# name
Visceral leishmaniasis: Spatiotemporal heterogeneity and
                drivers underlying the hotspots in Muzaffarpur, Bihar, India

# metadata.dc.description.abstract[].value
Background:
Despite the overall decrease in visceral leishmaniasis (VL) incidence on the Indian subcontinent, there remain spatiotemporal clusters or ‘hotspots’ of new cases. The characteristics of
these hotspots, underlying transmission dynamics, and their importance for shaping control
strategies are not yet fully understood and are investigated in this study for a VL endemic
area of ~100,000 inhabitants in Bihar, India between 2007–2015.
Methodology/Principal findings
VL incidence (cases/10,000/year) dropped from 12.3 in 2007 to 0.9 in 2015, which is just
below the World Health Organizations’ threshold for elimination as a public health problem.
Clustering of VL was assessed between subvillages (hamlets), using multiple geospatial
and (spatio)temporal autocorrelation and hotspot analyses. One to three hotspots were
identified each year, often persisting for 1–5 successive years with a modal radius of
~500m. The relative risk of having VL was 5–86 times higher for inhabitants of hotspots,
compared to those living outside hotspots. Hotspots harbour significantly more households
from the two lowest asset quintiles (as proxy for socio-economic status). Overall, children
and young adelescents (5–14 years) have the highest risk for VL, but within hotspots and at
the start of outbreaks, older age groups (35+ years) show a comparable high risk.
Conclusions/Significance:
This study demonstrates significant spatiotemporal heterogeneity in VL incidence at subdistrict level. The association between poverty and hotspots confirms that VL is a disease of
‘the poorest of the poor’ and age patterns suggest a potential role of waning immunity as underlying driver of hotspots. The recommended insecticide spraying radius of 500m
around detected VL cases corresponds to the modal hotspot radius found in this study.
Additional data on immunity and asymptomatic infection, and the development of spatiotemporally explicit transmission models that simulate hotspot dynamics and predict the impact
of interventions at the smaller geographical scale will be crucial tools in sustaining
elimination.

# metadata.dc.relation.ispartof[].value
PLoS Neglected Tropical Diseases, 2018, vol. 12, p. e0006888

# metadata.dc.source[].value
Articles publicats en revistes (ISGlobal)

# metadata.dc.title[].value
Visceral leishmaniasis: Spatiotemporal heterogeneity and
                drivers underlying the hotspots in Muzaffarpur, Bihar, India