Insect Repellants

Insect Repellants

By Trevor Shewfelt, Pharmacist at the Dauphin Clinic Pharmacy

We now have this and most other articles published in the Parkland Shopper on our Website. Please visit us at www.dcp.mb.ca

The information in this article is intended as a helpful guide only. It is not intended to be used as a substitute for professional advice. If you have any questions about your medications and what is right for you see your doctor, pharmacist or other health care professional.

Mosquitoes are out in full force. I was visiting a friend with my daughter Emily last night and just standing in his garage we were getting eaten alive. I guess water and warmth is just what the little vampires were waiting for. You gals and guys making a living in the bush/swamp/field every day have my respect and gratitude. I think I would lose my mind if I was bitten all working day long.

So how do us inside workers avoid getting eaten during our brief excursions outside? Try to reduce the amount of time you spend outdoors between sunset and sunrise. I know these are the only hours you aren’t working. I didn’t say avoiding being bit would be easy. The peak hours for mosquitoes are at sunrise and sunset. Make sure your screens on your doors and windows don’t have rips or tears. Remove standing water like childrens wading pools from your property. Use bug repellant with DEET. Remember that DEET is NOT recommended for children under 6 months of age.

There have been a lot of DEET questions at the pharmacy lately. Here is what Health Canada says: repellents with concentration of DEET of 30% will protect you for approximately 6 hours, DEET 15% for ~5 hours, DEET 10% for ~3 hours, and DEET 5% for ~2 hours. Health Canada says that you should not use DEET on infants under 6 months of age. You can use DEET of 10% or less on children aged 6 months to 2 years if it is absolutely necessary. You can use DEET of 10% or less on children aged 2 to 12 years not more than 3 times per day.

I won’t specifically give advice for pregnant women, because I don’t want to be sued. However, my wife is pregnant and we decided that we could accept the risk of spraying DEET repellent on her clothing only. You pregnant women out there may want to discuss the risks of this option with your health care provider.

Repellants with 30% DEET and higher will no longer be registered in Canada because of fears of the health risks with long term exposure. However, since there have been no actual reports of problems, products with 30% DEET in them already will be allowed to be sold still. Health Canada hopes to phase out the 30% DEET products eventually.

Insect repellants and sunscreens are an interesting challenge. Sunscreens should be put on liberally and often and insect repellants should be used only a little and not often. So this is why combination products with both sun screens and insect repellants were phased out Dec 31/03. Also there was evidence that the chemicals in the combo products counter-acted each other. So how do you apply when you need both? Apply the sunscreen first and work it in. Then apply the bug spray.

Although not as big a panic as last year, whenever you talk about mosquitos, someone asks about West Nile Virus. West Nile Virus was first identified in Africa in 1937. It spread to Europe and it was first reported in North America in New York City in 1999. Since then it has spread to most parts of the US and Canada. The first known human case of West Nile Virus (WNV) in Manitoba was in July of 2003. West Nile Virus is carried by mosquitoes. That means that the mosquito bites an infected animal (often a bird), picks up WNV and then bites the human and gives them WNV.

What are the symptoms of WNV? Most people who become infected with WNV do not become ill, and so won’t report an illness to their doctor. According to Manitoba Health in 2003 141 people saw their doctor and were confirmed to be infected with WNV. Of those 1 had no symptoms, 105 had West Nile Fever, and 35 had the more serious neurological symptoms. West Nile Fever has flu like symptoms such as fever, headache, fatigue and body aches. West Nile Fever is usually considered mild and resolves on its own. The much more rare West Nile neurological syndrome is more serious. The neurological syndrome can include encephalitis, an inflammation of the lining of the brain. Encephalitis can have serious complications including paralysis, confusion, coma or death. Anyone experiencing symptoms like persistent high fever, muscle weakness and headache should seek medical attention.

As of June 21, 2005 there were no mosquitos caught of the type that spreads West Nile Virus in the Parkland. There were also no dead birds (Corvids like crows) reported in the Parkland.

For more information visit:
Health Canada’s Insect Repellent Page: www.hc-sc.gc.ca/pmra-arla/english/consum/insectrepellents-e.html
Manitoba Health’s WNV page: www.gov.mb.ca/health/wnv

As always if you have any questions or concerns about these or other products, ask your pharmacist.