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Rickettsioses are emerging infectious diseases caused by rickettsiae in association with arthropods. We report the detection of spotted fever group rickettsiae (SFGR) in Taiwan using molecular methods. Phylogenetic analyses of the 17-kd protein and citrate synthase (gltA) genes showed that SFGR TwKM01 detected in Rhipicephalus haemaphysaloides ticks was most similar to Rickettsia rhipicephali. Three TwKM01 isolates were obtained from three individual R. haemaphysaloides ticks. Small, intracellular, coccobacillary bacteria were found in infected L929 cells using immunofluorescence antibody testing and transmission electron microscopy. Two other SFGRs, TwKM02 and TwKM03, identified in Leptotrombidium chigger mites, were closely related to R. australis and R. felis URRWXCal2, respectively. The TwKM03 strain was also detected in Ixodes granulatus ticks and widely distributed in Hualien, Kinmen, and Lienchiang counties in Taiwan. The endonucleases MaeII and HhaI selected for restriction fragment length polymor- phism analysis of the gltA and 17-kd polymerase chain reaction products, respectively, were useful for genotyping Rickettsia species TwKM01, TwKM02, TwKM03, and other SFGRs. Although their infectivity and pathogenicity for vertebrates are unknown, the finding of SFGRs raises the possibility that bacteria other than Orientia tsutsugamushi, Coxiella burnetii, and R. typhi may be involved in rickettsial diseases in Taiwan.

We report the first case of granulomatous amebic encephalitis caused by Acanthamoeba in a previously healthy farmer in Taiwan who fell into a ditch. The DNA amplicons of amebas identified by polymerase chain reaction in the cerebrospinal fluid specimen and the ditch water specimens were identical and shared strong homology with A. castellanii . He survived after treatment with amphotericin B, rifampin, and corticosteroids.

Dear Sir: We read with great interest the article published by Gunther and others1 that describes the amebiasis-related mortality among United States residents from 1990 to 2007. Of 134 amebiasis deaths during the study period, human immunodeficiency virus (HIV) infection was a co-existing condition in 14 (10.4%), which was statistically significantly more common than in the control, non-amebiasis group with a matched odds ratio of 7.7 (95% confidence interval, 3.16–18.77). Although more studies are warranted to identify the causes of the higher association between HIV infection and amebiasis deaths in the United States, the findings of several previous studies between the 1980s and 2000s2–6 concluded infection with Entamoeba histolytica that is pathogenic was rare in men who have sex with men (MSM). Regardless of HIV serostatus, this may hinder health care providers from considering invasive amebiasis high in the list of differential diagnosis when HIV-infected patients present with symptoms of amebic colitis or abscesses that are difficult to be differentiated from other competing causes of colitis or liver abscess.7 Although the spectrum of amebiasis is similar between HIV-infected patients and the general population,8,9 the amebiasis-related mortality rate is low in developed countries where HIV-infected MSM have long been recognized as a high risk group for amebiasis.8,10,11 In the two largest case series of invasive amebiasis in HIV-infected men in Taiwan and Japan, Hung and others8 and Watanabe and others9 retrospectively reviewed 67 and 170 cases of invasive amebiasis, respectively, and the amebiasis-related mortality rate was 0% and 1.2%, respectively, despite a high percentage of amebic abscess and complications. Recent studies that report cases of invasive amebiasis in MSM and bisexuals in other developed countries12,13 and a higher frequency of amebiasis, detected by specific antigen assays for E. histolytica and serologies, in both developed and developing countries14–17 should raise concerns and warrant reevaluation of amebiasis in patients with HIV infection, especially in MSM.

Rickettsioses are emerging infectious diseases caused by rickettsiae in association with arthropods. We report the detection of spotted fever group rickettsiae (SFGR) in Taiwan using molecular methods. Phylogenetic analyses of the 17-kd protein and citrate synthase (gltA) genes showed that SFGR TwKM01 detected in Rhipicephalus haemaphysaloides ticks was most similar to Rickettsia rhipicephali. Three TwKM01 isolates were obtained from three individual R. haemaphysaloides ticks. Small, intracellular, coccobacillary bacteria were found in infected L929 cells using immunofluorescence antibody testing and transmission electron microscopy. Two other SFGRs, TwKM02 and TwKM03, identified in Leptotrombidium chigger mites, were closely related to R. australis and R. felis URRWXCal(2), respectively. The TwKM03 strain was also detected in Ixodes granulatus ticks and widely distributed in Hualien, Kinmen, and Lienchiang counties in Taiwan. The endonucleases MaeII and HhaI selected for restriction fragment length polymorphism analysis of the gltA and 17-kd polymerase chain reaction products, respectively, were useful for genotyping Rickettsia species TwKM01, TwKM02, TwKM03, and other SFGRs. Although their infectivity and pathogenicity for vertebrates are unknown, the finding of SFGRs raises the possibility that bacteria other than Orientia tsutsugamushi, Coxiella burnetii, and R. typhi may be involved in rickettsial diseases in Taiwan.