The Ecological Dynamics of Fecal Contamination and Salmonella Typhi and Salmonella Paratyphi A in Municipal Kathmandu Drinking Water.
Author(s)
Type
Journal Article
Abstract
One of the UN sustainable development goals is to achieve universal access to safe and affordable drinking water by 2030. It is locations like Kathmandu, Nepal, a densely populated city in South Asia with endemic typhoid fever, where this goal is most pertinent. Aiming to understand the public health implications of water quality in Kathmandu we subjected weekly water samples from 10 sources for one year to a range of chemical and bacteriological analyses. We additionally aimed to detect the etiological agents of typhoid fever and longitudinally assess microbial diversity by 16S rRNA gene surveying. We found that the majority of water sources exhibited chemical and bacterial contamination exceeding WHO guidelines. Further analysis of the chemical and bacterial data indicated site-specific pollution, symptomatic of highly localized fecal contamination. Rainfall was found to be a key driver of this fecal contamination, correlating with nitrates and evidence of S. Typhi and S. Paratyphi A, for which DNA was detectable in 333 (77%) and 303 (70%) of 432 water samples, respectively. 16S rRNA gene surveying outlined a spectrum of fecal bacteria in the contaminated water, forming complex communities again displaying location-specific temporal signatures. Our data signify that the municipal water in Kathmandu is a predominant vehicle for the transmission of S. Typhi and S. Paratyphi A. This study represents the first extensive spatiotemporal investigation of water pollution in an endemic typhoid fever setting and implicates highly localized human waste as the major contributor to poor water quality in the Kathmandu Valley.
Date Issued
2016-01-06
Date Acceptance
2015-12-09
Citation
PLOS Neglected Tropical Diseases, 2016, 10 (1)
ISSN
1935-2735
Publisher
Public Library of Science
Journal / Book Title
PLOS Neglected Tropical Diseases
Volume
10
Issue
1
Copyright Statement
© 2016 Karkey et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any
medium, provided the original author and source are
credited.
access article distributed under the terms of the
Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any
medium, provided the original author and source are
credited.
License URL
Sponsor
Bill & Melinda Gates Foundation
Bill & Melinda Gates Foundation
National Institute for Health Research
Identifier
PII: PNTD-D-15-01140
Grant Number
OPP1068440
OPP1092240
HPRU-2012-10080
Subjects
Tropical Medicine
06 Biological Sciences
11 Medical And Health Sciences
Publication Status
Published
Article Number
e0004346
Date Publish Online
2016-01-06