Zoonotic diseases of poultry: a threat to profitable poultry production. A review.

Zoonosis is defined as diseases and/or infections which are transmitted naturally between vertebrate animals and man (Gillian et al 2008; WHO 2010). Zoonotic diseases associated with poultry include; Avian influenza, Avian tuberculosis, Salmonellosis, Ornithosis, Cryptosporidiosis and Campylobacteriosis. Birds infected with these diseases may have diarrhoea and discoloured dropping, but some birds may show no symptom of disease. Free-range animals are more likely to carry these infections than those raised and housed in a laboratory setting. Zoonotic diseases are heterogeneous group of infections with varied epidemiology, clinical features and control measures. The causative organism may be viral, bacterial, fungal, protozoan parasites or unconventional agents (WHO 2010). Any disease or infection that is naturally transmissible from vertebrate animal to human and vice-versa is classified as zoonosis (Taria et a l 2004; WHO 2010). Over 200 zoonoses have been described and they have been known for centuries. Transmission may occur in number of settings, ranging from indirect contact through food or drinking water contaminated by microbes, ( e.g. campylobacteriosis and salmonellosis) or indirectly via vector such as mosquitoes or tick and contaminated inanimate objects, oral ingestion or inhalation of aerosolized materials to direct-contact through occupational exposure on farm, during leisure or from pet(s).