Prospective Cohort Study of Single-Day Doxycycline Therapy for Mediterranean Spotted Fever.

The objective of this study is to evaluate the results of single-day doxycycline therapy for Mediterranean spotted fever (MSF). This is a prospective cohort study of cases with confirmed MSF treated with the single-day doxycycline regimen in a teaching hospital from 1990 to 2015. Patients received two oral doses of 200 mg of doxycycline for 1 day. The outcomes evaluated were the time interval between the start of treatment and apyrexia, the time interval between the start of treatment and disappearance of other symptoms, and the adverse reactions to treatment and death. The study included 158 subjects, 18 of whom (11.4%) had a severe form of MSF and 31 (19.6%) were >65 years. The interval between onset of symptoms and start of treatment was 4.31 ± 1.54 days. All patients recovered uneventfully. Fever disappeared 2.55 ± 1.14 days after the start of treatment. The remaining symptoms (headache, arthromyalgia) disappeared 3.63 ± 1.35 days after the start of treatment. Only one patient had a delay in reaching apyrexia (8 days). The fever disappeared somewhat later in severe cases (median, 3 days; interquartile range [IQR], 2 to 4 days) than in nonsevere cases (median, 2 days; IQR, 2 to 3 days). Likewise, the remaining symptoms disappeared later in severe cases (median, 5 days; IQR, 4 to 6 days) than in nonsevere cases (median, 3 days; IQR, 3 to 4 days). The outcome was similar in both elderly and nonelderly patients. Eight patients had mild adverse effects possibly related to treatment. The results of the study confirm that single-day doxycycline therapy is an effective and well-tolerated treatment for MSF, including elderly patients and severe cases.