Avian Influenza Vaccination of Poultry and Passive Case Reporting, Egypt

Timothée Vergne

, Vladimir Grosbois, Yilma Jobre, Ahmed Saad, Amira Abd El Nabi, Shereen Galal, Mohamed Kalifa, Soheir Abd El Kader, Gwenaëlle Dauphin, François Roger, Juan Lubroth, and Marisa Peyre

Author affiliations: Author affiliations: Centre International de Recherche en Agriculture pour le Développement, Montpellier, France (T. Vergne, V. Grosbois, F. Roger, M. Peyre); French Agency for Food, Environmental and Occupational Health and Safety, Maisons-Alfort, France (T. Vergne); Food and Agriculture Organization of the United Nations, Cairo, Egypt (Y. Jobre, A. Saad, A. Abd El Nabi); Central Laboratory for Veterinary Quality Control of Poultry Production, Giza, Egypt (S. Galal, M, Kalifa); General Organisation for Veterinary Services, Cairo (S. Abd El Kader); Food and Agriculture Organization of the United Nations, Rome, Italy (G. Dauphin, J. Lubroth)

Abstract

We investigated the influence of a mass poultry vaccination campaign on passive surveillance of highly pathogenic avian influenza subtype (H5N1) outbreaks among poultry in Egypt. Passive reporting dropped during the campaign, although probability of infection remained unchanged. Future poultry vaccination campaigns should consider this negative impact on reporting for adapting surveillance strategies.

Egypt reported its first occurrence of highly pathogenic avian influenza (HPAI) virus subtype H5N1 in poultry on February 16, 2006 (1), and its first case in a human on March 20, 2006. As of June 2011, Egypt was the country most affected by HPAI (H5N1) outside of Asia (2). Vaccination of domestic (backyard) and commercial poultry, which began in March 2006, and other measures were implemented to control the disease, but outbreaks among poultry and humans continued to be regularly reported from various districts located mainly in the delta region of the country (3). In July 2009, vaccination of domestic poultry was stopped (4). The objective of this study was to assess the effect of vaccination of domestic poultry on the passive reporting of HPAI (H5N1) cases among poultry. The completeness of the passive surveillance of poultry cases at the district level during and after the mass vaccination campaign was estimated by using a 4-source capture-recapture method (5).