Discovery of a leptospirosis cluster amidst a pneumonic plague outbreak in a miners' camp in the Democratic Republic of the Congo.

Eric Bertherat,Jean-Christophe Shako,Mathieu Picardeau,Melissa J Mueller

doi:10.3390/ijerph110201824

Abstract

Conditions in the Democratic Republic of the Congo provide an ideal environment for leptospirosis and plague, both of which can cause severe pulmonary manifestations. In December 2004, an outbreak of lethal pneumonia occurred in a local mining camp, affecting 130 persons and killing 57 of them. Clinical signs, fast disease spread, and initial laboratory investigations suggested pneumonic plague. While leptospirosis had not recently been described in the region, it was considered as a differential diagnosis. Anti-Leptospira antibodies were detected by microscopic agglutination test (MAT). A confirmed case of leptospirosis was defined as having consistent clinical signs and any one of the following: seroconversion or four-fold increase in MAT titre for paired serum samples, or a MAT titre ≥ 1:400 for acute-phase serum samples. Twenty-nine of the 54 patients or convalescents tested for leptospirosis were seropositive. Two cases showed a confirmed infection for both plague and leptospirosis. While evidence supports the plague nature of this outbreak, the results suggest that some of the suspected plague cases might be due to leptospirosis. In any case, this diagnosis will have to be evoked in the future if a similar outbreak occurs in this region of Africa.

Highlights

Human leptospirosis is an emerging disease with over 500,000 severe cases occurring annually and a case fatality rate exceeding 10% [1]
We were able to collect paired serum samples for six of the 54 patients tested for leptospirosis
We found one of these patients exhibited seroconversion for leptospirosis (Patient 27)

Summary

Introduction

Human leptospirosis is an emerging disease with over 500,000 severe cases occurring annually and a case fatality rate exceeding 10% [1]. Leptospirosis is a zoonosis caused by spirochetes of the genus. The bacterium enters the bloodstream via abrasions in the skin or through mucous membranes after contact with contaminated moist soil, water, or aerosolized droplets. Environmental contamination arises when leptospires are shed in urine of infected animal reservoirs such as rodents, cattle, pigs, and various wild animals. Leptospirosis is transmitted to humans by direct contact with tissue or urine from infected animals. Severity of leptospirosis ranges from subclinical infection to severe forms including cardiac, renal, and pulmonary failures. Pulmonary findings for patients with leptospirosis were reported in 17%–70% of patients in several large studies and included hemoptysis, respiratory distress, cough, difficulty breathing, and pulmonary hemorrhage [3]

Results

Discussion

Conclusion