Fever and Chills After a Tick Bite Are Rising in Canada

The same tick that spreads Lyme disease carries a second illness, and it is climbing. Health officials say anaplasmosis is harder to catch early and rougher on the body once it takes hold.

Fever and chills after a tick bite are the usual opening, along with headache and muscle pain, which is precisely the problem. Nothing about that opening says tick bite, so people wait it out as a summer bug while the infection gets a head start.

What does a black-legged tick actually carry?

A bacterial infection spread by the black-legged tick, also called the deer tick, the same species behind most Lyme disease cases in Canada. Kirsten Crandall, a scientific adviser with Quebec's public health institute, told CTV News that the two illnesses come from the same tick and behave differently in the body.

The bacteria infect white blood cells, which is part of why fever and chills after a tick bite can escalate quickly in some people. Canada has had a run of seasonal outbreak stories this summer, including West Nile virus turning up in Ontario mosquitoes. Quebec's provincial guidance on anaplasmosis notes the same tick transmits it to animals as well, and cases have turned up in horses and dogs alongside people.

Why are tick-borne infections spreading in Canada?

Ticks are expanding their range as conditions warm, and the diseases they carry travel with them. Anaplasmosis is now described in Canadian medical literature as the second most common tick-borne disease in the country after Lyme, with case counts rising fastest in Ontario, Quebec, Manitoba and Nova Scotia.

A practice article published in the Canadian Medical Association Journal this summer described an eastern Ontario patient whose infection caused inflammation of the heart muscle, a rare and serious complication, and urged front-line clinicians to keep anaplasmosis in mind for feverish patients from tick country. Severe complications can include organ failure, respiratory failure and neurological problems. Deaths remain uncommon, and the infection is genuinely serious rather than merely inconvenient.

How does this differ from the tick illness everyone knows?

Two differences matter for you specifically. There is no preventive treatment for anaplasmosis of the kind sometimes offered after a high-risk bite. And the transmission window is shorter. With Lyme disease, removing a tick within 24 hours usually protects you. With anaplasmosis, the bacteria can be passed along even when the tick comes off inside that first day.

The other difference is visibility. Lyme sometimes announces itself with a distinctive expanding rash. Anaplasmosis rarely announces anything, which is why diagnosis tends to arrive later and why telling a doctor about your outdoor exposure changes what they test for. Lyme remains far more common in Canada, with hundreds of cases reported in Quebec alone each year, and anaplasmosis is growing at a faster rate from a smaller base.

When should you see a doctor after a tick bite?

Speed is the whole defence. The faster a tick comes off, the lower your odds of getting sick from anything it carries. Check your whole body after time outdoors, especially after walking through grass, brush or wooded trails, and shower within a couple of hours of coming inside. Use repellent, wear long sleeves and long trousers in tick habitat, and keep fine-tipped tweezers somewhere easy to reach. Pull an attached tick straight out and save it in a sealed container in case a clinician wants it identified.

Then watch yourself for the two weeks that follow a tick bite. If fever, chills, headache or unexplained muscle aches turn up, do not wait it out. Tell a doctor about the exposure, because that single detail is what points them toward the right test and early treatment. The same vigilance applies to other seasonal risks, whether that is heat illness on the trail, or the skin changes worth checking after a summer outdoors.

What are the first symptoms after a tick bite?

Fever and chills after a tick bite, along with headache and muscle aches, typically appear within one to two weeks. There is usually no distinctive rash, which is why it is commonly mistaken for influenza or a summer virus. Telling a clinician about recent time in tick habitat is often what prompts the right test.

How is this different from the tick illness people know?

Both come from the black-legged tick. Anaplasmosis has no preventive treatment after a bite, and its transmission window is shorter, so removing a tick within 24 hours does not reliably protect you as it usually does with Lyme. It also rarely produces the expanding rash that can signal Lyme early.

How do you remove a tick safely?

Use fine-tipped tweezers, grasp the tick as close to the skin as possible, and pull straight out with steady pressure without twisting or crushing it. Clean the area afterwards. Save the tick in a sealed container in case identification helps, and note the date so you can track symptoms over the following two weeks.

Where in Canada are these infections turning up?

Cases are concentrated in regions where black-legged ticks are established, primarily Ontario, Quebec, Manitoba and Nova Scotia, with the range expanding as ticks move into new areas. It was first reported in Canada in Alberta and has since spread eastward, appearing in people, horses and dogs.

If you have been bitten or you feel unwell after time outdoors, getting checked early is what keeps a treatable infection from becoming a serious one. Medimap can help you find a walk-in clinic near you or browse the Health Hub for more on seasonal health risks.

This article is general information and not medical advice. It is not a substitute for care from your own doctor. If you develop a high fever, confusion or difficulty breathing after a tick bite, seek urgent care or call 911.