Biologists have discovered a virus-carrying microbe, a close relative of the leishmania parasite, along with the leishmania parasite in kala-azar victims – a finding that may provide new leads for understanding and devising better ways to treat this disease and its complications such as post kala-azar dermal leishmaniasis1.

In recent years, Leishmania donovani , the parasite that causes kala-azar, has developed resistance to antimonial drugs. The other co-infecting pathogens, such as human immunodeficiency virus, have been found to intensify the burden of this disease, particularly in developing countries like India.

Scientists from the CSIR-Indian Institute of Chemical Biology, Kolkata and Banaras Hindu University, Varanasi, led by Subhajit Biswas, identified Leptomonas seymouri , a virus-carrying microbe in most of the blood samples of kala-azar patients.

The studied samples contained both drug-sensitive and drug-resistant leishmania parasites. The researchers say that the virus can activate specific immune cells, triggering the host’s innate immune responses. This, in turn, might aggravate kala-azar and post kala-azar complications.

This work will possibly encourage further research towards the development of virus vaccines and antivirals for the management of kala-azar and its complications, says Biswas.