Wednesday, March 26, 2003 - © 2003 Welland Tribune

Bite can hurt more ways than one

By WAYNE CREIGHTON, Tribune Staff

Wednesday, March 26, 2003 - 09:00

Local News - ST. CATHARINES - One of leading authorities on the West Nile virus, Brock University medical entomologist Fiona Hunter has studied biting flies for most
of her career and never been concerned about being bitten.

Until this summer. “This year I will actually make sure I’m not bitten,’’ said Hunter Tuesday following a press briefing by Regional Niagara’s Public Health Department concerning the upcoming West Nile virus season.

“I’ve never, ever worried about it before,’’ she added. “I don’t react to mosquito bites, so why worry?

“My family all spends a lot of time outdoors and regularly get bitten by mosquitoes, but this year we are certainly going to be much more cautious.”

Hunter, who in conjunction with the Ontario Ministry of Health and Long Term Care, has been looking at the abundance and diversity of adult mosquitoes across southern Ontario as part of the West Nile virus Surveillance Program, says her heightened level of caution is well-founded.

“West Nile virus isn’t as predictable as it was previously thought to be. It’s not just a disease that affects older people,’’ said Hunter. “Here in Niagara, we had a seven-year-old testing positive and that really hit close home for me so we will all take precautions.” She says the greatest deterrent to the spread of West Nile virus is public education.

“I’m a total advocate of public education,’’ said Hunter. “I really am.”

Public education will continue again this summer with the health department resuming a direct mail campaign throughout Niagara as well as notices on their web-site as well as a information phone line and an video on COGECO Cable 10.

The Dead Bird Surveillance Program will begin again April with residents asked to call (905) 688-8248, ext. 7335 or 1-800505-6074 when they see a dead crow. Last year more than 2,000 people called the program.

Public education and source reduction are the two key components of Tier 1 in the Region’s three-tier integrated pest management strategy.

“We do know that the the mosquito most likely to bite you was probably born and bred in your own neighbourhood,’’ said Dr. Doug Sider, associate medical officer of health for Niagara. “So, reducing mosquito breeding sites and using insect repellent, wearing long-sleeved shirts and long pants during times of peak mosquito activity is critical to avoiding infection.”

Sider explained that Niagara will begin the 2003 mosquito season at a Tier 2 response level in which non-chemical methods and chemical control will be used.

Non-chemical methods include the flushing and vacuuming of urban catch basins which are a prime mosquito breeding ground and the use of low impact larvicide when mosquito larvae are identified.

Hunter noted that a student of hers even went so far as to visit some of Niagara’s sewers recently to look for over-wintering adult mosquitoes.”

“It was -20 out and he was down in sewer system and found hundreds of over-wintering adult mosquitoes just waiting for things to warm up enough outside so they get out there and start biting people.

“The strategy that’s being used in the United States is to target culex pipiens in the catch basins early so that you could squelch those populations and you wouldn’t get the huge amplification in the bird population,’’ said Hunter.

“If you can keep the bird disease down, then the likelihood of spillover in the human population is much smaller.

“That’s why the big push all over the Midwest to control the culex pipiens in the catch basins because we know there are tens of thousands of catch basins available as breeding sites.

“They’re not as obvious to people as bird baths or other pools of standing water are but they’re there and they are seething masses of mosquito larvae breeding grounds.”

Tier 3 uses pesticides applied by air or through the use of ultra-low volume sprayers to control adult mosquitoes and will not be implemented without discussions with the Chief Medical Officer of Health for Ontario, Medical Officers of Health in adjoining health units, the Ministry of the Environment and other appropriate agencies.

“I want to emphasize that this is a last resort,’’ said Sider. “People can only get the West Nile virus infection when bitten by an adult mosquito. Our aim is to control the mosquito population before larvae begin to mature into adults and avoid the consideration of spraying or fogging our neighborhoods.

“The most effective means of avoiding the need for the implementation of Tier 3 strategy is the full employment of Tier 1 and Tier 2 strategies.”

Sider added that much of the pest management strategy is based on assumptions that what’s gone on the past the couple of years will continue to occur.

“We’re still learning the very complex ecology of this infection within North America,’’ said Sider in response to a question about predictions for this summer. “Each year will be a substantial learning experience and I think we have to plan on that what we’ve seen, especially in 2002, will reoccur and possibly be greater.

“Time will tell if we’ve overplanned or underplanned.”

“But I don’t really know for certain what’s going to happen and we’ve planned in some senses on a worst case scenario.”
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