SaltWire E-Edition

Insect bites cause nasty reactions for some

Mosquito and black fly bites can give people serious discomfort

LAURA CHURCHILL DUKE SPECIAL TO SALTWIRE NETWORK

Nobody likes to get an itchy fly bite, but ravenous flying insects are an inevitable part of summer. When five-year-old Mary Eddy of bitten Conception Bay South, N.L. gets by blackflies, she has a far more intense reaction than most people.

Her older brother used to have nasty reactions too, but didn’t have as severe swelling as his sister, said their mother, Sarah.

By the time he was four, he had outgrown the reactions. So far, Mary has not.

But the family is hopeful she will. To keep the black flies away, Eddy has tried sprays, bracelets and other gadgets, all to no avail. They end up regularly using Benedryl and Rupall allergy medications in the spring and summer.

Melissa Butt, from Clarenville, N.L., doesn’t remember having a reaction to black flies as a child, but as an adult, she has terrible ones. She was once bitten on the neck and had to go to the hospital because it was swelling so badly.

“I still love summer,” she said. “I just have to have allergy meds and After Bite (insect bite itch and pain relief remedy) on me all the time.”

INFLAMMATION, NOT ALLERGY

According to Dr. Gina Lacuesta, a specialist in allergy and clinical immunology and a professor at Dalhousie University in Halifax, N.S., the diagnosis of an allergic reaction is reserved for stinging insect reactions where anaphylaxis is more possible. When it comes to biting insects, like mosquitoes and black flies, it’s referred to as a local inflammatory process.

Local redness, swelling, itching, sometimes hives, low-grade fever and lymph node swelling can occur, said Lacuesta, depending on the location

develop and severity of the bite. This can and worsen even 24 hours after being bitten and can last for days to weeks sometimes.

At its worst, there can be bullous formation — large, fluid-filled sacs that need to burst and drain clear fluid.

“It can happen with any insect bite like back flies, mosquitoes, or spiders,” she explained.

In her practice, Lacuesta usually only sees someone once or twice a year with so many of these bug bites that it causes systemic symptoms of dizziness, low blood pressure or hives all over — symptoms that really sound like anaphylaxis.

For everyone else, while these aren’t allergy symptoms per se, Lacuesta said it’s the immune system reacting to proteins in the female insects’ saliva that gets injected into the skin.

According to Hugh Whitney, retired chief veterinary officer for Newfoundland, these proteins (called anticoagulants) are produced by the mosquito to make sure the blood does not coagulate when they are drinking. With time, we become immune to these proteins, so we feel the itch less than before.

This is one reason that children may react more to a mosquito bite than an adult, as the child has not yet developed immunity to the protein, said Whitney. This is also why we may feel itchier when we are bitten by a mosquito when on holiday — our body may not be used to the proteins produced by the mosquitoes in that particular area, he said.

If you’re worried about infection, if the bite site continues to get more swollen, painful and redder after a few days, or if the swelling affects functioning, then it may be time to seek medical attention, said Lacuesta.

If you are generally unwell, or clearly have signs of anaphylaxis like dizziness or passing out, hives all over, having trouble breathing or swallowing, you need to be referred to an allergist to discuss next steps and precautions, she said.

Anyone suffering from a bug bite,

symptomatically. Lacuesta said, should treat it Apply ice or use topical steroids, such as a hydrocortisone one per cent cream, which is available over the counter. Non-sedating antihistamines can help with itching, but oral Benadryl has side effects of sedation. There are also topical numbing creams like After Bite that can help with itching.

WHO ATTRACTS MOSQUITOES?

There is conflicting information about how some people are more attractive to mosquitoes than others, said Whitney. This includes ideas around blood type, diet, drinking beer, weight and being pregnant.

There are a few important factors, according to Whitney, which include body heat, carbon dioxide production and the production of certain organic compounds present in sweat or exhaled breath.

“The warmer the better for the mosquito,” he explained. “Therefore, someone who is exercising, heavier, pregnant, dressed in dark clothes will be warmer than other people and attract mosquitoes.”

Blood type, specifically type O, may be more attractive to mosquitoes, but Whitney believes body heat and carbon dioxide are more crucial factors.

CONTRIBUTED

DEALING WITH BUGS

Trying not to get bitten in the first place, or keeping the bugs away altogether, is another story.

“I live in Labrador West and I don’t find anything helps keep them away,” said Julia Vardy.

Newfoundland resident Lexie Pardy is redesigning her backyard to make it more bat-friendly by putting up bat houses. A single brown bat can eat 1,000 or more insects a night and a nursing bat can eat 4,000 a night, she noted.

One of the big things to help keep mosquitoes away is to get rid of things in the yard that may hold water, like tires, buckets or cans, as these are breeding sites for mosquitoes, explained Murray Colbo, a former biology professor at Memorial University in Newfoundland, who has retired to Wolfville, N.S.

Spraying something like Bti, a biological or a naturally-occurring bacterium found in soils, can help kill off mosquitoes, but it’s a controversial choice.

Lindsey Caul, who has a biology degree and a lifelong love of insects, is against the idea of spraying.

“I just get a little rowdy when people go straight for big blanket solutions like spray them all,” said Caul. “There is way more to understand about the situation.”

There would be no way to fumigate the outdoors for a couple of biting insect species without also talking out massive numbers of non-bothersome species that are just minding their own business, additionally poisoning everything that eats them and then everything that eats them, cautioned Caul.

Additionally, just nuking the biting insects alone would have a massive impact since they are a huge food source for a lot of smaller things in the ecosystem. For example, while Bti may kill mosquito larvae in ponds, it also kills any caterpillars that ingest it.

MORE MOSQUITOES?

Many claim that mosquitoes are now more prevalent than ever, but is this actually the case?

Whitney said that any increase in mosquitoes would likely be related to weather conditions, unless there has been a significant change in local

standing habitat, such as more available water in the area with organic material in it.

If we have a warm, damp summer we will see a lot of mosquitoes. If it’s warm and dry there will be fewer, just as if it is cold, he said.

“We usually use 10C as the temperature above which there is mosquito activity. This varies by species, but is commonly used for general discussion,” explained Whitney.

“Over the long term, we would expect an increase in mosquito activity if our summers are longer and warmer due to climate warming,” added Whitney, noting that it would be difficult to measure and no baseline has yet to be established.

TRACKING MOSQUITO SPECIES

The NL Mosquito Project, which Whitney was a part of, ran through the summers of 2018 and 2019. The goal was to determine the number of

Newfoundland mosquito species that live in and Labrador, establishing their range and looking for the presence of any mosquito-borne viruses that might impact human health and to anticipate the impact of climate warming on mosquitoes and the viruses they carry.

The study was funded by the Public Health Agency of Canada, through the Infectious Diseases and Climate Change Fund.

There are now 39 different species of mosquitoes identified to date in the province.

Not that it helps if you are being bitten, but only a very few of the many species in Newfoundland actually bite humans, said Colbo.

“The study did confirm the presence of two viruses in Newfoundland that we already knew were here and which can cause human illness, including snowshoe hare virus and Jamestown Canyon virus,” said Whitney.

“We did not find West Nile virus, which makes us the only Canadian province not to detect this virus.”

But, Whitney noted, that doesn’t mean the virus is not present.

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2022-07-05T07:00:00.0000000Z

2022-07-05T07:00:00.0000000Z

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