2005 - Lyme Disease

Table 1. Lyme Disease Cases by Race and Sex, Indiana, 2005

  2005 2001-2005
Cases Rate* Cases
Total 34 0.54 138
   White 21 0.38 104
   Black 0 0 2
   Other 0 0 2
   Not Reported 13 - 30
   Male 24 0.78 80
   Female 10 0.31 57
   Not Reported 0 - 1
*Rate per 100,000 population based on the U.S. Census Bureau’s population data as of July 1, 2005

Lyme disease is caused by the bacterium Borrelia burgdorferi and is the most commonly diagnosed tick-borne disease in Indiana. It is transmitted by the deer tick (Ixodes scapularis) by using small wild rodents as its reservoir. Transmission can occur after the tick has been attached and feeding for approximately 36 hours. Signs and symptoms can appear 3 to 30 days postexposure but generally occur 7 to 14 days postexposure.

In 2005, 34 cases of Lyme disease were reported in Indiana, for a rate of less than 1 case per 100,000 population (Table 1). Figure 1 shows the number of reported cases per year for 2001-2005. Incidence of disease was greatest during the summer months (Figure 2). Over 70 percent of reported cases occur from May through September when ticks are active. As shown in Figure 3, age-specific rates were highest among adults aged 30-39 years (0.97), followed by children aged 10-19 years (0.77). Lyme disease cases were reported more in the northwestern part of the state. Twenty-one counties reported Lyme disease cases; however, only two counties, Lake (1.0) and Porter (3.2), reported five or more cases (Figure 4).

You can learn more about Lyme disease by visiting the following Web sites: