This has been a summer of rare illnesses. Things like Hantavirus, West Nile Virus, and most recently, the bubonic plague, have been making headlines in the past few weeks. Many of these illnesses are acquired while outdoors, so it is important to know how they're spread, the symptoms, and how to prevent these things from happening.

Bubonic Plague

Recently, a seven-year-old girl caught a case of the bubonic plague, a disease that killed millions of Europeans in the Middle ages. The girl got the disease after coming in contact with a dead squirrel at a Colorado camping ground. The girl is recovering and will survive after treatment.

How it's spread: Bubonic plague is spread when a person comes in contact with infected fleas that are found on rodents like rats, mice and squirrels.

Symptoms: Sudden high fever, chills, headache, weakness, swollen lymph nodes, seizures and hemorrhages under the skin. 

Where it occurs: Bubonic Plague is very rare as only about 10 cases occur each year in the U.S. Most cases occur in the Southwest. The latest case in in Colorado.

How to avoid It: Avoid contact with rodents; eliminate rock and wood piles where rodents can breed near the home, check pets for fleas and have them treated.

Hantavirus

This summer, some people who camped at Yosemite National Park, died from Hantavirus and thousands of others may have been exposed to the illness.

How it's spread: Hantavirus is contracted when a person touches or breathes in air particles that contain urine, saliva or feces  from certain mice or rats, especially deer mice.

Symptoms: Symptoms can form within one to six weeks after exposure. They include flu-like symptoms such as chills, fever and muscle aches. This then progresses to dry coughs, headache, nausea and vomiting, followed by shortness of breath as the lungs fill with fluid.

Where it occurs: It can occur anywhere in the U.S. where infected rodents dwell. The most recent case was at Yosemite National Park in California.

How to avoid it: Eliminate rodent nesting areas. Open windows of buildings that have been closed for a while and allow the area to air out for half an hour. If you see mouse droppings, spray them with a mix of water and bleach, wait 15 minutes and mop up or wipe with paper towels.

West Nile Virus

The U.S. is facing its worst case of West Nile virus in a decade. Hundreds of people were affected by the illness and dozens of people died. Texas was hit with the worst of it and even declared a state of emergency this summer.

How it's spread: Bites from infected mosquitoes.

Symptoms: Most people have no symptoms, however West Nile virus can develop into West Nile fever with symptoms like fever, headache, tiredness, and body aches, skin rash and swollen lymph glands. Those with the more serious West Nile disease can have symptoms such as headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.

Where it occurs:It can occur in all states, but Texas too the hardest hit this year.

How to avoid it: Get ride of standing water, which can serve as breeding grounds for mosquitoes. Be sure to wear strong insect repellants that contain DEET, picaridin, IR3535 or oil of lemon eucalyptus, especially outdoors.