• Antibiogram Development in the Setting of a High Frequency of Multi-Drug Resistant Organisms at University Teaching Hospital, Lusaka, Zambia

      Roth, Brenna M; Laps, Alexandra; Yamba, Kaunda; Heil, Emily L; Johnson, J Kristie; Stafford, Kristen; Hachaambwa, Lottie M; Kalumbi, Mox; Mulenga, Lloyd; Patel, Devang M; et al. (MDPI AG, 2021-06-28)
      Antimicrobial resistance is a global challenge requiring reliable surveillance data collection and use. Prior studies on resistance in Zambia depended on laboratory methods with limited standardization. Since 2015, the University Teaching Hospital (UTH) microbiology laboratory has used the Vitek 2 Compact (bioMerieux, Inc., Marcy-l'Étoile, France) for standardized identification and susceptibility testing. We conducted a cross-sectional study of 2019 bacterial isolates collected from July 2015 to April 2017 to identify bacterial causes of infections, their susceptibility to commonly used antibiotics at UTH, and develop hospital antibiograms with a multidisciplinary team using World Health Organization guidance. We found high levels of antibiotic resistance among Gram negative bacteria. Escherichia coli and Klebsiella pneumoniae were highly resistant to all antibiotics except amikacin and carbapenems. E. coli had susceptibilities of 42.4% to amoxicillin/clavulanic acid, 41.4% to ceftriaxone, 40.2% to ciprofloxacin, and 10.4% to trimethoprim/sulfamethoxazole (TMP/SMX). K. pneumoniae had susceptibilities of 20.7% to amoxicillin/clavulanic acid, 15.6% to ceftriaxone, 48.5% to ciprofloxacin, and 12.3% to TMP/SMX. The high resistance to 3rd generation cephalosporins indicates high rates of beta-lactamase production. This is information that clinicians need to inform clinical decision making and choice of empiric antibiotics and that UTH requires to inform antimicrobial stewardship such as improvements in antibiotic use.
    • Antimicrobial usage at a large teaching hospital in Lusaka, Zambia

      Callahan, P.; Herbert, A.; Hachaambwa, L. (Public Library of Science, 2020)
      Antimicrobial resistance is a growing global health concern. Antimicrobial stewardship (AMS) curbs resistance rates by encouraging rational antimicrobial use. However, data on antimicrobial stewardship in developing countries is scarce. The objective of this study was to characterize antimicrobial use at the University Teaching Hospital (UTH) in Lusaka, Zambia as a guiding step in the development of an AMS program. This was a cross-sectional, observational study evaluating antimicrobial appropriateness and consumption in non-critically ill adult medicine patients admitted to UTH. Appropriateness was defined as a composite measure based upon daily chart review. Sixty percent (88/146) of all adult patients admitted to the general wards had at least one antimicrobial ordered and were included in this study. The most commonly treated infectious diseases were tuberculosis, pneumonia, and septicemia. Treatment of drug sensitive tuberculosis is standardized in a four-drug combination pill of rifampicin, isoniazid, pyrazinamide and ethambutol, therefore appropriateness of therapy was not further evaluated. The most common antimicrobials ordered were cefotaxime (n = 45), ceftriaxone (n = 28), and metronidazole (n = 14). Overall, 67% of antimicrobial orders were inappropriately prescribed to some extent, largely driven by incorrect dose or frequency in patients with renal dysfunction. Antimicrobial prescribing among hospitalized patients at UTH is common and there is room for optimization of a majority of antimicrobial orders. Availability of certain antimicrobials must be taken into consideration during AMS program development.
    • Carbapenem resistance in Pseudomonas aeruginosa and Acinetobacter species at a large tertiary referral hospital in Lusaka, Zambia

      Kaluba, Ciluvya Kavimba; Samutela, Mulemba Tillika; Kapesa, Christine; Muma, John Bwalya; Hang'ombe, Bernard Mudenda; Hachaambwa, Lottie; Mukomena, Patrice; Yamba, Kaunda (2021-07-28)
      Background: Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter species and are among the leading causes of hospital-acquired infections (HAI). Treating patients with HAI caused by these pathogens is usually a challenge due to intrinsic and acquired resistance to the commonly used and affordable antibiotics, which has been heightened by the emergence of metallo-β lactamases thereby exhibiting resistance to carbapenems. Currently, carbapenem resistance represents an increasing problem in the health care settings globally but there is still a paucity of data on carbapenem resistance in our setting. Objective: To detect carbapenem resistance and the susceptibility to other antimicrobial agents in P. aeruginosa and Acinetobacter species isolated from blood, sputum, skin and soft tissue specimens between March, 2018 and June, 2019 at the University Teaching Hospital (UTH), Lusaka, Zambia. Method: This was a retrospective hospital based study, involving routine blood, sputum, skin and soft tissue samples submitted to the microbiology laboratory. Conventional microbiology methods were used to identify the organisms, while Kirby-Bauer disc diffusion method was used to determine the antimicrobial susceptibility profiles of the isolates. In order to detect carbapenemase production in P. aeruginosa isolates that were resistant to imipenem by disc diffusion, the isolates were subjected to the modified carbapenem inactivation method (mCIM) method. Results: A total of 384 samples were analyzed, of which 84 P. aeruginosa and 11 Acinetobacter species were isolated. The P. aeruginosa isolates were susceptible to imipenem (94%), piperacillin-tazobactum (95.2%), amikacin (91%), ciprofloxacin (69%), gentamicin (63.1%) and ceftazidime (51.2%). The Acinetobacter species isolates were most susceptible to amikacin (90.9%), imipenem (82.9%) and piperacillin-tazobactum (82.8%), ciprofloxacin, tetracycline and cefepime all at 27.3% each but had the lowest susceptibility at 9.1% to both gentamicin and cefotaxime. Carbapenem resistance in P. aeruginosa was 5/84 (6%) and 2/11 (18.2%) in Acinetobacter species. Carbapenemase production was confirmed in all five P. aeruginosa isolates. Conclusion: Carbapenem resistance was low in both organisms demonstrating that imipenem is still an effective treatment choice for invasive infections caused by these organisms in our setting. In order to reduce HAI and improve patient outcome, there is need to strengthen antimicrobial surveillance/stewardship and infection control at the UTH. © 2021 The Authors
    • Retrospective Review of Virologic and Immunologic Response in Treatment-Experienced Patients on Third-Line HIV Therapy in Lusaka, Zambia

      Zulu, Paul Msanzya; Toeque, Mona-Gekanju; Hachaambwa, Lottie; Chirwa, Lameck; Fwoloshi, Sombo; Siwingwa, Mpanji; Mbewe, Melody; Rosser, Joelle I; Stafford, Kristen A; Lindsay, Brianna; et al. (SAGE Publications, 2021-06-03)
      Established antiretroviral therapy (ART) programs in sub-Saharan Africa have well-defined first-and second-line therapies but no standard third-line ART regimen. The impact of third-line ART on patients with multiclass-resistant HIV in resource-limited settings has not been well characterized. We conducted a retrospective review of patients on third-line ART at the University Teaching Hospital in Lusaka, Zambia. We assessed virologic and immunologic outcomes following 6 months of third-line therapy and found among those with a documented viral load, viral suppression (≤1000 copies/ml) at 24 weeks was 95% (63/66) with a mean increase in CD4 count of 116 cells/mm3 and viral suppression of 63% (63/100) by imputation of missing data. This study suggests that third-line therapy is clinically and virologically effective among patients with multiclass-resistance in a resource-limited setting in sub-Saharan Africa.
    • Screening for Diabetes Mellitus among Tuberculosis Patients: Findings from a Study at a Tertiary Hospital in Lusaka, Zambia

      Fwoloshi, S.; Hachaambwa, L.; Chiyenu, Kaseya (Hindawi Limited, 2018)
      Background: Diabetes mellitus (DM) is known to be associated with active tuberculosis (TB). Zambia is a low-income sub-Saharan African country with a high TB burden and increasing numbers of newly diagnosed DM patients. Materials and Methods: This was an observational study conducted at the University Teaching Hospital in Lusaka, Zambia, from October 2014 to February 2016. Adult patients with active TB were screened for DM. Results. A total of 127 individuals were enrolled in the study. Six patients (5%) were found to have diabetes. Of these, three had a prior diagnosis of diabetes and were on medication while three were newly diagnosed. Low education level was significantly associated with DM (p=0.001; 95% CI 0.001-0.148). Conclusion: The prevalence of DM among individuals with smear positive TB in our study population was similar to that of the general population in Zambia. Copyright 2018 Sombo Fwoloshi et al.
    • Three transmission events of Vibrio cholerae O1 into Lusaka, Zambia

      Mwaba, John; Debes, Amanda K; Murt, Kelsey N; Shea, Patrick; Simuyandi, Michelo; Laban, Natasha; Kazimbaya, Katayi; Chisenga, Caroline; Li, Shan; Almeida, Mathieu; et al. (Springer Nature, 2021-06-14)
      Background: Cholera has been present and recurring in Zambia since 1977. However, there is a paucity of data on genetic relatedness and diversity of the Vibrio cholerae isolates responsible for these outbreaks. Understanding whether the outbreaks are seeded from existing local isolates or if the outbreaks represent separate transmission events can inform public health decisions. Results: Seventy-two V. cholerae isolates from outbreaks in 2009/2010, 2016, and 2017/2018 in Zambia were characterized using multilocus variable number tandem repeat analysis (MLVA) and whole genome sequencing (WGS). The isolates had eight distinct MLVA genotypes that clustered into three MLVA clonal complexes (CCs). Each CC contained isolates from only one outbreak. The results from WGS revealed both clustered and dispersed single nucleotide variants. The genetic relatedness of isolates based on WGS was consistent with the MLVA, each CC was a distinct genetic lineage and had nearest neighbors from other East African countries. In Lusaka, isolates from the same outbreak were more closely related to themselves and isolates from other countries than to isolates from other outbreaks in other years. Conclusions: Our observations are consistent with i) the presence of random mutation and alternative mechanisms of nucleotide variation, and ii) three separate transmission events of V. cholerae into Lusaka, Zambia. We suggest that locally, case-area targeted invention strategies and regionally, well-coordinated plans be in place to effectively control future cholera outbreaks.