# Human brucellosis in pregnancy in western Uganda: High seroprevalence and health risk factors identified in a cross-sectional study

## TL;DR

A study in western Uganda found that 14% of pregnant women had evidence of brucellosis, a zoonotic infection linked to risky food practices and livestock exposure, highlighting the need for screening and prevention.

## Contribution

The study is the first to report brucellosis seroprevalence and risk factors among pregnant women in Uganda.

## Key findings

- 14% of pregnant women tested seropositive for brucellosis.
- Consumption of fresh milk or under-cooked meat increased infection risk.
- Lack of formal education and home livestock rearing were significant risk factors.

## Abstract

Human brucellosis is a neglected zoonosis that can cause anemia, miscarriage and pre-term birth, yet its burden during pregnancy in Uganda is unknown. This study determined the seroprevalence and associated risk factors for brucellosis among pregnant women at a Tertiary Hospital in Uganda.

This cross-sectional study was conducted in the antenatal clinic of Kampala International University Teaching Hospital, western Uganda (September–December 2024). Consecutive participants provided sociodemographic and livestock-exposure data and 5 mL of venous blood was drawn. Sera were screened with the Rose Bengal Plate Test; all reactive samples and 10% of non-reactive samples were confirmed with an indirect IgG/IgM ELISA. Multivariable logistic regression identified factors independently associated with seropositivity with significance set at P < 0.05.

Of 207 enrolled women (median gestation = 24 weeks), 29 were ELISA-confirmed seropositive, giving a prevalence of 14.0% (95% CI 9.2–18.8). Independent risk factors were lack of formal education (adjusted odds ratio [aOR] 4.05, 95% CI 1.02–16.01), consumption of fresh milk or under-cooked meat (aOR 5.70, 95% CI 1.94–16.76), frequent contact with animal manure (aOR 3.29, 95% CI 1.29–8.47) and rearing livestock at home (aOR 3.75, 95% CI 1.36–10.32).

One in seven pregnant women in this mixed livestock–human ecosystem showed evidence of brucellosis, far above the WHO elimination threshold. Integrating RBPT-based screening into routine antenatal care, promoting milk pasteurization and safe meat preparation, improving manure handling and strengthening herd vaccination through One-Health collaboration could reduce maternal infection and adverse pregnancy outcomes in similar smallholder settings.

Brucellosis is a bacterial disease that spreads from livestock to people through unpasteurized milk, undercooked meat or direct animal contact. Although pregnancy is a vulnerable period, there is almost no information on how common the infection is among pregnant women in East Africa. We invited all women who attended the antenatal clinic of Kampala International University Teaching Hospital in rural western Uganda between September and December 2024 to take part in a one-time blood test and short interview. Using a two-step laboratory algorithm (Rose Bengal Plate Test followed by IgG/IgM ELISA), we found that 14% of participants had Brucella antibodies, indicating serological evidence of exposure. Women without formal schooling, those who drank fresh milk or ate under-cooked meat, those who handled animal manure and those who reared animals at home were three- to six-times more likely to be infected. The results highlight the need for antenatal screening, food-safety messages, and closer collaboration between veterinary and maternal-health services to protect mothers and babies in similar smallholder settings