Background and Aim: Inappropriate use of antimicrobials exacerbates antimicrobial resistance (AMR) in the poultry sector. Information on factors driving AMR in the layer poultry sector is scarce in Zambia. This study examined the drivers of AMR in the layer poultry sector in the Lusaka and Copperbelt Provinces of Zambia. Materials and Methods: This cross-sectional study employed a structured questionnaire in 77 layer poultry farms in the provinces of Lusaka and Copperbelt, Zambia, from September 2020 to April 2021. Data analysis was conducted using Stata version 16.1. Antimicrobial resistance was defined as the presence of multidrug resistance (MDR) isolates. Multivariable regression analysis was used to identify drivers of AMR. Results: In total, 365 samples were collected, from which 339 (92.9%) Escherichia coli and 308 (84.4%) Enterococcus spp. were isolated. Multidrug resistance was identified in 39% of the E. coli and 86% of the Enterococcus spp. The overall prevalence of AMR in layer poultry farms was 51.7% (95% confidence interval [CI]: 40.3%–63.5%). Large-scale farmers (Adjusted odds ratio [AOR] = 0.20, 95% CI: 0.04%–0.99%) than small-scale and farmers who were aware of AMR than those who were unaware (AOR = 0.26, 95% CI: 0.08%–0.86%) were less likely to experience AMR problems. Conclusion: This study found a high prevalence of AMR in layer poultry farming linked to the type of farm management practices and lack of AMR awareness. Evidence of high MDR in our study is of public health concern and requires urgent attention. Educational interventions must increase AMR awareness, especially among small- and medium-scale poultry farmers. Keywords: antimicrobial resistance, drivers, Escherichia coli, poultry, risk factors, Zambia.

Background/Objectives: Antimicrobial Resistance (AMR) remains a growing public health threat, underscoring the need for robust surveillance of Antimicrobial Consumption (AMC) and Antimicrobial Use (AMU). This study analysed AMC and AMU trends in Zambia’s human and animal health sectors, identifying priority areas for antimicrobial stewardship (AMS) under a One Health framework. Methods: A retrospective study was conducted in February 2025, utilising data from 2018 to 2023. Sources of data included the Zambia Medicines Regulatory Authority (ZAMRA) and the WOAH Animal Antimicrobial Use (ANIMUSE) Global Database platform. AMC was analysed using the WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS) methodology. Antimicrobials were classified using the WHO Anatomical Therapeutic Chemical (ATC) system, and consumption was measured in Defined Daily Doses (DDDs) per 1000 inhabitants per day (DID). Antibiotics were further categorised using the WHO Access, Watch, and Reserve (AwaRe) classification. Data analysis was performed using IBM SPPS version 25.0. Results: In the human health sector, oral antibiotics accounted for 88% of total consumption. Penicillins (33%), cephalosporins (19.2%), and macrolides (12.4%) were the most consumed classes. In 2023, 98,651,882.42 DDDs per 1000 inhabitants/day were recorded, with amoxicillin, ceftriaxone, and sulfamethoxazole/trimethoprim leading as the most consumed antibiotics. According to the consumption of antibiotics by the WHO AwaRe classification, 47% were Access, 40% Watch, and 3% Reserve group antibiotics. In animal health, tetracyclines dominated (63%), followed by sulphonamides (26%) and penicillins (11%). AMU in animal health peaked in 2023. Conclusions: This study found high AMC and AMU, especially Watch-group antibiotics and tetracyclines, highlighting the need for strengthened antimicrobial stewardship, regulatory oversight, and integrated One Health surveillance to mitigate AMR risks in Zambia.

Background/Objectives: Antimicrobial resistance (AMR) is a major global health threat that undermines treatment in humans and animals. In Zambia, where livestock production underpins food security and livelihoods, AMR challenges are aggravated by limited surveillance, weak diagnostics, and poor regulatory enforcement, facilitating the spread of resistant pathogens across the human–animal–environment interface. This study aims to analyse AMR patterns of bacterial isolates collected from Zambia’s animal health sector between 2020 and 2024, to generate evidence that informs national AMR surveillance, supports antimicrobial stewardship (AMS) interventions, and strengthens One Health strategies to mitigate the spread of resistant pathogens. Methods: We conducted a retrospective descriptive analysis of previously collected routine laboratory data from five well-established animal health AMR surveillance sentinel sites between January 2020 and December 2024. Data were analysed by year, sample type, and antimicrobial susceptibility testing (AST) profiles using WHONET. Results: A total of 1688 samples were processed, with faecal samples accounting for 87.6%. Animal environmental samples (feed, manure, litter, abattoir/meat processing floor, wall, and equipment surface swabs) (collected from abattoirs, water, and farms) increased significantly over time (p = 0.027). Overall, Escherichia coli (E. coli) (50.4%) and Enterococcus spp. (30%) were the most frequently isolated bacteria. E. coli exhibited high resistance to tetracycline (74%) and ampicillin (72%) but remained susceptible to aztreonam (98%), nitrofurantoin (95%), and imipenem (93%). Enterococcus spp. were susceptible to penicillin (84%) and ampicillin (89%) but showed borderline resistance to vancomycin (53%) and linezolid (50%). Klebsiella spp. demonstrated resistance to ciprofloxacin (52%) and gentamicin (40%), whereas Salmonella spp. remained highly susceptible. Notably, resistance to amoxicillin/clavulanic acid rose sharply from 22.2% to 81.8% (p = 0.027). Across 1416 isolates, high levels of multidrug resistance (MDR) were observed, particularly in E. coli (48.4%) and K. pneumoniae (18.6%), with notable proportions progressing toward possible Extensively Drug-Resistant (XDR) and Pan-Drug-Resistant (PDR) states. Conclusions: The findings of this study reveal rising resistance to commonly used antibiotics in the animal health sector. Despite the lack of molecular analysis, our findings underscore the urgent need for AMS programs and integrated AMR surveillance under Zambia’s One Health strategy.

Antimicrobial resistance (AMR) among Escherichia coli from food animals is a rising problem, and heavy antimicrobial use in poultry is a contributing factor. In Zambia, studies linking poultry-associated AMR and antibiotic use (AMU) are rare. This study aimed to investigate commercial and medium-/small-scale poultry farmers’ usage of antimicrobials based on a questionnaire survey in ten districts of Zambia. In addition, the study characterized extended-spectrum β-lactamase (ESBL)-producing E. coli isolates obtained from poultry in the same districts. Data regarding knowledge and usage of antimicrobials were collected from commercial and medium-/small-scale poultry farmers using a pre-tested structured questionnaire. At the same time, cloacal samples were collected and analyzed. One hundred and fifty E. coli isolates were tested for antimicrobial susceptibility using eight antibiotic classes. The isolates were further screened for ESBL production by streaking them on cefotaxime (CTX)-supplemented MacConkey agar, then subjecting them to sequencing on a NextSeq. The questionnaire survey showed that more medium-/small-scale than commercial poultry farmers used antimicrobials (OR = 7.70, 95% CI = 2.88–20.61) but less prescriptions (OR = 0.02, 95% CI = 0.00–0.08). Susceptibility testing revealed that resistance was highest to ampicillin (128/148, 86.5%) and tetracycline (101/136, 74.3%) and that the prevalence of multidrug resistance (MDR) (28/30, 93.3%) was high. Whole-genome sequencing (WGS) of eight (8/30, 26.7%) isolates with CTX Minimum Inhibitory Concentration (MIC) ≥ 4 µg/mL revealed the presence of ESBL-encoding genes bla_CTX-M-14, bla_CTX-M-55, and bla_TEM. WGS also detected other AMR genes for quinolones, aminoglycosides, phenicols, tetracycline, macrolides, and folate-pathway antagonists. Altogether, the questionnaire survey results showed a higher proportion of AMU and lower prescription usage among medium-/small-scale farmers. In addition, our results emphasize the circulation of ESBL-producing E. coli strains with associated MDR. It is critical to educate farmers about AMR risks and to encourage responsible usage of antimicrobials. Furthermore, there is a need to strengthen regulations limiting access to antimicrobials. Finally, there is a need to establish a one health system to guide public health response.

Background: Zambia, like many low- and middle-income countries, faces a growing burden of antimicrobial resistance (AMR), driven by the misuse of antimicrobials in both human and animal health, a limited diagnostic capacity, and weak regulatory enforcement. To address this challenge, Standard Treatment Guidelines (STGs) were developed for the veterinary sector, which represents a major milestone in the country’s AMR containment strategy. STGs are evidence-based protocols that guide veterinary professionals in consistently and appropriately diagnosing and treating animal diseases. They promote the rational use of veterinary medicines, and can mitigate AMR and improve animal health outcomes. By translating the best evidence into best practices, STGs also provide a practical foundation for antimicrobial stewardship (AMS) programs. Until 2023, Zambia lacked nationally adopted STGs for the veterinary sector. The introduction and standardization of these guidelines are expected to promote prudent antimicrobial use and raise the standard of care delivered to animal patients across the country. Objective: The aim of this paper is to provide a practical reference for future revisions of STGs and outline the successful methodology used to create STGs in the Zambian animal sector. Methods: A situational analysis was conducted to identify priority animal health conditions and existing treatment gaps within the veterinary sector. A multidisciplinary expert committee was then formed, comprising veterinarians, veterinary paraprofessionals, academics, regulatory authorities, and private sector stakeholders, to lead the development of the STGs. The process was guided by the WHO methodology for developing treatment guidelines, including a comprehensive review of the clinical evidence, local disease patterns, antimicrobial resistance data, and existing treatment practices. Draft STGs were developed with clearly defined, species-specific treatment protocols tailored to the Zambian context. For the validation process, the AGREE II instrument was used to assess the quality, clarity, and applicability of the guidelines. Structured stakeholder consultations with practitioners, policy-makers, and technical experts were held to ensure that the guidelines were practical, evidence-based, and aligned with national priorities. The validated drafts were then disseminated and piloted in selected districts. Conclusions: The development of the species-specific STGs represents an essential turning point in the country’s efforts to promote responsible veterinary care and contain AMR. STGs have become a prominent key support in the delivery of quality animal care. Further, the guidelines will assist in the optimization of antimicrobial use in animal health in Zambia.

Background/Objectives: The right diagnostic tests, for the right patient, at the right time, are key to optimising antimicrobial use (AMU) and preventing antimicrobial resistance (AMR). This study evaluated diagnostic stewardship trends and AMR patterns in Zambian surveillance sentinel sites from 2020 to 2024. Methods: This descriptive, retrospective study analysed routine laboratory data from January 2020 to December 2024 at seven designated AMR surveillance sentinel sites across Zambia. Data on clinical specimens submitted for antimicrobial susceptibility testing were extracted from WHONET and analysed by year, specimen type, and antimicrobial susceptibility profile. Results: A total of 184,788 bacteriology specimens were processed over five years. Urine was the most frequently collected specimen, peaking above 20,000 in 2024. Escherichia coli was the most commonly isolated organism among 15 priority pathogens, comprising 25.9% of the 30,013 isolates. Though a statistically significant increasing trend in total organism isolations was observed annually, only Shigella sp. demonstrated a substantial increase in non-susceptibility to azithromycin (p = 0.027). High resistance was observed with doxycycline, azithromycin, clindamycin, trimethoprim/sulfamethoxazole, ciprofloxacin, and rifampicin, exhibiting resistance ranging from 50% to 80%. Critical AMR alerts included 65% for Vancomycin-Resistant Enterococcus (VRE), 72% for linezolid, and 44% for carbapenems, and possible ESBL-producing Enterobacterales showing the highest overall resistance at 35%, across sentinel sites. Conclusions: Zambia faces a concerning and significant increase in AMR, with high resistance prevalence across commonly used antibiotics. Critical resistance alerts for VRE, linezolid, carbapenems, and possible ESBL-producing Enterobacterales underscore an urgent need for robust antimicrobial stewardship and continuous diagnostic surveillance.