Human tick bite records in a United States Air Force population, 1989–1992: implications for tick-borne disease risk

Abstract

Reports of tick parasitism were recorded for US Air Force personnel (n = 410) from 30 states and the District of Columbia. Of 462 ticks involved in attacks on people, the lone star tick, Amblyomma americanum, and the American dog tick, Dermacentor variabilis, were the most common species represented (34.2% and 34.0%, respectively). Two vectors of Lyme disease, Ixodes pacificus and Ixodes scapularis (including the former Ixodes dammini) also parasitized people but were less common (1.7% and 9.1%, respectively). In addition, 34 (7.3%) brown dog ticks, Rhipicephalus sanguineus, were identified from human hosts. Most ticks submitted for identification were adults (66.5%) and nymphs (29.1%). Larvae were submitted infrequently (<5%). Of those specimens examined for feeding status, 50.0% had blood-fed to some degree. Patients from which ticks were removed were predominantly male (56.8%) and ranged in age from 1 to 76 years with 55.3% (n = 152) being under 20 years. The head and neck area and the lower extremities were the most common sites of attachment by ticks (37.7% and 24.3%, respectively), but ticks were found attached on other areas of the body also, including the trunk, upper extremities, buttocks, and groin. Most ticks (65.5%) bit their victims during May, June, or July, but parasitism occurred during all months of the year. Our data suggest that people from all age groups and from across the United States are vulnerable to parasitism by ticks and, potentially, tick-borne diseases.