Spotted fever and murine typhus in the Negev desert region of Israel, 1981.

During 1981, 52 cases of rickettsiosis caused by the spotted fever group of rickettsiae were reported in a population of 250 000 living in the Negev desert region of Israel. Retrospectively, at least 5 of these cases were serologically shown to have been caused by Rickettsia typhi, the agent of murine typhus. Most cases of rickettsial disease occurred in the summer months and one half of all cases occurred in children aged 9 years or less. While the specificity of a physician's diagnosis of the rickettsial diseases appears to be high (i.e., few cases of other diseases are misdiagnosed as either spotted fever or murine typhus), the sensitivity of the physician's diagnosis may be lower (i.e., many cases of these diseases presenting as fevers of unknown origin are not diagnosed as rickettsial disease). These findings may also be important for other countries of the region.