Antimicrobial resistance in livestock and poor quality veterinary medicines

The annual market in Africa for substandard and non-registered veterinary medicine is estimated to be 400 million United States dollars,5 equal to that of the officially registered, quality-assured veterinary drug market.6 Numerous cases of antimicrobial resistance in humans have been traced to resistant microbes suspected of originating in livestock,7,8 which is particularly concerning as infected livestock can be asymptomatic.8 Transmission of resistant bacteria from livestock to humans can occur through the consumption of meat, direct contact with colonized animals or manure spread in the environment.7 The strongest correlation between interspecies pathogen transmission is observed in countries with policies to reduce agricultural antibiotic use. Poor-quality medicines that provide sub-therapeutic doses of active pharmaceutical ingredient, whether due to inadequate amounts of pharmaceutical, ineffective release, presence of impurities or degradation of compounds, are believed to contribute to antimicrobial resistance by exposing microbes to a level of antibiotic that will not effectively kill the whole microbial population.10 Poor-quality veterinary medicine as a contributor to antimicrobial resistance has been mentioned anecdotally in the literature, but systematic studies are lacking. Pharmaceutical quality is often assessed using high-performance liquid chromatography on field samples, an expensive, laboratory-based test that requires well-trained staff and a long waiting period for results.To sufficiently survey veterinary medicine quality in low- and middle-income countries, portable technologies that can provide quantitative information about the active pharmaceutical ingredient in an efficient and affordable manner are needed. The International Cooperation on Harmonization of Technical Requirements for Registration of Veterinary Medicinal Products programme develops global standards for veterinary medicine and helps countries establish drug registration protocols.15 The World Organization for Animal Health National Focal Point for Veterinary Products has established a network of global veterinary product experts, with each member nation represented by a local authority on veterinary health and medicine.16 Post-market identification Organizations concerned with antimicrobial resistance should work to raise awareness among government stakeholders in low- and middle-income countries about the issues surrounding poor-quality veterinary medicine, enco