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Background Hepatitis E virus (HEV) infection in several industrialized and developing countries is associated with the consumption of pork and other meat products, an exposure risk among the majority of blood donors. We aimed to evaluate the prevalence of HEV in plasma from healthy blood donors in Thailand. Study design and methods We screened blood samples collected between October and December 2015, from 30,115 individual blood donors in 5020 pools of six, for HEV RNA using in-house real-time reverse-transcription polymerase chain reaction (RT-PCR). Thrice-reactive samples were subjected to a commercial real-time RT-PCR (cobas HEV test) and evaluated for anti-HEV immunoglobulin M and immunoglobulin G antibodies. Genotyping using nested RT-PCR, nucleotide sequencing, and phylogenetic analysis was performed. Results Twenty-six donors were positive for HEV RNA by the in-house assay, nine of whom were also positive by cobas test. None of the latter were reactive for anti-HEV immunoglobulin M or immunoglobulin G antibodies. Six samples were successfully genotyped and found to be HEV genotype 3. Thus, the frequency of HEV infection among healthy Thai blood donors is 1 in 1158. Conclusion The presence of HEV RNA in the Thai blood supply was comparable to the rates reported in western European countries, but higher than in North America and Australia.

Hepatitis B virus (HBV) infection affects an estimated two billion people worldwide. Since 1992, Thailand implemented universal HBV vaccination as part of the expanded program on immunization (EPI) for newborns. This study aims to compare genotypes and characterize HBV by assessing pre-S/S and basic core promoter (BCP)/precore (PC) mutations in populations born before and after EPI implementation. A nationwide serosurvey conducted in 2014 assessed the impact of universal HBV vaccination in Thailand. Two cohort groups were established based on whether they were born before or after 1992. HBV DNA was amplified from HBsAg positive samples by PCR and sequenced. HBV genotypes, pre-S/S regions, and BCP/PC mutations were characterized. From a total of 5,964 subjects, there were 2,805 (47.0%) and 3,159 (53.0%) individuals who were born before and after EPI implementation, respectively. The overall prevalence of HBsAg was 2.2%. The prevalence of HBsAg was significantly higher in the before EPI group (4.3%) than in the after EPI group (0.3%) (P

Perinatal transmission of hepatitis B virus (HBV) has been controlled incompletely despite adequate immunoprophylaxis in infants. The aim of this study was to characterize virological factors of HBV associated with vaccine failure in Thailand. Sera of 14 infected infants (13 HBeAg-positive and one HBeAg-negative) with vaccine failure and their respective mothers (group M1) were tested quantitatively for HBV DNA by real-time PCR, HBV genotypes and mutations were characterized by direct sequencing. Sera collected from 15 HBeAg-positive (group M2) and 15 HBeAg-negative (group M3) mothers whose infants had been vaccinated successfully served as controls. The results showed that group M1 and group M2 mothers had equal titers of HBV DNA but higher titers than group M3. All infected infants and their respective mothers had the same HBeAg status and HBV genotypes. DNA analysis in a pair of HBeAg-negative infant and mother revealed that both were infected with an HBV precore mutant (G1896A). Escape mutants in the “a” determinant region (residues 144 and 145) were detected in two (14%) infected infants. The prevalence of BCP mutations/deletions in groups M2 and M3 was higher significantly than in group M1 (P = 0.022 and P

Background Hepatitis A virus (HAV) infects both humans and non-human primates, in experimentally infected chimpanzees is typically milder than in humans. In 1982, Abe and Shikata reported a first case of a chimpanzee with fulminant hepatitis caused by spontaneous HAV infection, and the underlying mechanisms of the disease remain unknown. Methods To characterize denoted CFH-HAV, we conducted cloning and near full-length sequence analysis. Results Phylogenetic analyses of VP1-2A and complete sequence comparison between various genotypes and the sample sequence showed clustering in genotype IB. Based on BLAST analysis, the sequence was most closely related to the wild-type (HM175/WT) isolate. Amino acid and nucleic acid similarities were 99.8% and 94.41%, respectively. Conclusions The chimpanzee may have been infected with human HAV genotype IB. The substitutions in VP2, VP4, 2B, 2C, and 3D, which may enhance virus proliferation, contributed to disease severity culminating in fulminant hepatic failure.

Vaccination against hepatitis B virus (HBV) immediately after birth prevents neonatal infection by vertical transmission from HBV carrier mothers. There is an ongoing debate whether infant vaccination is sufficient to protect against infection when exposed to HBV later in life. We studied 222 Thai infants born to HBsAg -/+ and HBeAg -/+ mothers who were vaccinated with recombinant hepatitis B vaccine at 0-1-2-12 months of age. A subset of 100 subjects received a booster dose at age 5 years. Blood samples collected yearly for 20 years were examined for anti-HBs antibodies and serological markers of hepatitis B infection (anti-HBc, HBsAg, and in selected cases HBeAg, anti-HBe, HBV DNA). During the 20-year follow-up, no subject acquired new chronic HBV infection or clinical hepatitis B disease. During the first decade, possible subclinical breakthrough HBV infection (anti-HBc seroconversion) was only observed in subjects born to HBsAg +/HBeAg + mothers (6/49 [12.2%]). During the second decade, breakthrough HBV infections were detected in all groups (18/140 [12.8%]). Increases in anti-HBs concentrations that were unrelated to additional HBV vaccination or infection were detected in approximately 10% of subjects in each decade. Primary infant vaccination with a recombinant hepatitis B vaccine confers long-term protection against clinical disease and new chronic hepatitis B infection despite confirmed hepatitis B exposure.

Although hepatitis B virus (HBV) infection is endemic in Southeast Asia, molecular epidemiological data on HBV circulating in some countries are limited. The aims of this study were to evaluate the seroprevalence of HBV and its genetic variability among migrant workers from Cambodia, Laos, and Myanmar in Thailand. Sera collected from 1,119 Cambodian, 787 Laotian, and 1,103 Myanmarese workers were tested for HBsAg. HBV DNA was amplified and the pre-S/S region was sequenced for genotyping and genetic mutation analysis. HBsAg was detected in 282 (9.4%). The prevalence of HBsAg among migrant workers from Cambodia, Laos, and Myanmar was 10.8%, 6.9%, and 9.7%, respectively. Of 224 subjects positive for HBV DNA, 86% were classified as genotype C (99% were sub-genotype C1) and 11.6% were genotype B (30.8%, 34.6%, and 30.8% were sub-genotypes B2, B3, and B4, respectively). Various point mutations in the “a” determinant region were detected in approximately 18% of these samples, of which Ile126Ser/Asn was the most frequent variant. Sequencing analysis showed that 19.1% of samples had pre-S mutations, with pre-S2 deletion as the most common mutant (7.7%) followed by pre-S2 start codon mutation (3.8%) and both pre-S2 deletion and start codon mutation (3.3%). High prevalence of HBV infection (approximately 7–11%) was found among migrant workers from Cambodia, Laos, and Myanmar, which may reflect the current seroprevalence in their respective countries. The data also demonstrated that HBV sub-genotype C1 was the predominant strain and various mutations of HBV occurring naturally were not uncommon among these populations. J. Med. Virol. 82:1341–1349, 2010. © 2010 Wiley-Liss, Inc.

The objectives were to evaluate the impact of the universal hepatitis B (HB) vaccination programme on the prevalence of hepatitis B surface antigen (HBsAg) carriers and immunity to HB virus infection among children < 18 years and to determine the HB seroprevalence in the Thai population. We enrolled people in four provinces including Chiangrai Udon Thani Chonburi and Nakhon Si Thammarat to geographically represent populations in the North Northeast Center and South of the country respectively. Serology for HBsAg anti-hepatitis B surface (anti-HBs) and antihepatitis B core (anti-HBc) was tested using ELISA commercial kits. In total 6213 subjects aged 6 months to 60 years from the four provincial hospitals and two to three district hospitals of each participating province participated. Overall HBsAg anti-HBs and anti-HBc seropositive rates amounted to 4% 41.6% and 26.5% respectively. Of 2887 participants aged 6 months to 18 years 2303 were born after (group I) and 584 prior to (group II) HB vaccine integration into the expanded programme on immunization of each participating province. The HBsAg seropositive rate was 0.7% among group I children and 4.3% among group II children. The prevalence rate of anti-HBc was 2.9% in group I and 15.8% in group II. In children under 18 years the HBsAg carrier rate was 0.98% among complete vaccinees and 1.36% among participants without vaccination. This finding supports the efficacy of universal HB immunization in reducing the prevalence of HB infection in Thailand which is a highly endemic country. (authors)

A male orangutan suffered from ulcers at the buccal mucosa. We obtained swab fluid from the base of both vesicles and ulcers and collected blood for further separation into serum, plasma and peripheral blood mononuclear cells (PBMC) for detection of antibody to herpesvirus by serology and herpesvirus DNA by polymerase chain reaction (PCR) using consensus degenerate primers. Serology was positive for human EBV IgG but negative for Epstein-Barr virus (EBV) immunoglobulin (IgM), as well as for both human cytomegalovirus and herpes simplex virus IgG and IgM. Upon PCR, we obtained a 232-bp product of virus DNA from PBMC, but not from lesions, serum or plasma. We confirmed the positive result by direct sequencing and compared the nucleotide sequence with other nucleotide sequences applying the BLAST program from GenBank. The sequence was similar to lymphocryptovirus of macaque (93%), marmoset (93%), gorilla (90%) and human EBV (90%). We aligned this sequence with other sequences in GenBank and performed phylogenetic analysis, showing that it probably belongs to the gammaherpesvirus group.

Objective: Many studies focusing on the association between hepatitis C virus (HCV) infection and oral lichen planus (OLP) have been conducted. Diversities of geographical locations could be a major factor influencing the prevalence of HCV. This study was aimed to define whether there was a relationship between the OLP and HCV infection in Thailand. Materials and methods: Serum samples of 60 patients (with OLP) and 60 controls (without OLP), whose age and gender were matched, were respectively screened for anti-HCV by ELISA (third generation), and reverse transcription polymerase chain reaction (RT-PCR) for HCV-RNA. Results: We found five patients (8.33%) with OLP infected with HCV: three patients were positive for both anti-HCV and HCV-RNA; one patient was only positive for anti- HCV; and one patient was only positive for HCV-RNA; whereas all the controls were negative for both anti-HCV and HCV-RNA (P = 0.029). Three of five cases of OLP with HCV infection had histories of blood transfusions over 10 years ago. Conclusion: The present study reports a small, but statistically significant high prevalence of HCV infection among patients with OLP, although the underlying mechanism still remains unknown.

Background Hepatitis B virus (HBV) is a public health problem worldwide and apart from infecting humans, HBV has been found in non-human primates. Methods We subjected 93 non-human primates comprising 12 species to ELISA screening for the serological markers HBsAg, antiHBs and antiHBc. Subsequently, we detected HBV DNA, sequenced the whole HBV genome and performed phylogenetic analysis. Results HBV infection was detected in gibbon (4/15) and orangutan (7/53). HBV DNA isolates from two gibbons and seven orangutans were chosen for complete genome amplification. We aligned the Pre-S/S, Pre-C/C and entire genomes with HBV sequences and performed phylogenetic analysis. The gibbon and orangutan viruses clustered within their respective groups. Conclusions Both geographic location and host species influence which HBV variants are found in gibbons and orangutans. Hence, HBV transmission between humans and non-human primates might be a distinct possibility and additional studies will be required to further investigate this potential risk.