The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.

Human leptospirosis involves the classic epidemiological triad (agent, host and environment); hence the investigations should include the knowledge on Leptospira within the animals and the environment. The objectives of this study are to explore the abundance of Leptospira in different climate zones...

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Main Authors: Janith Warnasekara, Shalka Srimantha, Indika Senavirathna, Chamila Kappagoda, Nirmani Farika, Achala Nawinna, Suneth Agampodi
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0263719
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author Janith Warnasekara
Shalka Srimantha
Indika Senavirathna
Chamila Kappagoda
Nirmani Farika
Achala Nawinna
Suneth Agampodi
author_facet Janith Warnasekara
Shalka Srimantha
Indika Senavirathna
Chamila Kappagoda
Nirmani Farika
Achala Nawinna
Suneth Agampodi
author_sort Janith Warnasekara
collection DOAJ
description Human leptospirosis involves the classic epidemiological triad (agent, host and environment); hence the investigations should include the knowledge on Leptospira within the animals and the environment. The objectives of this study are to explore the abundance of Leptospira in different climate zones of Sri Lanka and to describe the presence of Leptospira in the same water source at serial time points. First, water and soil samples were collected from different parts of Sri Lanka (Component-1); second, water sampling continued only in the dry zone (Component-2). Finally, serial water sampling from ten open wells was performed at five different time points (Component-3). Quantitative PCR of water and metagenomic sequencing of soil were performed to detect Leptospira. Three replicates for each sample were used for PCR testing, and positive result of two or more replicates was defined as 'strongly positive,' and one positive replicate was defined as positive. In the water and soil sample analysis in the whole country (Component-1), two out of 12 water sites were positive, and both were situated in the wet zone. Very small quantities of the genus Leptospira were detected by 16 amplicon analysis of soil in all 11 sites. In the dry zone water sample analysis (Component-2), only samples from 6 out of 26 sites were positive, of which one site was strongly positive. In the serial sample analysis (Component-3), Six, five, four, five, and six wells were positive in serial measurements. All wells were positive for at least one time point, while only one well was positive for all five time points. Proximity to the tank and greater distances from the main road were associated with strong positive results for Leptospira (P<0.05). The presence of Leptospira was not consistent, indicating the variable abundance of Leptospira in the natural environment. This intermittent nature of positivity could be explained by the repetitive contamination by animal urine.
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spelling doaj.art-7fc8306fb0eb41fda5e90e526061a59a2022-12-21T19:29:26ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-01172e026371910.1371/journal.pone.0263719The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.Janith WarnasekaraShalka SrimanthaIndika SenavirathnaChamila KappagodaNirmani FarikaAchala NawinnaSuneth AgampodiHuman leptospirosis involves the classic epidemiological triad (agent, host and environment); hence the investigations should include the knowledge on Leptospira within the animals and the environment. The objectives of this study are to explore the abundance of Leptospira in different climate zones of Sri Lanka and to describe the presence of Leptospira in the same water source at serial time points. First, water and soil samples were collected from different parts of Sri Lanka (Component-1); second, water sampling continued only in the dry zone (Component-2). Finally, serial water sampling from ten open wells was performed at five different time points (Component-3). Quantitative PCR of water and metagenomic sequencing of soil were performed to detect Leptospira. Three replicates for each sample were used for PCR testing, and positive result of two or more replicates was defined as 'strongly positive,' and one positive replicate was defined as positive. In the water and soil sample analysis in the whole country (Component-1), two out of 12 water sites were positive, and both were situated in the wet zone. Very small quantities of the genus Leptospira were detected by 16 amplicon analysis of soil in all 11 sites. In the dry zone water sample analysis (Component-2), only samples from 6 out of 26 sites were positive, of which one site was strongly positive. In the serial sample analysis (Component-3), Six, five, four, five, and six wells were positive in serial measurements. All wells were positive for at least one time point, while only one well was positive for all five time points. Proximity to the tank and greater distances from the main road were associated with strong positive results for Leptospira (P<0.05). The presence of Leptospira was not consistent, indicating the variable abundance of Leptospira in the natural environment. This intermittent nature of positivity could be explained by the repetitive contamination by animal urine.https://doi.org/10.1371/journal.pone.0263719
spellingShingle Janith Warnasekara
Shalka Srimantha
Indika Senavirathna
Chamila Kappagoda
Nirmani Farika
Achala Nawinna
Suneth Agampodi
The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
PLoS ONE
title The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
title_full The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
title_fullStr The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
title_full_unstemmed The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
title_short The variable presence of Leptospira in the environment; an epidemiological explanation based on serial analysis of water samples.
title_sort variable presence of leptospira in the environment an epidemiological explanation based on serial analysis of water samples
url https://doi.org/10.1371/journal.pone.0263719
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