Risk factors for the occurrence and spread of Highly Pathogenic Avian Influenza H5N1 in commercial poultry farms in Kano, Nigeria

Abstract

Outbreaks of Highly Pathogenic Avian Influenza (HPAI) subtype H5N1 occurred previously for three consecutive years, 2006, 2007 and 2008 in Kano State, Nigeria, causing heavy economic losses to farmers and the government. It was against this background that risk factors for the occurrence and spread of HPAI H5N1 among commercial poultry farms in the State were evaluated. A total of 64 farms comprising 32 affected (AF) and 32 non-affected (NAF) farms were enrolled for this study. Questionnaires were designed and administered to the selected farms through interviews with farm owners or farm managers during on-site visits. Information on flock profile including farm characteristics and environment, husbandry practices, biosecurity practices, farm trade practices and employee activities were obtained and analyzed. Pearson Chi square and Fisher's exact tests were used to compare categorical variables. Values of p< 0.05 were considered significant. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to measure the strength and statistical significance of associations between the variables and occurrence and spread of HPAI H5N1 in commercial poultry farms in the State. The most significant risk factors were the presence of untreated surface water on farms (OR 18.6, 95%CI 2.24-154.34, p = 0.001), exchange of egg crates between traders and farmers (OR 12.1, 95%CI 1.43-102.61, p = 0.006), allowing egg crates of traders into poultry pens (OR 11.67, 95%CI 2.37-57.86, p = 0.001) and allowing rodents/wild birds access to poultry feed (OR 3.65, 95%CI 0.23-1.87, p = 0.024). It was recommended that veterinary inspection to enforce and encourage best biosecurity practices for the poultry farms should be introduced and sustained.

Assessment of biosecurity measures against Newcastle disease in commercial poultry farms in Benue state, Nigeria

“…The study revealed that contrary to reports from other states in Nigeria such as Abuja, Plateau and Kano states, poultry farms in Benue state were not concentrated in a particular area but are dispersed which might be due to difference in town planning policy with no designated farm areas in Benue state unlike Kano and Abuja where particular areas are designated for farms (Wakawa, 2012;Balami et al, 2014). Hence the risk of spread of ND and other avian diseases between farms due to close proximity will be reduced and the practice of poor biosecurity by a farm is less likely to endanger the investment of a neighboring farm.…”

“…The risk of local poultry in introducing NDV to commercial poultry is further supported by previous study indicating that local poultry flocks maintains the NDV in circulation and act as reservoirs and carriers (Assam et al, 2011;Lawal et al, 2016). This study also revealed that some poultry farms have in their vicinity ponds and dams a converging point for wild water fowls, ducks and other migratory birds which have been identified as reservoirs of ND virus which may also increases the risks of NDV introduction and maintenance (Echeonwu et al, 1993;Oladele et al, 2012;Wakawa et al, 2012). Some of the poultry farms have dense vegetation within the farms and also abandoned materials near poultry houses.…”

“…This highlights poor hygiene and sanitation practices of commercial poultry farmers in the study area. Bushy surroundings around poultry farms would allow breeding of insects and rodents which will attract wild birds and reptiles likely to introduce NDV into the farm (Wakawa et al, 2012). These rodents and wild birds may have access to poultry feed and might contaminate the feed and litter with their excrement containing infectious diseases agents (Cardona & Kuney, 2002).…”

“…Biosecurity level in commercial poultry production systems is minimal or in some cases nonexisting and this may lead to the spread of multiple infections within and between farms (Permin, 1997). Previous studies in Kogi and Kano states, Nigeria revealed that farmers' practices such as keeping of multi-aged and multi-species poultry on the same farm, improper disposal of dead poultry and contaminated litter, poor farm traffic control and sanitation were identified as major biosecurity risks in commercial poultry farms (Ameji et al, 2012;Wakawa, 2012). However, no work has been conducted to assess the biosecurity of poultry farms in Benue state, Nigeria from available literature.…”

Awareness and mitigation measures on highly pathogenic avian influenza in pastoral poultry flocks of North‐central Nigeria: any challenging gap?

“…There are published reports on HPAI H5N1 in commercial and village chickens (Thomas et al 2005;Wakawa et al 2012;Musa et al 2013;Alders et al 2014), but there is paucity of such information on avian influenza in pastoral bird flocks, which often scavenge and are potentially exposed to avian influenza virus infections. To the best of our knowledge, this study was the first to investigate knowledge/awareness of and biosecurity measures for HPAI H5N1 in pastoral poultry flocks.…”