Visceral leishmaniasis outbreaks in Bihar: community-level investigations in the context of elimination of kala-azar as a public health problem

Parasites & Vectors

Madan Prashad Sharma¹  Tanmay Mahapatra²  Sridhar Srikantiah²  Khushbu Priyamvada²  Pushkar Dubey²  Joy Bindroo²  Lloyd A. C. Chapman³  Caryn Bern⁴  Allen W. Hightower⁵ 

[1] Bihar State Programme (Kala-azar), Patna, India;CARE-India Solutions for Sustainable Development, Patna, India;Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene and Tropical Medicine, London, UK;Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA, USA;Independent consultant, Bangkok, Thailand;

关键词: Visceral leishmaniasis;    Epidemiology;    Risk factors;    Outbreak investigation;    India;   

DOI  :  10.1186/s13071-020-04551-y

来源: Springer

【 摘 要 】

BackgroundWith visceral leishmaniasis (VL) incidence at its lowest level since the 1960s, increasing attention has turned to early detection and investigation of outbreaks.MethodsOutbreak investigations were triggered by recognition of case clusters in the VL surveillance system established for the elimination program. Investigations included ascertainment of all VL cases by date of fever onset, household mapping and structured collection of risk factor data.ResultsVL outbreaks were investigated in 13 villages in 10 blocks of 7 districts. Data were collected for 20,670 individuals, of whom 272 were diagnosed with VL between 2012 and 2019. Risk was significantly higher among 10–19 year-olds and adults 35 or older compared to children younger than 10 years. Outbreak confirmation triggered vector control activities and heightened surveillance. VL cases strongly clustered in tolas (hamlets within villages) in which > 66% of residents self-identified as scheduled caste or scheduled tribe (SC/ST); 79.8% of VL cases occurred in SC/ST tolas whereas only 24.2% of the population resided in them. Other significant risk factors included being an unskilled non-agricultural laborer, migration for work in a brick kiln, living in a kuccha (mud brick) house, household crowding, habitually sleeping outside or on the ground, and open defecation.ConclusionsOur data highlight the importance of sensitive surveillance with triggers for case cluster detection and rapid, careful outbreak investigations to better respond to ongoing and new transmission. The strong association with SC/ST tolas suggests that efforts should focus on enhanced surveillance in these disadvantaged communities.

【 授权许可】

CC BY