Title:
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Arsenic exposure and outcomes of antimonial treatment in
visceral leishmaniasis patients in Bihar, India: a retrospective
cohort study
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Author:
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Perry, Meghan R.; Prajapati, Vijay K.; Menten, Joris; Raab, Andrea; Feldmann, Joerg; Chakraborti, Dipankar; Sundar, Shyam; Fairlamb, Alan H.; Boelaert, Marleen; Picado, Albert
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Abstract:
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BACKGROUND: In the late twentieth century, emergence of high
rates of treatment failure with antimonial compounds (SSG) for
visceral leishmaniasis (VL) caused a public health crisis in
Bihar, India. We hypothesize that exposure to arsenic through
drinking contaminated groundwater may be associated with SSG
treatment failure due to the development of antimony-resistant
parasites. METHODS: A retrospective cohort design was employed,
as antimony treatment is no longer in routine use. The study was
performed on patients treated with SSG between 2006 and 2010.
Outcomes of treatment were assessed through a field
questionnaire and treatment failure used as a proxy for parasite
resistance. Arsenic exposure was quantified through analysis of
5 water samples from within and surrounding the patient's home.
A logistic regression model was used to evaluate the association
between arsenic exposure and treatment failure. In a secondary
analysis survival curves and Cox regression models were applied
to assess the risk of mortality in VL patients exposed to
arsenic. RESULTS: One hundred and ten VL patients treated with
SSG were analysed. The failure rate with SSG was 59%. Patients
with high mean local arsenic level had a non-statistically
significant higher risk of treatment failure (OR = 1.78, 95% CI:
0.7-4.6, p = 0.23) than patients using wells with arsenic
concentration <10 mug/L. Twenty one patients died in our
cohort, 16 directly as a result of VL. Arsenic levels >/= 10
mug/L increased the risk of all-cause (HR 3.27; 95% CI: 1.4-8.1)
and VL related (HR 2.65; 95% CI: 0.96-7.65) deaths. This was
time dependent: 3 months post VL symptom development, elevated
risks of all-cause mortality (HR 8.56; 95% CI: 2.5-29.1) and of
VL related mortality (HR 9.27; 95% CI: 1.8-49.0) were detected.
DISCUSSION/CONCLUSION: This study indicates a trend towards
increased treatment failure in arsenic exposed patients. The
limitations of the retrospective study design may have masked a
strong association between arsenic exposure and selection for
antimonial resistance in the field. The unanticipated strong
correlation between arsenic exposure and VL mortality warrants
further investigation. |
Subject(s):
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-Arsènic -Leishmaniosi -Salut pública -Índia -Arsenic -Leishmaniasis -Public health -India |
Rights:
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cc by (c) Perry et al., 2015
http://creativecommons.org/licenses/by/3.0/es/ |
Document type:
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Article Article - Published version |
Published by:
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Public Library of Science (PLoS)
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