# Prevalence and determinants of nasal carriage of methicillin-resistant Staphylococcus aureus among internally displaced persons in Mogadishu, Somalia: A community based cross-sectional study

## TL;DR

This study found a high rate of MRSA nasal carriage among displaced people in Mogadishu, with recent displacement and smaller households increasing the risk.

## Contribution

The first community-based study on MRSA nasal carriage among internally displaced persons in Mogadishu.

## Key findings

- MRSA nasal carriage prevalence was 51.9% among internally displaced persons in Mogadishu.
- Recent displacement (1-15 months) increased MRSA carriage risk by nearly threefold.
- Smaller households (1-4 members) had higher odds of MRSA carriage compared to larger households.

## Abstract

•First community-based study of methicillin-resistant Staphylococcus aureus (MRSA) in Mogadishu internally displaced persons.•MRSA nasal carriage prevalence was 51.9%.•Recent displacement increased risk of carriage.•Smaller households had higher MRSA odds.•Targeted interventions needed to reduce antimicrobial resistance.

First community-based study of methicillin-resistant Staphylococcus aureus (MRSA) in Mogadishu internally displaced persons.

MRSA nasal carriage prevalence was 51.9%.

Recent displacement increased risk of carriage.

Smaller households had higher MRSA odds.

Targeted interventions needed to reduce antimicrobial resistance.

Internal displacement creates complex health challenges, particularly regarding the spread of antimicrobial resistance (AMR). In Somalia, internally displaced persons (IDPs) reside in overcrowded settlements with limited sanitation, creating conditions that favor the transmission of methicillin-resistant Staphylococcus aureus (MRSA). While clinical infections are reported, community-based data on asymptomatic carriage is scarce. This study investigated the prevalence and predictors of nasal MRSA carriage among IDPs in Mogadishu.

A community-based cross-sectional study was conducted in the Daynile and Kahda districts of Mogadishu. A total of 428 IDPs were enrolled using systematic random sampling. Data on sociodemographics, housing, and medical history were collected via structured questionnaires. Anterior nasal swabs were cultured on Mannitol Salt Agar, and MRSA was confirmed using cefoxitin disk diffusion per Clinical & Laboratory Standards Institute (CLSI) guidelines. Multivariable logistic regression was used to identify independent predictors of carriage.

A total of 428 participants were enrolled (mean age 24.5 years). The overall prevalence of MRSA nasal carriage was 51.87% (222/428). In the multivariable analysis, the duration of displacement and household size were significant predictors of carriage. Recent arrival in the camp (1-15 months) was a strong risk factor (adjusted odds ratio = 2.92; 95% confidence interval: 1.64-5.19) compared to long-term residents. Additionally, smaller household sizes (1-4 members) showed higher odds of carriage (adjusted odds ratio = 2.08; 95% confidence interval: 1.23-3.51) compared to larger households, potentially reflecting specific housing vulnerabilities among newer, smaller family units.

The burden of MRSA carriage is exceptionally high among displaced populations in Mogadishu. The findings suggest that recent displacement and living conditions associated with newer arrivals are critical drivers of transmission. Public health interventions should target recent arrivals with improved shelter and hygiene promotion to mitigate the spread of resistant pathogens.