West Nile virus and Lyme Disease: Here’s what you need to know

Have you ever wondered how a simple tick or mosquito bite can lead to a serious illness?

Mark Loeb, infectious disease specialist and professor in the Department of Pathology & Molecular Medicine, says diseases that are transmitted by arthropods, like mosquitos and ticks, are called vector-borne diseases.

At McMaster, researchers are working to better understand this type of transmission and the pathogens that spread this way. Soon, through Global Nexus, the university will be home to a new state-of-the-art insectary, which will allow for on-campus containment and study of disease vectors, like the ones discussed here by Loeb. The new facility will enable and inform a range of studies into vaccines, therapeutics and other protective measures.

Loeb, who is a part of the Global Nexus executive committee, shared how these infectious diseases are transmitted to humans and how they affect our immune system.

West Nile virus

West Nile is spread through the bite of an infected mosquito. Mosquitoes become infected with the virus when they bite infected birds.

“Most people who get infected won’t develop any symptoms,” says Leob, “but 20 per cent will have a flu-like syndrome and about one in 150 will get serious symptoms, including meningitis, encephalitis or paralysis.”

People who are middle-aged or older are most at risk, he explains, along with people with weak immune systems.

Loeb, a member of the Michael G. DeGroote Institute for Infectious Disease Research, says prevention measures include using mosquito repellent, wearing long-sleeves and pants when you know you’ll be exposed to mosquitos, and getting rid of standing water, which can become mosquito breeding sites around your home.

Lyme disease

Lyme disease is spread through the bite of an infected blacklegged tick, says Loeb, adding that it must be attached to your skin for at least 24 hours to transmit the bacteria that cause Lyme disease.

Most cases in Ontario occur from June to August, cautions Loeb.

“Left untreated, there can be serious complications including inflammation of the heart, meningitis or arthritis and nerve damage,” he adds.

With symptoms like fever, headache, muscle aches along with an enlarging rash, Loeb explains you may feel like you just caught the flu.

Loeb says the best way to prevent getting Lyme disease is to avoid tick bites by using insect repellent, wearing proper clothing and removing ticks as soon as possible after bites.