Common UTI Antibiotics Are Failing in Tanzania as Drug-Resistant Bacteria Spread in the Community

Urinary tract infections are among the most common reasons adults seek medical care worldwide, and in low- and middle-income countries they are a leading driver of antibiotic prescriptions. Yet the bacteria responsible are increasingly shrugging off the drugs that primary care clinics rely on. A new cross-sectional study from Mwanza, Tanzania, published in PLOS Global Public Health, offers one of the clearest snapshots to date of just how deep the problem runs outside hospital walls, where most infections are actually treated.

Researchers from the Catholic University of Health and Allied Sciences and collaborating institutions enrolled more than a thousand symptomatic adults at two busy primary healthcare facilities in Mwanza, a lakeside city in northwestern Tanzania. Between May and August 2024, the team recruited patients attending the Igoma and Buzuruga Health Centres who presented with symptoms suggestive of a urinary tract infection. To ensure the infections were genuinely community-acquired rather than picked up in medical settings, participants were excluded if they had been hospitalized within the previous 30 days or had undergone urinary catheterization, both of which are classic routes for healthcare-associated infection.

The scale of the survey was unusual for a primary care setting. In total, 1,005 adults were enrolled, with a median age of 32 years and a striking female majority: 727 participants, or 72.3 percent, were women, consistent with the well-known biological predisposition of women to urinary tract infections. The study also captured an important behavioral signal, as nearly two-thirds of participants, 64.3 percent, reported having been diagnosed with a urinary tract infection within the previous six months, suggesting frequent recurrence or repeated empirical treatment in this population. The median duration of symptoms before patients sought care was eight days, with an interquartile range of five to fifteen days.

Each participant provided a midstream urine specimen, which the researchers cultured in the laboratory to identify the causative organism. Culture-confirmed infection was found in 221 participants, a positivity rate of 22.0 percent with a 95 percent confidence interval of 19.5 to 24.7 percent. Two pathogens dominated the landscape. Escherichia coli, the Gram-negative bacterium that normally lives harmlessly in the gut but thrives in the urinary tract, accounted for 32.9 percent of isolates. Staphylococcus aureus, a Gram-positive species more often associated with skin and soft tissue infections, was close behind at 24.7 percent, a notably high proportion that underscores how the microbial ecology of community-acquired urinary infections can differ from textbook expectations.

Perhaps the most clinically consequential finding concerned symptoms. Only 35.7 percent of culture-confirmed cases presented with the classic triad of urinary complaints: dysuria, the painful or burning sensation during urination; frequency, the need to urinate unusually often; and urgency, the sudden compelling urge to void. The majority of patients with laboratory-proven infection therefore arrived with atypical or non-specific presentations. This matters enormously in resource-limited primary care, where diagnosis is usually syndromic, meaning clinicians prescribe antibiotics based on symptoms alone. If most true infections lack hallmark symptoms, and if many symptomatic patients do not have bacterial infection at all, empirical treatment becomes a guessing game that fuels both under-treatment and unnecessary antibiotic use.

The antimicrobial susceptibility testing, performed using the disc diffusion method in which antibiotic-impregnated discs are placed on agar plates inoculated with bacteria and zones of inhibited growth are measured, revealed alarming resistance patterns in E. coli. Resistance to ampicillin, an older penicillin, stood at 93.4 percent, effectively rendering the drug useless. Ciprofloxacin, a fluoroquinolone that is often a second-line oral option and a mainstay of empirical UTI therapy in many guidelines, failed against 62.3 percent of isolates. Trimethoprim-sulfamethoxazole, the inexpensive combination known as cotrimoxazole that is widely used across sub-Saharan Africa, showed 60.7 percent resistance, while the augmented penicillin amoxicillin-clavulanic acid and tetracycline were defeated by 57.4 percent and 55.7 percent of isolates respectively.

Even more troubling were the markers of advanced resistance mechanisms. In total, 82.8 percent of E. coli isolates were multidrug-resistant, meaning they were non-susceptible to agents from three or more antibiotic classes. Furthermore, 20.3 percent exhibited extended-spectrum beta-lactamase phenotypes. ESBLs are enzymes that bacteria produce to hydrolyze, or chemically dismantle, most penicillins and cephalosporins, the beta-lactam antibiotics that form the backbone of empirical treatment worldwide. ESBL-producing organisms typically leave carbapenems, expensive intravenous drugs that are often unavailable in primary care facilities in the region, as the only reliable option. The presence of such phenotypes in one in five community-acquired E. coli urinary infections signals that resistance genes once confined to hospitals are now circulating freely in the general population.

The Staphylococcus aureus findings carried their own warning. Among these isolates, 64.6 percent were resistant to cefoxitin, a cephalosporin used in the laboratory as a surrogate marker for methicillin resistance. Methicillin-resistant S. aureus, or MRSA, is resistant to nearly all beta-lactam antibiotics and typically requires agents such as vancomycin or linezolid, treatments that are costly and rarely accessible at the primary care level in Tanzania. A methicillin resistance rate approaching two-thirds among community urinary isolates suggests that MRSA, long a hospital scourge, has established a substantial foothold outside institutional settings, complicating any empirical strategy that assumes staphylococcal urinary infections will respond to standard oral agents.

Taken together, the data paint a picture of community-acquired urinary tract infection as a substantial and quietly worsening burden among adult outpatients in Mwanza. Roughly one in five symptomatic adults who walked into these two health centres carried a culture-confirmed infection, and the organisms recovered from them were overwhelmingly resistant to the inexpensive oral antibiotics that constitute first-line empirical therapy in the region. The combination of high resistance, frequent atypical symptoms, and heavy reliance on syndromic prescribing creates a vicious cycle: inaccurate diagnosis leads to inappropriate antibiotic use, which in turn selects for ever more resistant bacteria, which then make accurate diagnosis even more critical.

The authors argue that the findings demand concrete structural responses. Improved access to microbiological diagnostics at primary healthcare facilities, so that treatment can be guided by culture and susceptibility results rather than guesswork, is a central recommendation. Strengthened antimicrobial stewardship programs, which monitor and optimize how antibiotics are prescribed and dispensed, are equally urgent, as is the development of locally informed treatment guidelines that reflect the actual resistance profile of circulating pathogens rather than imported assumptions. Without such measures, the study suggests, common urinary infections in the community will continue to drift toward the untreatable end of the spectrum, quietly eroding one of the most fundamental tools of modern medicine.

Subject of Research: Antimicrobial resistance in bacteria causing community-acquired urinary tract infections among adult outpatients at primary healthcare facilities in Mwanza, Tanzania

Article Title: Multidrug resistance in bacteria causing community-acquired urinary tract infections among adult outpatients attending primary healthcare facilities in Mwanza, Tanzania

Article References: Emmanuel, E. G., Khamis, A., Michael, E., Muhizi, D., Thomas, J., Okamo, B., Mkassy, F. I., Konje, E. T., Silago, V., Mushi, M. F., & Mshana, S. E. (2026). Multidrug resistance in bacteria causing community-acquired urinary tract infections among adult outpatients attending primary healthcare facilities in Mwanza, Tanzania. PLOS Global Public Health, 6(10), e0005638. https://doi.org/10.1371/journal.pgph.0005638

Image Credits: AI Generated

DOI: 10.1371/journal.pgph.0005638

Keywords: antimicrobial resistance, urinary tract infections, Escherichia coli, Staphylococcus aureus, multidrug resistance, ESBL, MRSA, primary healthcare, Tanzania, antibiotic stewardship, community-acquired infection, diagnostics