LYME-DISEASE SURVEILLANCE IN MARYLAND, 1992

The incidence of Lyme disease (LD) reported to the Maryland Department of Health and Mental Hygiene during 1992 was 6.5/100,000 population, ranging from 29.3 cases/100,000 on the Eastern Shore (74.4% of all cas es) to no cases in the mountains of western Maryland. Among the 317 re ported patients, 44.4% gave a history of tick exposure and 78.9% had p ositive serologic test results. For the 187 (59.0%) patients meeting t he Centers for Disease Control and Prevention (CDC) surveillance case definition, erythema migrans (EM) occurred in 69.5%, with arthritic (2 6.7%), neurologic (13.4%), and cardiac (2.1%) manifestations being les s frequent. Patients nor meeting the surveillance case definition were significantly more likely to have influenza-like symptoms, a smaller rash, and arthralgia. Patients meeting the CDC criteria were more like ly to have an onset during the major transmission season in the summer (odds ratio (OR): 2.1; confidence interval (CI): 1.2 to 3.6) since th is was the time when most (115/130) patients with EM were detected. Po sitive serologic results were more likely (OR: 2.2; CI: 1.2 to 4.2) in those not meeting the case definition. The treatment given to patient s thought to have LD was almost always that recommended in the literat ure and there was no difference between treatment prescribed for patie nts meeting and those not meeting the case definition. These data show that physicians in Maryland are treating many patients for LD who are clinically diagnosed as having LD (e.g., febrile patients with flulik e symptoms, patients with arthralgias or erythematous rashes < 5 cm in size) and who have positive serologic test results but who do not mee t the CDC surveillance case definition. These patients and the large n umber of unreported patients being seen and treated for LD or tick bit es must be added to the overall burden of LD in the state.