No abstract

culturing the Lyme disease spirochete Borrelia burgdorferi in 1985. This organism was subsequently isolated from blood, cerebrospinal fluid, joint fluid, skin, bone, and autopsy tissues from humans. Fluorescent-antibody tests with murine monoclonal antibodies confirmed that seven of these isolates were B. burgdorferi and that two others belonged to the genus Borrelia. Lyme disease, first recognized in 1975, is a tick-borne infection that can result in long-term rheumatologic or neurologic disorders. A spirochete isolated from Ixodes dammini in 1982 was later found to be the etiologic agent of the illness (6, 16). Since then, this bacterium, called Borrelia burgdorferi, has been detected in tissue specimens from patients who were diagnosed clinically as having Lyme disease (4, 5, 8, 9, 16). These specimens include blood, cerebrospinal fluid (CSF), joint fluids, and skin tissues. At the Texas Department of Health, we began culturing for B. burgdorferi during the spring of 1985. Blood, CSF, joint fluids, bone scrapings, autopsy tissues, and skin tissues from patients whose physicians suspected Lyme disease were submitted to our laboratory. These specimens were placed in modified BSK II medium in an attempt to isolate B. burgdorferi (1). Our findings are reported here. MATERIALS AND METHODS Specimens were collected by physicians and shipped overnight to the Texas Department of Health Laboratory in Austin. Blood, CSF, and joint fluids were sent either on wet or dry ice; skin and autopsy tissues were shipped in approximately 1 ml of either brain heart infusion or thioglycolate medium; and bone scrapings (from the right wrist of the patient) were placed directly into BSK II medium by the physician.

Since the first reported case in 1941, Rocky Mountain spotted fever in humans has been reported from many areas of Texas, with two major foci, one located in the north-central region and the other in the eastern region of the state. During the period 1979-1988, 421 cases of RMSF were reported, reaching 108 cases in 1983 and declining in subsequent years. Statewide surveillance programs to detect spotted fever group rickettsiae in tick populations were initiated in 1976. In recent years, the SFG infectivity rates in these tick species have included Dermacentor variabilis, 5.2%; Amblyomma americanum, 7.1%; Rhipicephalus sanguineus, 2.9%; and Ixodes scapularis, 10.2%. Further determination of involved rickettsial species and pathogenicity is needed, as many of these specimens are collected from humans and during epidemiological investigations. Various foci of murine typhus occur in Texas. During 1979-1988, 400 human cases were reported. The majority of cases occurred in people who resided in south Texas. Several investigations have shown a possible link between typhus infections and exposure to Ctenocephalides felis. Other rickettsial infections currently reported in Texas include Q fever and ehrlichiosis.