Elimination of visceral leishmaniasis in the Indian subcontinent: a comparison of predictions from three transmission models
Author(s)
Type
Journal Article
Abstract
We present three transmission models of visceral leishmaniasis (VL) in the Indian subcontinent (ISC) with structural differences regarding the disease stage that provides the main contribution to transmission, including models with a prominent role of asymptomatic infection, and fit them to recent case data from 8 endemic districts in Bihar, India. Following a geographical cross-validation of the models, we compare their predictions for achieving the WHO VL elimination targets with ongoing treatment and vector control strategies. All the transmission models suggest that the WHO elimination target (<1 new VL case per 10,000 capita per year at sub-district level) is likely to be met in Bihar, India, before or close to 2020 in sub-districts with a pre-control incidence of 10 VL cases per 10,000 people per year or less, when current intervention levels (60% coverage of indoor residual spraying (IRS) of insecticide and a delay of 40 days from onset of symptoms to treatment (OT)) are maintained, given the accuracy and generalizability of the existing data regarding incidence and IRS coverage. In settings with a pre-control endemicity level of 5/10,000, increasing the effective IRS coverage from 60 to 80% is predicted to lead to elimination of VL 1–3 years earlier (depending on the particular model), and decreasing OT from 40 to 20 days to bring elimination forward by approximately 1 year. However, in all instances the models suggest that L. donovani transmission will continue after 2020 and thus that surveillance and control measures need to remain in place until the longer-term aim of breaking transmission is achieved.
Date Issued
2017-03-06
Date Acceptance
2017-01-07
Citation
Epidemics, 2017, 18, pp.67-80
ISSN
1755-4365
Publisher
Elsevier
Start Page
67
End Page
80
Journal / Book Title
Epidemics
Volume
18
Copyright Statement
© 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license
(http://creativecommons.org/licenses/by/4.0/).
(http://creativecommons.org/licenses/by/4.0/).
License URL
Subjects
Science & Technology
Life Sciences & Biomedicine
Infectious Diseases
Visceral leishmaniasis
Kala-azar
Elimination
Mathematical modelling
Indoor residual spraying
Detection and treatment
Indian subcontinent
Neglected tropical disease
Sandfly
Transmission dynamics
Predictions
AZAR DERMAL LEISHMANIASIS
KALA-AZAR
SAND FLIES
RURAL BIHAR
EPIDEMIOLOGY
BANGLADESH
NEPAL
ARGENTIPES
INFECTION
DYNAMICS
Publication Status
Published