Cross-sectional serosurvey of Leptospira species among slaughter pigs, goats, and sheep in Uganda

PLoS Negl Trop Dis. 2024 Mar 15;18(3):e0012055. doi: 10.1371/journal.pntd.0012055. eCollection 2024 Mar.

Abstract

Introduction: Leptospira are a group of bacteria, including pathogenic types that cause leptospirosis. In Uganda, Leptospira exposure has been reported in humans, with domesticated animals being speculated as the source. However, comparable evidence of Leptospira prevalence and circulating serovars/serogroups in animals is only documented for cattle, and dogs. Our study determined Leptospira seroprevalence, associated risk factors and serogroups circulating among slaughtered pigs, goats, and sheep in Uganda.

Methods: During an 11-month cross-sectional survey in selected slaughter facilities in three regions of Uganda, we collected blood from 926 pigs, 347 goats, and 116 sheep. The age, sex, breed, and origin of each sampled animal were noted. The samples were tested for anti-Leptospira antibodies using the microscopic agglutination test, based on a panel of 12 serovars belonging to 12 serogroups.

Results: Leptospira seroprevalence was 26.67% (247/926, 95%CI 23.92-29.61) among pigs, and 21.81% (101/463, 95%CI 18.29-25.80) in goats and sheep (small ruminants). L. interrogans Australis and L. kirschneri Grippotyphosa were the commonest serovars among pigs, as was L. borgpetersenii Tarassovi in small ruminants. Pigs sourced from the Eastern (Odds Ratio [OR] = 2.82, 95%CI 1.84-4.30) and Northern (OR = 3.56, 95%CI 2.52-5.02) regions were more likely to be seropositive, compared to those from the Central region. For small ruminants, being female (OR 2.74, 95% CI 1.69-4.57) and adult (OR 4.47, 95% CI 1.57-18.80) was significantly more associated with Leptospira seropositivity. Conclusion/significance: Detection of a moderate seroprevalence, and several Leptospira serogroups among pigs, sheep, and goats from all regions of Uganda, supports existing reports in cattle and dogs, and implies widespread Leptospira exposure in domestic animals in Uganda. These findings may inform future programs for the control of leptospirosis in livestock in Uganda.

MeSH terms

  • Animals
  • Animals, Domestic
  • Antibodies, Bacterial
  • Cross-Sectional Studies
  • Female
  • Goats
  • Leptospira*
  • Leptospirosis* / epidemiology
  • Leptospirosis* / microbiology
  • Leptospirosis* / veterinary
  • Male
  • Ruminants
  • Seroepidemiologic Studies
  • Sheep
  • Swine
  • Uganda / epidemiology

Substances

  • Antibodies, Bacterial

Grants and funding

This work was funded by the German Federal Ministry of Economic Cooperation and Development (BMZ) through the project “Boosting Uganda’s investment in livestock development (BUILD)” led by KR (Grant number BMZ001; https://www.bmz.de/en/). KR received additional support from the CGIAR Research Program on Livestock (CRP001; https://livestock.cgiar.org/), the CGIAR Research Program and Agriculture for Nutrition and Health (CRP003; https://a4nh.cgiar.org/) as well as the CGIAR Initiative on One Health (CGL003; https://www.cgiar.org/initiative/one-health/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.