Transmission cycle of murine typhus in Greece.

A field study, based on a follow up of the 49 human cases of the disease that occurred on the island of Evia in 1985, has established the transmission cycle of murine typhus in Greece for the first time. In 1993, two types of traps were used to catch 53 rats, all of them Rattus norvegicus, in the localities where the cases had occurred. Some 300 fleas, all of them probably Xenopsylla cheopis, and a few ticks and mites were collected from the rats. Eight of the fleas were found positive for Rickettsia typhi by PCR and anti-R. typhi antibodies were found in the sera of 48 (91%) of the rats at titres between 1:8 and 1:524,288 and in 22 (42%) at titres > 1:256. The commensal rat population in the general area of study was both ubiquitous and abundant. Murine typhus is obviously endemic in the area and probably of much greater public health significance than the number of reported cases indicates.