Dr. Conway McLean, Journal columnist

Infectious disease is once again the topic of the day. Actually, it would be more accurate to say it was the topic of the year (and counting). There certainly are some strange medical conditions resulting from infections. One that has gained some notoriety in recent years is particularly fiendish due to the many serious long term consequences that can be experienced.

Lyme disease is an infection caused by a particular type of bacteria. One interesting facet is the method of transmission. The microbe is spread by a tick bite, which is easily the most common means of getting this disease. The name itself comes from a town in Connecticut where, in 1970, several children developed what looked like rheumatoid arthritis, apparently resulting from a tick bite. In 1982, a scientist identified the bacteria which causes the disease and subsequently had the bacterium named after him.

The most common sign of the infection is an expanding red rash, often compared to a bulls-eye, although you can still have Lyme without this rash. When it is present, it is typically seen at the site of the tick bite about a week after it occurs. The symptoms initially vary greatly, often mimicking various other diseases. Many afflicted with Lyme experience chronic fatigue, or flu-like symptoms including headache, fever, and general malaise. Joint pain and swelling are common, hence the proposed diagnosis of rheumatoid arthritis for those children in Connecticut.

Most cases of Lyme disease can be cured with a few weeks of oral antibiotics, when identified in a timely fashion. But, too often, it is not and those infected will have debilitating symptoms sometimes lasting more than half a year, even after finishing an appropriate course of antibiotics.

Some of the changes experienced may not develop for months or even years after the initial infection. Meningitis may be noted, in which there is inflammation of the membranes surrounding your brain. Also possible is paralysis of one side of your face, although temporary. Other neurologic changes can include numbness, weakness in your arms or legs, even problems with balance. Of great concern, heart problems can also occur as part of the constellation of manifestations of Lyme disease.

Numerous terms have been applied to this scenario, in which disabling pain, fatigue, or difficulty thinking are experienced well after the initial event, especially when it lasts more than 6 months. The condition may be referred to as Post-Treatment Lyme Disease Syndrome , Chronic Lyme disease , even late-stage Lyme disease , all names for this poorly defined condition. We know some of the symptoms experienced, we just have trouble explaining why.

Lyme disease case rates have been increasing exponentially of late. Early in our study of Lyme, a majority of the infections were concentrated in the northeastern region of the United States. But recent reports have found Lyme in every state and in many countries around the world. Apparently, Lyme disease has extended well beyond the traditionally defined areas. In the last few decades, the number of new cases has increased both in the US and globally. Lyme disease is now the most commonly reported disease that is due to an organism transmitting an infectious pathogen into another living organism (termed a vector-borne disease ).

This is now one of the critical questions as yet unanswered: how common is Lyme disease? The CDC states that only 10 percent of Lyme disease cases are being recorded, the rest going undiagnosed and untreated. This translates into approximately 300,000 estimated cases in the United States each year. Some studies suggest that the incidence of Lyme may be as high as 1 million cases per year.

Some well-known celebrities have suffered from Lyme disease, often derailing their career. A world-famous country singer developed dysphonia, which left them temporarily unable to sing, an obvious hindrance to their career. Another music star was bedridden for five months, while one reported alternating weeks with a fever and whole body aches.

Because we have no vaccine for bacterial infections, there is no means of preventing the infection. But reducing the risk of the initial tick bite will result in less cases of Lyme disease. The CDC recommends modifying one s behavior, such as avoiding regions that tend to harbor these creatures. Wear clothing that provides protection, such as long-sleeved shirts, reducing the amount of exposed skin. Repellents containing DEET have been shown to effectively decrease the risk of tick bites. Also, light-colored clothing allows easier identification of the creature. Naturally, removal of any ticks identified from your body is also helpful.

The majority of people who contract Lyme and receive appropriate treatment, a course of antibiotics, do get better with time. Unfortunately, 10 to 20 percent don t, subsequently falling into this chronic disease syndrome category. How to treat these long-term symptoms is still a mystery. Others deal with symptoms similar to those experienced with Lyme disease, but never get a definitive diagnosis for their condition. They may live for months or years, debilitated but ignorant of how or why they are ailing, weakened, feverish.

Perhaps the biggest question on this topic is why are there sometimes prolonged symptoms with Lyme disease? Why do some patients experience PTLDS, Post-treatment Lyme Disease Syndrome, and not others? Some experts believe these bacteria trigger an auto-immune response causing symptoms lasting long after the infection is gone. Auto immune responses are known to occur following other infections: Guillain-BarrÈ syndrome, Reiter s syndrome after a chlamydia infection, and strep throat leading to rheumatic heart disease. Other experts hypothesize that PTLDS results from a persistent infection, but one we are currently not able to detect.

Lyme disease is apparently occurring more frequently, with dozens of tick species implicated. Yet diagnosis remains difficult, especially in the absence of the characteristic bulls-eye rash. Should you or a loved-one experience some of these signs or symptoms, be sure your health care provider considers Lyme disease in your listing of possible causes. No one knows when some of the chronic manifestations of this mysterious ailment will occur. Once again, further evidence modern medicine has a long way to go.