Seroprevalence of low pathogenic avian influenza (H9N2) and associated risk factors in the Gyeonggi-do of Korea during 2005-2006

Woo, Jong-Tae;Park, Bong-Kyun

  • Published : 20080600

Abstract

Between November 2005 and March 2006, a total of 253 poultry flocks in the Gyeonggi-do of Korea were examined for seroprevalence against avian influenza (AI) using a hemagglutination inhibition (HI) test and an agar gel precipitation test. No low pathogenic avian influenza (LPAI) virus was isolated from 47 seropositive flocks that lacked clinical signs during sampling. The unadjusted percentage of seroprevalence rates of layer and broiler flocks were not significantly different, i.e., 26% (25/96) and 23% (22/97), respectively. The HI titer of the layers (mean = 89) was higher than the broilers (mean = 36; p < 0.001). A cross-sectional study was conducted for the seroprevalence of LPAI in the layers. Of 7 risk factors, farms employing one or more workers had a higher seropositive prevalence as compared to farms without hired employees (adjusted prevalence OR = 11.5, p = 0.031). Layer flocks older than 400 d had higher seropositivity than flocks younger than 300 d (OR = 4.9, p = 0.017). The farmers recognized at least one of the clinical signs in seropositive flocks, such as decreased egg production, respiratory syndromes, and increased mortality (OR = 2.3, p = 0.082). In a matched case-control study, 20 pairs of case and control flocks matched for type of flock, hired employees, age, and flock size were compared. Frequent cleansing with disinfectants was associated with a decreased risk of seropositivity (OR = 0.2, p = 0.022). Although there was a low statistical association, using a foot disinfectant when entering the building led to a decreased rate of seropositivity (OR = 0.3, p = 0.105).

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References

  1. Alexander DJ. The epidemiology and control of avian influenza and Newcastle disease. J Comp Pathol 1995, 112, 105-126 https://doi.org/10.1016/S0021-9975(05)80054-4
  2. Alexander DJ. A review of avian influenza in different bird species. Vet Microbiol 2000, 74, 3-13 https://doi.org/10.1016/S0378-1135(00)00160-7
  3. Cannon RM, Roe RT. Livestock Disease Surveys: A Field Manual for Veterinarians. Australian government publishing service, Canberra, 1982
  4. Halvorson DA, Karunakaran D, Newman JA. Avian influenza in caged laying chickens. Avian Dis 1980, 24, 288-294 https://doi.org/10.2307/1589789
  5. Henzler DJ, Kradel DC, Davison S, Ziegler AF, Singletary D, Debok P, Castro AE, Lu H, Eckroade R, Swayne D, Lagoda W, Schmucker B, Nesselrodt A. Epidemiology, production losses, and control measures associated with an outbreak of avian influenza subtype H7N2 in Pennsylvania (1996-98). Avian Dis 2003, 47 (Suppl), 1022-1036 https://doi.org/10.1637/0005-2086-47.s3.1022
  6. Johnson DC, Maxfield BG, Moulthrop JI. Epidemiologic studies of the 1975 avian influenza outbreak in chickens in Alabama. Avian Dis 1977, 21, 167-177 https://doi.org/10.2307/1589337
  7. Lamb RA and Krug RM. Orthomyxoviridae: the viruses and their replication. In: Fields BN, Knipe DM, Howley PM, Chanock RM, Melnick JL, Momath TP, Roizman S (eds.). Fields Virology. 3rd ed. Lippincott-Raven, Philadelphia, PA, 1996
  8. Lee CW, Suarez DL, Tumpey TM, Sung HW, Kwon YK, Lee YJ, Choi JG, Joh SJ, Kim MC, Lee EK, Park JM, Lu X, Katz JM, Spackman E, Swayne DE, Kim JH. Characterization of highly pathogenic H5N1 avian influenza A viruses isolated from South Korea. J Virol 2005, 79, 3692-3702 https://doi.org/10.1128/JVI.79.6.3692-3702.2005
  9. McQuiston JH, Garber LP, Porter-Spalding BA, Hahn JW, Pierson FW, Wainwright SH, Senne DA, Brignole TJ, Akey BL, Holt TJ. Evaluation of risk factors for the spread of low pathogenicity H7N2 avian influenza virus among commercial poultry farms. J Am Vet Med Assoc 2005, 226, 767-772 https://doi.org/10.2460/javma.2005.226.767
  10. Ministry of Agriculture and Forestry (MAF). Standard operating procedure for control and eradication of avian influenza. p. 59, MAF, Seoul, 2004
  11. Mo IP, Brugh M, Fletcher OJ, Rowland GN, Swayne DE. Comparative pathology of chickens experimentally inoculated with avian influenza viruses of low and high pathogenicity. Avian Dis 1997, 41, 125-136 https://doi.org/10.2307/1592452
  12. Naeem K, Naurin M, Rashid S, Bano S. Seroprevalence of avian influenza virus and its relationship with increased mortality and decreased egg production. Avian Pathol 2003, 32, 285-289 https://doi.org/10.1080/1030794503100009788
  13. National Veterinary Research and Quarantine Service (NVRQS). Animal infectious disease data management system. NVRQS, Anyang, 2006
  14. Nili H, Asasi K. Natural cases and an experimental study of H9N2 avian influenza in commercial broiler chickens of Iran. Avian Pathol 2002, 31, 247-252 https://doi.org/10.1080/03079450220136567
  15. Office International des Epizooties (OIE). Chapter 2.7.12. Avian influenza. In: Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. 5th ed. OIE, Paris, 2005
  16. Office International des Epizooties (OIE). Chapter 3.8.9. Guidelines for the surveillance of avian influenza. In: Terrestrial Animal Health Code 2005. OIE, Paris, 2005
  17. Sims LD, Ellis TM, Liu KK, Dyrting K, Wong H, Peiris M, Guan Y, Shortridge KF. Avian influenza in Hong Kong 1997-2002. Avian Dis 2003, 47 (Suppl), 832-838
  18. Sung HW, Lee YJ, Choi JG, Lee YG, and Kim JH. Characterization of Korean avian influenza viruses and subtype-specific detection of AIV. In: Annual Report of National Veterinary Research and Quarantine Service, pp. 711-731, NVRQS, Anyang, 2004
  19. World Health Organization (WHO). WHO Manual on Animal Influenza Diagnosis and Surveillance. WHO, Geneva, 2002
  20. World Health Organization (WHO). WHO Guidelines for the Collection of Human Specimens for Laboratory Diagnosis of Avian Influenza Infection. WHO, Geneva, 2005
  21. Yoon H, Park CK, Nam HM, Wee SH. Virus spread pattern within infected chicken farms using regression model: the 2003-2004 HPAI epidemic in the Republic of Korea. J Vet Med B Infect Dis Vet Public Health 2005, 52, 428-431 https://doi.org/10.1111/j.1439-0450.2005.00891.x
  22. Ziegler AF, Davison S, Acland H, Eckroade RJ. Characteristics of H7N2 (Nonpathogenic) avian influenza virus infections in commercial layers, in Pennsylvania, 1997-98. Avian Dis 1999, 43, 142-149 https://doi.org/10.2307/1592774