Assessing Enrofloxacin use practices and residue levels of Enrofloxacin/Ciprofloxacin in breast and liver tissues of broiler chicken sold in selected markets in Kampala Capital City-Uganda

Abstract

Human exposure to veterinary drugs like fluoroquinolones occurs due to the presence of their residues in foods from animal sources in varying concentrations. The existence of antibiotics residues in foodstuff can pose great public health problems to consumers. To limit the risks from such exposure, Maximum Residue Levels (MRLs) for specific drugs have been set by various continental regulatory bodies. Withdrawal time (WDT) allows tissue concentrations of the drugs to reduce to levels below the drug’s MRL but these are largely not adhered to by farmers. The purpose of this study was to assess enrofloxacin use patterns and assess residue levels of enrofloxacin/ciprofloxacin in breast muscle and liver tissues of broiler chickens sold for consumption in Kampala capital city. A total of 68 chicken breast tissues and liver tissues samples were collected from main markets over one month. Analysis was performed using HPLC coupled with a UV detector. For the enrofloxacin use patterns sub-study, 34 broiler farmers and 10 veterinary drug vendors were interviewed using a questionnaire. From the field survey, the most used antibiotics for the management of poultry diseases were enrofloxacin (100%), oxytetracycline (80%), and amprolium (30%). Enrofloxacin was prescribed majorly for the management of respiratory diseases (100%), and salmonella infections (40%), but also for disease prevention (60%). On average every week, over 15 farmers procured or got prescriptions of enrofloxacin to treat their chicken. The most used brands of enrofloxacin were Enrosol-s® (61.8%), Enrovet® (17.6%), and Enroveto-20® (14.7%). Most of the farmers interviewed had completed secondary and tertiary levels of education (76.5%). The veterinary drugs vendors included; one veterinary extension officer, 5 veterinary assistants, and 4 veterinary surgeons. Enrofloxacin/ciprofloxacin residues were identified in 35.3% (12/34) of the muscle and 38.2% (13/34) of the liver tissues analyzed. Furthermore, of those samples of muscle and liver that tested positive for enrofloxacin/ciprofloxacin, 25% (3/12) and 38.5% (5/13) respectively had drug concentrations higher than the recommended MRLs. The overall mean concentration of enrofloxacin/ciprofloxacin in the broiler chicken muscle and liver tissues was found to be 83.6 (±34.5) µg/kg and 171.5 (±75.9) µg/kg. More so, although over 76% of the farmers knew the WDT for enrofloxacin, none of them adhered to this. This could be attributed to the fact that the veterinary drug vendors do not always emphasize the importance of WDT. In this study, over 70% of the farmers reported that the veterinary drug vendors were not giving them WDT information.