Rickettsia sibirica mongolitimonae infection, Sri Lanka.

Charlotte Cordier,Marine Cailleaux,Emmanouil Angelakis,Caroline Leyer,Didier Raoult,Pierre Tattevin

doi:10.3855/jidc.8743

Abstract

Rickettsia sibirica mongolitimonae was recently reported as a common rickettsiosis in France. Current serological evidence suggests the presence of scrub typhus and spotted fever group rickettsiosis in Sri Lanka. We detected a human case of R. sibirica mongolitimonae in Sri Lanka. A skin biopsy of the eschar was tested for the presence of Rickettsia spp. using qPCR assay targeting a 109-bp fragment of a hypothetical protein and by PCR amplification and sequencing targeting the ompA gene. A 30-year-old woman who had just returned from travel to a jungle in Sri Lanka was evaluated as an outpatient for fever. Examination revealed an enlarged axillary lymph node, a maculopapular rash and an eschar at her left flank and a skin biopsy of the eschar was performed. The skin biopsy was positive for the presence of Rickettsia spp. by qPCR and PCR amplification and sequencing targeting the ompA gene revealed R. sibirica mongolitimonae. Immunofluorescence assay on an acute serum sample for spotted fever group rickettsial antigens (Rickettsia conorii conorii, R. sibirica mongolitimonae, Rickettsia felis) and typhus group rickettsiae (Rickettsia typhi) was negative. The patient was treated by oral doxycycline (200 mg/day) for one week. R. sibirica mongolitimonae should be considered in the differential diagnosis of patients with suspected rickettsiosis in, or returning from, Sri Lanka.

Highlights

Rickettsia sibirica mongolitimonae was recently reported as a common rickettsiosis in France
The first human case of infection with R. sibirica mongolitimonae was reported in France in 1996 in patient with rope-like lymphangitis extending from the eschar to the draining lymph node [3]
Serology An acute serum sample was tested by immunofluorescence assay (IFA) for spotted fever group (SFG) rickettsial antigens (Rickettsia conorii conorii, R. sibirica mongolitimonae, Rickettsia felis) and typhus group rickettsiae (Rickettsia typhi) as previously described [15]

Summary

Introduction

Tick-borne rickettsioses are zoonoses caused by spotted fever group (SFG) Rickettsia spp. [1]. The first human case of infection with R. sibirica mongolitimonae was reported in France in 1996 in patient with rope-like lymphangitis extending from the eschar to the draining lymph node [3]. Human cases of R. sibirica mongolitimonae infection have been only described in the Mediterranean area and in South Africa [6]. We detected a human case of R. sibirica mongolitimonae in Asia and most in Sri Lanka in a patient with fever and eschar after a tick bite. Serology An acute serum sample was tested by immunofluorescence assay (IFA) for SFG rickettsial antigens (Rickettsia conorii conorii, R. sibirica mongolitimonae, Rickettsia felis) and typhus group rickettsiae (Rickettsia typhi) as previously described [15]. IFA was considered positive for Rickettsia spp. infection when a single antibody titer of IgG ≥1/128 combined with an IgM titer ≥1/64 against one or more antigens of the tested species [15]

Results

Method Number of patients

Discussion