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Grand RoundsWeekly Evidence Brief

Infectious Diseases

Edition

30-Second Takeaway

  • One- and three-month rifapentine–isoniazid regimens for TB contacts had similar completion and safety in HIV-negative adults.
  • Xpert followed by Xpert XDR plus phenotypic DST was the most cost-effective DR-TB diagnostic backbone in South Africa.
  • Omicron-era outpatient COVID-19 antivirals mainly shorten illness; effects on hospitalization and death remain limited or uncertain.
  • Postpandemic homelessness was linked to ~70-fold higher invasive GAS incidence, driven by skin breakdown and injection drug use.
  • Plasma microbial cell-free DNA sequencing greatly increases pathogen yield in pediatric cCAP but needs quantitative thresholds to avoid overcalling infection.

Week ending February 14, 2026

Concise updates in TB prevention, COVID-19 care, and complex infectious threats

One- vs three-month rifapentine–isoniazid for LTBI in exposed, HIV-negative contacts

PLOS MEDICINEFeb 10, 2026

This Brazilian phase 4 RCT randomized 500 HIV-negative recent contacts with LTBI to 1 month of daily HP (1HP) vs 3 months of weekly HP (3HP). Treatment completion was high in both arms, 89.6% with 1HP and 84.1% with 3HP, without a statistically significant difference. Grade >2 targeted adverse events or discontinuation occurred in 16.1% of 1HP vs 10.4% of 3HP recipients; adjusted risk differences crossed null. Discontinuation for any side effect was numerically higher with 1HP (7.2%) than 3HP (4.4%). The trial did not assess efficacy, but both regimens showed high completion and acceptable safety, supporting either option for HIV-negative contacts.

Cost-effective DR-TB diagnosis: Xpert→Xpert XDR plus phenotypic DST in South Africa

BMC MEDICINEFeb 10, 2026

A decision-analytic model compared nine diagnostic strategies for detecting isoniazid, rifampicin, and fluoroquinolone resistance in microbiologically confirmed TB in South Africa. The preferred cost-effective strategy was Xpert MTB/RIF followed by Xpert XDR plus phenotypic DST, with an ICER of USD 6,554 per DALY averted. tNGS plus phenotypic DST yielded the best health outcomes but was not cost-effective at conventional willingness-to-pay thresholds. When phenotypic DST was unavailable, tNGS alone could be cost-effective, indicating a potential role where culture capacity is limited. Sensitivity analyses showed diagnostic accuracy and time to appropriate treatment strongly influenced cost-effectiveness rankings.

Living rapid review of outpatient COVID-19 antivirals in the Omicron era

ANNALS OF INTERNAL MEDICINEFeb 9, 2026

This American College of Physicians living rapid review included seven Omicron-period studies of adult outpatients treated with oral antivirals. Ensitrelvir 125 mg may not shorten time to recovery and may increase adverse events, without serious safety differences. Molnupiravir probably improves recovery, shortens time to recovery, and reduces persistent symptoms at 3–6 months, without clear mortality or hospitalization benefit. Nirmatrelvir–ritonavir may increase recovery and shorten illness but probably increases adverse events, generally non-serious. Simnotrelvir–ritonavir clearly reduces time to recovery and probably increases adverse events. Head-to-head data show no recovery difference between molnupiravir and favipiravir, or between molnupiravir and nirmatrelvir–ritonavir.

Invasive GAS incidence is ~70-fold higher among people experiencing homelessness in Canada

JAMA NETWORK OPENFeb 10, 2026

This cross-sectional analysis examined 503 invasive group A streptococcal infections in Toronto and Peel Region from 2022 to 2023. Persons experiencing homelessness had iGAS incidence 70.7-fold higher than housed persons, with substantial increases in both groups postpandemic. Compared with housed adults, homeless patients were less often immunocompromised but more likely to inject drugs and have nonintact skin. They more frequently presented with soft tissue infections and had lower odds of death despite their extreme incidence burden. Emm1 and emm12 predominated in housed adults, whereas emm49, 74, 80, 82, and 92 dominated among persons experiencing homelessness. Findings support targeted wound care, harm reduction, shelter-based interventions, and emm type–informed surveillance for this population.

References

Numbered in order of appearance. Click any reference to view details.

Additional Reads

Optional additional studies from this edition.

Edition context

Clinical signal

  • Short-course rifapentine–isoniazid options for LTBI in recent contacts are acceptable and similarly safe in HIV-negative populations, allowing programmatic flexibility.
  • DR-TB programs in high-burden settings can improve value by layering Xpert→Xpert XDR on phenotypic DST instead of jumping directly to tNGS+DST.
  • Current outpatient COVID-19 antivirals offer symptom and recovery benefits, with modest toxicity, but clear mortality or hospitalization benefits are lacking.