Frequent shedding of multi-drug resistant pneumococci among adults living with HIV on suppressive antiretroviral therapy in Malawi

Abstract

People living with human immunodeficiency virus (PLHIV) on antiretroviral therapy (ART) are reported to have three times higher carriage ofStreptococcus pneumoniaethan their HIV-uninfected counterparts in point prevalence studies. Using a longitudinal cohort study design, we assessed pneumococcal carriage density, shedding and antibiotic resistance profiles, as well as nasal mucosal immunity, in otherwise healthy PLHIV on ART for at least one year, compared to HIV-uninfected participants in Malawi. Pneumococcal carriage density was higher among PLHIV compared to HIV-uninfected participants. Moreover, PLHIV were twice more likely to shed pneumococci than HIV-uninfected participants. In PLHIV, aerosol shed pneumococci were more often multi-drug resistant (MDR) than nasopharyngeal carried isolates recovered from the same individual. Consistent with high shedding, PLHIV exhibited heightened neutrophil-mediated nasal mucosa inflammation. We propose that PLHIV should be considered in intervention strategies, such as vaccination, as they could be an important reservoir for transmission of MDRS. pneumoniae.

Estimating pneumococcal carriage dynamics in adults living with HIV in a mature infant pneumococcal conjugate vaccine program in Malawi, a modelling study

“…Nonetheless, the baseline and follow-up density of pneumococcal carriage remained comparable between HIV groups. Thus, it remains unclear whether the slow NVT clearance is linked to reported cotrimoxazole or penicillin-resistant pneumococci among ALWHIV in this setting [21]. If indeed the reported drugs select for resistant NVT, it may suggest that colonisation of resistant NVT pneumococci in ALWHIV may be inefficiently cleared at the mucosal level, leading to prolonged duration of pneumococcal carriage.…”

“…Our study did not explicitly account for simultaneous carriage of multiple serotypes because latex agglutination was used for serotyping a single bacterial colony [21]. Absence of multiple serotype detection may have biased downward on acquisition rates by missing acquisition events of new serotype while detecting resident serotype and carriage duration by failing to detect serotype when another dominant serotype is present [2].…”

“…Inclusion criteria included asymptomatic adults aged 18 to 45 years living with at least one child under 5 years old. Adults with 4 weeks prior use of antibiotics (except cotrimoxazole), history of smoking, pregnancy, and current respiratory track illness were excluded from the study [21].…”

“…Nasomune study nasopharyngeal (NP) samples were obtained from each Malawian adult through written consent. Study ethics approval was granted by the Malawi National Health Sciences Research Ethics Committee (NHSRC) (21/24/2680) and the Liverpool School of Tropical Medicine Research Ethics (21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35).…”

“…Adults with 4 weeks prior use of antibiotics (except cotrimoxazole), history of smoking, pregnancy, and current respiratory track illness were excluded from the study [21].…”