VL can be transmitted in two different ways depending on the region. In the Mediterranean, Middle East and Brazil, VL is caused by Leishmania infantum and is a zoonotic disease, which is transmitted through the bite of infected female phlebotomine sand flies and infects dogs or foxes. However, in South India and East Africa, VL is caused by Leishmania donovani and is anthroponotic, which means it is transmitted by inter-human transmission. These differences have important implications with respect to how the disease can be successfully controlled. .
As mentioned before, Visceral Leishmaniasis in Brazil is caused by L. infantum that is zoonotic. From 1980 to 2003, a total of 51,222 cases were officially notified in Brazil. But with VL being very underreported, it can be assumed the actual people infected will be greater. When VL first started to spread, the main reservoir for the disease was thought to be the domestic dogs, due to its high susceptibility to disease and high skin parasitism. Between 1980~1991, 137,246 dogs were killed by the activities under Brazilian Leishmaniasis Control Program (BLCP). Brazil is the only county endemic for VL that has conducted systematic control programs since 1980, although it might not be quite effective. However, culling of the dogs proved useless as the immunological screening of anti-Leishmaniasis antibodies was limited. Also it was impossible to find out how many dogs they had to kill to reduce the cases of VL and the owners greatly opposed the culling of their dogs. Later, it was proven that the culling of the dogs did not reduce the cases of VL, which shows that it was an ineffective action of the BLCP. BLCP has proven quite ineffective in reducing incidence of human cases, as it has not made any improvements in its control measures of diagnosis, early treatment of human cases, immunological screening of seropositive dogs and insecticide spraying against phlebotomine sandflies established in the 1950s.
Infectious diseases which have not been considered failures up to this point in Brazil are dengue fever and visceral leishmaniasis. ... Epidemics could have also been overestimated causing timing of the epidemic to be off (Lowe et al., 2014). ...
