Operational research to identify amenable barriers to kala-azar elimination in Bangladesh

Abstract

Visceral leishmaniasis (VL) is caused by protozoan Leishmania transmitted by the bite of Phlebotomus sand flies. The disease causes fever, emaciation, enlargement of liver and spleen, and darkening of the skin. Globally there are 200,000 to 400,000 VL cases from 79 countries and 20,000 to 40,000 consequent deaths annually. Eighty percent of the global VL cases are reported from South Asia where the disease is known as kala-azar meaning black fever. In Bangladesh, 12,000 to 25,000 kala-azar cases occurred every year during 2004-2008. South Asian kala-azar has been targeted for elimination since 2005 with a new agreement signed among Bangladesh, Bhutan, India, Nepal and Thailand in September 2014. The aim is to bring down the annual incidence to less than 1 per 10,000 population. Five strategies were identified: i) disease surveillance; ii) early diagnosis and treatment; iii) vector control; iv) social mobilization; v) research to support elimination. Operational Research (OR) to provide evidence on how to improve the performance of the programme is the basis of the research reported in this Thesis. I focus on kala-azar surveillance and on barriers to early diagnosis and treatment. I used qualitative and quantitative (mixed) methods in Mymensingh district in Bangladesh. After screening 9824 households obtained from multi-stage cluster sampling, I found 102 kala-azar cases who participated in the quantitative component of the study. Of them, 29 also participated in qualitative studies with in-depth interviews and focus group discussions. The monthly tallies of kala-azar cases reported to the government under-represented the actual cases that occurred by about 50% (95% CI: 37% - 63%). Supply and administration of kala-azar treatment drug at the Upazila (sub-district) Health Complex (UHC) significantly and positively associated with recording. Under-reporting arose due to high demands on responsible staff and the reporting burden for multiple diseases. The study found a median delay of two months between onset of fever and confirmatory diagnosis of kala-azar. There was low pre-illness awareness regarding symptoms and available treatment facilities. Most care seeking started with unqualified village doctors in the community. The frequency of early diagnosis was greater in public than private facilities. The qualified providers, adhering to the national guidelines, had to wait for the development of palpable spleen before confirming diagnosis of treatment. Delay arose with treatment for other febrile systemic illnesses, particularly typhoid. Other causes of delay included poverty, limited education, and various transport difficulties. To improve kala-azar control in Bangladesh a community awareness campaign designed in local context is needed. The national guidelines for kala-azar diagnosis need to be reviewed and modified. The government health system needs to be able to test for kala-azar at the union and village level. There is scope to improve surveillance which is the only source of information on the nationwide incidence of kala-azar. Findings of this Thesis reinforce the importance and complexity of the multi-country kala-azar elimination programme now underway in South Asia. The next five years will be very important to the eventual elimination of kala-azar. Show more