HBV infection in indigenous children, 20 years after immunization in Taiwan: a community-based study.

OBJECTIVES: Hepatitis B virus infection is hyperendemic in Taiwan. In the past, the infection rate has been higher in indigenous villages. The prevalence of chronic HBV infection among indigenous children after immunization remains unknown. METHODS: A total of 843 indigenous children were checked for the hepatitis B seromarker. Another 606 metropolitan children were enrolled for comparison in 2005. RESULTS: The seroprevalences (%) of HBsAg, (hepatitis B surface antigen) anti-HBs, (antibody to hepatitis B surface antigen) and anti-HBc (antibody to hepatitis B core antigen) among indigenous and metropolitan children were 3.2 vs. 0.17 (p<0.001), 47.4 vs. 51.2 (p=0.164), and 10.7 vs. 1.7 (p<0.001), respectively. Among the indigenous children, who were divided into three age groups, the prevalences of HBsAg and anti-HBc increased with age, while anti-HBs decreased significantly (p=0.025, 0.002, and <0.001, respectively). Children with positive HBsAg had a significantly higher mean (SD) age (10.2 (2.2) vs. 9.2 (2.1) years, p=0.024) and a higher ALT value (16.4 (8.0) vs. 10.6 (8.3) IU/L, p=0.001). In a multivariable analysis, indigenous residency, older age group and abnormal ALT value were independent factors associated with positive HBsAg. CONCLUSIONS: The seroprevalence of hepatitis B infection has obviously declined among indigenous children 20 years after mass immunization programs launched in Taiwan. However, it is still higher than that of metropolitan children. Higher rates of chronic HBV infection in the mothers might be one important explanation for this finding.

Hepatitis C virus infection among children in aboriginal areas in Taiwan.

The prevalence of hepatitis C virus (HCV) infection among adults in aboriginal areas has been shown to be higher than in urban areas in Taiwan. Whether the prevalence of HCV infection is also higher among children in aboriginal areas remains unclear. In total, 1176 schoolchildren in four aboriginal areas were invited to participate in the study. All children were tested for serum antibodies to HCV (anti-HCV) and liver enzymes. The age range of children was 6-13 years. Another 606 sex- and age-matched schoolchildren from an urban area served as controls. There was no statistically significant difference in prevalence of anti-HCV between aboriginal and Han Chinese students in aboriginal areas. The prevalence of anti-HCV was 0.3% (4/1176) in aboriginal areas, which was similar to the prevalence of 0% (0/606) in the urban area. The four anti-HCV seropositive aboriginal children were all negative for HCV RNA. Our data suggest that the high prevalence of anti-HCV among aboriginal adults might be due to subsequent exposure to risk factors after school age.

Induction of Epstein-Barr virus (EBV) reactivation in Raji cells by doxorubicin and cisplatin.

BACKGROUND: Epstein-Barr virus (EBV) can be activated in B-lymphoid cells to enter the lytic cycle by various kinds of stimuli, including 12-O-tetradecanoylphorbol-1 3-acetate (TPA), butyric acid, calcium ionophore A23187, transforming growth factor-beta and anti-immunoglobulin crosslinking. EBV reactivation has been clinically observed in patients receiving systemic chemotherapy. This study sought in vitro evidence to suggest whether anticancer drugs may directly contribute to the EBV reactivation. MATERIALS AND METHODS: Raji cells, an EBV-containing Burkitt's lymphoma cell line, were used as the experimental model. TPA served as a positive control for chemical induction of EBV reactivation. Expression of the BZLF1 transcript of EBV and its encoded protein, ZEBRA, were examined by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and flow cytometry, respectively. Transactivation activity of ZEBRA was further assessed by a luciferase reporter assay of EBV DR-promoter activity and a flow cytometry assay assessing the endogenous expression of EA-D (BMRFl). RESULTS: Doxorubicin and cisplatin, two commonly used anticancer agents, induced a dose-dependent up-regulation of BZLF1 mRNA and ZEBRA protein. The luciferase reporter activity and the expression of endogenous EA-D protein, also increased by doxorubicin and cisplatin, indicated an up-regulation of the transactivating activity of ZEBRA. CONCLUSION: These data indicate that cytotoxic anticancer drugs may up-regulate the expression and the transactivating activity of BZLF1, and suggest that systemic chemotherapy may be a risk factor for EBV reactivation in patients with EBV-associated malignancies.

Strongyloides stercoralis infection: a health issue regarding indigenous people in Taiwan.

Strongyloidiasis, caused by Strongyloides stercoralis, is endemic in tropical and subtropical regions. Whether or not the infection rate is higher among indigenous populations in Taiwan remains unclear. The aim of our study was to assess the racial demographics, diagnoses and clinical details of strongyloidiasis. A total of 41 patients (27 males and 14 females) with strongyloidiasis at a tertiary referral centre in eastern Taiwan in a 21-year period were investigated retrospectively. The majority (36/41, 88%) of these patients lived in rural townships. Common clinical symptoms were anorexia, abdominal pain, nausea, vomiting, fever, coughing and diarrhea. The laboratory abnormalities were anemia, eosinophilia, and leukocytosis. The average age of the indigenous patients was younger than that of the Hans Chinese patients. Alcoholism among the indigenous Taiwanese (all males) was significantly more frequent than in the Hans Chinese, which might be one of the reasons that the indigenous males had a higher infection rate than Hans Chinese males. The group of patients with intestinal strongyloidiasis exhibited a significant lower mortality and a higher recovery rate than those with hyperinfection syndrome. Leptospirosis should be considered as an underlying factor associated with strongyloidiasis, especially in indigenous patients. The relationship and mechanism of leptospira-induced overwhelming infection including strongyloidiasis remains to be elucidated.