June 2018 Board Meeting - Ticks and Lyme Disease Surveillance Information Report

Prepared By:

Amandeep Hans, Health Promotion Specialist, Environmental Health Department

Date:

June 11, 2018

Subject:

Background

Ticks are a relative to the spider and are a crawling, non-flying insect. They vary in size and colour. Ticks are very small (1 to 5 mm) when unfed and female ticks get larger and change colour when fed. Ticks are usually found in wooded areas or areas with long grass, where they attach themselves to humans and animals passing by.

Ticks can spread many diseases including Lyme Disease, Rocky Mountain Spotted Fever, Powassan Virus Disease, and Tularemia. Blacklegged ticks (Ixodes scapularis, formerly called deer ticks) spread the bacteria that cause Lyme disease. The bacteria (Borrelia burgdorferi) are most likely to be transmitted after the tick has been attached to you for more than 24 hours.

The most common symptom of Lyme disease is an expanding bulls-eye skin rash. The rash can begin at the site of the tick bite between three and 30 days after exposure and usually grows in size for several days. Many people never get or see a rash. If the disease is left untreated, other symptoms may develop in the weeks following exposure, including rash, fever, chills, headache, fatigue, muscle and joint aches, problems with your heartbeat, breathing, balance and short-term memory. In rare cases Lyme disease may result in death.

Southwestern Ontario is an established area for Lyme disease. Closer to home, Point Pelee National Park has been identified as an endemic area for blacklegged deer ticks as well as the north shore of Lake Erie, particularly in areas around Long Point, Turkey Point, Rondeau Park and the St. Lawrence Islands National Park. Ticks can be active anytime the temperature is above freezing but the greatest risk of exposure to a tick is during the spring, summer and early fall months.

During the spring and early summer months, ticks can be very small (called nymphs) and once attached can often go unnoticed. This results in a higher chance of being infected with Lyme disease.

Anyone can get Lyme disease, but people who spend more time outdoors are at higher risk. These include: hikers, campers, hunters, people who live or work in an area near woods or overgrown bush, or people who have outdoor jobs. For Lyme disease, there are no vaccines to prevent the illness. Early detection is important to help reduce the risk of developing long-term health effects. Residents can reduce the risk of Lyme disease by using personal protection measures.

To prevent tick bites: 

• Avoid walking in tall grass and stay on the centre of paths.
• Cover up. Wear long- sleeved shirts and pants. Tuck your pants into your socks and wear closed toed shoes.
• Use insect repellant containing DEET or Icaridin on exposed skin and clothing (read and follow directions for use on children). 
• Do a full body check on yourself and your children after being outdoors. 
• Shower within 2 hours of being outdoors.
• Carefully remove any ticks with a tick key or a pair of tweezers.

Current Initiatives

The Windsor Essex County Health Unit’s (WECHU) role is to measure and evaluate the risk of tick-borne disease in our area.  To measure the local distribution and incidence of ticks and Lyme disease cases in Windsor and Essex County (WEC), WECHU uses three surveillance techniques:

Active surveillance involves dragging a white cloth through grassy areas. The ticks attach themselves to the cloth and can be easily spotted. Ticks collected on the cloth are sent to the lab for testing. Tick dragging is performed twice yearly to identify areas in WEC that have populations of blacklegged ticks. Areas for dragging are selected based on known tick habitats as well as areas deemed suitable for potential tick habitats.

Passive surveillance involves residents of Windsor and Essex County submitting ticks to the health unit for identification and subsequent testing if the tick is identified as a blacklegged tick. Passive surveillance is mainly for collection of data and should not be used for diagnostic purposes.

• In 2017, 386 ticks were submitted through passive surveillance
  • Dermacentor variabills (329 ticks, 84.5%),
  • Ixodes scapularis (32 ticks, 8.2%),
  • Two tested positive for B. burgdorferi. (Lyme Disease)
  • Amblyomma americanum (7 ticks, 1.8%).

Human case surveillance is another important method to determine the level of risk in the community. Lyme disease is a disease of public health significance in Ontario. WECHU investigates reported cases of Lyme disease in the region, although the number of cases fluctuates from year to year.  In 2017, there were 7 cases of Lyme disease in WEC residents.

Public education awareness campaign in 2017 included key messages that focused on different types of ticks, preventing tick bites, tick removal, tick submission and the cause and symptoms of Lyme disease. These messages were communicated through the WECHU website, social media, presentations and print materials (fact sheets). All surveillance related activities will continue in 2018. Tick dragging was done on May 17, 2018 at 2 sites: Ojibway Nature Centre and Chrysler Greenway. Twelve dog ticks and four black-legged ticks (males) were collected during the tick–dragging session. The black-legged ticks have been sent to the lab for further testing.

References

• Government of Canada. (2017). Lyme Disease.
• Public Health Ontario. (2018). Lyme Disease.
• Windsor-Essex County Health Unit. (2017). Vector-borne Diseases in Windsor-Essex.

Consultation:

The following individuals contributed to this report:

• Theresa Marentette, Acting CEO and Director, Health Protection Division

• Phil Wong, Manager, Environmental Health Department

• Mike Tudor, Manager, Environmental Health Department

• Saamir Pasha, Epidemiologist, Epidemiology and Evaluation Department

Approved by:

Theresa Marentette, Acting CEO