CALGARY – A state-of-the-art lab has opened at the University of Calgary to house tiny, biting insects responsible for spreading a disease that kills up to 30,000 people every year.
Sandflies, which are smaller than mosquitoes, live only for a month, but infect a million people each year with the parasite Leishmania, which causes a chronic disease called leishmaniasis.
There is no vaccine. Those who don’t die often end up with lifelong disfiguring scars. Treatment, which involves intravenous medications, can be painful and expensive.
At the insectary at the university’s Cumming School of Medicine, a colony of sandflies is being raised to understand more about how the disease is transmitted and the immune system’s response.
In the lab, the flies are exposed to blood infected with Leishmania parasites. Female flies pass on the organisms to mice by biting them.
“It’s no different than raising fruit flies for genetics research. The parasite itself is not one of these crazy Ebola-level pathogens, but of course we’re putting the two things together,” said Nathan Peters, a professor in the Department of Microbiology, Immunology and Infectious Diseases.
“Our containment level is unique in terms of making sure that those flies, once they’re infected with the parasite, don’t end up where they’re not supposed to be.”
Peters said the research could also help understand other diseases transmitted by insects, such as malaria, Zika and West Nile.
Researchers have been trying to come up with a leishmaniasis vaccine for years, but promising ones never seem to be successful. He suggested the immune system is likely to hold the key.
“When the sandflies bite you, you respond to that very differently in comparison to when a needle prick goes into your skin,” Peters said.
“In the case of the sandflies, it’s very inflammatory and a lot of these immune cells come out of our blood into this tiny little area in the skin.
“The parasite actually infects the cells of your immune system that are sent to fight off any pathogens that might come along for the ride.”
There are three forms of the disease. The most common results in lesions and ulcers on the skin and can lead to serious disability.
Another form attacks the mucous membranes of the nose, mouth and throat. The most serious form shows up in the spleen and liver and if untreated is fatal in 95 per cent of cases.
Leishmaniasis is considered a tropical disease but due to climate change, cases are starting to show up in new regions, including the island of Sicily, the south of France and Spain.
An infectious disease specialist at the school says she treats a handful of patients each year.
“Many of the patients I see didn’t expect to contract this disease on their vacation. They often are on an excursion, like a common jungle adventure, as part of their trip,” said Dr. Bonnie Meatherall.
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