PHMDC Header

Featured Topics

Image: Featured Topic

Watch for Blue-Green Algae

Between Memorial Day and Labor Day we test water at local swimming beaches for blue-green algae to determine if they are safe for swimming and recreation, and to reduce chance for illness.

Harmful algal blooms vary in their appearance, looking like scum, foam, or a mat, and despite their name, can be different colors. Lots of sunlight, high water temperatures and low wind levels usually cause them to grow.

Certain blue-green algae blooms produce toxins that can cause symptoms such as stomach upset, rashes, and respiratory irritation. Dogs that come into contact with algal blooms can also get sick and sometimes die because their bodies are smaller and they tend to swallow a lot of water. Both people and pets should avoid being in water where algal blooms are present.

Water is tested at beaches weekly, and if a water test shows concerning results, we will close the beach by posting signs and updating our website. Water is then checked daily until levels blue-green algae return to acceptable levels.

People can check to see if a beach is open before they go by checking our website, Facebook or Twitter pages, or by signing up for beach condition alerts. Even if one beach is closed, others may be open.

Image: Featured Topic


Summer means lots of time spent outdoors; in the woods, at parks, and in our own backyards. It also means the possibility of a bite from an infected deer tick.

The number of deer ticks increased significantly in Dane County in the past few years, and ticks were seen early in the spring due to our milder than usual winter. This means we should be checking for ticks on our bodies not only when we’ve been in the woods, but even in our own backyards.

A bite from an infected deer tick can lead to Lyme disease also cause other diseases such as anaplasmosis, babesiosis, ehrlichiosis and spotted fever rickettsiosis. 

Lyme disease is on the rise in Dane County.  Untreated Lyme disease can produce a wide range of symptoms, including fever, rash, facial paralysis and arthritis. Symptoms of the other diseases spread by deer ticks are very similar and all may occur anywhere from 3 to 30 days after a bite. When treated with appropriate antibiotics in the early stage of symptoms, recovery is usually rapid and complete. 

There are steps you can take to protect yourself from tick bites:

  • Avoid wooded and brushy areas with high grass, and walk in the center of trails if hiking.
  • Use repellents containing 20 to 30% DEET both on exposed skin and clothing, carefully following product instructions.
  • As soon as possible after coming indoors, bathe or shower, conducting a full-body tick check using a mirror. Remember: ticks can be as small as a poppy seed or sesame seed.
  • Tumble clothing you’ve worn outdoors on high heat in a dryer as well, to kill any ticks you’ve missed.

Dogs also are very susceptible to tick bites and the diseases they cause, and ticks might be hard to notice on them. As with humans, prevention is the best defense. Use a tick preventive product on your dog and check it daily for ticks.

Image: Featured Topic

Preventing Mosquito Bites and Disease

Mosquitoes are a real nuisance in the summer months, but their bite can do more than just make you itch; they can transmit diseases like West Nile virus.

Mosquitoes, birds and people can get West Nile Virus. About 1 in 5 people will develop a fever with other symptoms like headache, body aches, joint pain, vomiting, diarrhea, or rash after being bitten by a mosquito that has the virus. Most people recover completely, but in some people, fatigue and weakness can last for weeks or months and they can get more serious infections like encephalitis or meningitis.

Public Health Madison & Dane County (PHMDC) staff monitor mosquito populations each summer, treating water on public land that has high numbers of mosquitoes known to carry and transmit West Nile virus. The treatment limits the buildup of West Nile virus infection in the bird population, which protects human health by reducing the amount of virus in the environment.

Mosquitoes can also transmit Zika virus, but in over 10 years of monitoring, Public Health has never found the two species of mosquitoes in our area that are Zika carriers. They will continue to monitor for them this summer.

Prevention efforts focus on preventing mosquito bites, and getting rid of standing water where mosquitoes can breed.

In order to prevent mosquito bites you should:

  • Wear long-sleeved shirts and long pants from dusk through dawn. That's when many mosquitoes are most active.
  • Install or repair screens on windows and doors to keep mosquitoes outside.
  • Use EPA-registered insect repellents, following product instructions.
  • Treat clothing and gear with permethrin or purchase permethrin-treated items.

In order to eliminate mosquito breeding areas:

  • Once a week, empty and scrub, turn over, cover, or throw out containers that hold water, such as flower pots, gutters, buckets, pool covers, pet water dishes, discarded tires, birdbaths, rain barrels, and trash cans.