Prevalence and Risk Factors for Campylobacter Infection of Chicken in Peri-Urban Areas of Nairobi, Kenya

Campylobacter species are the most common cause of bacterial food borne disease affecting humans in both developed and developing countries [1]. It is estimated that 400 to 500 million cases of Campylobacter enteritis occur annually around the world [2]. Endocarditis, reactive arthritis, hemolytic uremic syndrome and septicemia are the complications that are occasionally seen [2,3]. Rare complications such as meningitis, acute cholecystitis and Guillain Barré syndrome have been reported [3,4] Human infections are mainly caused by Campylobacter jejuni and Campylobacter coli and rarely Campylobacter lari [5]. There are many possible sources of campylobacter infection in humans including contaminated poultry meat [6], untreated raw milk [7] and contaminated water [8-10]. The bacteria in the gastrointestinal tract of chicken and cattle can contaminate the carcass during slaughter and subsequently be transmitted to humans [2]. Milk can be contaminated with campylobacter in cattle faeces during milking, while water gets contaminated with chicken or cattle feaces from the environment. The main risk factor for human infection is consumption of raw or undercooked poultry meat contaminated with pathogenic campylobacter species [11]. Campylobacter species are carried in the intestinal tracts of birds and mammals which shed them in large numbers to contaminate the environment including water sources [12]. Poultry meat is the most commonly incriminated cause of food borne campylobacter infections occurring in humans in many parts of the world [2] with fresh chicken as the main risk factor [13]. Avian species especially domestic chickens are frequently infected primarily with Campylobacter jejuni and Campylobacter coli during rearing [1,14]. Campylobacter invade chicken early in life through contaminated drinking water [15,16], unhygienic chicken house environment [17], wild birds, flies and rodents [18]. Risk factors that have been associated with Campylobacter colonization of chickens include season of the year [19], several poultry houses and presence of other animals in the farm [15]. Contaminated drinking water, administration of antibiotics [15,20], poor hygiene [19,21,22], old age of the flock and that of houses at the farm [22] have also been incriminated as risk factors for the infection.