Antimicrobial Use and Veterinary Care among Agro-Pastoralists in Northern Tanzania

Abstract

Frequent and unregulated use of antimicrobials (AM) in livestock requires public health attention as a likely selection pressure for resistant bacteria. Studies among small-holders, who own a large percentage of the world’s livestock, are vital for understanding how practices involving AM use might influence resistance. We present a cultural-ecological mixed-methods analysis to explore sectors of veterinary care, loosely regulated AM use, and human exposure to AMs through meat and milk consumption across three rural to peri-urban Tanzanian ethnic groups (N = 415 households). Reported use of self-administered AMs varied by ethnic group (Maasai: 74%, Arusha: 21%, Chagga: 1%) as did consultation with professional veterinarians (Maasai: 36%, Arusha: 45%, Chagga: 96%) and observation of withdrawal of meat and milk from consumption during and following AM treatment (Maasai: 7%, Arusha: 72%, Chagga: 96%). The antibiotic oxytetracycline was by far the most common AM in this sample. Within ethnic groups, herd composition differences, particularly size of small-stock and cattle herds, were most strongly associated with differences in lay AM use. Among the Arusha, proxies for urbanization, including owning transportation and reliance on “zero-grazing” herds had the strongest positive associations with veterinarian consultation, while distance to urban centers was negatively associated. For Maasai, consultation was negatively associated with use of traditional healers or veterinary drug-shops. Observation of withdrawal was most strongly associated with owning technology among Maasai while Arusha observance displayed seasonal differences. This “One-Health” analysis suggests that livelihood and cultural niche factors, through their association with practices in smallholder populations, provide insight into the selection pressures that may contribute to the evolution and dissemination of antimicrobial resistance.

Towards a bottom-up understanding of antimicrobial use and resistance on the farm: A knowledge, attitudes, and practices survey across livestock systems in five African countries

“…High levels of engagement in the “informal veterinary sector” – characterized by “lay” diagnoses and treatment, limited input from trained health professionals, and the practicing of other non-prudent practices (e.g., use of nonprescribed antimicrobials, nonadherence to withdrawal periods)– are consistent with findings from other studies conducted in the project countries including among Maasai pastoralists in Tanzania and Kenya [26,30,42,43], cattle keepers in Eastern Province, Zambia [44] and poultry farmers in Ghana, Kenya, Tanzania, Zambia, and Zimbabwe [26–35] (see Table S17 for a more details of these studies). Collectively, these results further confirm the negative impacts of the Structural Adjustment Policies that relegated the public veterinary services in many African countries to policy and regulation functions [45].…”

“…Unfortunately, within most LMICs, there is currently little information on AMU practices and motivating factors in livestock systems [2,19,25]. Available studies generally find that farmers administer antimicrobials themselves, mostly without prescriptions or using input from animal health professionals, and often engage in other non-prudent practices, such as not observing withdrawal periods [26–35]. However, there has not been a comprehensive study of the knowledge, attitudes, and practices (KAP) associated with AMU or AMR to identify the factors associated with observance of prudent or non-prudent AMU practices.…”

Antimicrobial use and resistance in food-producing animals and the environment: an African perspective

“…Although AMR is a global threat [13], the situation in Africa is compounded by a number of factors that include lack of access to appropriate antimicrobial therapy, weak of regulation in the use of antimicrobials for human and animal, weak surveillance systems, lack of updated antimicrobial use and treatment guidelines. Others are lack of continuing education on antimicrobial use (AMU) for prescribers, tendency for animal owners to stock drugs and engaging unskilled people to treat animals, high degree of drugs abuse by livestock keepers and unregulated disposal of waste in dumps [14][15][16][17].…”

Industrialization is associated with elevated rates of horizontal gene transfer in the human microbiome

“…The Datoga are pastoralists, raising primarily cattle, and consuming high levels of meat and dairy products from their animals. Like other pastoral farmers in northern Tanzania, they administer antibiotics to their herds 25,26 . Our results suggest that these recent agricultural practices rapidly altered the fitness landscape in the guts of Datoga people and have already impacted the patterns of gene transfers within their microbiomes.…”