Ntombi B. Mudenda

Dr. Ntombi B. Mudenda

orcid

Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 November 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
SMSteward Mudenda
Steward Mudenda
JCJoseph Chizimu
Joseph Chizimu
VDVictor Daka
Victor Daka
MKMaisa Kasanga
Maisa Kasanga
WMWebrod Mufwambi
Webrod Mufwambi
RCRoma Chilengi
Roma Chilengi
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.

2 November 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
Taona SinyawaTaona Sinyawa
Taona Sinyawa
FGFusya Goma
Fusya Goma
CCChikwanda Chileshe
Chikwanda Chileshe
NMNtombi B. Mudenda
Ntombi B. Mudenda
Steward MudendaSteward Mudenda
Steward Mudenda
RCRoma Chilengi
Roma Chilengi
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.

1 November 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
CCChikwanda Chileshe
Chikwanda Chileshe
FGFusya Goma
Fusya Goma
NMNtombi B. Mudenda
Ntombi B. Mudenda
Steward MudendaSteward Mudenda
Steward Mudenda
Taona SinyawaTaona Sinyawa
Taona Sinyawa
RCRoma Chilengi
Roma Chilengi
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.

10 November 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
JCJoseph Chizimu
Joseph Chizimu
AKAubrey Chichonyi Kalungia
Aubrey Chichonyi Kalungia
Steward MudendaSteward Mudenda
Steward Mudenda
ZMZoran Miyanda Muhimba
Zoran Miyanda Muhimba
CLChileshe Lukwesa
Chileshe Lukwesa
RCRoma Chilengi
Roma Chilengi
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.

1 January 2026 in Access Microbiology
Verified
Journal Article
Open access
SNSitumbeko J. Nasilele
Situmbeko J. Nasilele
MSMisheck Shawa
Misheck Shawa
HKHarvey Kakoma Kamboyi
Harvey Kakoma Kamboyi
BPBruno Stephen July Phiri
Bruno Stephen July Phiri
TLTapiwa Lundu
Tapiwa Lundu
KMKaampwe Mayovu Muzandu
Kaampwe Mayovu Muzandu
Background. Carbapenem and third-generation cephalosporin (3GC) resistance among Gram-negative bacteria poses a serious threat to human and animal health. This study aimed to identify and characterize carbapenem- and 3GC-resistant Enterobacterales isolated from poultry in Lusaka Province, Zambia. Methods. Ninety pooled cloacal samples were collected from market-ready broiler chickens in the Chongwe and Chilanga districts of Lusaka Province. The isolates were screened for 3GC and carbapenem resistance using the disc diffusion and broth microdilution methods. PCR and Sanger sequencing were performed for species identification and detection of β-lactamase-encoding ( bla ) genes, including bla CTX-M , bla TEM , bla OXA-1 and bla SHV . Hierarchical clustering was used to assess phenotypic and genotypic relationships. Results. A total of 83 3GC-resistant Gram-negative isolates were recovered, of which 12% were also carbapenem resistant. Escherichia coli was the most prevalent species, followed by Klebsiella pneumoniae and Enterobacter spp., then Pseudomonas aeruginosa, other Pseudomonas spp., Acinetobacter baumannii , Citrobacter freundii and Aeromonas caviae . Multidrug resistance occurred in 84.3% of the isolates, with the highest resistance to ampicillin, tetracycline and co-trimoxazole. Overall, 80.7% of the isolates harboured at least one of the four tested bla genes, with bla CTX-M and bla TEM being the most common. Hierarchical clustering revealed that isolates from both districts shared similar phenotypic and genotypic resistance patterns. Conclusions. The presence of multidrug- and carbapenem-resistant Enterobacterales from poultry highlights the emergence of carbapenem resistance in Zambia’s food production sector. The detection of imipenem-resistant isolates indicates the potential for transmission of resistance genes between animals and humans. These findings underscore the need for prudent antimicrobial use, strengthened stewardship and a One Health surveillance approach to contain the spread of carbapenem resistance genes.

7 November 2025 in Antibiotics
Verified
Journal Article
Open access
PDF file
JCJoseph Chizimu
Joseph Chizimu
Steward MudendaSteward Mudenda
Steward Mudenda
VDVictor Daka
Victor Daka
WMWebrod Mufwambi
Webrod Mufwambi
ZMZoran Miyanda Muhimba
Zoran Miyanda Muhimba
RCRoma Chilengi
Roma Chilengi
Background/Objectives: Antimicrobial resistance (AMR) is a critical global health threat, with sub-Saharan Africa disproportionately affected. Antimicrobial stewardship (AMS) programs are essential in combating AMR; however, data on their implementation in resource-limited settings like Zambia remain scarce. This study assessed the post-implementation status of World Health Organization (WHO) AMS core elements in selected public hospitals in Zambia. Methods: A cross-sectional pre- and post-intervention survey was conducted in 11 public hospitals across Zambia’s 10 provinces. Baseline (pre-implementation) and 12-month follow-up (post-implementation) assessments were carried out using the WHO-adapted Periodic National and Healthcare Facility Assessment Tool. The six AMS core elements evaluated included leadership, accountability, AMS actions, education, monitoring, and feedback. Results: The average AMS program score increased from 59% at pre-implementation to 81% at post-implementation. Significant improvements were observed in education and training (+36%) and accountability (+31%). While leadership and monitoring also showed positive trends, gaps persisted in AMS actions (63%) and feedback/reporting mechanisms (68%). Drug and Therapeutics Committee (DTC) functionality improved by 23%, with 90% of facilities now holding regular DTC meetings. Implementation of AMS actions, such as ward rounds, rose from 0% to 73%. Challenges remained in clinical audit feedback, resource mobilization, and prescribing optimization. Variability across facilities highlighted differences in leadership, resources, and technical capacity. Conclusions: AMS implementation in Zambia improved substantially across key domains. However, sustained leadership, adequate financing, and continuous capacity-building are needed to address persistent gaps and ensure long-term success in mitigating AMR.