Impact of prolonged co-trimoxazole prophylaxis on colonisation with antibiotic resistant bacteria in persons newly diagnosed with HIV-infection: CoTrimResist - a randomised placebo-controlled trial
In brief
One year of co-trimoxazole leaves resistant-bacteria carriage unchanged overall
In a randomized trial of 537 adults newly diagnosed with HIV in Tanzania, daily co-trimoxazole briefly reduced nasal Staphylococcus aureus and MRSA carriage, while ESBL-producing E. coli colonization rose faster. By one year, colonization rates did not differ from placebo, and neither did mortality or serious adverse events; the long-term resistance impact remains unclear.
- Journal
- International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (Q1)
- Published
- 29 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Bjørn Blomberg, Joel Manyahi, Sabrina Moyo, Marit Tellevik, Said Aboud, Kanika Kuwelker, et al.
- PMID
- 42810510
- DOI
- 10.1016/j.ijid.2026.109150
Why clinicians should know about it
- Picked for Microbiology (medical) (paper of the day, 30 September 2026): Prophylaxis impact on resistant colonisation
Abstract
OBJECTIVE: To assess whether prolonged co-trimoxazole prophylaxis for people with HIV in sub-Saharan Africa increases colonisation with antibiotic-resistant bacteria. METHODS: The CoTrimResist trial (NCT03087890) randomised newly diagnosed Tanzanian adults with HIV and CD4 counts >350/µL to daily co-trimoxazole or placebo for one year. Clinical data, rectal and nasopharyngeal/nasal swabs were collected at enrolment, two weeks, six months, and one year. Primary outcomes were carriage of extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) and Klebsiella species (ESBL-K), methicillin-resistant Staphylococcus aureus (MRSA), and penicillin-non-susceptible pneumococci (PNSP). FINDINGS: Among 537 participants (median age 37 years; 77% female), 259 received co-trimoxazole and 278 placebo. Co-trimoxazole temporarily reduced nasal S. aureus carriage at two weeks (risk difference -7.3%; 95% CI -12.0% to -2.6%) and six months (-7.6%; 95% CI -13.9% to -1.3%), and MRSA at two weeks (-4.5%; 95% CI -8.0% to -1.1%). ESBL-EC colonisation increased more rapidly with co-trimoxazole. At one year, there were no between-group differences in colonisation rates, mortality or serious adverse events. Intercurrent use of other antibiotics was associated with increased carriage of ESBL-EC. CONCLUSIONS: Prolonged co-trimoxazole prophylaxis leads to transient reductions in S. aureus and MRSA and early increase in ESBL-EC, but shows no persistent effect on colonisation with antimicrobial-resistant bacteria at one year.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.