Sunbathing, a possible risk factor of murine typhus infection in Greece

BACKGROUND: There are few studies about the presence of murine typhus in Greece. Our objective was to conduct a large scale retrospective investigation to determine the clinical and epidemiological features of patients diagnosed with murine typhus in Greece. METHODOLOGY/PRINCIPAL FINDINGS: From 2012 to 2019 serum samples from hospitalized patients and outpatients throughout Greece suspected for murine typhus infection were tested by immunofluorescence assay for Rickettsia typhi. Immunofluorescence positive samples obtained since 2016 were also tested by qPCR targeting R. typhi. Clinical and epidemiological data were retrospectively collected for the patients with confirmed murine typhus. Overall, we tested 5,365 different patients and, in total, 174 patients from all geographic regions of Greece were diagnosed with murine typhus. The most frequently reported sign or symptom was fever (89%), followed by headache (84%) and rash (81%). The classical triad of fever, headache, and rash was present in 72% of patients during their illness. Severe infections with complications including acute renal failure or septic shock were not recorded. The majority of cases (81%) occurred during May–October and peaked in June and September. Most of patients (81%) infected in Athens, recalled that their only activity the last weeks before symptoms onset was swimming on the beach and 59% of them also reported an insect bite while sunbathing. CONCLUSIONS/SIGNIFICANCE: Our results may reflect the reemergence of murine typhus in Greece and we highlight the importance of awareness of this difficult-to-recognize undifferentiated febrile illness.