ardeid birds and Culex species of mosquitoes. Humans are accidental/dead end hosts of JEV infection because they cannot sustain high viral titers. Factors affecting the clinical manifestations and pathogenesis of JEV infection are not well understood. Though, vaccines are currently available against JEV, it has to be further improved. Here we review the literature on the JEV life cycle, pathogenesis and host immune responses to JEV infection.
Topics: Animals; Encephalitis Virus, Japanese; Encephalitis, Japanese; Genome, Viral; Humans; Immunity; Virus Replication
PubMed: 21238600
DOI: 10.1016/j.micinf.2011.01.002 -
Emerging Microbes & Infections Dec 2023Tick-borne encephalitis (TBE) is an infection of the central nervous system caused by the tick-borne encephalitis virus (TBEV). TBE is endemic in parts of Europe and...
Tick-borne encephalitis (TBE) is an infection of the central nervous system caused by the tick-borne encephalitis virus (TBEV). TBE is endemic in parts of Europe and Asia. TBEV is transmitted to humans primarily by ticks. There have been 5 TBE cases identified in Japan, all on the northern island of Hokkaido. Rodents with TBEV antibodies and ticks have been identified throughout Japan, indicating that TBEV infection might be undiagnosed in Japan. Residual serum and cerebrospinal fluid (CSF) collected in 2010-2021 from 520 patients ≥1 year-of-age previously hospitalized with encephalitis or meningitis of unknown etiology at 15 hospitals (including 13 hospitals outside of Hokkaido) were screened by ELISA for TBEV IgG and IgM antibodies; TBEV infection was confirmed by the gold standard neutralization test. Residual serum was available from 331 (63.6%) patients and CSF from 430 (82.6%) patients; both serum and CSF were available from 189 (36.3%). Two patients were TBE cases: a female aged 61 years hospitalized for 104 days in Oita (2000 km south of Hokkaido) and a male aged 24 years hospitalized for 11 days in Tokyo (1200 km south of Hokkaido). Retrospective testing also identified a previous TBEV infection in a female aged 45 years hospitalized for 12 days in Okayama (1700 km south of Hokkaido). TBEV infection should be considered as a potential cause of encephalitis or meningitis in Japan. TBE cases are likely undiagnosed in Japan, including outside of Hokkaido, due to limited clinical awareness and lack of availability of TBE diagnostic tests.
Topics: Animals; Humans; Male; Female; Encephalitis, Tick-Borne; Japan; Retrospective Studies; Ixodes; Encephalitis Viruses, Tick-Borne; Meningitis
PubMed: 37906509
DOI: 10.1080/22221751.2023.2278898