Risk factors for pneumococcal carriage in adults living with HIV on antiretroviral therapy in the infant pneumococcal vaccine era in Malawi

AIDS. 2022 Nov 15;36(14):2045-2055. doi: 10.1097/QAD.0000000000003365. Epub 2022 Aug 19.


Objective: Adults living with HIV (ALWHIV) on antiretroviral therapy (ART) are at high risk of pneumococcal carriage and disease. To help evaluate carriage risk in African ALWHIV at least 4 years after infant pneumococcal conjugate vaccination introduction in 2011, we assessed association between pneumococcal carriage and potential risk factors.

Methods: Nasopharyngeal swabs were collected from adults aged 18-40 years attending an ART clinic during rolling, cross-sectional surveys in Blantyre, Malawi between 2015 and 2019. We fitted generalized additive models to estimate the risk of sex, social economic status (SES), living with a child less than 5 years, and ART duration on carriage.

Results: Of 2067 adults, median age was 33 years (range 28-37), 1427 (69.0%) were women, 1087 (61.4%) were in low-middle socioeconomic-status (SES), 910 (44.0%) were living with a child less than 5 years, and median ART duration was 3 years (range 0.004-17). We estimated 38.2 and 60.6% reductions in overall and vaccine-serotype carriage prevalence. Overall carriage was associated with low SES, living with a child less than 5 years and shorter duration on ART. By contrast, vaccine-type carriage was associated with living without a child less than 5 years and male sex.

Conclusion: Despite temporal reductions in overall and vaccine-serotype carriage, there is evidence of incomplete vaccine-serotype indirect protection. A targeted-vaccination campaign should be considered for ALWHIV, along with other public health measures to further reduce vaccine-serotype carriage and therefore disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Carrier State / epidemiology
  • Child, Preschool
  • Cross-Sectional Studies
  • Female
  • HIV Infections* / complications
  • HIV Infections* / drug therapy
  • Humans
  • Infant
  • Infant, Newborn
  • Malawi / epidemiology
  • Male
  • Nasopharynx
  • Pneumococcal Infections* / epidemiology
  • Pneumococcal Infections* / prevention & control
  • Pneumococcal Vaccines
  • Prevalence
  • Risk Factors
  • Streptococcus pneumoniae


  • Pneumococcal Vaccines