Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.

Leptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a countr...

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Main Authors: Leon Biscornet, Koussay Dellagi, Frédéric Pagès, Jastin Bibi, Jeanine de Comarmond, Julien Mélade, Graham Govinden, Maria Tirant, Yann Gomard, Vanina Guernier, Erwan Lagadec, Jimmy Mélanie, Gérard Rocamora, Gildas Le Minter, Julien Jaubert, Patrick Mavingui, Pablo Tortosa
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2017-08-01
Series:PLoS Neglected Tropical Diseases
Online Access:http://europepmc.org/articles/PMC5591009?pdf=render
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author Leon Biscornet
Koussay Dellagi
Frédéric Pagès
Jastin Bibi
Jeanine de Comarmond
Julien Mélade
Graham Govinden
Maria Tirant
Yann Gomard
Vanina Guernier
Erwan Lagadec
Jimmy Mélanie
Gérard Rocamora
Gildas Le Minter
Julien Jaubert
Patrick Mavingui
Pablo Tortosa
author_facet Leon Biscornet
Koussay Dellagi
Frédéric Pagès
Jastin Bibi
Jeanine de Comarmond
Julien Mélade
Graham Govinden
Maria Tirant
Yann Gomard
Vanina Guernier
Erwan Lagadec
Jimmy Mélanie
Gérard Rocamora
Gildas Le Minter
Julien Jaubert
Patrick Mavingui
Pablo Tortosa
author_sort Leon Biscornet
collection DOAJ
description Leptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a country ranking first worldwide according to historical data, to establish epidemiological links between animal reservoirs and human disease, and to identify drivers of transmission.A total of 223 patients with acute febrile symptoms of unknown origin were enrolled in a 12-months prospective study and tested for leptospirosis through real-time PCR, IgM ELISA and MAT. In addition, 739 rats trapped throughout the main island were investigated for Leptospira renal carriage. All molecularly confirmed positive samples were further genotyped.A total of 51 patients fulfilled the biological criteria of acute leptospirosis, corresponding to an annual incidence of 54.6 (95% CI 40.7-71.8) per 100,000 inhabitants. Leptospira carriage in Rattus spp. was overall low (7.7%) but dramatically higher in Rattus norvegicus (52.9%) than in Rattus rattus (4.4%). Leptospira interrogans was the only detected species in both humans and rats, and was represented by three distinct Sequence Types (STs). Two were novel STs identified in two thirds of acute human cases while noteworthily absent from rats.This study shows that human leptospirosis still represents a heavy disease burden in Seychelles. Genotype data suggests that rats are actually not the main reservoir for human disease. We highlight a rather limited efficacy of preventive measures so far implemented in Seychelles. This could result from ineffective control measures of excreting animal populations, possibly due to a misidentification of the main contaminating reservoir(s). Altogether, presented data stimulate the exploration of alternative reservoir animal hosts.
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spelling doaj.art-0f4d78c67e3f43828f75fb2a231311272022-12-22T02:58:09ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352017-08-01118e000583110.1371/journal.pntd.0005831Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.Leon BiscornetKoussay DellagiFrédéric PagèsJastin BibiJeanine de ComarmondJulien MéladeGraham GovindenMaria TirantYann GomardVanina GuernierErwan LagadecJimmy MélanieGérard RocamoraGildas Le MinterJulien JaubertPatrick MavinguiPablo TortosaLeptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a country ranking first worldwide according to historical data, to establish epidemiological links between animal reservoirs and human disease, and to identify drivers of transmission.A total of 223 patients with acute febrile symptoms of unknown origin were enrolled in a 12-months prospective study and tested for leptospirosis through real-time PCR, IgM ELISA and MAT. In addition, 739 rats trapped throughout the main island were investigated for Leptospira renal carriage. All molecularly confirmed positive samples were further genotyped.A total of 51 patients fulfilled the biological criteria of acute leptospirosis, corresponding to an annual incidence of 54.6 (95% CI 40.7-71.8) per 100,000 inhabitants. Leptospira carriage in Rattus spp. was overall low (7.7%) but dramatically higher in Rattus norvegicus (52.9%) than in Rattus rattus (4.4%). Leptospira interrogans was the only detected species in both humans and rats, and was represented by three distinct Sequence Types (STs). Two were novel STs identified in two thirds of acute human cases while noteworthily absent from rats.This study shows that human leptospirosis still represents a heavy disease burden in Seychelles. Genotype data suggests that rats are actually not the main reservoir for human disease. We highlight a rather limited efficacy of preventive measures so far implemented in Seychelles. This could result from ineffective control measures of excreting animal populations, possibly due to a misidentification of the main contaminating reservoir(s). Altogether, presented data stimulate the exploration of alternative reservoir animal hosts.http://europepmc.org/articles/PMC5591009?pdf=render
spellingShingle Leon Biscornet
Koussay Dellagi
Frédéric Pagès
Jastin Bibi
Jeanine de Comarmond
Julien Mélade
Graham Govinden
Maria Tirant
Yann Gomard
Vanina Guernier
Erwan Lagadec
Jimmy Mélanie
Gérard Rocamora
Gildas Le Minter
Julien Jaubert
Patrick Mavingui
Pablo Tortosa
Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
PLoS Neglected Tropical Diseases
title Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
title_full Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
title_fullStr Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
title_full_unstemmed Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
title_short Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.
title_sort human leptospirosis in seychelles a prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir
url http://europepmc.org/articles/PMC5591009?pdf=render
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