Human Infection with Rickettsia honei, Thailand

• Main Authors: Jiang, Ju, Sangkasuwan, Vichai, Lerdthusnee, Kriangkrai, Sukwit, Suchitra, Chuenchitra, Tippawan, Rozmajzl, Patrick J., Eamsila, Chirapa, Jones, James W., Richards, Allen L.
• Other Authors: NAVAL MEDICAL RESEARCH CENTER SILVER SPRING MD
• Format: Text
• Language: English
• Published: 2005
• Subjects: Medicine and Medical Research; Microbiology; *INFECTIOUS DISEASES; *RICKETTSIA; REPRINTS; SIGNS AND SYMPTOMS; ANTIGENS; TYPHUS; THAILAND; ISLANDS; TICKS; ETIOLOGY; TT-118; SFG(SPOTTED FEVER GROUP); RICKETTSIA HONEI; Flinders; Rattus rattus
• Online Access: http://www.dtic.mil/docs/citations/ADA469012; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA469012

The original Thai tick typhus isolate, TT-118, was obtained from a mixed pool of Ixodes sp. and Rhipicephalus sp. larval ticks from Rattus rattus trapped in Chiangmai Province, Thailand, in 1962 (1) and has recently been determined to be a strain of Rickettsia honei, the etiologic agent of Flinders Island spotted fever (2). No isolate has been associated with Thai tick typhus in humans, and TT-118 was found only to be moderately pathogenic for guinea pigs and gerbils (1). However, evidence of spotted fever rickettsiosis has been seen in Thailand; this evidence comes from 2 reports of a total of 11 cases, 3 cases from Chiangmai and 8 cases from the Thailand-Burma border. All 11 patients had signs and symptoms characteristic of spotted fever rickettsiosis, and their sera were reactive to spotted fever group (SFG) rickettsial antigens, including those derived from TT-118 (3,4). Additional proof of the presence of spotted fever rickettsiae in Thailand derives from rodent (5) and human (6,7) serosurveys. In addition, spotted fever agents have been demonstrated in Thai ticks by using molecular biology techniques to detect rickettsiae (8 10). Collectively, these reports indicate that SFG rickettsiae and rickettsioses exist within Thailand. However, at the time of this writing, detection of an SFG rickettsia from a human source had not been reported in Thailand. Pub. in Jnl. of Emerging Infrectious Diseases, v11 n9 p1473-1475, September 2005.