Journal Article

Diagnostic Stewardship Trends and Antimicrobial Resistance Profiles of Bacteria Isolated in Zambia: A Five-Year Retrospective Study (2020–2024)

Shikanga, O-Tipo, Siame, Amon, Sakalimbwe, Loveness, Chileshe, Chikwanda, Hangoma, Jimmy, Yamba, Kaunda, Mudenda, Ntombi B., Nakazwe, Ruth, Sinyange, Nyambe, Mudenda, Steward, Chibwe, Bertha, Chanda, Duncan, Masaninga, Freddie, Chizimu, Joseph Yamweka, Mwadetsa, Sandra Diana, Mukale, Samson, Kasanga, Maisa, Mainda, Geoffrey, Chilengi, Roma, Gardner, Priscilla, Shawa, Misheck, Shempela, Doreen Mainza, Daka, Victor, Simwinji, Fred Mulako, Goma, Fusya, Mufwambi, Webrod, Mwangilwa, Kelvin, Chibi, Mpela, Chambaro, Herman, Sinyawa, Taona, Muma, John Bwalya, Bambala, Andrew, Lukwesa, Chileshe, Kaunda, Kaunda, Suzuki, Yasuhiko, Kalungia, Aubrey Chichonyi, Muhimba, Zoran, Mutila, Malambo, Nakajima, Chie, Hadunka, Mwendalubi Albert

2025

Overview

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.

• Publisher: MDPI AG
• Subject: Antibacterial agents / Antibiotic resistance / Antibiotics / Antimicrobial resistance / Azithromycin / Bacteria / Bacteriology / Beta lactamases / Carbapenems / Ciprofloxacin / Clindamycin / Decision making / Diagnosis / diagnostic stewardship / Doxycycline / Drug resistance / Drug resistance in microorganisms / E coli / Enterobacterales / Escherichia coli / High resistance / Laboratories / Linezolid / Methicillin / Penicillin G / priority pathogens / Rifampin / sentinel surveillance / Statistical analysis / Sulfamethoxazole / Surveillance / Tetracycline / Tetracyclines / Trends / Trimethoprim / Vancomycin