The prevalence of antimicrobial drug resistance of non-typhoidal Salmonella in human infections in sub-Saharan Africa: a systematic review and meta-analysis

ABSTRACT

Introduction

Non-typhoidal Salmonella (NTS) bacteremia is common in sub-Saharan Africa. We examined the prevalence of antibiotic resistance to fluoroquinolones, third-generation cephalosporins, and multi-drug resistance (MDR) in NTS human isolates from sub-Saharan Africa.

Methods

A systematic review was conducted using a search in Ovid Medline, Embase, and African Index Medicus of publications between 2000 and 2021. A random-effects model meta-analysis was performed using data from 66 studies that included 29,039 NTS blood and 1,065 stool isolates.

Results

The pooled prevalence proportions of MDR were 0.685 (95% CI 0.574–0.778) and 0.214 (0.020–0.785) in blood vs. stool isolates. The corresponding estimates of fluoroquinolones resistance were 0.014 (0.008–0.025) vs. 0.021 (0.012–0.036) and third-generation cephalosporins resistance 0.019 (0.012–0.031) vs. 0.035 (0.006–0.185). Similar results were found for children and adults. Resistance prevalence to these antibiotics in blood isolates increased between 2000–2010 and 2011–2021. The guidelines employed to determine antimicrobial resistance and epidemiological characteristics (e.g. sample size, study duration) correlated with the resistance prevalence.

Conclusions

The prevalence of MDR and resistance to fluoroquinolones and third-generation cephalosporins in NTS in sub-Saharan Africa is alarming.

Expert opinion

Standardized surveillance of antimicrobial drug resistance in NTS in sub-Saharan Africa is warranted to guide healthcare policymaking and antibiotic stewardship programs.

Plain Language Summary

Non-typhoidal Salmonella (NTS) usually causes diarrheal disease, but some patients might develop bloodstream infection. The occurrence and case fatality of bloodstream infections caused by NTS are high in sub-Saharan Africa. However, the information on antibiotic resistance of these bacteria in this region is scarce. We performed a systematic review and meta-analysis to examine the prevalence of multi-drug resistance (MDR) and resistance to antibiotics used to treat NTS bloodstream infection: fluoroquinolones and third-generation cephalosporins in NTS isolates from patients from sub-Saharan Africa.

We used data from 66 studies. In NTS blood isolates, the combined prevalence was 1.4% for fluoroquinolones resistance, 1.9% for resistance to third-generation cephalosporins, and 68.5% for MDR. These estimates were 2.1%, 3.5%, and 21.4% in stool isolates. The prevalence of resistance to fluoroquinolones and third-generation cephalosporins in blood isolates has increased in the past 2 decades. The guidelines employed to determine antimicrobial resistance and the study epidemiological characteristics were related to the resistance prevalence.

The high prevalence of MDR in NTS raises concerns, and the emergence of resistance to fluoroquinolones and third-generation cephalosporins is worrisome. Strengthening the monitoring of antimicrobial drug resistance in NTS is essential to guide patients’ care and policymaking in sub-Saharan Africa.

KEYWORDS:

• Antimicrobial drug resistance
• non-typhoidal salmonella
• multi-drug resistance
• fluoroquinolones
• third-generation cephalosporins
• Sub-Saharan Africa

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Data availability statement

All data used in this study appear in Supplementary Tables S11-S12.

Author contributions

KM, YA, AA, ESD and DC contributed to the conception and design; YA, MO, SA were responsible for data abstraction; YA and KM, were responsible for data analysis; all authors contributed to the interpretation of the results; YA, KM drafted the paper; all authors contributed to revising the paper critically for intellectual content; and the final approval of the version to be published; all authors agreed to be accountable for all aspects of the work.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14787210.2024.2368989

Additional information

Funding

This paper was not funded.