Case Report: Coinfection with Rickettsia monacensis and Orientia tsutsugamushi

Abstract

Rickettsia monacensis and Orientia tsutsugamushi are bacteria of the family Rickettsiaceae, which causes fever, rash, and eschar formation; outdoor activities are a risk factor for Rickettsiaceae infection. A 75-year-old woman presented with fever, rash, and eschar and was confirmed as being scrub typhus based on a nested-polymerase chain reaction (N-PCR) test for a 56-kDa gene of O. tsutsugamushi; the genome was identified as the Boryong genotype. In addition, a pan-Rickettsia real-time PCR test was positive and a N-PCR test using a Rickettsia-specific partial outer membrane protein A (rOmpA) confirmed R. monacensis. This is the first case wherein a patient suspected of having scrub typhus owing to the presence of rash and eschar was also found to be coinfected with O. tsutsugamushi and R. monacensis based on molecular testing.

Figure 1.

A 75-year-old woman was admitted with chills and rash as the primary complaints. (A) Eschar lesion identified on the head. (B) Erythematous rash on the face. (C) Conjunctival suffusion in both the eyes. (D) Maculopapular rash on the abdomen. (E) Phylogenetic tree for Rickettsia spp. based on the partial outer membrane protein A (ompA) gene (521 nucleotides). The number at the node represents the bootstrap confidence levels for 1,000 replicates. The black triangles represent the isolates obtained in our study. (F) Phylogenetic tree for Orientia tsutsugamushi based on the partial 56-kDa protein gene (435 nucleotides). The number at the node represents bootstrap confidence levels for 1,000 replicates. The black triangles represent the isolates obtained in our study. This figure appears in color at www.ajtmh.org.