Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.

<h4>Background</h4>Leptospirosis is a widespread zoonosis with global impact, particularly among vulnerable populations in resource-poor settings in tropical countries. Rodents have been considered to be the main reservoir of the disease; however, a wide variety of mammals can act as hos...

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Main Authors: Linda Grillová, Hilde Angermeier, Marc Levy, Marine Giard, Stéphane Lastère, Mathieu Picardeau
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2020-09-01
Series:PLoS Neglected Tropical Diseases
Online Access:https://doi.org/10.1371/journal.pntd.0008662
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author Linda Grillová
Hilde Angermeier
Marc Levy
Marine Giard
Stéphane Lastère
Mathieu Picardeau
author_facet Linda Grillová
Hilde Angermeier
Marc Levy
Marine Giard
Stéphane Lastère
Mathieu Picardeau
author_sort Linda Grillová
collection DOAJ
description <h4>Background</h4>Leptospirosis is a widespread zoonosis with global impact, particularly among vulnerable populations in resource-poor settings in tropical countries. Rodents have been considered to be the main reservoir of the disease; however, a wide variety of mammals can act as hosts as well. Here we examine the genetic diversity of Leptospira strains from biological samples of patients and animals in French Polynesia (FP) from 2011 to 2019.<h4>Methodology/principal findings</h4>From 2011 to 2019, we have collected 444 blood samples from patients diagnosed as having leptospirosis. The limited volume of clinical material and low amount of leptospiral DNA in blood samples led us to develop a nested PCR targeting the secY locus that enabled us to amplify and sequence 244 samples (55%). In addition, 20 Leptospira strains recovered from the blood of patients from 2002 to 2011 were sequenced and fully characterized at the serogroup level and used as reference strains for the association of different phylogenetic branches with respective serogroups. The secY sequences were compared with publicly available sequences from patients and animal reservoirs in FP (n = 79). We identified rats as the main source of infection for L. borgpetersenii serogroup Ballum and L. interrogans serogroup Icterohaemorrhagiae, dogs as the main source of infection for L. interrogans serogroup Australis, and farm pigs as the main source of infection for L. interrogans serogroups Pomona or Canicola. L. interrogans was associated with the most severe infections with 10 and 5 fatal cases due to serogroups Icterohaemorrhagiae and Australis, respectively. Mortality was significantly associated with older age (p-value < 0.001).<h4>Conclusions/significance</h4>We described the population dynamics of leptospires circulating among patients in FP, including two patients who were reinfected with unrelated Leptospira genotypes, and clarified the local role of the animal reservoirs in the transmission route of leptospirosis to humans. Routine Leptospira genotyping directly on biological samples should allow the epidemiological follow-up of circulating strains and assess the impact of control interventions on disease transmission.
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spelling doaj.art-274edff3b8144f2f8d6bdf089878e2eb2022-12-21T20:08:17ZengPublic Library of Science (PLoS)PLoS Neglected Tropical Diseases1935-27271935-27352020-09-01149e000866210.1371/journal.pntd.0008662Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.Linda GrillováHilde AngermeierMarc LevyMarine GiardStéphane LastèreMathieu Picardeau<h4>Background</h4>Leptospirosis is a widespread zoonosis with global impact, particularly among vulnerable populations in resource-poor settings in tropical countries. Rodents have been considered to be the main reservoir of the disease; however, a wide variety of mammals can act as hosts as well. Here we examine the genetic diversity of Leptospira strains from biological samples of patients and animals in French Polynesia (FP) from 2011 to 2019.<h4>Methodology/principal findings</h4>From 2011 to 2019, we have collected 444 blood samples from patients diagnosed as having leptospirosis. The limited volume of clinical material and low amount of leptospiral DNA in blood samples led us to develop a nested PCR targeting the secY locus that enabled us to amplify and sequence 244 samples (55%). In addition, 20 Leptospira strains recovered from the blood of patients from 2002 to 2011 were sequenced and fully characterized at the serogroup level and used as reference strains for the association of different phylogenetic branches with respective serogroups. The secY sequences were compared with publicly available sequences from patients and animal reservoirs in FP (n = 79). We identified rats as the main source of infection for L. borgpetersenii serogroup Ballum and L. interrogans serogroup Icterohaemorrhagiae, dogs as the main source of infection for L. interrogans serogroup Australis, and farm pigs as the main source of infection for L. interrogans serogroups Pomona or Canicola. L. interrogans was associated with the most severe infections with 10 and 5 fatal cases due to serogroups Icterohaemorrhagiae and Australis, respectively. Mortality was significantly associated with older age (p-value < 0.001).<h4>Conclusions/significance</h4>We described the population dynamics of leptospires circulating among patients in FP, including two patients who were reinfected with unrelated Leptospira genotypes, and clarified the local role of the animal reservoirs in the transmission route of leptospirosis to humans. Routine Leptospira genotyping directly on biological samples should allow the epidemiological follow-up of circulating strains and assess the impact of control interventions on disease transmission.https://doi.org/10.1371/journal.pntd.0008662
spellingShingle Linda Grillová
Hilde Angermeier
Marc Levy
Marine Giard
Stéphane Lastère
Mathieu Picardeau
Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
PLoS Neglected Tropical Diseases
title Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
title_full Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
title_fullStr Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
title_full_unstemmed Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
title_short Circulating genotypes of Leptospira in French Polynesia : An 9-year molecular epidemiology surveillance follow-up study.
title_sort circulating genotypes of leptospira in french polynesia an 9 year molecular epidemiology surveillance follow up study
url https://doi.org/10.1371/journal.pntd.0008662
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