One Health, Wildlife Health, Vector Born Zoonotic Disease
Kala-azar or Visceral Leishmaniasis (VL) is a parasitic disease which has been recorded in South-East Asia during early 1800’s. It seems to have blowout along the Ganges and the Brahmaputra rivers, the major transport routs of Bengal and Bangladesh. In this area, Kala-azar was first described in 1824 in the Jessore district where about 75,000 people died. An intensive control program aimed at the eradication of malaria was mounted in the late 1950s and early 1960s throughout the South Asian sub-continent with the main effort based on indoor residual spraying (IRS) of DDT. Kala-azar is mainly caused by Leishmania donovani, L. infantum, or L. chagasi, but occasionally these species may cause other forms of disease. The cutaneous form of the disease is caused by more than 15 species of Leishmania. Leishmaniasis is mainly transferred by the bite of infected female phlebotomine sandflies which can transmit the protozoa Leishmania. This sandflies act as the vector.
VL is now endemic in many Bangladeshi areas, with the Mymensingh district representing over 50% of the cases. There is substantial underreporting. In 2007, the estimated number of active cases was 136,500. However, less than 5,000 cases were reported that same year. The estimated incidence of VL, according to recent studies, is 15.6/1,000 person-years in Fulbaria and 27/10,000 population in Godagari and Rajshahi.
A survey, conducted in 2006-2007, showed that when seeking care outside the community, 52% of patients made use of the public sector, 13% used poorly trained private practitioners and 28% used local chemists in order to obtain treatment. The awareness of VL is very low. Generally, in communities, VL is seen as ‘any fever that cannot be cured by the local drug sellers’.
As sandflies play a significant role in spreading the dangerous VL disease in different parts of Bangladesh, so this alarming rate of occurring VL in Bangladesh lead me to fix the mind setup to work with sand flies.