CADILLAC — Summer is a time for bonfires, pool parties, camping, spending time outdoors, and, unfortunately, pesky mosquitoes.
And when it comes to mosquitoes, there’s always the concern of disease, said Dr. Jennifer Morse, the medical director of District Health Department No. 10.
Last year, there were 104 serious illnesses and nine deaths related to one such disease, West Nile virus, in Michigan, according to a Michigan Department of Health and Human Services press release.
Nationally, there were 2,544 human cases of the virus and 137 deaths reported to the Centers for Disease Control and Prevention in 2018.
There’s not only the potential for annoying bites with mosquitoes, but potential diseases. And there could be more mosqutioes this year.
Potential for more mosquitoes this year
Howard Russell, an insect diagnostician and entomologist at Michigan State University, said in a past interview that the rainy weather during the spring and beginning of the summer will definitely have an impact on the mosquito population.
More rain makes more stagnant water, which means there’s more area for mosquitoes to breed in. There was lots of water this spring which will go toward determining how many mosquitoes there are.
Mosquitoes can generally be split into summer mosquitoes and spring mosquitoes. Spring mosquitoes produce one generation, but summer mosquitoes continue to produce generations as long as water is available.
They depend on summer rain. You won’t see many of those mosquitoes in a dry summer, but if it’s really wet, or we get lots of rain events with two or three inches of rain filling up low-lying areas, we’ll see several generations of summer mosquitoes.
“As long as there’s water there, they’ll continue to reproduce generation after generation,‘ Russell said.
At high summer temperatures, sometimes the process takes just a week. Summer nights with temperatures above 70 degrees and no wind are perfect for mosquitoes.
So if it’s wet from now until September there will be a lot of generations, which can increase the chances of disease, he said.
The diseases that pose risks in Michigan
Eastern equine encephalitis and West Nile virus are the two main mosquito-borne diseases found throughout Michigan, Morse said.
These diseseases are found through the testing of sick birds and horses and people can get sick too.
There are vaccines that people can get for their horses, but as for people they usually only get minimal disease from them, she said.
If someone finds a dead bird they can report it to the Michigan Department of Natural Resources. The DNR Wildlife Disease Lab can be contacted at 517-336-5030 or people can report it online at the department’s Michigan Emerging Diseases website.
West Nile virus
On June 20, a MDHHS press release said the first 2019 West Nile virus activity for Michigan was confirmed in mosquitoes collected in Saginaw and Oakland counties and a Canada goose in Kalamazoo County.
People who work in outdoor occupations or like to spend time outdoors are at increased risk for West Nile virus infection from mosquito bites. Adults 60 years old and older have the highest risk of severe illness caused by West Nile virus.
Symptoms of West Nile virus include a high fever, confusion, muscles weakness and a severe headache. More serious complications include neurological illnesses, such as meningitis (inflammation of the membranes that surround the brain and spinal cord) and encephalitis (inflammation of the brain), according to the release.
Morse said about 1 in 5 people who are infected develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea or rash. Less than 1% of those people get seriously ill and get symptoms like bad headaches, high fevers, encephalitis or meningitis.
She said 10% of those who do get serious symptoms do die.
“Unfortunately it is possible,‘ she said.
West Nile virus is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. Most people who contract the virus have no clinical symptoms of illness, but some may become ill three to 15 days after the bite of an infected mosquito.
As summer temperatures rise, mosquitoes and the virus develop more quickly so it is important to protect yourself from mosquito bites as the weather warms, according to the release.
Mosquitoes that transmit West Nile virus may breed near people’s homes in storm drains, shallow ditches, retention ponds and unused pools. They will readily come indoors to bite if window and door screens are not maintained.
Eastern equine encephalitis
With Eastern equine encephalitis, most people don’t have symptoms and only about 5% of people infected do, Morse said.
These symptoms include chills, fever and joint pain. Symptoms can last longer and stick around a couple of weeks.
This disease is also more likely in people over 60 but also in children and people with a weak immune system, like someone fighting cancer, Morse said.
Only 1% of people with Eastern equine encephalitis get serious symptoms like West Nile virus. About 30% of people who get seriously sick will die, so it has a higher fatality rate than West Nile virus, she said.
She said the disease is less common in humans and it is more likely a horse will contract it. There is a vaccine available for horses and people who own horses should consider this important investment.
There is no specific treatment for West Nile virus or Eastern equine encephalitis. They are like a cold or the stomach flu and basically you treat the symptoms of the patient until they get better.
The symptoms and complications get treated, but not the virus itself and it takes about a week or two for the viruses to go away naturally, she said.
Interestingly, the most diagnosed, mosquito-spread disease in Michigan is malaria, Morse said.
There were 16 cases of diagnosed malaria in Michigan last year. None of them were contracted in Michigan and were all travel-related and acquired outside of the country, she said.
So it’s not just when you’re in Michigan that you should worry about mosquitoes, but also in other countries. Certain areas like Central and South America and Africa have risks for malaria and zika.
“Before traveling, people need to investigate what diseases they need to be concerned about in those areas as well,‘ she said.
She said there’s also a risk for diseases like chikungunya and dengue, which are creeping into Texas, but not normally found in Michigan.
How to protect yourself from pesky bites
“It only takes one bite from an infected mosquito to cause a severe illness, so take extra care during peak mosquito-biting hours, which are dusk and dawn,‘ said Dr. Joneigh Khaldun, MDHHS chief medical executive and chief deputy director for health. “We urge Michiganders to take precautions such as using insect repellant, wearing long-sleeved shirts and long pants when outdoors during those time periods.‘
The best way to prevent West Nile virus or any other mosquito-borne illness is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites.
• Using Environmental Protection Agency registered insect repellents with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol and 2-undecanone. Follow the product label instructions and reapply as directed.
• Don’t use repellent on children under 2 months old. Instead dress your child in clothing that covers arms and legs and cover crib, stroller and baby carrier with mosquito netting.
• Wearing shoes and socks, light colored long pants and a long-sleeved shirt when outdoors.
• Making sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or other openings.
• Using bed nets when sleeping outdoors or in conditions with no window screens.
• Eliminating all sources of standing water that can support mosquito breeding around your home, including water in bird baths, abandoned swimming pools, wading pools, old tires and any other object holding water once a week.
Russell said one of the key things to prevent mosquito bites is to make sure eaves and troughs are cleared out and anything that will hold water. This includes livestock tanks or bird feeders if they’re allowed to sit there.
Morse said she’s always preaching insect repellant and using a repellant that works for mosquitoes and ticks can help prevent all sorts of disease.
She said the EPA has a catalog people can search through for different repellants for their needs, whether it’s for adults or kids or for mosquitoes or ticks.
People might not want repellent because they don’t think it’s safe or it smells funny, but they can find one they can live with, she said.
Besides disease, reactions to bites are another reason to avoid mosquitoes.
“In general mosquito bites aren’t a fun thing to have,‘ Morse said.
Kids can have bad reactions and both children and adults can get a bad infection if they scratch the bite badly enough and break the skin with their nails.
Putting ice packs or anti-itch cream on mosquito bites right away can help with the itching sensation, she said.
Personally this year she has seen lots of struggles with mosquitoes and her kids have already gotten lots of bites. We’ve all had nights as kids where we had trouble sleeping because we’ve had so many mosquito bites, she said.
“Prevention is a lot easier and less miserable than trying to treat them,‘ she said.