Scientists move closer to vaccine against visceral leishmaniasis

An international team of scientists are reportedly coming closer to developing a vaccine against visceral leishmaniasis, or black fever.

Visceral leishmaniasis is a parasitic protozoan infection carried in the bite of phlebotomine sandflies. It is characterized by high fever, substantial weight loss, anemia, and severe swelling of the spleen and liver. When left untreated, it is almost always fatal, according to the World Health Organization.

Leishmaniasis, in its four forms, affects 12 million people. There are approximately 1.5 million new cases diagnosed every year, according to

The study, which was published online in the journal Nature Genetics, identifies a single major genetic risk factor for the disease. The scientists were able to pinpoint a variation in a specific region of the major immune response locus, known as the major histocompatibility complex, which contributes to the severity of the parasite's effects.

"Earlier genetic studies of visceral leishmaniasis in inbred mice allowed us to clearly demonstrate the importance of the MHC in regulating this disease," Professor Jenefer Blackwell of the University of Western Australia said, reports. "Now, major advances in human genetics and the ability to compare the genomes of large numbers of people with and without the disease have allowed us to identify the precise molecular basis to this MHC control in humans. This will have a major impact on refining research towards the ultimate goal of a vaccine."