How it spreads: The disease is transmitted to humans by infected blacklegged ticks who in turn were infected by small rodents. It is not spread from human to human.
Treatment : If the infection is caught early, a three-week course of antibiotics can usually stop its spread to joints and the nervous system.
Prevention: Tuck shirts into pants and pants into socks. Use insect repellent with DEET on exposed skin and permethrin on clothes (available at stores that sell outdoor equipment). Perform tick checks of the whole body, and remove any ticks with sharp tweezers. It is rare to contract Lyme disease if the tick has been on your body for fewer than 24 hours.
Incidence:—Most reported Lyme disease cases come from New England and upper Midwestern states. All states reported 28,921 confirmed and 6,277 probable cases of Lyme disease to the CDC in 2008, a 5 percent increase over 2007.
BATS, RACCOONS and SKUNKS
What it is: A viral disease that infects mammals.
How it spreads: Rabies is transmitted through the bites of wild, rabid animals.
Incidence: The majority of rabies cases reported to the CDC occur in wildlife, although most wild animals are not rabid. Last year in St. Louis County, Mo., 590 bats were tested; 23 had rabies. Domestic pets account for 7 percent of animal rabies cases. Human cases are extremely rare, with one or two a year nationwide. The death of a Texas County man in 2008 was the first in Missouri since 1959.
Symptoms: -- The virus infects the central nervous system and is fatal if not treated early. Early symptoms include fever, headache and weakness. Anxiety, confusion, paralysis and hallucinations can develop.
Treatment: If you are bitten by a wild animal, wash the area with soap and water and seek treatment immediately. Prophylactic shots can prevent rabies infection.
Prevention: Make sure your pets' rabies vaccinations are up to date. If you find a live or dead bat in your home, do not attempt to capture it. Call your county's health department, which will come collect the bat so it can be tested for disease.
What it is: An infection of the blood around the spinal cord and brain. Viral meningitis is generally less severe and tends to resolve on its own.
How it spreads: Bacterial meningitis is contagious in close contact among people through the exchange of saliva or respiratory secretions, although it is not as easily transmitted as the cold or flu and is not spread through the air.
Who it affects: Teenagers at sleep-away camp and college students living in dorms are at increased risk for meningococcal disease.
Symptoms: Common symptoms include fever, headache and stiff neck that may be accompanied by nausea, vomiting, sensitivity to light or an altered mental state. Rare but serious cases can result in the loss of limbs, deafness, seizures or brain damage.
Treatment: Early diagnosis is important to prevent severe illness and the spread of the disease. Meningococcal infections can be treated with antibiotics such as penicillin.
Prevention: A vaccine for bacterial meningitis protects about 90 percent of people who get it. The CDC recommends the vaccine for everyone ages 11 to 18.
Incidence: 1,000 to 2,600 Americans get meningococcal disease every year. About one in 10 cases is fatal.
What it is: A group of bacterial strains found in the intestines that are mostly harmless. Some strains can cause diarrhea and intestinal illnesses.
How it spreads: E. coli is spread through contact with water or food contaminated with animal feces. Raw milk, undercooked meat, swimming pools and bodies of water can all contain the bacteria.
Symptoms: Stomach cramps, diarrhea and vomiting.
Treatment: The symptoms can be treated with hydration. Antibiotics are generally not recommended. Most infections resolve within a week. Rarely, severe infections can lead to kidney damage and death.
Prevention: Wash hands with soap and water after using the bathroom or changing diapers. Avoid swallowing pool or lake water. Cook meat and wash fruits and vegetables thoroughly.
Incidence: There are an estimated 70,000 E. coli infections each year in the United States. Many people who are infected don't seek medical care or aren't tested for E. coli.