Newcastle Disease in Local Chickens of Live Bird Markets and Households in Zamfara State, Nigeria

Newcastle disease constitutes a major constraint to rural poultry production system in Nigeria. This study used serological method to estimate the level of circulating antibodies against ND in nonvaccinated village chickens, raised under traditional management system in Zamfara State, Nigeria. Competitive Enzyme Linked Immunosorbent Assay was used to analyze 504 chicken sera for Newcastle disease virus antibodies from randomly selected households and live bird markets. Higher seroprevalence rate of Newcastle disease virus antibodies was detected in both household and live bird markets. Overall, seropositive rate was found to be 32.5% (164/504). About 35.8% (115/321) sero-positive rate was obtained from live bird markets while 26.8% (49/183) seropositive rate was found in households. Comparison was made between the sero prevalence of house hold and live bird markets as well as between sexes. Live bird markets show a statistically significant higher prevalence rate ( ) when compared with chickens sampled from households (OR 1.53; 95%？CI, 1.024–2.275). The prevalence of ND indicated the presence of the virus amongst the population, and hence there should be an improvement in the vaccine campaign against ND for rural poultry especially the use of thermostable vaccine to reduce the chances of vaccine failure. 1. Introduction Newcastle disease (ND) is a major viral disease of economic importance in poultry [1] and rated as one of the greatest constraints to the development of rural poultry production in Nigeria and in most developing countries, causing serious threats [2]. All ages of different species of birds are susceptible to ND, although being substantially less with advancement to maturity [3]. The acute and virulent form may result in 90% mortality or more in affected flocks [4]. It is an acute, rapidly spreading, contagious, nervous and respiratory disease of birds of all ages [5]. The clinical signs of ND are known to vary based on the virulence and tropism of the ND virus involved, species of the bird, age of the host, immune status, and environmental condition [6]. Nigeria poultry population is estimated to be 137.6 million, with backyard poultry population constituting 84% (115.8 million) and 16% (21.7 million) of exotic poultry, with a higher percentage of this poultry raised for subsistence production [7]. Village poultry production provides an important source of high quality protein, is reserved for times of celebrations, and is a good source of income for rural families [8]. This category of birds represents a significant part of the Nigerian