Spotted Fever Group Rickettsioses in Israel, 2010-2019.

Regev Cohen,Sharon Reisfeld,Eyal Leshem,Gabriel Weber,Talya Finn,Ronen Ben Ami,Adi Beth-Din,Dar Klein,Neta Petersiel,Frida Babushkin,Yafit Atiya-Nasagi,Galia Zaide,Alaa Atamna,Hiba Zayyad,Yasmin Maor,Nicola Makhoul,Yael Paran,Lior Nesher,Miriam Weinberger

doi:10.3201/eid2708.203661

Abstract

In a multicenter, nationwide, retrospective study of patients hospitalized with spotted fever group rickettsiosis in Israel during 2010–2019, we identified 42 cases, of which 36 were autochthonous. The most prevalent species was the Rickettsia conorii Israeli tick typhus strain (n = 33, 79%); infection with this species necessitated intensive care for 52% of patients and was associated with a 30% fatality rate. A history of tick bite was rare, found for only 5% of patients; eschar was found in 12%; and leukocytosis was more common than leukopenia. Most (72%) patients resided along the Mediterranean shoreline. For 3 patients, a new Rickettsia variant was identified and had been acquired in eastern, mountainous parts of Israel. One patient had prolonged fever before admission and clinical signs resembling tickborne lymphadenopathy. Our findings suggest that a broad range of Rickettsia species cause spotted fever group rickettsiosis in Israel.

Highlights

In a multicenter, nationwide, retrospective study of patients hospitalized with spotted fever group rickettsiosis in Israel during 2010–2019, we identified 42 cases, of which 36 were autochthonous
Using a large database from the national reference center, we studied the specific species of Rickettsia that cause SFGRs in Israel and characterized their unique epidemiology and clinical features
The study included SFGR diagnosed by molecular methods at the Israel Institute for Biological Research (IIBR; Ness Ziona, Israel), which serves as the national reference center for Rickettsia

Summary

Introduction

Nationwide, retrospective study of patients hospitalized with spotted fever group rickettsiosis in Israel during 2010–2019, we identified 42 cases, of which 36 were autochthonous. Studies from Portugal indicate that compared with Mediterranean spotted fever, ISF is characterized by lower rates of eschar and tick-exposure history, higher frequency of gastrointestinal symptoms, and greater severity of illness with a high case-fatality rate [10,12,13]. The etiology of SFGR in Israel is thought to be R. conorii ITTS on the basis of limited molecular identification of this strain from clinical cases and from ticks [9,15,25]. The yearly variations in disease severity and clinical manifestations are intriguing and may suggest involvement of >1 species of spotted fever group (SFG) Rickettsia.

Methods

Results

Conclusion