Rights statement: This is the author’s version of a work that was accepted for publication in Water Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Water Research, 130, 2018 DOI: 10.1016/j.watres.2017.11.068
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Spatial and temporal dynamics of pathogenic Leptospira in surface waters from the urban slum environment
AU - Casanovas-Massana, Arnau
AU - Costa, Federico
AU - Riediger, Irina N
AU - Cunha, Marcelo
AU - de Oliveira, Daiana
AU - Mota, Diogenes C
AU - Sousa, Erica
AU - Querino, Vladimir A
AU - Nery, Nivisson
AU - Reis, Mitermayer G
AU - Wunder, Elsio A
AU - Diggle, Peter J
AU - Ko, Albert I
N1 - This is the author’s version of a work that was accepted for publication in Water Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Water Research, 130, 2018 DOI: 10.1016/j.watres.2017.11.068
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Leptospirosis has emerged as an important urban health problem as slum settlements have expanded worldwide. Yet the dynamics of the environmentally transmitted Leptospira pathogen has not been well characterized in these settings. We used a stratified dense sampling scheme to study the dynamics of Leptospira abundance in surface waters from a Brazilian urban slum community. We collected surface water samples during the dry, intermediate and rainy seasons within a seven-month period and quantified pathogenic Leptospira by quantitative PCR (qPCR). We used logistic and linear mixed models to identify factors that explained variation for the presence and concentration of Leptospira DNA. Among 335 sewage and 250 standing water samples, Leptospira DNA were detected in 36% and 34%, respectively. Among the 236 samples with positive results geometric mean Leptospira concentrations were 152 GEq/mL. The probability of finding Leptospira DNA was higher in sewage samples collected during the rainy season when increased leptospirosis incidence occurred, than during the dry season (47.2% vs 12.5%, respectively, p = 0.0002). There was a marked spatial and temporal heterogeneity in Leptospira DNA distribution, for which type of water, elevation, and time of day that samples were collected, in addition to season, were significant predictors. Together, these findings indicate that Leptospira are ubiquitous in the slum environment and that the water-related risk to which inhabitants are exposed is low. Seasonal increases in Leptospira presence may explain the timing of leptospirosis outbreaks. Effective prevention will need to consider the spatial and temporal dynamics of pathogenic Leptospira in surface waters to reduce the burden of the disease.
AB - Leptospirosis has emerged as an important urban health problem as slum settlements have expanded worldwide. Yet the dynamics of the environmentally transmitted Leptospira pathogen has not been well characterized in these settings. We used a stratified dense sampling scheme to study the dynamics of Leptospira abundance in surface waters from a Brazilian urban slum community. We collected surface water samples during the dry, intermediate and rainy seasons within a seven-month period and quantified pathogenic Leptospira by quantitative PCR (qPCR). We used logistic and linear mixed models to identify factors that explained variation for the presence and concentration of Leptospira DNA. Among 335 sewage and 250 standing water samples, Leptospira DNA were detected in 36% and 34%, respectively. Among the 236 samples with positive results geometric mean Leptospira concentrations were 152 GEq/mL. The probability of finding Leptospira DNA was higher in sewage samples collected during the rainy season when increased leptospirosis incidence occurred, than during the dry season (47.2% vs 12.5%, respectively, p = 0.0002). There was a marked spatial and temporal heterogeneity in Leptospira DNA distribution, for which type of water, elevation, and time of day that samples were collected, in addition to season, were significant predictors. Together, these findings indicate that Leptospira are ubiquitous in the slum environment and that the water-related risk to which inhabitants are exposed is low. Seasonal increases in Leptospira presence may explain the timing of leptospirosis outbreaks. Effective prevention will need to consider the spatial and temporal dynamics of pathogenic Leptospira in surface waters to reduce the burden of the disease.
KW - Leptospira
KW - Leptospirosis
KW - Surface water
KW - Public health
KW - Sewage
KW - Urban slum
U2 - 10.1016/j.watres.2017.11.068
DO - 10.1016/j.watres.2017.11.068
M3 - Journal article
C2 - 29220718
VL - 130
SP - 176
EP - 184
JO - Water Research
JF - Water Research
SN - 0043-1354
ER -