Multi-Drug Resistance in Tanzania's Surgical Wards
Imagine undergoing life-saving surgery only to find your healing wound invaded by unseen invaders—bacteria that defy standard medications, prolong suffering, and threaten your survival.
This scenario plays out daily in hospitals worldwide, but nowhere more acutely than in low and middle-income countries like Tanzania, where surgical site infections (SSIs) have become a devastating complication of medical care 1 4 .
Of bacterial pathogens causing SSIs at MNH
Average extension of hospital stay due to SSIs
In SSI rates with IPC-AMS interventions
At Tanzania's largest referral hospital, an invisible crisis is unfolding. In 2014, researchers at Muhimbili National Hospital (MNH) made a startling discovery: approximately 63% of bacterial pathogens causing surgical site infections were multi-drug resistant (MDR), with some pathogens showing 100% resistance to commonly used antibiotics 1 6 .
Surgical site infections occur when bacteria contaminate the incision site during or after a surgical procedure. While SSIs remain a global concern, their impact is disproportionately felt in developing countries where resources for infection prevention are often limited 4 .
The World Health Organization estimates that in low and middle-income countries, SSIs affect up to one-third of patients undergoing surgery—significantly higher than rates in developed nations 8 .
To understand the alarming scale of antimicrobial resistance in surgical settings, Tanzanian researchers conducted a comprehensive investigation at Muhimbili National Hospital between September 2011 and February 2012 1 6 . This research would provide the first systematic analysis of the superbugs plaguing the country's largest referral hospital.
Researchers aseptically collected two pus swabs or pus samples from the depth of each patient's wound, transporting them immediately to the laboratory in special transport media to preserve any bacteria present 6 .
In the laboratory, samples were cultured on blood agar and MacConkey agar—standard media for growing bacteria. The team then used both conventional biochemical tests and advanced automated systems (API 20E and VITEK) to identify the bacterial species present 1 6 .
Using the Kirby Bauer disc diffusion method, researchers tested isolated bacteria against various antibiotics. They placed antibiotic-impregnated discs on bacteria-inoculated agar plates and measured the zones where bacteria failed to grow, indicating antibiotic effectiveness 1 6 .
The study specifically screened for methicillin-resistant Staphylococcus aureus (MRSA) using cefoxitin discs, and extended-spectrum beta-lactamase (ESBL) production in Gram-negative bacteria using combination disc methods 6 .
This systematic approach allowed researchers to create a comprehensive profile of both the identity and drug resistance patterns of bacteria causing SSIs at MNH.
The findings from the Muhimbili study revealed a disturbing landscape of antimicrobial resistance that threatened to undermine surgical care effectiveness.
Of the 100 patients sampled, 90% had positive bacterial growth—an exceptionally high rate of infection. Researchers isolated 147 pathogenic bacteria, with Gram-negative organisms dominating at 77.5% compared to 22.5% Gram-positive bacteria 1 6 .
| Bacterial Species | Prevalence | Classification |
|---|---|---|
| Pseudomonas aeruginosa |
|
Gram-negative |
| Staphylococcus aureus |
|
Gram-positive |
| Klebsiella pneumoniae |
|
Gram-negative |
| Escherichia coli |
|
Gram-negative |
| Other Gram-negative species |
|
Gram-negative |
| Other Gram-positive species |
|
Gram-positive |
Of the 18 S. aureus isolates detected, 44% were MRSA—resistant to all beta-lactam antibiotics. Even more concerning, three of these strains (17%) carried both MRSA and induced clindamycin resistance 6 .
Understanding how scientists identify and characterize these resistant pathogens reveals the complexity of combating antimicrobial resistance. The Muhimbili study employed a range of specialized tools and techniques:
Blood Agar - General-purpose medium that supports growth of diverse bacteria.
MacConkey Agar - Selective medium that differentiates between Gram-negative bacteria.
API 20E System - Standardized identification system for Enterobacteriaceae.
VITEK Automated System - Advanced automated microbial identification and susceptibility testing.
Kirby Bauer Disc Diffusion - Method for testing antibiotic effectiveness against bacterial isolates.
Double Disc Approximation - Confirmatory test for extended-spectrum beta-lactamase production.
Cefoxitin Disc - Key reagent for detecting methicillin resistance in staphylococci.
Mueller Hinton Agar - Standard medium for antibiotic susceptibility testing.
The findings from Muhimbili and subsequent studies across Tanzania have far-reaching implications for clinical practice, public health policy, and community health.
Multi-drug resistant infections create a cascade of negative effects on healthcare systems and patients:
Research conducted at Dodoma Regional Referral Hospital demonstrated the power of combined Infection Prevention and Control (IPC) and Antimicrobial Stewardship (AMS) programs 8 . This initiative included:
On hand hygiene and surgical techniques
30-60 minutes before incision
Involving various specialists
For faster, accurate diagnosis
The results were dramatic: post-caesarean section SSI rates dropped from 48% to 17% after implementation, proving that systematic interventions can effectively reduce infections even in resource-limited settings 8 .
The Muhimbili researchers issued an urgent call for changes in antibiotic prescription policies—a core component of antimicrobial stewardship 1 6 . This involves:
A 2025 umbrella review reinforced that prolonging antibiotic prophylaxis beyond 24 hours after surgery provides no significant benefit compared to immediate discontinuation after incision closure, supporting more conservative antibiotic use 3 .
The battle against multi-drug resistant bacteria in Tanzanian hospitals represents a microcosm of a global health challenge. The predominance of resistant pathogens causing surgical site infections at Muhimbili National Hospital serves as both a warning and a call to action.
Science has revealed the scale of the problem and continues to provide tools for detection.
Addressing AMR requires a multidisciplinary approach across sectors.
IPC-AMS programs show significant progress is possible even with limited resources.
In the enduring war between human ingenuity and bacterial evolution, our greatest weapons may be the very practices that prevent infections in the first place—proving that sometimes, the best medicine is not having to use it at all.