Author:
Abdelwhab El-Sayed M,Erfan Ahmed M,Grund Christian,Ziller Mario,Arafa Abdel-Satar,Beer Martin,Aly Mona M,Hafez Hafez M,Harder Timm C
Abstract
Abstract
Background
The endemic status of highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 in Egypt continues to devastate the local poultry industry and poses a permanent threat for human health. Several genetically and antigenically distinct H5N1 lineages co-circulate in Egypt: Strains of clade 2.2.1 proper replicate mainly in backyard birds causing the bulk of human infections, while a variant lineage within 2.2.1 (2.2.1v) appears to be perpetuated mainly in commercial poultry farms in Egypt. Viruses of the 2.2.1v lineage represent drift variants escaping from conventional vaccine-induced immunity and some of these strains also escaped detection by commercial real time reverse transcriptase PCR (RT-qPCR) protocols due to mismatches in the primers/probe binding sites.
Results
We developed therefore a versatile, sensitive and lineage-specific multiplex RT-qPCR for detection and typing of H5N1 viruses in Egypt. Analytical characterization was carried out using 50 Egyptian HPAIV H5N1 strains isolated since 2006 and 45 other avian influenza viruses (AIV). A detection limit of 400 cRNA copies per ml sample matrix was found. Higher diagnostic sensitivity of the multiplex assay in comparison to other generic H5 or M-gene based RT-qPCR assays were found by examination of 63 swab samples from experimentally infected chickens and 50 AIV-positive swab samples from different host species in the field in Egypt.
Conclusions
The new multiplex RT-qPCR assay could be useful for rapid high-throughput monitoring for the presence of HPAIV H5N1 in commercial poultry in Egypt. It may also aid in prospective epidemiological studies to further delineate and better control spread of HPAIV H5N1 in Egypt.
Publisher
Springer Science and Business Media LLC
Subject
Infectious Diseases,Virology
Reference26 articles.
1. WHO/OIE/FAO H5N1 Evolution Working Group: Continuing progress towards a unified nomenclature for the highly pathogenic H5N1 avian influenza viruses: divergence of clade 2.2 viruses. Influenza Other Respi Viruses 2009, 3: 59-62. 10.1111/j.1750-2659.2009.00078.x
2. Meleigy M: Egypt battles with avian influenza. Lancet 2007, 370: 553-554. 10.1016/S0140-6736(07)61274-4
3. Fasina FO, Ifende VI, Ajibade AA: Avian influenza A(H5N1) in humans: lessons from Egypt.Euro Surveill; 2009.,15(4): [http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19473
4. Peiris JS, de Jong MD, Guan Y: Avian influenza virus (H5N1): a threat to human health. Clinical Microbiol Rev 2007, 20: 243-267. 10.1128/CMR.00037-06
5. Aly MM, Arafa A, Hassan MK: Epidemiological findings of outbreaks of disease caused by highly pathogenic H5N1 avian influenza virus in poultry in Egypt during 2006. Avian Dis 2008, 52: 269-277. 10.1637/8166-103007-Reg.1
Cited by
17 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献