Leptospira Seroprevalence and Risk Factors in Health Centre Patients in Hoima District, Western Uganda.

Anou Dreyfus,Jonathan W Dyal,Charles Kajura,Dominic A Travis,Steven Kakooza,Lordrick Alinaitwe,Michael Mahero,Lawrence Mugisha,Katharine M Pelican,David R Boulware,Raewynne Pearson,Clovice Kankya

doi:10.1371/journal.pntd.0004858

Abstract

BackgroundThe burden of human leptospirosis in Uganda is unknown. We estimated the seroprevalence of Leptospira antibodies, probable acute/recent leptospirosis, and risk factors for seropositivity in humans in rural Western Uganda.Methodology and Principal Findings359 non-pregnant adults visiting the Kikuube and Kigorobya Health Centers were sequentially recruited during March and April 2014. A health history survey and serum were collected from consented participants. Overall, 69% reported having fever in the past year, with 49% reporting malaria, 14% malaria relapse, 6% typhoid fever, 3% brucellosis, and 0% leptospirosis. We tested sera by microscopic agglutination test (MAT) against eight Leptospira serovars representing seven serogroups. Leptospira seroprevalence was 35% (126/359; 95%CI 30.2–40.3%) defined as MAT titer ≥ 1:100 for any serovar. The highest prevalence was against L. borgpetersenii Nigeria (serogroup Pyrogenes) at 19.8% (71/359; 95%CI 15.9–24.4%). The prevalence of probable recent leptospirosis (MAT titer ≥1:800) was 1.9% (95%CI 0.9–4.2%) and uniquely related to serovar Nigeria (serogroup Pyrogenes). Probable recent leptospirosis was associated with having self-reported malaria within the past year (p = 0.048). Higher risk activities included skinning cattle (n = 6) with 12.3 higher odds (95%CI 1.4–108.6; p = 0.024) of Leptospira seropositivity compared with those who had not. Participants living in close proximity to monkeys (n = 229) had 1.92 higher odds (95%CI 1.2–3.1; p = 0.009) of seropositivity compared with participants without monkeys nearby.Conclusions/SignificanceThe 35% prevalence of Leptospira antibodies suggests that exposure to leptospirosis is common in rural Uganda, in particular the Nigeria serovar (Pyrogenes serogroup). Leptospirosis should be a diagnostic consideration in febrile illness and “smear-negative malaria” in rural East Africa.

Highlights

Leptospirosis is a zoonotic bacterial disease with a worldwide distribution that is endemic in subtropical and tropical countries
Leptospirosis is an emerging zoonotic disease caused by bacteria of the genus Leptospira
We found 35% of study participants had antibodies to at least one Leptospira serovar, predominantly L. borgpetersenii sv Nigeria representing the Pyrogenes serogroup (20% of all participants)

Summary

Introduction

Leptospirosis is a zoonotic bacterial disease with a worldwide distribution that is endemic in subtropical and tropical countries. Leptospira is a Genus of spirochetes that comprise 20 species and almost 300 different serovars (sv). They have a large range of mammalian hosts which carry adapted serovars in their renal tubules and excrete them in the environment for months or years. Infection patterns vary depending on the climate and rainfall, and the socioeconomic, occupational, or recreational activities which bring a susceptible host into contact with infected water or animals. Leptospirosis outbreaks in animals and humans often occur after flooding [4]. The burden of human leptospirosis in Uganda is unknown. We estimated the seroprevalence of Leptospira antibodies, probable acute/recent leptospirosis, and risk factors for seropositivity in humans in rural Western Uganda

Results

Discussion

Conclusion