Fact
Sheet
Visceral
Leishmaniasis
/
Kala
‐
azar
Key facts
Visceral leishmaniasis, commonly known as kala‐azar, is a parasitic disease caused by Leishmania protozoan and transmitted by sandflies.
It is one of neglected tropical diseases which can be fatal if not treated, with an estimated 500,000 cases occur annually.
Symptoms include prolonged fever, weight loss, swelling of liver and spleen and is a type of leishmaniasis that affects internal organ (other leishmaniasis infection involve skin and mucous membrane). The transmission cycle can be zoonotic or 1950s. Unfortunately the disease quickly re‐emerged when these campaigns were terminated and sandfly vector population increased again.
Regional
burden
of
visceral
leishmaniasis
VL can be found in more than 60 countries in the world, with a total of 200 million people at risk. However, the majority (more than 90%) of VL cases occur in just six countries: Bangladesh, India, Nepal, Sudan, Ethiopia and Brazil.
In SEA region, the three most affected countries are Bangladesh, India and Nepal,
Characteristics
and
Transmission
Humans are infected via the bite of phlebotomine sandflies, which have the parasite Leishmania inside them and inject them to humans. Only female flies can transmit the disease. These flies normally breed in forest areas, caves, cracks in the mud walls, or the burrows of small rodents. That is why in some villages, when houses are in close proximity with cattle or cattlesheds, there are high probability of having sandflies around. The period between sandfly bite until appearance of symptoms is between 2 require considerable technical expertise and potentially dangerous, thus can not be done everywhere.
Prevention
and
control
limited evidence that bednets provide protection against VL in paerticular, as effectiveness of the bed nets depend on sleeping traditions of the population and the biting habits of the local vectors.
Elimination
initiative
and
challenges
Despite the difficulties to control VL in the world, there are several factors specific to Indian subcontinent that makes elimination feasible. Biological factors include anthroponotic cycle, with humans being the only reservoir and Phlebotomus argentipes sandflies the only known vector. New and more effective diagnostic test (the rK39 ICTs) and drugs (such as miltefosine) are available and can be used in the field. More importantly, there is strong political commitment and inter‐country collaboration. The VL elimination initiative was launched in 2005 by the signing of a Memorandum of Understanding among India, Bangladesh and Nepal. The target is set for 2015., to reduce annual incidence of kala azar to less than one per 10 000 population at district or sub‐district level and to reduce case fatality rates.
The strategies for elimination are:
Early diagnosis and complete case management
Integrated vector management and vector surveillance
Effective disease surveillance through passive and active case detection Social mobilization and building partnerships
Implementation and operational research private doctors or untrained people who provide expensive, incomplete or inappropriate treatment.
Post kala azar dermal leishmaniasis (PKDL) patienst with only skin signs resulting from delayed or incomplete treatment, are reservoirs of infection responsible for continued transmission.
