An infection caused by the bite of a sand fly, visceral leishmaniasis has a 100% fatality rate if left untreated. Characterized by bouts of fever, significant weight loss, swelling of the spleen and liver, and anaemia, the disease can only be treated with medication that kills the parasite that causes the infection. This kind of leishmaniasis has been recurrent mainly in East Africa, but has been detected in other parts of the world.
With a bachelor’s degree in biotechnology and a master’s degree in biochemistry, researcher Smriti Sharma has spent much of her time at the Institute of Medical Sciences in Varanasi, India, studying this disease. Sharma travelled to Atlanta this fall as one of ASTMH’s 2016 Annual Meeting Travel Awardees, an honor that provides full funding for new researchers to participate in the event.
We asked her about her research and why it’s important for her to study visceral leishmaniasis in her home country.
What drew you to visceral leishmaniasis as your disease of study?
Visceral leishmaniasis (VL) is the most severe form of leishmaniasis. In terms of global incidence and burden, leishmaniasis only stands next to malaria, with 350 million people at risk of infection. VL is responsible for approximately 30,000 deaths per year in the developing world, according to the WHO. This lethal disease poses a potential hazard to society, and this was one of the main reasons I was drawn toward studying it.
How would you explain visceral leishmaniasis to a regular person on the street?
Visceral leishmaniasis is commonly called black fever and is caused by the bite of an infected sand fly. These flies commonly inhabit humid places like cracks or animal shelters. The typical symptoms of the disease include fever, weight loss, fatigue, anaemia and enlargement of spleen. The disease symptoms are often mistaken for other diseases like malaria, but it is very easy to diagnose this disease using rapid diagnostic kits. It is the most severe form of leishmaniasis and is lethal if left untreated.
Why is it important to you to study it in your native country of India?
VL is a serious health problem in parts of India and East Africa. In India, 90% of VL occurs in Bihar State. My research supervisor, Professor Shyam Sundar, has been working on treatment and eradication of this disease in Bihar for decades and has achieved many research and treatment milestones. It was a great opportunity for me to work with Professor Sundar on visceral leishmaniasis in endemic sites of this disease. We worked on precious clinical samples of patients with VL and have contributed significantly in understanding the immunology and molecular biology of the disease.
What are the future implications of your research for prevention or control of visceral leishmaniasis?
My research has been less diagnostic and more about understanding the immune responses during active disease. I’ve focused on understanding the contribution of neutrophils during active VL and have reported a very novel subset of neutrophils that are of low density and strongly express HLA-DR. These APC-like neutrophils are unable to cause T cells to proliferate. Instead they strongly express PD-L1 and can contribute to exhaustion of PD-1 expressing T cells during active disease. Neutrophils during leishmaniasis behave as “frustrated phagocytes” trying to restore immune response, but end up further exhausting T cells. This is a very important finding toward understanding the immunology of the disease.
What was the greatest benefit of attending the ASTMH conference?
I got a chance to personally discuss my work with a diverse and brilliant audience of researchers and experts! This year ASTMH also chose students to co-chair sessions with senior scientists. This is a very unique concept. I was also given an opportunity to co-chair one of the important sessions, “Kinetoplastida: Molecular Biology and Immunology,” during the meeting. The competitions, like the Young investigator award, give a boost of confidence, as we are able to present and defend our research work in front of a global audience. It’s a great meeting.
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