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1.
Antibody detection against selected potentially zoonotic vector‐borne alphaviruses and flaviviruses was conducted on sera from bats from all six parishes in Grenada, West Indies. Sera were tested for (i) antibodies to flaviviruses West Nile virus, St. Louis encephalitis virus, Ilhéus virus, Bussuquara virus (BSQV), Rio Bravo virus and all four serotypes of dengue virus (DENV) by plaque reduction neutralization test (PRNT); (ii) antibodies to alphaviruses western equine encephalitis virus, Venezuelan equine encephalitis virus and eastern equine encephalitis virus by epitope‐blocking enzyme‐linked immunosorbent assay (ELISA); and (iii) antibodies to the alphavirus chikungunya (CHIKV) by PRNT. Two species of fruit bats were sampled, Artibeus jamaicensis and Artibeus lituratus, all roosting in or within 1,000 m of human settlements. Fifteen (36%) of the 42 bats tested for neutralizing antibodies to CHIKV were positive. The CHIKV‐seropositive bats lived in localities spanning five of the six parishes. All 43 bats tested for epitope‐blocking ELISA antibody to the other alphaviruses were negative, except one positive for Venezuelan equine encephalitis virus. All 50 bats tested for neutralizing antibody to flaviviruses were negative, except one that had a BSQV PRNT80 titre of 20. The CHIKV serology results indicate that bats living close to and within human settlements were exposed to CHIKV in multiple locations. Importantly, bats for this study were trapped a year after the introduction and peak of the human CHIKV epidemic in Grenada. Thus, our data indicate that bats were exposed to CHIKV possibly during a time of marked decline in human cases.  相似文献   

2.
A serosurvey of antibodies against selected flaviviruses and alphaviruses in 384 bats (representing 10 genera and 14 species) was conducted in the Caribbean island of Trinidad. Sera were analysed using epitope‐blocking enzyme‐linked immunosorbent assays (ELISAs) specific for antibodies against West Nile virus (WNV), Venezuelan equine encephalitis virus (VEEV) and eastern equine encephalitis virus (EEEV), all of which are zoonotic viruses of public health significance in the region. Overall, the ELISAs resulted in the detection of VEEV‐specific antibodies in 11 (2.9%) of 384 bats. Antibodies to WNV and EEEV were not detected in any sera. Of the 384 sera, 308 were also screened using hemagglutination inhibition assay (HIA) for antibodies to the aforementioned viruses as well as St. Louis encephalitis virus (SLEV; which also causes epidemic disease in humans), Rio Bravo virus (RBV), Tamana bat virus (TABV) and western equine encephalitis virus (WEEV). Using this approach, antibodies to TABV and RBV were detected in 47 (15.3%) and 3 (1.0%) bats, respectively. HIA results also suggest the presence of antibodies to an undetermined flavivirus(es) in 8 (2.6%) bats. Seropositivity for TABV was significantly (P < 0.05; χ2) associated with bat species, location and feeding preference, and for VEEV with roost type and location. Differences in prevalence rates between urban and rural locations were statistically significant (P < 0.05; χ2) for TABV only. None of the aforementioned factors was significantly associated with RBV seropositivity rates.  相似文献   

3.
Historically, Australia was considered free of rabies and rabieslike viruses. Thus, the identification of Australian bat lyssavirus (ABLV) in 1996 in a debilitated bat found by a member of the public precipitated both public health consternation and a revision of lyssavirus taxonomy. Subsequent observational studies sought to elaborate the occurrence and frequency of ABLV infection in Australian bats. This paper describes the taxonomic diversity of bat species showing evidence of ABLV infection to better inform public health considerations. Blood and/or brain samples were collected from two cohorts of bats (wild‐caught and diagnostic submissions) from four Australian states or territories between April 1996 and October 2002. Fresh brain impression smears were tested for ABLV antigen using fluorescein‐labelled anti‐rabies monoclonal globulin (CENTOCOR) in a direct fluorescent antibody test; sera were tested for the presence of neutralising antibodies using a rapid fluorescent focus inhibition test. A total of 3,217 samples from 2,633 bats were collected and screened: brain samples from 1,461 wild‐caught bats and 1,086 submitted bats from at least 16 genera and seven families, and blood samples from 656 wild‐caught bats and 14 submitted bats from 14 genera and seven families. Evidence of ABLV infection was found in five of the six families of bats occurring in Australia, and in three of the four Australian states/territories surveyed, supporting the historic presence of the virus in Australia. While the infection prevalence in the wild‐caught cohort is evidently low, the significantly higher infection prevalence in rescued bats in urban settings represents a clear and present public health significance because of the higher risk of human exposure.  相似文献   

4.
The inter-epizootic reservoir host of Rift Valley fever virus (RVFV) remains unknown, although the namaqua rock rat, Aethomys namaquensis, as well as bats have been implicated. Bats can be asymptomatically infected with rabies, as well as several arboviruses; the possibility that they can act as host for RVFV therefore exists. To examine this possibility, 350 different samples (brain, liver, salivary glands and brown fat) obtained from 150 bats (comprising seven species) were tested for RVFV antigen using an enzyme linked immunosorbent assay (ELISA). None of the samples tested positive, but the ELISA proved to have limited sensitivity (> or = 10(3) TCID50/ml). In order to determine whether bats could be infected with RVFV, one Miniopterus schreibersii and two Eptesicus capensis bats were inoculated by the oral or intramuscular route with 100 ml and 30 ml, respectively, of a RVFV suspension with a titre of 10(6) TCID50/ml. None of the bats developed any clinical signs. A low concentration of RVFV antigen was found in the liver and urine of M. schreibersii, but not in brain tissue. A third E. capensis bat was inoculated by the intramuscular route and sacrificed on day 18. A low level of antigen was detected in the brown fat. These results demonstrate that bats can be infected with RVFV, and that further studies should be done to determine the potential of different bat species to act as reservoir hosts for RVFV during inter-epizootic periods.  相似文献   

5.
Hepatitis B virus (HBV) is the prototype of the Orthohepadnavirus genus and represents an important cause of chronic hepatitis, liver cirrhosis, and hepatic cancer in humans worldwide. To verify the occurrence and genetic variability of orthohepadnavirus among neotropical bats, we tested 81 liver samples of New World bats from São Paulo State, Southeastern Brazil, collected during 2012. PCR, sequencing, and phylogenetic analysis of Surface/Polymerase and Core viral genes confirmed the occurrence of the first isolate of bat orthohepadnavirus detected in South America. These results may contribute to subsequent studies of the origin, variability, host species, and evolution of bat orthohepadnaviruses in South America.  相似文献   

6.
During March 2013, we investigated the presence and the levels of Schmallenberg virus (SBV) circulation in three dairy cow herds and three sheep flocks in Central Macedonia, Greece. In two cow herds, a high number of abortions had been observed during the winter. Six bulk-tank milk samples and 147 individual sera were screened for SBV-specific antibodies by ELISA. Positive reactions were obtained from 5 out of 6 bulk-tank milk samples, 58 out of 90 sera from the 3 cow herds, and 2 sera from 2 of the 3 sheep flocks. Twenty-two ELISA-positive sera were tested by serum neutralization test (SNT). SNT confirmed the presence of neutralizing antibodies against SBV in all samples tested, with titers ranging between 1:32 and ≥1:256. No neutralizing antibodies against Akabane virus (AKAV) or Shamonda virus (SHAV) were detected, indicating that neutralizing antibodies against SBV do not cross react with AKAV or SHAV in SNT. ELISA testing of bulk-tank milk samples proved to be convenient and reliable. None of the tested sera was found positive for SBV by real-time RT-PCR, indicating that the sampling was conducted past the viremia stage. This is the first report of SBV circulation in Greece.  相似文献   

7.
蝙蝠作为流行性乙型脑炎病毒宿主的研究   总被引：5，自引：0，他引：5  
1986、1988、1990和1997年的7－8月，在云南省共捕获653只蝙蝠，其中棕果蝠（Rousettus leschenaulti)593只，金管鼻蝠（Murina aurata)60只，采集血清及剖取脑组织作病毒分离和抗体检查。用细胞法和乳鼠法分离到6株病毒，带毒率为0．96％，其中从捕自景洪的棕果蝠脑组织中分离到3株，从河口的棕果蝠血清中分离到2株，从捕自耿马的金管鼻蝠脑组织中分离出1株。棕果蝠和金管鼻蝠的带毒率分别为0．84％和1．67％。这6株病毒能引起C6／36和BHK21细胞病变和导致乳小白鼠或3－4周龄小白鼠发病和死亡，并具有典型的嗜神经病毒感染症状，经血凝抑制，补体结合，免疫荧光和中和试验鉴定。新分离的6株病毒均为乙脑病毒（JE virus)。同期用血凝抑制试验对采获的425份棕果蝠血清作乙脑病毒抗体检查。阳性153－份，阳性率为36％，人有较高的感染率，。本次从棕果蝠和金管鼻蝠体内分离出乙脑病毒属具有重要流行病学意义。  相似文献   

8.
Twenty-six captive, adult Egyptian fruit bats (Rousettus aegyptiacus) were tested for the presence of rabies virus neutralizing antibodies (RVNA) using a rapid fluorescent focus inhibition test before and after vaccination. The bats were randomly assigned into three treatment groups: group A (n = 10) bats each received one 0.1-ml dose of monovalent inactivated rabies vaccine, group B (n = 10) bats each received two 0.1-ml doses of vaccine given 30 days apart, and group C (n = 6) bats remained unvaccinated. Plasma was collected from all bats before vaccination and on days 14, 30, 60, and 360. All bats were seronegative before vaccination, and all unvaccinated animals remained negative throughout the study. Rabies virus neutralization titers remained above 0.5 IU/ml from day 30 through day 360 for both vaccinated groups. Group B had significantly higher titers on day 60. This study demonstrated a measurable humoral immune response after vaccination with an inactivated rabies vaccine, with two doses producing a higher level of RVNA. This study confirms the feasibility of a rabies vaccination program for Egyptian fruit bats.  相似文献   

9.
Bats have been demonstrated to be natural reservoirs of severe acute respiratory syndrome coronavirus (SARS CoV) and Middle East respiratory syndrome (MERS) CoV. Faecal samples from 248 individuals of 20 bat species were tested for partial RNA‐dependent RNA polymerase gene of CoV and 57 faecal samples from eight bat species were tested positive. The highest detection rate of 44% for Scotophilus kuhlii, followed by 30% for Rhinolophus monoceros. Significantly higher detection rates of coronaviral RNA were found in female bats and Scotophilus kuhlii roosting in palm trees. Phylogenetic analysis classified the positive samples into SARS‐related (SARSr) CoV, Scotophilus bat CoV 512 close to those from China and Philippines, and Miniopterus bat CoV 1A‐related lineages. Coronaviral RNA was also detected in bat guano from Scotophilus kuhlii and Myotis formosus flavus on the ground and had potential risk for human exposure. Diverse bat CoV with zoonotic potential could be introduced by migratory bats and maintained in the endemic bat population in Taiwan.  相似文献   

10.
Bats are hosts of diverse coronaviruses (CoVs) known to potentially cross the host–species barrier. For analysing coronavirus diversity in a bat species‐rich country, a total of 421 anal swabs/faecal samples from Costa Rican bats were screened for CoV RNA‐dependent RNA polymerase (RdRp) gene sequences by a pancoronavirus PCR. Six families, 24 genera and 41 species of bats were analysed. The detection rate for CoV was 1%. Individuals (n = 4) from four different species of frugivorous (Artibeus jamaicensis, Carollia perspicillata and Carollia castanea) and nectivorous (Glossophaga soricina) bats were positive for coronavirus‐derived nucleic acids. Analysis of 440 nt. RdRp sequences allocated all Costa Rican bat CoVs to the α‐CoV group. Several CoVs sequences clustered near previously described CoVs from the same species of bat, but were phylogenetically distant from the human CoV sequences identified to date, suggesting no recent spillover events. The Glossophaga soricina CoV sequence is sufficiently dissimilar (26% homology to the closest known bat CoVs) to represent a unique coronavirus not clustering near other CoVs found in the same bat species so far, implying an even higher CoV diversity than previously suspected.  相似文献   

11.
An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies in turkey serum to hemorrhagic enteritis virus. The ELISA antigen was extracted from turkey spleens and partially purified with fluorocarbon. Antibodies were demonstrated in serum samples of breeding and meat flocks that had been naturally exposed to infection. These samples were also examined in parallel by agar-gel precipitin (AGP); most of the sera were AGP-positive. ELISA, however, was more sensitive in detecting antibodies in day-old sera that were AGP-negative. The passively acquired antibodies were no longer detected by 4 weeks of age. A brisk but short-lived secondary response was detected by ELISA in the sera of turkeys immunized with beta-propiolactone-inactivated extract of infected spleens.  相似文献   

12.
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13.
Five serological methods of diagnosing African horse sickness were evaluated, using a battery of serum samples from experimental horses vaccinated and challenged with each serotype of African horse sickness virus (AHSV1 through AHSV9): agar gel immunodiffusion (AGID), indirect fluorescent antibody (IFA), complement fixation (CF), virus neutralization (VN), and enzyme-linked immunosorbent assay (ELISA). The 5 tests were also compared using a panel of field samples, convalescent equine sera with antibodies to domestic equine viral diseases, and sera from horses awaiting export. The ELISA described in this paper was group specific. It did not require calibration with a standard positive serum but did yield elevated values with negative sera that were repeatedly frozen and thawed or heat inactivated. The IFA test was sensitive but could not be used on some field sera as the control cells exhibited fluorescence, possibly due to the animal being recently vaccinated with cell culture material. Sixty-two experimental sera were compared by VN, CF, AGID, and ELISA. Forty sera, 10 positive and 30 negative, were correctly classified by the 5 serologic assays. The 22 remaining sera gave mixed reactions. The AGID had no false positive results but had false negative results for up to 20% of the samples, depending upon the comparison. The VN, CF, and ELISA were similar in their variability. The length of time that virus could be recovered from a viremic blood sample was compared in an evaluation of storage methods for virus isolation samples. Washed erythrocytes were held at 4 C, washed erythrocytes plus stabilizer were held at -70 C, and blood that was drawn into a preservative (oxalate/phenol/glycerol) was held at 4 C.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

14.
Megachiropteran bats are biologically important both as endangered species and reservoirs for emerging human pathogens. Reliable detection of antibodies to specific pathogens in bats is thus epidemiologically critical. Eight variable flying foxes (Pteropus hypomelanus) were immunized with 2,4-dinitrophenylated bovine serum albumin (DNP-BSA). Each bat received monthly inoculations for 2 months. Affinity-purified IgG was used for production of polyclonal and monoclonal anti-variable flying fox IgG antibodies. ELISA and western blot analysis were used to monitor immune responses and for assessment of polyclonal and monoclonal antibody species cross-reactivity. Protein G, polyclonal antibodies, and monoclonal antibodies detected specific anti-DNP antibody responses in immunized variable flying foxes, with protein G being the most sensitive, followed by monoclonal antibodies and then polyclonal antibodies. While the polyclonal antibody was found to cross-react well against IgG of all bat species tested, some non-specific background was observed. The monoclonal antibody was found to cross-react well against IgG of six other species in the genus Pteropus and to cross-react less strongly against IgG from Eidolon helvum or Phyllostomus hastatus. Protein G distinguished best between vaccinated and unvaccinated bats, and these results validate the use of protein G for detection of bat IgG. Monoclonal antibodies developed in this study recognized immunoglobulins from other members of the genus Pteropus well, and may be useful in applications where specific detection of Pteropus IgG is needed.  相似文献   

15.
Recombinant p40 produced by baculovirus was used in an ELISA to screen samples of serum taken from 80 cats in Istanbul. The sera were also analysed for feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Antibodies to Borna disease virus- (BDV) p40 were detected in 34 (42-5 per cent) of the 80 cats. Seventy-three per cent of the sera which were positive for FIV and 26 per cent of the sera which were negative for FIV had antibodies to BDV. There was no difference in the percentage of sera which were positive for BDV between the cats that were positive or negative for FeLV. Three of the cats had neurological disease and two of these had antibodies to BDV. Six sera with low, medium or high optical densities (ODS) by ELISA were analysed by Western blotting. Only the sera with medium and high ODS reacted specifically with p40 at a dilution of 1 in 1,000.  相似文献   

16.
Epidemiology and control of Menangle virus in pigs   总被引：6，自引：0，他引：6  
OBJECTIVE: To describe the epidemiology and eradication of Menangle virus infection in pigs. DESIGN: Field observations and interventions, structured and unstructured serological surveys, prospective and cross-sectional serological studies and laboratory investigations. PROCEDURE: Serum samples were collected from pigs at a 2600-sow intensive piggery in New South Wales that experienced an outbreak of reproductive disease in 1997. Serum samples were also collected from piggeries that received pigs from or supplied pigs to the affected piggery and from other piggeries in Australia. Serum and tissue samples were collected from pigs at piggeries experiencing reproductive disease in New South Wales. Sera and faeces were collected from grey-headed flying foxes (Pteropus poliocephalus) in the region of the affected piggery. Serum samples were tested for neutralising antibodies against Menangle virus. Virus isolation was attempted from faeces. RESULTS: Following the outbreak of reproductive disease, sera from 96% of adult pigs at the affected piggery, including sows that produced affected litters, contained neutralising antibodies against Menangle virus. Neutralising antibodies were also detected in sera from 88% of finisher pigs at two piggeries receiving weaned pigs from the affected piggery. No evidence of Menangle virus infection was found in other piggeries in Australia. In cross-sectional studies at the affected piggery, colostral antibodies were undetectable in most pigs by 14 to 15 weeks of age. By slaughter age or entry to the breeding herd, 95% of pigs developed high antibody titres (> or = 128) against Menangle virus in the virus neutralisation test. Menangle virus was eradicated from the affected piggery following a program of serological testing and segregation. Neutralising antibodies against Menangle virus were also detected in P poliocephalus from two colonies in the vicinity of the affected piggery. Two piggery workers were infected with Menangle virus. There was no evidence of infection in cattle, sheep, birds, rodents, feral cats and a dog at the affected piggery. CONCLUSIONS: Serological evidence of infection with Menangle virus was detected in pigs at a piggery that had experienced reproductive disease, in pigs at two associated piggeries and in fruit bats in the region of the piggery. Two humans were infected. The mode of transmission between pigs is unknown, but spread by faecal or urinary excretion is postulated. This virus can be eradicated by the segregation of pigs into discrete age groups.  相似文献   

17.
Two serological tests--the virus-neutralization (VN) test in chicken embryo fibroblasts (CEF) using a cell-culture-adapted virus, and the enzyme-linked immunosorbent assay (ELISA)--were used for evaluating the immune response in chickens against fowlpox virus. The VN test was conducted in 96-well tissue-culture plates using a fowlpox virus that was adapted to induce cytopathic effects (CPE) in CEF in 48 hr. The ELISA was carried out with an antigen prepared by precipitation of a cell-culture-propagated virus suspension with ammonium sulfate and concentration by centrifugation. A 0.1 M acetate buffer, pH 5, was used as the sensitizing solution for maximum specific binding of the antigen to the microplate plastic well. No antibodies were detected by the VN test in 228 serum samples taken from chickens at irregular intervals between 1 and 39 weeks of age, even though the birds were vaccinated against fowlpox at 13 weeks of age. However, in sera collected 4 weeks after a sample of laying hens was challenged with fowlpox virus, VN titers of 1/10 to 1/40 were detectable. On the other hand, significant antibody reactions were detected by the ELISA on sera from chickens during the growing period, following vaccination and challenge. Although no maternal antibodies were found at 1 week of age, a continuous increase in the mean ELISA titers to fowlpox was demonstrated during the entire experimental period. This study showed that the ELISA was considerably more sensitive and practical than the VN test.  相似文献   

18.
The presence of serum antibodies directed against classical swine fever (CSF) virus and other pestiviruses among the wild boar (Sus scrofa) population in Croatia was investigated. During 2003, serum samples from 214 wild boars were collected in 10 hunting areas in the continental part of the country.The sera were examined by enzyme immunoassay (ELISA) and in the virus neutralization test (VNT). Out of 214 sera tested 111 (51.87 %) were positive by ELISA and regarding neutralising antibodies, against CSFV 75 (35.05 %) samples were positive. In the VNT with the C-strain (conventional live vaccine strain China) and the strain Uelzen were used. Samples were also tested for neutralizing antibodies against border disease virus (BDV) using the strain 137/4 and against bovine viral diarrhoea virus (BVDV) using the NADL strain. Neutralizing antibodies against the C-strain were detected in 36 sera (16.82 %), against strain Uelzen in 17 sera (7.94 %) and in 22 sera (10.28 %) against both strains. In five sera (2.33 %) neutralizing antibodies against BVDV and BDV were found.  相似文献   

19.
The intensification of dog, cat and livestock vaccination campaigns significantly reduced rabies cases in humans and domestic animals in Ceará State, Brazil. However, sylvatic animals—bats (order Chiroptera), wild canids, raccoons and non‐human primates— remain as reservoirs for the virus. Our hypothesis is that surveillance and monitoring of rabies virus in bats, especially passive surveillance, is of fundamental importance, besides the implementation of health education and strengthening of surveillance actions in humans exposed to aggressions. Thus, we assessed the occurrence of rabies virus in animals focusing on bats, before and after launching of the Sylvatic Rabies Surveillance Program in 2010. Surveillance data from the 184 municipalities of Ceará State were analysed, collected during the periods 2003–2010 (active surveillance) and 2011–2016 (passive surveillance), respectively. A total of 13,543 mammalian samples were received for rabies diagnosis from 2003 to 2016. Of these, 10,960 were from dogs or cats (80.9%), 1,180 from bats (8.7%), 806 from other sylvatic animals (foxes, marmosets, raccoons; 6.0%) and 597 from herbivores (cattle, goats, sheep, equines, pigs; 4.4%). A total of 588 (4.3%) samples were positive for rabies. About 8.4% (99/1,180) of the bat samples were infected with rabies virus, 92 (92.9%) of these were from non‐haematophagous bat species and 7 (7.1%) from haematophagous species. The number of bat samples received and infection rates increased considerably, after a shift from active surveillance (9/355 [2.5%] samples positive), to passive surveillance (90/825 [10.9%] samples positive). Surveillance of rabies virus in bats is fundamental for human and domestic animal health in Ceará State. Bats have to be considered as targets in surveillance and control programmes. Virus lineages should be characterized to increase knowledge on transmission dynamics of sylvatic rabies virus to domestic animals and the human population, and to provide additional evidence for planning and implementation of improved control measures.  相似文献   

20.
Two serological tests, the virus-neutralization (VN) test in tissue culture using a tissue-cell-adapted virus and the enzyme-linked immunosorbent assay (ELISA), were compared to detect antibodies against Massachusetts 41 and Connecticut 46 strains of Infectious Bronchitis Virus (IBV). The VN test was conducted in wells of microplates by the usual procedure. The two strains of IBV were adapted after 20 serial passages to induce CPE in 24 hours in chickens embryos kidney cells (CEKC). The ELISA test was carried out using partially virus following ultracentrifugation of each stain of IBV as antigen. The ELISA test detected higher geometric mean antibody titers (GMT) against both strains of IBV than did the VN test. One hundred four serum samples taken at 1, 3, 5, 9, 22, 24, and 26 weeks of age from a flock of chickens vaccinated with the Mass strain three times and the Conn strain of IBV two times during the growing period showed higher antibody titer responses to the Conn 46 than to the Mass 41 strain. Maternal antibodies in chicks one week of age were readily detected by the ELISA test, whereas low or insignificant titers were found by the VN test. Sera of vaccinated chickens collected following challenge with Mass 41 or Conn 46 strain of IBV showed that the ELISA was more sensitive and showed higher titers than did the VN test. Although the VN test showed no rise in GMT in the same sera tested with the heterologous virus, the ELISA showed a slight increase or cross-reaction. The serum samples from the unchallenged control group showed no change in GMT with either test or IBV strain.  相似文献   

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