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Lime Disease

The major tick-borne diseases that we see in the United States are: Lime disease, the rickettsial diseases, which now includes ehrlichiosis as well as Rocky Mountain Spotted Fever, babesiosis, which seems to live together with the causative agent of Lime disease, and people can get co-infected.

Lyme disease was first described in the mid 1970's during an epidemic of arthritis in Lyme, Connecticut. It was really recognized by a group of mothers of children who were affected with this disease that was initially diagnosed as juvenile rheumatoid arthritis. These mothers wondered why they were seeing a cluster of juvenile rheumatoid arthritis in Lyme, Connecticut and that led to the investigation of that as an outbreak and the discovery of Borrelia burgdorferi in the early 1980's as the causative agent of Lyme disease. This is a spirochetal bacteria. Lyme disease is the leading vector-borne disease in the United States.

Other ticks that feed on humans, such as some of the ticks we will talk about with some of these other diseases, particularly Rocky Mountain Spotted Fever, or dog ticks, don't appear to transmit infection. So the tick that transmits the disease is the deer tick which, when non-engorged, is about the size of the head of a pin. It can therefore be very easily missed. When we talk about the symptoms of infection, we will talk about why some people don't recognize the tick bite.

Most human infections occur in the period between May and August and that is when people are out and about and the ticks are around. Efficient transmission requires about 48 hours of feeing or attachment. This is why prevention can be an important part of anything when we talk about Lyme disease and its impact on the community, because it takes that long for the tick to be able to transmit infection.

The neurologic manifestations include cranial nerve involvement, and facial palsy is the most common cranial nerve involvement, so this is a Bell's palsy presentation. When you see a Bell's palsy, one of the infectious causes that you need to think about is Lyme disease. It may also, less commonly, present with a peripheral neuropathy or a mononeuropathy; this is relatively uncommon.

The other part of this stage of the illness is the joint manifestation. At this stage, they tends to be intermittent, asymmetric oligoarthritis. So it is a wrist that swells and then goes away with a knee at the same time and maybe then an elbow a month later.

That contrasts with the late stage of disease. These are people who may have gone through erythema migrans unnoticed and then months to a year or so later present with one of these late manifestations. The most common late manifestation of Lyme disease is chronic arthritis. This commonly presents with more than a year of synovitis. At this stage, this is not just arthralgia, but frank arthritis, with a swollen joint that may have been aspirated and may have white cells in the joint fluid. About ten percent of people with untreated erythema migrans will progress to chronic arthritis. It is usually asymmetric and in this case, monarthritis - occasionally

In terms of treatment, early disease responds very well to several different antibiotics. The two that are recommended most often are doxycycline and amoxicillin. The doxycycline is 100 mg twice daily and in general is continued for three weeks.

500 mg three times a day for three weeks. There is now the formulation of amoxicillin clavulanic acid or Augmentin that you can use twice a day at 875 mg; you don't need the clavulanic acid part, though; amoxicillin by itself is fine. There are certain settings where you can't use doxycycline, for instance in kids, where amoxicillin is the drug of choice. At this stage, treatment can and really should be given as oral antibiotics. The cure rate for three weeks of therapy is very high when it is used in early disease.

Late disease is where problems tend to come in. Here we are talking about joint, potentially cardiac and neurologic. In these settings, usually intravenous antibiotics are used. Probably the most commonly used drug is ceftriaxone, because it can be given once a day and usually given as 2 grams daily; there are some reports with 2 grams twice a day and there is 1 gram twice a day. For ceftriaxone, you don't need to give it more than once a day, so you eliminate the advantage of using it by giving it twice a day. So 2 grams a day is fine and it is usually given for three to four weeks. Very importantly, symptoms may take much longer to resolve, particularly those neurologic symptoms that I talked about - the mood changes and personality changes. If you are treating someone for central nervous system Lyme disease and you are using intravenous therapy, which is appropriate and you are going for four weeks, longer than four weeks rarely, if ever, is needed. I would say that it is an unusual setting where you would need to use therapy for longer than four weeks, but it is often done. We have all seen people who have been on antibiotics for Lyme disease for more than a year or two. There is no data that supports longer than four weeks of therapy. Occasionally people will need l need to be retreated and that is because they have documented evidence of relapse. Treatment at this stage is not perfect and there is a relapse rate of about five to ten percent. Those people may need to be retreated. In general, when you retreat them, it is for three to four weeks. Again, it is the same caveat - the symptoms can take much longer to resolve. So you can't call someone a treatment failure just because their symptoms last after you stop the antibiotics; you have to look for evidence of ongoing infection and that may be with those cerebrospinal fluid antibodies that I talked about.