Phylogenetics and Pathogenesis of Early Avian Influenza Viruses (H5N1), Nigeria

Aiki-Raji CO, Aguilar PV, Kwon Y-K, Goetz S, Suare. Phylogenetics and Pathogenesis of Early Avian Influenza Viruses (H5N1), Nigeria. Emerg Infect Dis. 2008 Nov
submited by kickingbird at Nov, 2, 2008 9:5 AM from Emerg Infect Dis. 2008 Nov

Abstract
Three highly pathogenic avian influenza subtype H5N1 and 4 Newcastle disease viruses were isolated from sick or dead chickens in southwestern Nigeria. Sequencing and phylogenetic analysis placed them within H5N1 subclade 2.2.2. Intravenous and intranasal pathogenicity tests produced systemic disease with vascular endothelial cell tropism in chickens.

The first official report of avian influenza virus (H5N1) in Africa was made in January 2006 (1). Before then, surveillance was ongoing at the poultry clinic of the University of Ibadan Veterinary Teaching Hospital to identify causes of death in chickens in Nigeria.

The Study

Nasopharyngeal and cloacal swab samples were collected from sick and dead birds found on farms near Ibadan, Nigeria, and injected into 10-day-old embryonating chicken eggs. Retrospective analysis of isolates obtained in or near January 2006 identified influenza virus (H5N1) in 3 samples. In addition, 4 Newcastle disease virus isolates were obtained, which highlights the cocirculation of Newcastle disease virus and influenza viruses (H5N1) in Nigerian poultry and emphasizes the need for specific virologic testing to distinguish the clinically similar poultry diseases caused by these 2 pathogens.