A cluster of cases of spotted fever in a kibbutz in southern Israel.

Abstract

During the 3-year period 1984-1986, 13 cases of spotted fever were clinically diagnosed and serologically confirmed among the 341 residents of an agricultural settlement in the Negev desert in southern Israel (attack rate 3.8%, expected attack rate 0.13%). The disease was observed more frequently during the warmer months, with a peak in June. Nine cases were children and adolescents and 4 were adults (attack rate 6.2% and 2.0% respectively; p less than 0.05). The clinical and laboratory findings were consistent with a multisystem involvement. A "tache noire" was not observed in any case. Four cases required hospitalization for complications including severe toxicity, intractable vomiting, thrombophlebitis and hyponatremia. Three of the hospitalized patients were adults and only one was a youngster. All patients recovered. The geographic distribution of the cases showed a clustering in the marginal area of residency: 8 cases occurred among the 121 residents of this area (6.6%), vs. only 5 cases among the 220 residents of the central area (2.3%) (p less than 0.05). This finding suggests that in endemic areas, the inhabitants of the interface between man's habitat and a wild ecological niche have a higher risk of acquiring spotted fever.