Antimicrobial Use Survey and Detection of ESBL-Escherichia coli in Commercial and Medium-/Small-Scale Poultry Farms in Selected Districts of Zambia.

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 ß-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 blaCTX-M-14, blaCTX-M-55, and blaTEM. 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.

Trends, patterns and relationship of antimicrobial use and resistance in bacterial isolates tested between 2015-2020 in a national referral hospital of Zambia.

Increased antimicrobial resistance (AMR) among bacteria underscores the need to strengthen AMR surveillance and promote data-based prescribing. To evaluate trends and associations between antimicrobial usage (AMU) and AMR, we explored a dataset of 34,672 bacterial isolates collected between 2015 and 2020 from clinical samples at the University Teaching Hospital (UTH) in Lusaka, Zambia. The most frequently isolated species were Escherichia coli (4,986/34,672; 14.4%), Staphylococcus aureus (3,941/34,672; 11.4%), and Klebsiella pneumoniae (3,796/34,672; 10.9%). Of the 16 drugs (eight classes) tested, only amikacin and imipenem showed good (> 50%) antimicrobial activity against both E. coli and K. pneumoniae, while nitrofurantoin was effective only in E. coli. Furthermore, 38.8% (1,934/4,980) of E. coli and 52.4% (2,079/3,791) of K. pneumoniae isolates displayed multidrug resistance (MDR) patterns on antimicrobial susceptibility tests. Among S. aureus isolates, 44.6% (973/2,181) were classified as methicillin-resistant (MRSA). Notably, all the MRSA exhibited MDR patterns. The annual hospital AMR rates varied over time, while there was a weak positive relationship (r = 0.38, 95% CI = 0.11-0.60) between the monthly use of third-generation cephalosporins (3GCs) and 3GC resistance among Enterobacterales. Overall, the results revealed high AMR rates that fluctuated over time, with a weak positive relationship between 3GC use and resistance. To our knowledge, this is the first report to evaluate the association between AMU and AMR in Zambia. Our results highlight the need to strengthen antimicrobial stewardship programs and optimize AMU in hospital settings.

Prevalence and predictors of virological failure in pediatric patients on HAART in sub-Saharan Africa: a systematic review and meta-analysis.

Antiretroviral treatment failure has emerged as a challenge in the management of pediatric human immunodeficiency virus (HIV) patients, especially in resource-limited countries despite accessibility to Highly Active Antiretroviral Therapy (HAART). A systematic review and meta-analysis was conducted to synthesize virological failure (VF) prevalence and ascertain its predictors in children in sub-Saharan Africa. An electronic database search strategy was conducted from January to September 2021 on PubMed, EMBASE, SCOPUS, HINARI, and CINAHL. Further, manual searching was conducted on non-indexed journals. Utilizing the JASP© version 0.17.2 (2023) statistical software, a meta-analysis of pooled prevalence of VF was estimated using the standardized mean differences. Further, selection models were used to assess the risk of bias and heterogeneity. The pooled odds ratios were estimated for the respective studies reporting on predictors of VF. The overall pooled estimate of the prevalence of VF in sub-Saharan Africa among the sampled population was 29% (95% CI: 27.0-32.0; p<0.001). Predictors of VF were drug resistance (OR: 1.68; 95% CI: 0.88-2.49; p < 0.001), poor adherence (OR: 5.35; 95% CI: 5.26-5.45; p < 0.001), nevirapine (NVP)-based regimen (OR: 5.11; 95% CI: 4.66-5.56; p < 0.001), non-usage of cotrimoxazole prophylaxis (OR: 4.30; 95% CI: 4.13-4.47; p < 0.001), higher viral load at the initiation of antiretroviral therapy (ART) (OR: 244.32; 95% CI: 244.2-244.47; p <0.001), exposure to the prevention of mother to child transmission (PMTCT) (OR: 8.02; 95%CI: 7.58-8.46; p < 0.001), increased age/older age (OR: 3.37; 95% CI: 2.70-4.04; p < 0.001), advanced World Health Organization (WHO) stage (OR: 6.57; 95% CI: 6.17-6.98; p < 0.001), not having both parents as primary caregivers (OR: 3.01; 95% CI: 2.50-3.53; p < 0.001), and tuberclosis (TB) treatment (OR: 4.22; 95% CI: 3.68-4.76; p <0.001). The mean VF prevalence documented is at variance with studies in other developing countries outside the sub-Saharan region. The high prevalence of HIV cases contrasting with the limited expertise in the management of pediatric ART patients could explain this variance.

Genomic Analysis of Mycobacterium tuberculosis Strains Resistant to Second-Line Anti-Tuberculosis Drugs in Lusaka, Zambia.

The emergence of pre-extensively drug-resistant tuberculosis (pre-XDR-TB) is a threat to TB control programs in developing countries such as Zambia. Studies in Zambia have applied molecular techniques to understand drug-resistance-associated mutations, circulating lineages and transmission patterns of multi-drug-resistant (MDR) Mycobacterium tuberculosis. However, none has reported genotypes and mutations associated with pre-XDR TB. This study characterized 63 drug-resistant M. tuberculosis strains from the University Teaching Hospital between 2018 and 2019 using targeted gene sequencing and conveniently selected 50 strains for whole genome sequencing. Sixty strains had resistance mutations associated to MDR, one polyresistant, and two rifampicin resistant. Among MDR strains, seven percent (4/60) had mutations associated with pre-XDR-TB. While four, one and nine strains had mutations associated with ethionamide, para-amino-salicylic acid and streptomycin resistances, respectively. All 50 strains belonged to lineage 4 with the predominant sub-lineage 4.3.4.2.1 (38%). Three of four pre-XDR strains belonged to sub-lineage 4.3.4.2.1. Sub-lineage 4.3.4.2.1 strains were less clustered when compared to sub-lineages L4.9.1 and L4.3.4.1 based on single nucleotide polymorphism differences. The finding that resistances to second-line drugs have emerged among MDR-TB is a threat to TB control. Hence, the study recommends a strengthened routine drug susceptibility testing for second-line TB drugs to stop the progression of pre-XDR to XDR-TB and improve patient treatment outcomes.

Perspectives on factors influencing transmission of COVID-19 in Zambia: a qualitative study of health workers and community members.

OBJECTIVE: To explore the health professionals' and community members' perspectives on the factors influencing transmission of the novel COVID-19 in Zambia. DESIGN: An exploratory qualitative study using in-depth interviews as data collection technique. SETTING: Four primary healthcare facilities and local communities of Lusaka city and Chirundu international border town under Lusaka province, Zambia. PARTICIPANTS: Purposive sampling of 60 study participants comprising health professionals (n=15) and community members (n=45). Health staff were health inspectors and surveillance officers. Community members included public market traders, civic and religious leaders, immigration officers, bus and international truck drivers. RESULTS: Both health professionals and community members were aware of the COVID-19 pandemic, the preventive and control measures. Nevertheless, stark differences were observed on the two groups' perspectives on COVID-19 and the factors influencing its transmission. Most health staff expressed high personal risk and susceptibility to the disease and a positive attitude towards the prevention and control measures. Conversely, myths and misconceptions influenced most community members' perspectives on the disease and their attitude towards the COVID-19 guidelines. Participants were unanimous on the low levels of adherence to the COVID-19 preventive and control measures in the community. Reasons for non-adherence included limited information on COVID-19, negative attitude towards COVID-19 guidelines, social movement and travel patterns, networks and interactions, living and work conditions, water and sanitation facilities, and observation of behaviours of important role models such as politicians and other community leaders. These factors were perceived to increase the risk of COVID-19 transmission. CONCLUSION: These findings highlight important factors influencing transmission of COVID-19 in Zambia. Future interventions should focus on providing information to mitigate myths and misconceptions, increasing people's risk perception to the disease, and improving attitude towards the prevention and control interventions and mitigating structural and socioeconomic barriers.

Clonal relationship between multidrug-resistant Escherichia coli ST69 from poultry and humans in Lusaka, Zambia.

Multidrug-resistant (MDR) Escherichia coli in food animals such as chickens is an emerging public health concern in Zambia. Additionally, the country's high demand for poultry products necessitates further investigation into the link between poultry and human MDR E. coli. Twenty cefotaxime-resistant E. coli isolates collected from poultry in Lusaka, Zambia, were screened for multidrug resistance and sequenced on MiSeq and MinION platforms. Genomes were assembled de novo and compared with 36 previously reported cefotaxime-resistant E. coli isolates from inpatients at the University Teaching Hospital, Lusaka. All (20/20, 100%) poultry isolates exhibited resistance to ampicillin, chloramphenicol and doxycycline. Phylogenetic analysis and hierarchical clustering showed a high degree of genetic relatedness between E. coli O17:H18-ST69 from poultry and humans. The E. coli O17:H18-ST69 clone accounted for 4/20 (20%) poultry- and 9/36 (25%) human-associated isolates that shared two plasmids harboring 14 antimicrobial resistance (AMR) genes. However, comparison analysis showed that the isolates also had other AMR plasmids distinct for each niche. Our results suggested clonal transmission of MDR E. coli between poultry and humans, with the potential acquisition of niche-specific AMR plasmids. Thus, the control of MDR E. coli requires a One Health approach involving both human and animal health sectors.

Risk mapping and eco-anthropogenic assessment of anthrax in the upper Zambezi basin.

In Zambia, anthrax has emerged as a serious disease decimating humans, livestock and wildlife with devastating effects on eco-tourism resulting in the destabilization of major pristine wildlife sanctuaries. Consequently, the thrust of this study was to establish the spatial distribution of anthrax and determine ecological drivers of its recurrence, maintenance and epidemiological linkage to anthropogenic activities. Environmental and biological samples were collected within the livestock production and conservation areas (n = 80). Each sample was serially tested for Bacillus anthracis positivity through blood agar culture and Gram stain technique, and then confirmation by multiplex polymerase chain reaction (MPCR). Questionnaires (n = 113) were conducted at independently distinct villages in terms of space and time. Most respondents showed that animals that died from anthrax were not properly disposed off. More likely than not, poverty being the main driver for anthrax carcass dressing and meat distribution contributed to environmental contamination with anthrax spores in areas where the animals subsequently died resulting in further environmental contamination, which is the major source of primary infection for livestock and wildlife. From the samples, 15 pure isolates of anthrax were obtained which were spatially distributed across four districts. Twelve, biologically plausible variables were found to be highly significant on multivariable logistic regression analysis model for questionnaires which included herd size (odds = 10.46; P = 0.005; CI 8.8-16), carcass disposal method (odds = 6.9; P = 0.001; CI = 3.4-9.8), access to veterinary services (odds = 10.87; P = 0.004; CI = 4.8-15.9) and management system (odds = 2.57; P = 0.001; CI = 1.3-7.5). In summary, the majority (78.7%) of anthrax outbreaks were observed in areas with low veterinary services (χ2  = 8.6162, P = 0.013) within the newly created districts of Nalolo, Mwandi and Luampa.