共查询到20条相似文献，搜索用时 437 毫秒
1.
2.
Serological and Virological Surveillance of Avian Influenza A Virus H9N2 Subtype in Humans and Poultry in Shanghai,China, Between 2008 and 2010 
下载免费PDF全文
下载免费PDF全文 Q. Wang L. Ju P. Liu J. Zhou X. Lv L. Li H. Shen H. Su L. Jiang Q. Jiang 《Zoonoses and public health》2015,62(2):131-140
We report the serological evidence of low‐pathogenic avian influenza (LPAI) H9N2 infection in an occupational poultry‐exposed population and a general population. A serological survey of an occupational poultry‐exposed population and a general population was conducted using a haemagglutinin‐inhibiting (HI) assay in Shanghai, China, from January 2008 to December 2010. Evidence of higher anti‐H9 antibodies was found in serum samples collected from poultry workers. During this period, 239 H9N2 avian influenza viruses (AIVs) were isolated from 9297 tracheal and cloacal paired specimens collected from the poultry in live poultry markets. In addition, a total of 733 influenza viruses were isolated from 1569 nasal and throat swabs collected from patients with influenza‐like symptoms in a sentinel hospital, which include H3N2, H1N1, pandemic H1N1 and B, but no H9N2 virus was detected. These findings highlight the need for long‐term surveillance of avian influenza viruses in occupational poultry‐exposed workers. 相似文献
3.
Wildlife surveillance associated with an outbreak of lethal H5N2 avian influenza in domestic poultry 总被引：2，自引：0，他引：2
Wildlife surveillance was conducted for influenza viruses in conjunction with the 1983-84 lethal H5N2 avian influenza epizootic in domestic poultry in Pennsylvania, New Jersey, Maryland, and Virginia. Virus-isolation attempts made on cloacal and tracheal swabs from 4,466 birds and small rodents within the quarantined areas and 1,511 waterfowl in nearby Maryland yielded only a single H5N2 isolate from a pen-raised chukar in Pennsylvania. Antibodies against hemagglutinin type 5 and/or neuraminidase type 2 were found in 33% of the aquatic birds tested; however, this finding could not be used to confirm previous H5N2 avian influenza virus activity because of the possibility of prior infections with multiple influenza subtypes. The low prevalence of lethal H5N2 avian influenza virus in wild birds and small rodents strongly indicated that these animals were not responsible for dissemination of the disease among poultry farms during the outbreak. 相似文献
4.
Siengsanan-Lamont J Robertson I Blacksell SD Ellis T Fenwick S Saengchoowong S Suwanpukdee S Yongyuttawichai P Sariya L Prompiram P Chaichoun K Wiriyarat W Pothieng D Ratanakorn P 《Veterinary microbiology》2011,148(2-4):213-218
A serological and virological surveillance program to investigate the HPAI H5N1 virus in wild bird populations was undertaken from February 2007 to October 2008. The purpose of the survey was to investigate the infection status in free ranging wild birds in Banglane district, Nakhon Pathom province, central Thailand. Samples from wild birds were collected every two months. Choanal and cloacal swabs, serum and tissue samples were collected from 421 birds comprising 44 species. Sero-prevalence of the virus tested by H5N1 serum neutralization test (using a H5N1 virus clade 1; A/chicken/Thailand/vsmu-3-BKK/2004) was 2.1% (8 out of 385 samples; 95% CI 0.7, 3.5). Species that were antibody positive included rock pigeons (Columba livia), Asian pied starling (Gracupica contra), spotted dove (Streptopelia chinensis), oriental magpie robin (Copsychus saularis), blue-tailed bee-eater (Merops philippinus), myna (Acridotheres spp.), and pond heron (Ardeola spp.). Prevalence by H5N1 virus isolation was 0.5% (2 out of 421 samples; 95% CI 0.0, 1.1); the two H5N1 virus-positive samples were from Asian pied starling (Gracupica contra) and white vented myna (Acridotheres grandis). Positive virological samples were collected in June 2007 while all positive serology samples were collected between May and August except for one sample collected in December 2007. No positive samples were collected in 2008. Molecular studies revealed that the wild bird H5N1 viruses were closely related to poultry viruses isolated in other parts of Thailand. However, there was no poultry H5N1 prevalence study performed in the study site during the time of this wild bird survey. Interpretation of source of virus isolates would include spill-over of H5N1 viruses from contaminated sources due to movement of domestic poultry and/or fomites from other areas; or infection of wild birds within the outbreak locations and then translocation by wild bird movement and interaction with wild birds inhabiting distant locations. 相似文献
5.
A. Comin J. A. Stegeman D. Klinkenberg L. Busani S. Marangon 《Zoonoses and public health》2011,58(4):244-251
Surveillance programmes for low pathogenicity (LPAI) and high pathogenicity avian influenza (HPAI) infections in poultry are compulsory for EU Member States; yet, these programmes have rarely been evaluated. In Italy, following a 1999 HPAI epidemic, control measures, including vaccination and monitoring, were implemented in the densely populated poultry area (DPPA) where all epidemics in Italy have been concentrated. We evaluated the monitoring system for its capacity to detect outbreaks rapidly in meat‐type turkey flocks. The evaluation was performed in vaccination areas and high‐risk areas in the DPPA, in 2000–2005, during which four epidemics occurred. Serum samples and cloacal swabs were taken from vaccinated birds and unvaccinated (sentinel) birds. We compared the detection rate of active, passive and targeted surveillance, by vaccination status, using multinomial logistic regression. A total of 13 275 samplings for serological testing and 4889 samplings for virological testing were performed; 6315 production cycles of different bird species were tested. The outbreaks detection rate in meat‐type turkeys was 61% for active surveillance (n = 222/363 outbreaks), 32% for passive surveillance and 7% for targeted surveillance. The maximum likelihood predicted values for the detection rates differed by vaccination status: in unvaccinated flocks, it was 50% for active surveillance, 40% for passive surveillance and 10% for targeted surveillance, compared to respectively 79%, 17% and 4% for vaccinated flocks. Active surveillance seems to be most effective in detecting infection, especially when a vaccination programme is in place. This is the first evaluation of the effectiveness of different types of surveillance in monitoring LPAI infections in vaccinated poultry using field data. 相似文献
6.
7.
Five antigen capture immunoassay test kits, Directigen Flu A (Becton Dickinson), QuickVue Influenza test kit (Quidel), FLU OIA (ThermoBiostar), Zstat Flu (ZymeTx, Inc.) and NOW FLU A Test (Binax) were used to detect avian influenza virus (AIV) in clinical specimens as per manufacturers' protocols. Each kit was shown to be specific for AIV propagated in embryonating chicken eggs (ECE); other respiratory viruses of poultry tested gave negative results. The Directigen Flu A kit proved to be 10-fold more sensitive than the other kits, capable of detecting 10(4.7) mean embryo lethal dose (ELD50)/ml in allantoic fluid; this is more sensitive than the hemagglutination test using chicken erythrocytes. None of the kits proved to be sufficiently sensitive to reliably detect AIV in oropharyngeal and cloacal swabs collected from chickens experimentally infected with AIV subtype H6N2. In two different experiments, individual swabs and pools of five or six swabs were tested. By virus isolation, 39 individual oropharyngeal swabs tested positive for AIV, but Directigen and Flu OIA only detected 2/39 and NOW FLU A 1/39. Zstat and QuickVue did not detect any. Five individual cloacal swabs positive by virus isolation were negative with all five kits. In a second experiment using pools of five swabs, 26 swab pools were positive by virus isolation and 5/26 were positive by Directigen, the only kit to provide any positive results. Five cloacal swab pools were also positive by virus isolation and 1/5 was positive by Directigen; all other test kits were negative. All of these experiments were performed using the H6N2 subtype of AIV. The results are disappointing, as the kits have proven to be insensitive for detecting AIV when compared with the gold standard, virus isolation. This limits their use in diagnostic field investigations. Individual or groups of chickens could be assumed to be positive for AIV if positive by any of the kits, but a negative result with any of the kits would not prove that birds were AIV free. 相似文献
8.
9.
Highly pathogenic avian influenza (HPAI) is a devastating viral disease of poultry and quick control of outbreaks is vital. Airborne transmission has often been suggested as a route of transmission between flocks, but knowledge of the rate of transmission via this route is sparse. In the current study, we quantified the rate of airborne transmission of an HPAI H5N1 virus strain between chickens under experimental conditions. In addition, we quantified viral load in air and dust samples. Sixteen trials were done, comprising a total of 160 chickens housed in cages, with three treatment groups. The first group was inoculated with strain A/turkey/Turkey/1/2005 H5N1, the second and third group were not inoculated, but housed at 0.2 and 1.1m distance of the first group, respectively. Tracheal and cloacal swabs were collected daily of each chicken to monitor virus transmission. Air and dust samples were taken daily to quantify virus load in the immediate surroundings of the birds. Samples were tested by quantitative RRT-PCR and virus isolation. In 4 out of 16 trials virus was transmitted from the experimentally inoculated chickens to the non-inoculated chickens. The transmission rate was 0.13 and 0.10 new infections per infectious bird at 0.2m and 1.1m, respectively. The difference between these estimates was, however, not significant. Two air samples tested positive in virus isolation, but none of these samples originated from the trials with successful transmission. Five dust samples were confirmed positive in virus isolation. The results of this study demonstrate that the rate of airborne transmission between chickens over short distances is low, suggesting that airborne transmission over a long distance is an unlikely route of spread. Whether or not this also applies to the field situation needs to be examined. 相似文献
10.
11.
12.
Stanislawek WL Meers J Wilks C Horner GW Morgan C Alexander DJ 《New Zealand veterinary journal》2001,49(1):18-23
AIMS: To determine the presence of avian paramyxovirus (APMV) types 1, 2, and 3 in caged and wild birds, and APMV-2 and -3 in poultry in New Zealand. METHODS: Blood samples collected from caged (231) and wild birds (522) from various regions of New Zealand in 1997-99 were tested by haemagglutination inhibition (HI) test for antibodies to APMV types 1, 2, and 3. Blood samples collected from 1778 commercial poultry in 1996-99 were tested for APMV-2 and APMV-3 antibodies and the samples that reacted with APMV-3 antigen were tested for antibodies to APMV-1. Isolation of APMV was attempted from cloacal swabs collected from 116 of the caged birds and 175 of the wild birds sampled. RESULTS: Antibodies to APMV types 1, 2, and 3 were detected in 4.8, 1.7, and 2.6%, respectively, of caged bird samples. The majority of these caged birds were 'exotic' or 'fancy' poultry breeds. Amongst wild birds, 4.2% had titres to APMV-2 and over half of these were passerine birds; 1.7% of the samples had titres to APMV-1 and 0.8% to APMV-3 antigen. No virus was isolated from any of the cloacal swabs tested. Of the 1778 poultry serum samples tested, only 5 reacted with APMV-3 antigen and these were later found to be cross-reactions to APMV-1. No reactions were detected with APMV-2 antigen. CONCLUSIONS: APMV-1 is present in caged birds, wild birds, and poultry of New Zealand. There is no conclusive evidence of the presence of APMV-2 and APMV-3 in poultry or APMV-3 in wild birds. The results do not provide conclusive evidence for the presence of APMV-2 in wild birds in New Zealand. 相似文献
13.
14.
An avian influenza (AI) surveillance was undertaken in Maharashtra state, India during the period 2010-2011. There are no reports of AI surveillance in emus from India. A total of 202 blood samples and 467 tracheal and cloacal swabs were collected from eight emu farms. A hemagglutination inhibition (HI) assay was performed for detection of antibodies against AI H5N1, H7N1, H9N2, and avian paramyxovirus type 1 (APMV-1) viruses. A microneutralization (MN) assay was performed to confirm the presence of neutralizing antibodies against AI H9N2 and to compare with HI assays. A total of 28.2% and 28.7% of samples were positive for antibodies against AI H9N2 by HI and MN assays, respectively, using > or = 1:40 as a cut-off titer; 15.3% samples were positive for APMV-1 by HI assay using a > or = 1:10 cut-off titer. Seropositivity of AI H9N2 was nil in the grower (<1 yr) age group and highest (78%) in the breeder (2-3 yr) age group, whereas seropositivity against APMV-1 was observed in all age groups. Performance of both HI and MN assays was similar, suggesting the utility of using the MN assay along with HI assay for surveillance studies. This is the first report of the seroprevalence of AI H9N2 and APMV-1 in emus in India. 相似文献
15.
Dobbin G Hariharan H Daoust PY Hariharan S Heaney S Coles M Price L Anne Muckle C 《Comparative immunology, microbiology and infectious diseases》2005,28(1):71-82
Cloacal and pharyngeal swabs from 100 tree-nesting Double-crested cormorant (DCC) chicks were examined by culture for commensal and potentially pathogenic bacteria. No Salmonella or Erysipelothrix were isolated from the cloacal swabs. Twenty-two cloacal swabs were positive for Campylobacter, of which 14 were C. jejuni, C. coli, and 1 C. lari. None belonged to common serotypes isolated from humans or animals in recent years in Canada. Tests for antimicrobial drug resistance among 187 commensal Escherichia coli isolates from the cloacal swabs indicated that < or =5% were resistant to any of the 12 antibiotics tested. This contrasts with the frequently high resistance rates among E. coli isolates from poultry. Pharyngeal swabs from DCC were negative for Pasteurella multocida. Culture of cloacal swabs from 100 ground-nesting DCC chicks resulted in the recovery of 19 Salmonella isolates, all of which were S. enterica serotype Typhimurium. None of these isolates were resistant to any of the 12 antibiotics tested. Altogether, these findings suggest that DCC from this region are not being colonized with commensal or potentially pathogenic enteric bacteria from agricultural or human sources and that enteric bacteria isolated from these birds are unlikely to contribute to a gene pool of antimicrobial drug resistance. 相似文献
16.
野生鸟类禽流感病毒感染情况的调查 总被引：1，自引：0，他引：1
为了解野生鸟类禽流感病毒(AIV)的携带感染情况,2006年～2010年,本研究在湖南省主要候鸟迁徙地收集115只野鸟组织或拭子样品、75份野鸟的新鲜粪便样品和72份血清样品。组织或拭子样品采用RT-PCR方法检测和鸡胚接种病毒分离鉴定,血清样品分别进行H5(含Re-5和Re-4)、H6、H7、H9、H10和H11抗体检测。结果表明,从斑鸠和绿头鸭组织中分别分离到H5N1亚型和H3N2亚型AIV;72份血清中有17份抗体为阳性,其中H5(Re-5)亚型5份、H5(Re-4)亚型1份、H6亚型1份、H7亚型2份和H9亚型8份,阳性率分别为6.94%、1.39%、1.39%、2.78%和11.11%。H10和H11亚型未检测到抗体阳性。 相似文献
17.
Kosuke SODA Maya YAMANE Chiharu HIDAKA Kozue MIURA Trang T. H. UNG Hang L. K. NGUYEN Hiroshi ITO Mai Q. LE Toshihiro ITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(12):1899
Low and highly pathogenic avian influenza viruses (LPAIVs and HPAIVs, respectively) have been co-circulating in poultry populations in Asian, Middle Eastern, and African countries. In our avian-flu surveillance in Vietnamese domestic ducks, viral genes of LPAIV and HPAIV have been frequently detected in the same individual. To assess the influence of LPAIV on the pathogenicity of H5 HPAIV in domestic ducks, an experimental co-infection study was performed. One-week-old domestic ducks were inoculated intranasally and orally with phosphate-buffered saline (PBS) (control) or 106 EID50 of LPAIVs (A/duck/Vietnam/LBM678/2014 (H6N6) or A/Muscovy duck/Vietnam/LBM694/2014 (H9N2)). Seven days later, these ducks were inoculated with HPAIV (A/Muscovy duck/Vietnam/LBM808/2015 (H5N6)) in the same manner. The respective survival rates were 100% and 50% in ducks pre-infected with LBM694 or LBM678 strains and both higher than the survival of the control group (25%). The virus titers in oral/cloacal swabs of each LPAIV pre-inoculation group were significantly lower at 3–5 days post-HPAIV inoculation. Notably, almost no virus was detected in swabs from surviving individuals of the LBM678 pre-inoculation group. Antigenic cross-reactivity among the viruses was not observed in the neutralization test. These results suggest that pre-infection with LPAIV attenuates the pathogenicity of HPAIV in domestic ducks, which might be explained by innate and/or cell-mediated immunity induced by the initial infection with LPAIV. 相似文献
18.
19.
Theodore J.D. Knight-Jones Ruth Hauser Doris Matthes Katharina D.C. St?rk 《Veterinary research》2010,41(4)
This study aimed to assess which method of wild waterbird surveillance had the greatest probability of detecting highly pathogenic avian influenza (HPAI) H5N1 during a period of surveillance activity, the cost of each method was also considered. Lake Constance is a major wintering centre for migratory waterbirds and in 2006 it was the site of an HPAI H5N1 epidemic in wild birds. Avian influenza surveillance was conducted using harmonised approaches in the three countries around the lake, Austria, Germany and Switzerland, from 2006–2009. The surveillance consisted of testing birds sampled by the following methods: live birds caught in traps, birds killed by hunters, birds caught in fishing nets, dead birds found by the public and catching live Mute Swans (Cygnus olor); sentinel flocks of Mallards (Anas platyrhynchos) were also used. Scenario tree analysis was performed including sensitivity analysis, followed by assessment of cost-effectiveness. Results indicated that if HPAI H5N1 was present at 1% prevalence and assuming HPAI resulted in bird mortality, sampling dead birds found by the public and sentinel surveillance were the most sensitive approaches despite residual uncertainty over some parameters. The uncertainty over the mortality of infected birds was an influential factor. Sampling birds found dead was most cost-effective, but strongly dependent on mortality and awareness of the public. Trapping live birds was least cost-effective. Based on our results, we recommend that future HPAI H5N1 surveillance around Lake Constance should prioritise sentinel surveillance and, if high mortality is expected, the testing of birds found dead. 相似文献
20.
Couacy-Hymann E Danho T Keita D Bodjo SC Kouakou C Koffi YM Beudje F Tripodi A de Benedictis P Cattoli G 《Zoonoses and public health》2009,56(1):10-15
The Virology Laboratory of the Central Laboratory of Animal Diseases in Ivory Coast at Bingerville received samples of wild and domestic avian species between February and December 2006. An RT-PCR technique was used to test for avian influenza (AI) and highly pathogenic AI subtype viruses. Among 2125 samples, 16 were type A positive; of which, 12 were later confirmed to be H5N1. Fifteen of these 16 type A positive samples were inoculated into the chorioallantoic cavity of 11-day-old embryonated hens' eggs for virus isolation. Eight produced virus with hemagglutination titres from 1/64 to 1/512. The 4/16 M-RT-PCR positive samples, which were H5N1 negative, were shown to be H7 subtype negative. The diagnostic efficiency of the laboratory for the surveillance of H5N1 in Ivory Coast was demonstrated. The positive cases of H5N1 were from a sparrowhawk (Accipter nisus); live market poultry and in free-range poultry, where the mortality rate was approximately 20% (2/10) and 96.7% (29/30) respectively. Currently, investigations into intensive poultry farms have proved negative for H5N1. No human cases have been reported this time. 相似文献