Most previous reports of Rocky Mountain spotted fever (RMSF) have included cases either not laboratory confirmed or confirmed by relatively weak diagnostic criteria. In the present study detailed epidemiological, clinical, and laboratory features of 262 confirmed or highly probable cases of RMSF reported from six states from 1977 to 1980 were analyzed. This analysis revealed that early clinical diagnosis of RMSF is difficult because the illness may have a gradual or an abrupt onset, the symptoms and signs may be unusual in timing or frequency, and the clinical appearance may vary depending on such factors as age and location of residence. RMSF was diagnosed later in those who died than in survivors, primarily because of atypical initial symptoms and the late onset of rash. RMSF should be considered in any individual who, during the spring and summer, has been in RMSF-endemic areas and develops a fever, regardless of the absence of rash or history of tick exposure.

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Surveillance of Rocky Mountain spotted fever (RMSF) in the United States has revealed a stable incidence of the disease from 1981 to 1983, with a median of 0.48 cases/100,000 population per year (range, 0.42-0.52). During this three-year period an increase in both the number and the percentage of total cases reported from the West South Central states was observed when compared with previous three-year periods. An expanded case report form, which was introduced in 1981 for use by state health departments, was received for 2,850 (87%) of the 3,294 cases reported in 1981-1983. Of these 2850 cases, 1375 (48%) were laboratory confirmed. Death from RMSF was more common in persons greater than or equal to 30 years of age (case-fatality ratio of 8.4%) than in persons less than 30 years (2.2%, P less than .001). Fatality was also associated with failure to obtain a history of a tick bite within 14 days before onset of illness (P less than .05) and with lack of treatment with tetracycline or chloramphenicol (P less than .01).

Body fluids and brain tissue from rabid human patients have demonstrated only low titers of interferon. Therefore, pharmacokinetic studies of systemically administered and locally injected leukocyte interferon were performed in 2 North American patients with suspected rabies who showed no clinically important side effects of this therapy. Similar therapy was given to 5 patients with symptomatic rabies in Europe and America. Although no prolongation of the clinical course was seen in 3 patients given high-dose intraventricular and systemic therapy, treatment was not initiated until between 8 and 14 days after symptoms were seen. The intraventricular dosage regimen produced cerebrospinal fluid levels that appeared to fall progressively over the 24 hours after injection and demonstrated good but somewhat delayed distribution into the lumbar sac. Titers produced by this therapy were 30- to 10,000-fold higher than those normally observed in this infection, however. In the patients treated at the highest dosage, a diminished and delayed antirabies neutralizing antibody titer was observed, probably a result of the administration of the exogenous interferon.

Q fever (Query Fever) is a zoonosis caused by the rickettsia Coxiella burnetii. Domestic ungulates such as sheep, cattle, and goats serve as the reservoir of infection for humans and shed the desiccation-resistant organism in urine, feces, milk, and especially in birth products. In humans the illness is generally mild; however, Q fever hepatitis is often seen and Q fever endocarditis is an uncommon, but frequently fatal complication. Q fever long has been recognized as an occupational hazard among persons working with animals or animal products, and in laboratories working with C. burnetii. Recently, Q fever outbreaks have occurred in medical research facilities using sheep as research animals. Recommendations are presented for reducing the risk of exposure to Q fever in persons not working with sheep in research facilities that use sheep. In addition, recommendations are presented for reducing the risk of infection in persons who work with sheep in research facilities.