scholarly journals Oral susceptibility of aedine and culicine mosquitoes (Diptera: Culicidae) to Batai Orthobunyavirus

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Luis M. Hernández-Triana ◽  
Arran J. Folly ◽  
Elsa Barrero ◽  
Sarah Lumley ◽  
Maria del Mar Fernández de Marco ◽  
...  
Keyword(s):  
Mosquito Species ◽  
Virus Transmission ◽  
Vero Cells ◽  
Infection Prevalence ◽  
Reverse Transcription Pcr ◽  
Virus Dissemination ◽  
Extrinsic Incubation Period ◽  
Aedes Detritus ◽  
Vector Competency ◽  
Positive Results

Abstract Background A number of zoonotic mosquito-borne viruses have emerged in Europe in recent decades. Batai virus (BATV), a member of the genus Orthobunyavirus, is one example of a relatively newly emerged mosquito-borne virus, having been detected in mosquitoes and livestock. We conducted vector competency studies on three mosquito species at a low temperature to assess whether Aedes and Culex mosquito species are susceptible to infection with BATV. Methods Colonised lines of Aedes aegypti and Culex pipiens and a wild-caught species, Aedes detritus, were orally inoculated with BATV strain 53.2, originally isolated from mosquitoes trapped in Germany in 2009. Groups of blood-fed female mosquitoes were maintained at 20 °C for 7 or 14 days. Individual mosquitoes were screened for the presence of BATV in body, leg and saliva samples for evidence of infection, dissemination and transmission, respectively. BATV RNA was detected by reverse transcription-PCR, and positive results confirmed by virus isolation in Vero cells. Results Aedes detritus was highly susceptible to BATV, with an infection prevalence of ≥ 80% at both measurement time points. Disseminated infections were recorded in 30.7–41.6% of Ae. detritus, and evidence of virus transmission with BATV in saliva samples (n = 1, days post-infection: 14) was observed. Relatively lower rates of infection for Ae. aegypti and Cx. pipiens were observed, with no evidence of virus dissemination or transmission at either time point. Conclusions This study shows that Ae. detritus may be a competent vector for BATV at 20 °C, whereas Ae. aegypti and Cx. pipiens were not competent. Critically, the extrinsic incubation period appears to be ≤  7 days for Ae. detritus, which may increase the onward transmissibility potential of BATV in these populations. Graphical Abstract

scholarly journals Oral susceptibility of aedine and culicine mosquitoes (Diptera: Culicidae) to Batai orthobunyavirus

2021 ◽  
Author(s):  
Luis Miguel Hernandez-Triana ◽  
Arran Folly ◽  
Elsa Barrero ◽  
Sarah Lumley ◽  
Maria del Mar Fernández de Marco ◽  
...  
Keyword(s):  
Mosquito Species ◽  
Virus Transmission ◽  
Vero Cells ◽  
Infection Prevalence ◽  
Virus Dissemination ◽  
Virus Rna ◽  
Aedes Detritus ◽  
Vector Competency ◽  
Positive Results ◽  
Batai Virus

Abstract Background A number of zoonotic mosquito-borne viruses have emerged in Europe in recent decades. Batai virus (BATV), orthobunyavirus, is one example having been detected in mosquitoes and livestock. We conducted vector competency studies on three mosquito species at a low temperature to assess whether Aedes and Culex mosquito species are susceptible to infection with BATV. Methods Colonised lines of Aedes aegypti and Culex pipiens, and a wild-caught species, Aedes detritus, were orally inoculated with BATV strain 53.2, originally isolated from mosquitoes trapped in Germany in 2009. Groups of blood-fed female mosquitoes were maintained at 20oC for seven or fourteen days. Individual mosquitoes were screened for the presence of BATV in body, leg and saliva samples for evidence of infection, dissemination and transmission, respectively. Batai virus RNA was detected by RT-PCR and positive results confirmed by virus isolation in Vero cells. Results Aedes detritus was highly susceptible to BATV with infection prevalence at or above 80% at both time points. Disseminated infections were recorded in 30.7–41.6% of Ae. detritus and evidence for virus transmission with BATV detected in saliva samples (n = 1, dpi = 14) was observed. Lower rates of infection for Ae. aegypti and Cx. pipiens with no evidence for virus dissemination or transmission at either time point. Conclusions This study shows Ae. detritus may be a competent vector for BATV at 20oC, whereas Ae. aegypti and Cx. pipiens were not competent. Critically, the extrinsic incubation period appears to be ≤ 7 days for Ae. detritus, which may increase the onward transmissibility potential of BATV in these populations.

scholarly journals Vector competence experiments with Rocio virus and three mosquito species from the epidemic zone in Brazil

1986 ◽  
Vol 20 (3) ◽  
pp. 171-177 ◽  
Author(s):  
Carl J. Mitchell ◽  
Oswaldo Paulo Forattini ◽  
Barry R. Miller
Keyword(s):  
First Generation ◽  
Vector Competence ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Infection Rates ◽  
Feeding Technique ◽  
Generation Progeny ◽  
In Vitro Feeding ◽  
Vector Competency

First-generation progeny of field-collected Psorophora ferox, Aedes scapularis, and Aedes serratus from the Rocio encephalitis epidemic zone in S.Paulo State, Brazil, were tested for vector competency in the laboratory. Psorophora ferox and Ae. scapularis are susceptible to per os infection with Rocio virus and can transmit the virus by bite following a suitable incubation period. Oral ID50S for the two species (10(4.1) and 10(4.3) Vero cell plaque forming units, respectively) did not differ significantly. Infection rates in Ae. serratus never exceeded 36%, and, consequently, an ID50 could not be calculated for this species. It is unlikely that Ae. serratus is an epidemiologically important vector of Rocio virus. The utility of an in vitro feeding technique for demonstrating virus transmission by infected mosquitoes and difficulties encountered in working with uncolonized progeny of field-collected mosquitoes are discussed.

scholarly journals Yellow Fever Outbreak in Eastern Senegal, 2020–2021

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1475
Author(s):  
Moussa Moïse Diagne ◽  
Marie Henriette Dior Ndione ◽  
Alioune Gaye ◽  
Mamadou Aliou Barry ◽  
Diawo Diallo ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Genomic Analysis ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
World Health ◽  
Effective Vaccine ◽  
Ministry Of Health

Yellow fever virus remains a major threat in low resource countries in South America and Africa despite the existence of an effective vaccine. In Senegal and particularly in the eastern part of the country, periodic sylvatic circulation has been demonstrated with varying degrees of impact on populations in perpetual renewal. We report an outbreak that occurred from October 2020 to February 2021 in eastern Senegal, notified and managed through the synergistic effort yellow fever national surveillance implemented by the Senegalese Ministry of Health in collaboration with the World Health Organization, the countrywide 4S network set up by the Ministry of Health, the Institut Pasteur de Dakar, and the surveillance of arboviruses and hemorrhagic fever viruses in human and vector populations implemented since mid 2020 in eastern Senegal. Virological analyses highlighted the implication of sylvatic mosquito species in virus transmission. Genomic analysis showed a close relationship between the circulating strain in eastern Senegal, 2020, and another one from the West African lineage previously detected and sequenced two years ago from an unvaccinated Dutch traveler who visited the Gambia and Senegal before developing signs after returning to Europe. Moreover, genome analysis identified a 6-nucleotide deletion in the variable domain of the 3′UTR with potential impact on the biology of the viral strain that merits further investigations. Integrated surveillance of yellow fever virus but also of other arboviruses of public health interest is crucial in an ecosystem such as eastern Senegal.

scholarly journals Ecology and Epidemiology of Eastern Equine Encephalitis Virus in the Northeastern United States: An Historical Perspective

2021 ◽  
Author(s):  
Philip M Armstrong ◽  
Theodore G Andreadis
Keyword(s):  
United States ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Bird Species ◽  
Disease Outbreaks ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Northeastern United States ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus

Abstract In the current review, we examine the regional history, ecology, and epidemiology of eastern equine encephalitis virus (EEEV) to investigate the major drivers of disease outbreaks in the northeastern United States. EEEV was first recognized as a public health threat during an outbreak in eastern Massachusetts in 1938, but historical evidence for equine epizootics date back to the 1800s. Since then, sporadic disease outbreaks have reoccurred in the Northeast with increasing frequency and northward expansion of human cases during the last 20 yr. Culiseta melanura (Coquillett) (Diptera: Culicidae) serves as the main enzootic vector that drives EEEV transmission among wild birds, but this mosquito species will occasionally feed on mammals. Several species have been implicated as bridge vectors to horses and humans, with Coquilletstidia perturbans (Walker) as a leading suspect based on its opportunistic feeding behavior, vector competence, and high infection rates during recent disease outbreaks. A diversity of bird species are reservoir competent, exposed to EEEV, and serve as hosts for Cs. melanura, with a few species, including the wood thrush (Hlocichia mustelina) and the American robin (Turdus migratorius), contributing disproportionately to virus transmission based on available evidence. The major factors responsible for the sustained resurgence of EEEV are considered and may be linked to regional landscape and climate changes that support higher mosquito densities and more intense virus transmission.

A Survey of Aedes (Diptera: Culicidae) Mosquitoes in Tunisia and the Potential Role of Aedes detritus and Aedes caspius in the Transmission of Zika Virus

2019 ◽  
Vol 56 (5) ◽  
pp. 1377-1383
Author(s):  
Wiem Ben Ayed ◽  
Fadila Amraoui ◽  
Youmna M’ghirbi ◽  
Francis Schaffner ◽  
Adel Rhaim ◽  
...  
Keyword(s):  
Zika Virus ◽  
New Caledonia ◽  
Vector Competence ◽  
Mosquito Species ◽  
Breeding Site ◽  
Widespread Species ◽  
Larval Habitats ◽  
Aedes Caspius ◽  
Aedes Detritus

Abstract The present study aimed to update the list of Aedes mosquito species occurring in Tunisia and to test the vector competence of Aedes (Ochlerotatus) caspius (Pallas) and Ae. (Ochlerotatus) detritus (Haliday), the locally most abundant and widespread species, to transmit Zika virus (ZIKV). In 2017–2018, mosquito larvae were collected from 39 different larval habitats in seven bioclimatic zones of Tunisia. The salinity and pH of each breeding site were measured. The survey revealed the presence of 10 Aedes species in Tunisia: Ae. (Stegomyia) albopictus (Skuse), Ae. (Ochlerotatus) berlandi (Séguy), Ae. caspius, Ae. detritus, Ae. (Finlaya) echinus (Edwards), Ae. (Finlaya) geniculatus (Olivier), Ae. (Acartomyia) mariae (Sergent and Sergent), Ae. (Ochlerotatus) pulcritarsis (Rondani), Ae. (Aedimorphus) vexans (Meigen), and Ae. (Fredwardsius) vittatus (Bigot). Of these 10 species, Ae. caspius and Ae. detritus were the most abundant in Tunisia. Aedes detritus and Ae. caspius larvae were reared until the imago stage under insectary conditions to test autogeny. The study showed that Ae. detritus is autogenous and stenogamous and Ae. caspius, anautogenous and eurygamous. Finally, the collected strains of these two species were experimentally infected with the Asian genotype of ZIKV, originally isolated from a patient in April 2014 in New Caledonia, to test their vector competence. Neither of these species was able to transmit ZIKV at 7 and 14 d postexposure. Further investigations are needed to test the competence of other Tunisian mosquito species that may be associated with ZIKV transmission.

scholarly journals Paramyxo- and Coronaviruses in Rwandan Bats

2019 ◽  
Vol 4 (3) ◽  
pp. 99 ◽  
Author(s):  
Wanda Markotter ◽  
Marike Geldenhuys ◽  
Petrus Jansen van Vuren ◽  
Alan Kemp ◽  
Marinda Mortlock ◽  
...  
Keyword(s):  
Morphological Identification ◽  
Related Sequence ◽  
Genetic Database ◽  
Reverse Transcription Pcr ◽  
Fruit Bat ◽  
Pcr Assays ◽  
Study Sites ◽  
Positive Results ◽  
High Diversity ◽  
Horseshoe Bats

A high diversity of corona- and paramyxoviruses have been detected in different bat species at study sites worldwide, including Africa, however no biosurveillance studies from Rwanda have been reported. In this study, samples from bats collected from caves in Ruhengeri, Rwanda, were tested for the presence of corona- and paramyxoviral RNA using reverse transcription PCR assays. Positive results were further characterized by DNA sequencing and phylogenetic analysis. In addition to morphological identification of bat species, we also did molecular confirmation of species identities, contributing to the known genetic database available for African bat species. We detected a novel Betacoronavirus in two Geoffroy’s horseshoe bats (Rhinolophus clivosus) bats. We also detected several different paramyxoviral species from various insectivorous bats. One of these viral species was found to be homologous to the genomes of viruses belonging to the Jeilongvirus genus. Additionally, a Henipavirus-related sequence was detected in an Egyptian rousette fruit bat (Rousettus aegyptiacus). These results expand on the known diversity of corona- and paramyxoviruses and their geographical distribution in Africa.

scholarly journals Comparison of Six RNA Extraction Methods for the Detection of Classical Swine Fever Virus by Real-Time and Conventional Reverse Transcription–PCR

2005 ◽  
Vol 17 (6) ◽  
pp. 574-578 ◽  
Author(s):  
Ming Y. Deng ◽  
He Wang ◽  
Gordon B. Ward ◽  
Tammy R. Beckham ◽  
Thomas S. McKenna
Keyword(s):  
Real Time ◽  
Classical Swine Fever Virus ◽  
Rna Extraction ◽  
Classical Swine Fever ◽  
Extraction Methods ◽  
Rt Pcr ◽  
Total Rna ◽  
Reverse Transcription Pcr ◽  
Rna Extraction Methods ◽  
Positive Results

Six RNA extraction methods, i.e., RNAqueous kit, Micro-to-midi total RNA purification system, NucleoSpin RNA II, GenElute mammalian total RNA kit, RNeasy mini kit, and TRIzol LS reagent, were evaluated on blood and 7 tissues from pig infected with classical swine fever virus (CSFV). Each of the 6 extraction methods yielded sufficient RNA for positive results in a real-time reverse transcription–PCR (RT-PCR) for CSFV, and all RNA, except the one extracted from blood by TRIzol LS reagent, yielded positive results in both a conventional RT-PCR for CSFV and a conventional RT-PCR for an endogenous gene encoding β-actin. The RNA extracted from blood by TRIzol LS reagent became positive in both conventional RT-PCR assays when it was diluted to 1:2, 1:4, or up to 1:64 in nuclease-free water. It is concluded that all 6 methods are more or less useful for the detection of CSFV by real-time and conventional RT-PCR in swine blood and tissues. However, some of the 6 reagents offer certain advantages not common to all 6 extraction procedures. For example, RNA extracted by the TRIzol LS reagent constantly had the highest yield; that by the RNAqueous kit had the highest A260/A280 ratio for almost all samples; and that by the NucleoSpin RNA II and the GenElute mammalian total RNA kit was most likely to be free of contaminations with genomic DNA.

Rift Valley fever virus transmission by different Egyptian mosquito species

1987 ◽  
Vol 81 (4) ◽  
pp. 694-698 ◽  
Author(s):  
Adel M. Gad ◽  
Mosaad M. Hassan ◽  
Sharif El Said ◽  
Mahmoud I. Moussa ◽  
Owen L. Wood
Keyword(s):  
Rift Valley ◽  
Rift Valley Fever ◽  
Rift Valley Fever Virus ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Fever Virus ◽  
Valley Fever

scholarly journals Successive Bloodmeals Enhance Virus Dissemination Within Mosquitoes And Increase Transmission Potential

2018 ◽  
Author(s):  
Philip M. Armstrong ◽  
Hanna Ehrlich ◽  
Angela Bransfield ◽  
Joshua L. Warren ◽  
Virginia E. Pitzer ◽  
...  
Keyword(s):  
Vector Competence ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Transmission Potential ◽  
The Public ◽  
Virus Dissemination ◽  
Virus Escape ◽  
Extrinsic Incubation Period ◽  
And Behavior ◽  
Transmission Status

SUMMARY PARAGRAPHThe recent Zika virus (ZIKV) and chikungunya virus (CHIKV) epidemics highlight the explosive nature of arthropod-borne (arbo) viruses transmitted by Aedes aegypti mosquitoes1,2. Vector competence and the extrinsic incubation period (EIP) are two key entomological parameters used to assess the public health risk posed by arboviruses3. These are typically measured empirically by offering mosquitoes an infectious bloodmeal and temporally sampling mosquitoes to determine infection and transmission status. This approach has been used for the better part of a century; however, it does not accurately capture the biology and behavior of many mosquito vectors which refeed frequently (every 2-3 days)4. Here we demonstrate that administration of a second non-infectious bloodmeal significantly shortens the EIP of ZIKV-infected Ae. aegypti by enhancing virus escape from the mosquito midgut. Similarly, a second bloodmeal increased the competence of this species for dengue virus and CHIKV. This effect was also observed for ZIKV in Aedes albopictus, suggesting that this species might be a more important vector than once thought and that this phenomenon may be common among other virus-vector pairings. Modeling of these findings reveals that a shortened EIP would result in a significant increase in the basic reproductive number, R0. This increase helps explain how Ae.aegypti can sustain an explosive epidemic like ZIKV despite its relatively poor vector competence in single-feed laboratory trials. Together, these data demonstrate a direct and unrecognized link between mosquito feeding behavior, EIP, and vector competence.

scholarly journals Molecular detection and maternal transmission of a bacterial symbiont Asaia species in field-caught Anopheles mosquitoes from Cameroon

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Claudine Grâce Tatsinkou Maffo ◽  
Maurice Marcel Sandeu ◽  
Amen Nakebang Fadel ◽  
Magellan Tchouakui ◽  
Daniel Nguiffo Nguete ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Nucleotide Sequence ◽  
Mosquito Species ◽  
Sub Saharan Africa ◽  
Malaria Vectors ◽  
Infection Prevalence ◽  
Sequence Variant ◽  
Maternal Transmission ◽  
Anopheles Mosquitoes ◽  
Low Genetic Diversity

Abstract Background Malaria control relies mainlyon insecticide-based tools. However, the effectiveness of these tools is threatened by widespread insecticide resistance in malaria vectors, highlighting the need for alternative control approaches. The endosymbiont Asaia has emerged as a promising candidate for paratransgenic control of malaria, but its biology and genetics still need to be further analyzed across Africa. Here, we investigated the prevalence of Asaia and its maternal transmission in the natural population of Anopheles mosquitoes in Cameroon. Methods Indoor-resting adult mosquitoes belonging to four species (An. coluzzii, An. arabiensis, An. funestus and An. gambiae) were collected from eight localities across Cameroon from July 2016 to February 2020. PCR was performed on the Asaia-specific 16S ribosomal RNA gene, and samples positive by PCR for Asaia were confirmed by Sanger sequencing and phylogenetic analysis. The vertical transmission of Asaia was investigated by screening F1 mosquitoes belonging to F0Asaia-positive females. Results A total of 895 mosquitoes were screened. We found 43% (384) Asaia infection prevalence in four mosquito species. Phylogenetic analysis revealed that Asaia from Cameroon clustered together with the strains of Asaia isolated from other parts of the world. In addition, seven nucleotide sequence variants were found with low genetic diversity (π = 0.00241) and nucleotide sequence variant diversity (Hd = 0.481). Asaia was vertically transmitted with high frequency (range from 42.5 to 100%). Conclusions This study provides field-based evidence of the presence of Asaia in Anopheles mosquitoes in Cameroon for exploitation as a symbiont in the control of malaria in sub-Saharan Africa. Graphical abstract

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