Ey. Stromdahl et al., Prevalence of infection in ticks submitted to the human tick test kit program of the US Army Center for Health Promotion and Preventive Medicine, J MED ENT, 38(1), 2001, pp. 67-74
In 1997, ticks removed from humans and received alive by the Tick-Borne Dis
ease Laboratory of the U.S. Army Center for Health Promotion and Preventive
Medicine (USACHPPM) were tested for pathogens by polymerase chain reaction
(PCR). Thirty-three of 222 (15%) Amblyomma americanum (L.) DNAs produced a
mplicons of the expected size of Ehrlichia chaffeensis Anderson, Dawson & W
ilson and 26/222 (12%) produced amplicons indicating Borrelia burgdorferi J
ohnson, Schmid, Hyde, Steigalt & Brenner. Five (2%) appeared to be co-infec
ted with both organisms. Thirteen of 308 (4%) Dermacentor variabilis (Say)
were POP-positive for spotted fever group rickettsiae. Restriction fragment
-length polymorphism analysis indicated all were Rickettsia montane. One hu
ndred twenty-seven D. variabilis from Monroe County, WI, were tested for B.
burgdorferi and 14 (11%) were positive. Five of 24 (21%) Ixodes scapularis
Say were positive for B. burgdorferi and one (2%) was positive for the age
nt of human granulocytic ehrlichiosis. Different species of ticks transmit
different pathogens, and most tick-borne diseases have similar early sympto
ms, therefore knowing the species and infection status of the tick enhances
the physician's ability to consider tick-borne agents as a potential cause
of disease and recommend appropriate therapy. Ongoing surveillance of the
vector species of human diseases provides an additional estimate of human e
ncounters, with infected ticks, and testing ticks removed from humans may i
ncrease our knowledge of the vector status of tick species for transmitting
tick-borne pathogens.