Spatial heterogeneity in projected leprosy trends in India.
BACKGROUND
Leprosy is caused by infection with Mycobacterium leprae and is characterized by peripheral nerve damage and skin lesions. The disease is classified into paucibacillary (PB) and multibacillary (MB) leprosy. The 2012 London Declaration formulated the following targets for leprosy control: (1) global interruption of transmission or elimination by 2020, and (2) reduction of grade-2 disabilities in newly detected cases to below 1 per million population at a global level by 2020. Leprosy is treatable, but diagnosis, access to treatment and treatment adherence (all necessary to curtail transmission) represent major challenges. Globally, new case detection rates for leprosy have remained fairly stable in the past decade, with India responsible for more than half of cases reported annually.


METHODS
We analyzed publicly available data from the Indian Ministry of Health and Family Welfare, and fit linear mixed-effects regression models to leprosy case detection trends reported at the district level. We assessed correlation of the new district-level case detection rate for leprosy with several state-level regressors: TB incidence, BCG coverage, fraction of cases exhibiting grade 2 disability at diagnosis, fraction of cases in children, and fraction multibacillary.


RESULTS
Our analyses suggest an endemic disease in very slow decline, with substantial spatial heterogeneity at both district and state levels. Enhanced active case finding was associated with a higher case detection rate.


CONCLUSIONS
Trend analysis of reported new detection rates from India does not support a thesis of rapid progress in leprosy control.
Department of Ecology & Evolutionary Biology, Princeton University, Princeton, NJ, USA.
Cara E
CE
Brook
International Centre for Reproductive Health, Ghent University, Ghent, Belgium.|The South African Department of Science and Technology/National Research Foundation (DST/NRF) Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa.
Roxanne
R
Beauclair
The South African Department of Science and Technology/National Research Foundation (DST/NRF) Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch, South Africa.
Olina
O
Ngwenya
Francis I. Proctor Foundation, University of California, San Francisco, CA, USA.
Lee
L
Worden
Yale University, School of Public Health, New Haven, CT, USA.
Martial
M
Ndeffo-Mbah
Francis I. Proctor Foundation, University of California, San Francisco, CA, USA.|Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA.|Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA.
Thomas M
TM
Lietman
School of Public Health, KIIT University, Bhubaneswar, Odisha, India.
Sudhir K
SK
Satpathy
Yale University, School of Public Health, New Haven, CT, USA.
Alison P
AP
Galvani
Francis I. Proctor Foundation, University of California, San Francisco, CA, USA. travis.porco@ucsf.edu.|Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA. travis.porco@ucsf.edu.|Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA. travis.porco@ucsf.edu.
Travis C
TC
Porco
D003140:Communicable Disease Control / Q000379:methods; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D019353:Endemic Diseases; D015994:Incidence; D007194:India / Q000453:epidemiology; D007918:Leprosy / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control*; D015233:Models, Statistical; D019371:Topography, Medical