Assessment of oxytetracycline residue levels in beef consumed in Dodoma Municipality catchment area,Tanzania

Abstract

Background: Worldwide, antimicrobials are widely used in food producing animals for treatment and/or prophylaxis of various bacterial infections because of continued high disease burdens as a result of poor animal health service delivery systems. For instance, in Tanzania, indiscriminate and irrational administration of antimicrobials, notably oxytetracycline (OTC) is not uncommon in rural areas because of under-developed animal health service delivery structure. The administration of OTC and other drugs is often done by animal keepers, without proper guidance of extension agents, thereby potentially leading to drug residues in meat and milk due to non-adherence to drug wash out periods. Despite this potential public health threat, to date there is no data about the extent of drug residue levels in beef consumed in places like Dodoma municipality where meat consumption is high. Objectives:The main objective was to establish the level of oxytetracycline residue levels in beef consumed within Dodoma Municipality catchment area. Methodolgoy:This was a cross-sectional study for which data on the knowledge, concerns and practices of animal keepers, traders, people involved in slaughtering animals and consumers was gathered using a semi-structured questionnaire. Quantification of drug residues in muscle, liver and kidney samples were collected and used in determining OTC levels using HPLC method. The quantitative data were analysed by Benferron’s and Student-Newman Keuls’ tests using Stata software version 13 for comparison of the residues between licensed and unlicensed premises and qualitative data were entered into Nvivo matrix for thematic analysis. Results:The outcomes of the study were: (1) The level of OTC residues were 0.6 mg/Kg, 0.25 mg/Kg and 1.28 mg/Kg for muscle, liver and kidney tissues respectively. These levels are unacceptably high when compared to Maximum Residue Limit (MRL) of 0.2mg/Kg, 0.6mg/Kg and 1.2mg/Kg for muscle, liver and kidney respectively as set by Codex Alimentarius Commission (CAC). The quantities of OTC residues in samples from licensed and unlicensed food vending settings were not significantly different (p = 0.3676). Regardless of the licensure status and source of the sample, 53% of muscle, 65% of liver and 7.1% of kidney tissues had residue amounts which were above MRL. (2) Level of knowledge, concerns and practices of animal keepers, consumers and extension agents in relation to drug withdrawal requirements were assessed. Most of animal keepers interviewed were ignorant of drug residues and withdrawal periods. The majority of consumers were not aware of the drug residues in beef whereas the businessmen and law enforcers were aware. Conclusion: The above results show how unacceptably high levels of drug residues have been introduced into the food chain and most of the consumers and farmers being ignorant of the impending public health threat of drug residues. The obtained results will be used in developing appropriate public health strategies in addressing drug residues which are now regarded as a global health threats and that must be tackled through a one health approach. It is envisaged that raising the awareness of beef value chain actors will be pivotal in reversing these negative trends.