Seroprevalence of Fowl Pox Antibody in Indigenous Chickens in Jos North and South Council Areas of Plateau State, Nigeria: Implication for Vector Vaccine

Fowl pox is a viral disease of domestic and wild birds. The large size of the genome makes it a useful vector for recombinant DNA technology. Although the disease has been described in both commercial and indigenous chickens in Nigeria, data are limited on seroprevalence in free range chickens. Such data are, however, important in the design and implementation of fowl pox virus vector vaccine. We surveyed current antibody status to fowl pox virus in free range chickens by testing 229 sera collected from 10 villages in Jos North and Jos South LGA of Plateau State Nigeria. Sera were analyzed by AGID against standard fowl pox antigen. Fifty-two of the 229 (23%) tested sera were positive for fowl pox virus antibody, and the log titre in all positive specimen was . Thirty (21%) and twenty-two (27%) of the samples from Jos South and Jos North, respectively, tested positive. This was, however, not statistically significant ( ). Generally the study showed a significant level of antibody to fowl pox virus in the study area. This observation may hinder effective use of fowl pox vectored viral vaccine. Fowl pox control is recommended to reduce natural burden of the disease. 1. Introduction Fowl pox is a viral disease caused by avipoxvirus belonging to the chordopoxvirinae subfamily of the poxviridae family, which induces pustular, benign, and proliferative lesions of the skin and diphtheritic lesions on the mucous membrane of the digestive and respiratory passages [1, 2]. The disease affects both domestic and free living birds in nature resulting in varying morbidity and mortality [3]. The diphtheritic form is usually more severe as it causes significant mortality and economic losses in affected flocks [4]. Although fowl pox is believed to be widespread in backyard and to some extent intensively reared poultry flocks in Nigeria [5], the epidemiologic details of the disease are not quite clear in free range indigenous chickens. While the virus is transmitted mechanically through wounds on the skin, biting insects such as mosquitoes and mites are also common vectors [6, 7]. Aerosols generated from infected birds or ingestion of contaminated food or water has also served as source of transmission [8], hence birds on free range may be clinically or subclinically infected and develop antibody to fowl pox virus through many of these ubiquitous exposure. The recent advance in vaccinology takes advantage of subunit of pathogens and delivery of multivaccine candidates [9]. The large size genome (200？kbp) of the fowl pox virus is used in recombinant DNA technology to insert