Clinical and Epidemiological Characteristics of Scrub Typhus and Murine Typhus among Hospitalized Patients with Acute Undifferentiated Fever in Northern Vietnam.

Sugihiro Hamaguchi,Shuji Ando,Yen Hai Doan,Le Quynh Mai,Nguyen Quang Tuan,Kenta Shimizu,Lay-Myint Yoshida,Jiro Arikawa,Ngo Chi Cuong,Dang Duc-Anh,Christopher M Parry,Pham Thanh Thuy,Doan Thu Tra,Koya Ariyoshi

doi:10.4269/ajtmh.14-0806

Abstract

A descriptive study on rickettsiosis was conducted at the largest referral hospital in Hanoi, Vietnam, to identify epidemiological and clinical characteristics of specific rickettsiosis. Between March 2001 and February 2003, we enrolled 579 patients with acute undifferentiated fever (AUF), excluding patients with malaria, dengue fever, and typhoid fever, and serologically tested for Orientia tsutsugamushi and Rickettsia typhi. Of the patients, 237 (40.9%) and 193 (33.3%) had scrub and murine typhus, respectively, and 149 (25.7%) had neither of them (non–scrub and murine typhus [non-ST/MT]). The proportion of murine typhus was highest among patients living in Hanoi whereas that of scrub typhus was highest in national or regional border areas. The presence of an eschar, dyspnea, hypotension, and lymphadenopathy was significantly associated with a diagnosis of scrub typhus (OR = 46.56, 10.90, 9.01, and 7.92, respectively). Patients with murine typhus were less likely to have these findings but more likely to have myalgia, rash, and relative bradycardia (OR = 1.60, 1.56, and 1.45, respectively). Scrub typhus and murine typhus were shown to be common causes of AUF in northern Vietnam although the occurrence of spotted fever group rickettsiae was not determined. Clinical and epidemiological information may help local clinicians make clinical diagnosis of specific rickettsioses in a resource-limited setting.

Highlights

Rickettsial infection is one of the common causes of acute undifferentiated fever (AUF) in Southeast Asia after malaria, dengue fever, and typhoid fever have been excluded.[1,2] There are three major rickettsiae causing disease: Orientia tsutsugamushi, the pathogen of scrub typhus, Rickettsia typhi, the pathogen of murine typhus, and the spotted fever group rickettsiae (SFGR)
Little is known about the clinical epidemiology of murine typhus and none of the rickettsiae has been fully investigated in northern Vietnam.[12]
Out of the remaining 342 patients with a negative enzyme-linked immunosorbent assay (ELISA), 210 patients were tested with commercially available IgG immunofluorescent assay (IFA) for R. typhi and 117 patients were positive

Summary

INTRODUCTION

Rickettsial infection is one of the common causes of acute undifferentiated fever (AUF) in Southeast Asia after malaria, dengue fever, and typhoid fever have been excluded.[1,2] There are three major rickettsiae causing disease: Orientia tsutsugamushi, the pathogen of scrub typhus, Rickettsia typhi, the pathogen of murine typhus, and the spotted fever group rickettsiae (SFGR). The clinical presentation of rickettsial diseases ranges from a mild, non-specific febrile syndrome to a life-threatening fatal condition They may mimic tropical febrile illnesses such as malaria, dengue fever, typhoid fever, and leptospirosis.[13] In particular, murine typhus is likely to be underdiagnosed or to be confused with a viral illness because patients usually do not. A qualitative description of the scrub typhus patients in this cohort has been recently published.[12]

MATERIALS AND METHODS

RESULTS

DISCUSSION