Development of PCR-RFLP method to distinguish between Cryptosporidium parvum and C. hominis in Taiwan water samples.

Cryptosporidium, a protozoan pathogen that causes cryptosporidiosis has emerged as an important source of diarrheal illness among humans and animals. The current routine laboratory technique used for Cryptosporidium diagnosis is light microscopy with acid-fast staining but the technique has low efficiency and sensitivity for species-specific identification. Single PCR to amplify a 220 bp fragment of 18 S ribosomal DNA of C. parvum and C. hominis was developed. The restriction enzymes, TaqI and VspI, were used to distinguish between amplicons of human and bovine C. parvum genotype. Water samples, collected from Lo-Na, Ton-Pu, Ho-Ping, and Jen-Ai, Taiwan contained only bovine C. parvum genotype whereas in the Ton-Pu and Jen-Ai samples C. hominis was also present. Thus, the used of PCR-RFLP allowed successful identification of Cryptosporidium in water samples and differentiation between human and bovine species.

Microbial contaminations of laboratory mice and rats in Taiwan from 2004 to 2007.

Limited data are available on the pathogen status of contemporary rodent colonies in Taiwan. Here we summarized the rodent pathogen diagnostic records of the Taiwan National Laboratory Animal Center during a 4-y period that representing approximately 10% of the rodent colonies in Taiwan. Demand for pathogen diagnostic service increased continuously from 2004 to 2007, with a 20% increase each year. In 2007, more than 20% of the mouse colonies were positive for mouse parvovirus, mouse hepatitis virus, Theiler murine encephalomyelitis virus, and Mycoplasma pulmonis, with fewer colonies diagnosed as having infections of pneumonia virus of mice, mouse adenovirus, lymphocytic choriomeningitis virus, and reovirus. Almost 40% of tested rat colonies were positive for Mycoplasma pulmonis and rat parvovirus, with fewer colonies containing Kilham rat virus, sialodacryoadenitis virus, pneumonia virus of mice, Sendai virus, and Syphacia spp. These data provide a sound overall picture of the health status of mouse and rat colonies in Taiwan.

Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan.

BACKGROUND: Incidence of Entamoeba histolytica infection and clinical manifestations and treatment response of invasive amebiasis (IA) in HIV-infected patients have rarely been investigated before. METHODOLOGY/PRINCIPAL FINDINGS: At the National Taiwan University Hospital, medical records of HIV-infected patients who received a diagnosis of IA between 1994 and 2005 were reviewed. The incidence of amebiasis was investigated in serial blood and stool samples from 670 and 264 HIV-infected patients, respectively, using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Sixty-four (5.8%) of 1,109 HIV-infected patients had 67 episodes of IA, and 89.1% of them were men having sex with men (MSM). The CD4 count at diagnosis of IA was significantly higher than that of the whole cohort (215 cells/microL vs. 96 cells/microL). Forty episodes (59.7%) were liver abscesses, 52 (77.6%) colitis, and 25 (37.3%) both liver abscesses and colitis. Fever resolved after 3.5 days of metronidazole therapy (range, 1-11 days). None of the patients died. The incidence of E. histolytica infection in MSM was higher than that in other risk groups assessed by serological assays (1.99 per 100 person-years [PY] vs. 0 per 100 PY; p<0.0001) and amebic antigen assays (3.16 per 100 PY vs. 0.68 per 100 PY; p = 0.12). In multiple logistic regression analysis, only MSM was significantly associated with acquisition of E. histolytica infection (adjusted odds ratio, 14.809; p = 0.01). Clustering of E. histolytica isolates by sequencing analyses from geographically-unrelated patients suggested person-to-person transmission. CONCLUSIONS/SIGNIFICANCE: HIV-infected MSM were at significantly higher risk of amebiasis than patients from other risk groups. Despite immunosuppression, amebic liver abscesses and colitis responded favorably to treatment.

Prevalence of intestinal infection due to Cryptosporidium species among Taiwanese patients with human immunodeficiency virus infection.

BACKGROUND/PURPOSE: Cryptosporidiosis causes significant morbidity and mortality in human immunodeficiency virus (HIV)-infected patients who do not receive highly active antiretroviral therapy. Related data on cryptosporidiosis in Taiwanese HIV-infected patients are very limited. This study assessed the prevalence of intestinal infection due to Cryptosporidium spp. among Taiwanese patients with HIV infection. METHODS: This retrospective review included 1044 patients with HIV infection treated between June 1994 and June 2004. Intestinal colonization due to Cryptosporidium spp. was identified by polymerase chain reaction and restriction fragment length polymorphism of stool specimens collected from 332 of the HIV-infected patients without gastrointestinal symptoms, 90% of whom were receiving highly active antiretroviral therapy. RESULTS: Five out of 1044 (0.5%) HIV-infected patients had a diagnosis of intestinal cryptosporidiosis by endoscopic biopsy or examinations of stool specimens. Intestinal colonization due to Cryptosporidium spp. was found in four of 332 (1.2%) asymptomatic HIV-infected patients between 2001 and 2003; two were due to C. hominis, and one each were due to C. felis and C. meleagridis. CONCLUSION: Our findings indicate that the prevalence of intestinal colonization due to Cryptosporidium is low among HIV-infected patients in Taiwan.