Infectious Diseases - Lyme Disease

Spread by the bites of infected deer ticks, Lyme disease is the most commonly reported vector-borne disease in the United States. (Vector-borne means the indirect transmission of an infectious agent that occurs when any animal that transmits human disease touches or FIGURE 7.2 Estimated HIV coinfection in persons reported with TB, 1993–2003 "Slide 24. Estimated HIV Coinfection in Persons Reported with TB, United States, 1993–2003," in 2004 Surveillance Slides, Centers for Disease Control and Prevention, National Center for HIV, STD, and TB Prevention, Division of Tuberculosis Elimination, 2006, http://www.cdc.gov/nchstp/tb/pubs/slidesets/surv/surv2004/default.htm (accessed January 17, 2006)bites an individual.) Lyme disease is caused by the Borrelia burgdorferi organism and produces early symptoms such as skin rashes, headache, fever, and general illness; if untreated, the disease can cause arthritis and heart damage.

The CDC began to track Lyme disease in 1982, and the disease was added to the list of nationally notifiable diseases in 1990. Figure 7.3 shows the dramatic increase in the number of reported cases since the early 1990s. In 2004 the CDC received reports of 19,804 cases of Lyme disease, with the majority of cases occurring in twelve northeastern and north central states—Connecticut, Rhode Island, New Jersey, New York, Pennsylvania, Delaware, Massachusetts, Wisconsin, Minnesota, Maine, New Hampshire, and Maryland. In these twelve states the average was 27.4 cases for every one hundred thousand persons.

In December 1998 the FDA announced approval for the world's first vaccine against Lyme disease. Doctors warned, however, that although the vaccine, LYMErix, developed by SmithKline Beecham, would help prevent Lyme disease, it would not eliminate the threat entirely. To achieve the best immunity, a person must receive a series of three shots over the course of a full year.

Because LYMErix is not 100% protective, the FDA warned that people still must take precautions against ticks. Wearing long-sleeved shirts and long pants, tucking pants legs into socks, and spraying the skin and/or clothing with tick repellents can keep ticks away from the skin. If a tick is found on the body, it should be removed promptly, and the affected individual should be alert for early symptoms of the disease. Immediate medical FIGURE 7.3 Reported cases of Lyme disease by year, 1991–2004 "Reported Cases of Lyme Disease by Year, United States, 1991–2004," in Lyme Disease, Centers for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases, 2005, http://www.cdc.gov/ncidod/dvbid/lyme/ld_UpClimbLymeDis.htm (accessed January 17, 2006)treatment is imperative to prevent long-term health damage from Lyme disease.