West Nile Cases Declining, Lyme Disease On The Rise

Although not as abundant as in previous years, Southern Health-Santé Sud wants to remind people that biting insects are still around and people should take the necessary precautions.

When discussing insect-borne illnesses, people’s minds jump to the infamous Lyme disease or West Nile Virus.

Dr. Michael Routledge Medical Officers of Health for Southern Health-Santé Sud, says around 15 years ago were the first reports of West Nile in Canada, and since then the number of reports has steadily decreased.

He says interestingly 70 to 80 per cent of people infected with West Nile virus have no symptoms.

“So there are a number of people who would now be immune to West Nile Virus. A number of people will have fairly mild symptoms that won’t require them to see a doctor, and a fairly small percentage of people will get neurological symptoms, which are more severe types of infections like encephalitis.”

Routledge notes reported cases have been decreasing, and when they do see outbreak it’s near the end of the season and people should be taking the necessary precautions.

Unfortunately, Lyme disease has been seeing the opposite, with reported cases on the rise. Routledge says they’ve been anticipating this increase for many years.

“We saw where established populations of ticks, infected with the bacteria that causes Lyme disease, basically expanded through Wisconsin, then Minnesota, and then southeastern Manitoba. Over the last number of years, we’ve seen these established populations of ticks grow in southern Manitoba.”

It’s essential to protect from these black-legged (deer) ticks, as symptoms can be quite severe. Routledge says they can treat the Lyme disease with antibiotics but recommends to do a thorough tick check after walking through the bush, as there is a 24 hour period before the disease can be transmitted.

In the case of the ‘red meat allergy-causing’ lone star tick, Routledge says they are still learning the science behind its potential relationship to allergies. He says there have been sporadic sightings, but there isn’t much evidence to indicate the infection is here in Manitoba.

While Lyme disease and West Nile Virus are prevalent in Manitoba, looking at the rest of the world, Malaria is one of the most significant. If people are travelling Routledge encourages you to speak to your health care provider. He says that in cases of Malaria or other insect-related illnesses, there are precise recommendations you want to take when travelling.