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Healthcare in the News Summer Time Means Tick and Mosquito Bite Time

Facts About Lyme Disease, Rocky Mountain Spotted Fever, and West Nile Virus

Lyme disease (LD) is a multi-stage, multi-system bacterial infection caused by the spirochete Borrelia burgdorferi, a spiral-shaped bacterium that is most commonly transmitted by a tick bite. The disease takes its name from Lyme, Connecticut, where the illness was first identified in the United States in 1975.

According to the Centers for Disease Control and Prevention (CDC), Lyme disease continues to be a rapidly emerging infectious disease, and is the leading cause of all insect-borne illness in the US. The number of annually reported cases has increased 25-fold since national surveillance began in 1982. About 20,000 people are infected each year in the US. The majority (95 percent) of cases are reported in Connecticut, Rhode Island, New York, Pennsylvania, Delaware, New Jersey, Maryland, Massachusetts, Maine, Minnesota, New Hampshire, and Wisconsin.

Rocky Mountain Spotted Fever (RMSF) is an infection caused by the bite of an infected tick. It affects about 250 to 1,200 people a year in the US and usually occurs from April until September, but it can occur anytime during the year where weather is warm. The mid-Atlantic and southeastern states are most affected. The disease is spread to humans from contact with the tick; it is not spread from one person to another.

The West Nile virus belongs to a group of viruses known as flaviviruses, commonly found in Africa, West Asia, Europe, and the Middle East. Flaviviruses are spread by insects, most often mosquitoes. Other examples of flaviviruses include yellow fever, Japanese encephalitis, dengue virus, and St. Louis encephalitis virus (West Nile virus is closely related to the St. Louis encephalitis virus).

The West Nile virus can infect humans, birds, mosquitoes, horses, and some other mammals. In 1999, the virus occurred in the Western hemisphere for the first time, with the first cases reported in New York City. Since then, West Nile virus is considered an emerging infectious disease in the US, as it has spread down the East Coast and to many Southern and Midwestern states.

West Nile virus occurs in late summer and early fall in temperate zones, but can occur year round in southern climates. Usually, the West Nile virus causes mild, flu-like symptoms. However, the virus can cause life-threatening illnesses such as encephalitis (inflammation of the brain), meningitis (inflammation of the lining of the brain and spinal cord), or meningoencephalitis (inflammation of the brain and its surrounding membrane).

Always consult your physician for more information.

[June 2009] Now that summer has officially arrived, millions of Americans will be picnicking in grassy fields and camping in the woods.

The American College of Emergency Physicians encourages people to go outdoors and enjoy the weather. But you should keep in mind that spending more time outdoors puts you at risk of getting bitten by mosquitoes and ticks.

"The bite itself may be nothing more than a minor annoyance," says Dr. Nick Jouriles, president of the American College of Emergency Physicians. "It's the disease that insects carry that can become a serious medical problem."

Insect-Borne Diseases

Ticks can carry Lyme disease, which is caused by one of three species of bacteria belonging to the genus Borrelia. In 70 to 80 percent of cases, the first symptom is a bull's eye-shaped skin rash called erythema migrans. This rash generally shows up between three and 30 days after the bite, according to the US Centers for Disease Control and Prevention (CDC).

Lyme disease can also cause fatigue, chills, fever, headache, muscle and joint aches, and swollen lymph nodes.

When caught early, Lyme disease is highly treatable with antibiotics. However, left untreated, it can spread to other parts of the body, causing debilitating problems such as severe headaches and neck stiffness from meningitis, shooting pains, heart palpitations, dizziness, and joint swelling.

Rocky Mountain spotted fever is another tick-borne disease, which is caused by the bacteria Rickettsia rickettsii. Though not as common as Lyme disease, it can be more severe, according to the American College of Emergency Physicians. It is also treatable with antibiotics.

Symptoms of Rocky Mountain spotted fever can include sudden fever, headache, excessive sweating, severe muscle aches, weakness, nausea and vomiting, and a rash on the hands, feet, arms, or ankles about five to 10 days after being bitten.

When a Tick Bite Occurs

To protect yourself from tick bites, check regularly for ticks and shower after potential exposure.

If you have been bitten, remove the tick by pulling it straight up with tweezers or between your fingertips if tweezers are not available. If possible, store the tick in a sealed plastic bag in your freezer so that you and the tick can be tested for Lyme disease right away if symptoms should occur.

Mosquitoes and West Nile Virus

For the most part, mosquitoes are just a warm-weather nuisance, although some people can have a severe allergic reaction to bites and require emergency treatment.

Mosquitoes can also carry West Nile virus. About 80 percent of people who are infected with West Nile virus show no symptoms; however, some people may develop a high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis, according to the CDC.

Mosquitoes can also transmit encephalitis, which is an inflammation of the brain.

To protect against bites, wear insect repellent, especially at night. Repellents containing DEET are highly effective, but repellant used on children should contain no more than 10 percent DEET. Never put DEET on infants.

Other steps you can take include:

  • staying inside at dusk and dawn, when mosquitoes are most active, or wearing long-sleeved pants and shirts when outside during those hours
  • making sure window screens are in good condition
  • avoid standing near stagnant pools of water, trash cans, and gardens where flowers are in bloom
  • keeping food, drinks, and garbage sealed

Always consult your physician for more information.

 

  
 
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