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A serological survey of human coronavirus antibodies among villagers in 10 provinces of Thailand was conducted during 2016–2018. Serum samples (n = 364) were collected from participants from the villages and tested for coronavirus antibodies using a human coronavirus IgG ELISA kit. Our results showed that 10.44% (38/364; 21 males and 17 females) of the villagers had antibodies against human coronaviruses. The odds ratio for coronavirus positivity in the villagers in the central region who were exposed to bats was 4.75, 95% CI 1.04–21.70, when compared to that in the non‐exposed villagers. The sociodemographics, knowledge, attitudes and practices (KAP) of the villagers were also recorded and analysed by using a quantitative structured questionnaire. Our results showed that 62.36% (227/364) of the villagers had been exposed to bats at least once in the past six months. Low monthly family income was statistically significant in increasing the risk for coronavirus seropositivity among the villagers (OR 2.91, 95% CI 1.13–7.49). In‐depth interviews among the coronavirus‐positive participants (n = 30) showed that cultural context, local norms and beliefs could influence to bat exposure activities. In conclusion, our results provide baseline information on human coronavirus antibodies and KAP regarding to bat exposure among villagers in Thailand. [ABSTRACT FROM AUTHOR]

From September 2016 to January 2019, we collected 710 rectal swabs from both healthy and sick dogs from small animal hospitals in 5 provinces of Thailand. The samples were tested for canine rotavirus group A (CRV) by using one‐step RT‐PCR specific to the VP6 gene. Our results showed that 0.70% (5/710) were positive for CRV. The five CRVs were then characterized by whole‐genome sequencing. Our results showed that the genotype of Thai CRVs is G3P[3], which is the predominant genotype reported in dogs. The Thai CRVs posed a novel genetic constellation 'G3‐P[3]‐I3‐R3‐C3‐M3‐A9‐N2‐T3‐E3‐H6', which has never been reported in CRVs from dogs but has been reported in rotaviruses from humans. Based on phylogenetic analysis, the Thai CRVs are the result of multiple reassortments in which gene segments might have originated from human and bat rotaviruses and suggests the zoonotic potential of the virus. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 < 0.001). HBV DNA was detected in 119 samples; 111 HBV-positive samples (93%) were genotype C (subgenotype C1). The 'a' determinant mutation was only detected in the 'before EPI' group. Twenty-two years after implementation of the EPI program, the HBV carrier rate is significantly reduced. The most prevalent genotype for the remaining HBV was C1. The 'vaccine escape' mutant, especially the 'a' determinant, was not detected after the launch of the EPI program, and the current HBV vaccine remains highly effective. J. Med. Virol. 88:664-673, 2016. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

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 < 0.001, respectively). In conclusion, instead of the HBeAg status, a high titer of HBV DNA in mothers was the major contributor to perinatal transmission of HBV. Escape mutants might be associated with vaccine failure in some infants. BCP mutations/deletions in mothers might contribute to the prevention of mother-to-infant transmission of HBV. J. Med. Virol. 84: 1177-1185, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. ( NCT00240500 and NCT00456625) [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the clinical applicability of quantitative serum hepatitis B surface antigen (HBsAg), hepatitis B e-antigen (HBeAg) and hepatitis B virus (HBV) DNA for predicting virological response (VR) to pegylated interferon (PEG-IFN) therapy. Methods: Thirty HBeAg-positive chronic hepatitis B patients who received PEG-IFN-α-2b for 48 weeks were enrolled. Quantitative HBsAg, HBeAg and HBV DNA were measured before, during and after the therapy. Paired liver biopsies were performed before and after treatment for covalently closed circular (ccc)DNA and intrahepatic HBV DNA analysis. Results: VR at 48 weeks post-treatment, defined as HBeAg seroconversion and HBV DNA less than 10 000 copies/mL was achieved in 10 (33.3%) patients. Responders had significantly lower baseline HBsAg, HBeAg, cccDNA and intrahepatic HBV DNA levels than non-responders. Baseline and reduced levels of log10 HBsAg and log10 HBeAg correlated well with those of log10 cccDNA and log10 total intrahepatic HBV DNA. Responders showed consistent decrease in serum HBsAg, HBeAg and HBV DNA levels during therapy. HBeAg level of 2.0 log10 sample to cut-off ratio at week 24 on therapy provided the best prediction of sustained virological response, with sensitivity and negative predictive values of 85% and 92%, respectively. One patient (3.3%) who cleared HBsAg at follow up exhibited a more rapid decline in serum HBsAg during therapy than those who developed VR without HBsAg clearance. Conclusion: Quantitative measurement of serum HBeAg during therapy may be superior to serum HBsAg and HBV DNA as a prediction of HBeAg seroconversion. Kinetics of HBsAg levels on therapy may help predict HBsAg clearance after treatment. [ABSTRACT FROM AUTHOR]

The nucleotide sequence of hepatitis C virus (HCV) genotype 6 found mostly in south China and south-east Asia, displays profound genetic diversity. The aim of this study to determine the genetic variability of HCV genotype 6 (HCV-6) in Thailand and locate the subtype distribution of genotype 6 in various geographic areas. Four hundred nineteen anti-HCV positive serum samples were collected from patients residing in - the central part of the country. HCV RNA positive samples based on reverse transcriptase- polymerase chain reaction (RT-PCR) of the 5′UTR were amplified with primers specific for the core and NS5B regions. Nucleotide sequences of both regions were analyzed for the genotype by phylogenetic analysis. To determine geographic distribution of HCV-6 subtypes, a search of the international database on subtype distribution in the respective countries was conducted. Among 375 HCV RNA positive samples, 71 had HCV-6 based on phylogenetic analysis of partial core and NS5B regions. The subtype distribution in order of predominance was 6f (56%), 6n (22%), 6i (11%), 6j (10%), and 6e (1%). Among the 13 countries with different subtypes of HCV-6, most sequences have been reported from Vietnam. Subtype 6f was found exclusively in Thailand where five distinct HCV-6 subtypes are circulating. HCV-6, which is endemic in south China and south-east Asia, displays profound genetic diversity and may have evolved over a considerable period of time. J. Med. Virol. 82:257-262, 2010. © 2009 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aims: This study was undertaken to determine the prevalence and characteristics of hepatitis B virus (HBV) genotypes, antigen subtypes, “a” determinant variants and pre-S gene mutations circulating on a large scale in Thailand. Methods: The sequences of the Pre-S1, Pre-S2 and S regions were determined in serum samples of 147 HBsAg and HBV DNA-positive subjects who had been enrolled from the nationwide seroepidemiological survey conducted on 6213 individuals in 2004. Results: The results showed that genotypes C, B and A accounted for 87.1%, 11.6% and 1.3%, respectively. The distribution of the HBV antigen subtypes was: adr (84.4%), adw (14.2%) and ayw (1.4%). Regarding the “a” determinant, 2/43 (4.65%) and 2/104 (1.92%) samples of vaccinated and non-vaccinated subjects, respectively, displayed mutations, all ofwhich were Thr126Asn. Sequencing analysis showed the pre-S mutations in 14 (9.5%) samples, with pre-S2 deletion as the most common mutant (4.1%) followed by pre-S2 start codon mutation (2.9%), both pre-S2 deletion and start codon mutation (2.0%), and pre-S1 deletion (0.7%). The pre-S mutations were associated with older age and higher mean serum HBsAg level. Conclusion: This study demonstrated that HBV genotype/subtype C/adr and B/adw were the predominant strains circulating in Thailand. The “a” determinant variants seemed to be uncommon, and might not be attributed to vaccine-induced mutation. [ABSTRACT FROM AUTHOR]

Objectives 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. Methods 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 anti-hepatitis 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. Results 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. Conclusions This finding supports the efficacy of universal HB immunization in reducing the prevalence of HB infection in Thailand which is a highly endemic country. [ABSTRACT FROM AUTHOR]

Background Lymphocryptovirus (LCV) is found in various non-human primates. As a herpesvirus naturally infecting gibbons it is closely related to human Epstein–Barr virus (EBV) with which it shares considerable genetic, biological and epidemiologic features. Methods We collected blood samples from 70 gibbons (51 Hylobates lar, 18 Hylobates pileatus and 1 Hylobates agilis) for further separation into serum and peripheral blood mononuclear cells (PBMC). Results Only 13 of 70 (18.6%) sera were serologically positive for human EBV IgG but 64 of 70 (91.4%) PBMCs yielded the partial LCV DNA polymerase gene by semi-nested PCR, which we subjected to direct sequencing. All sequences showed 84% nucleic acid and 91% amino acid identity to human EBV. Phylogenetic tree analysis demonstrated gibbon LCVs clustered separately from other gammaherpesvirinae but closely related to LCV of other species. Conclusions Based on LCV DNA detection, we discovered a high prevalence of LCV infection among gibbons. Further characterization of non-human primate LCV might thus provide new insight into both evolution and pathogenicity of gammaherpesvirinae. [ABSTRACT FROM AUTHOR]

Abstract: Viral hepatitis caused by hepatitis A virus (HAV) infection is a worldwide disease; in most cases, it causes an acute self-limited illness. The nucleotide sequence analysis of HAV has classified the virus in seven different genotypes, which include human (I–III and VII) and simian (IV–VI) groups. Most human strains belong to the genotype I, which has been divided into sub-genotypes IA and IB. The present study has been carried out to determine the prevalence of HAV genotypes from northern India and to correlate with their clinical characteristics. Peripheral venous blood collected from 546 cases of acute viral hepatitis was employed for enzyme-linked immunosorbent assays (ELISA) for the serological detection of hepatitis A–C and E viruses. A nested reverse transcription RT-PCR was performed to detect HAV genome, and the positive samples were sequenced to determine the HAV genotypes. Of 73 (13.4%) cases positive for IgM anti-HAV, 29 (39.7%) were positive for HAV RNA. Genotyping was done for 27 (93%) positive cases by direct nucleotide sequencing. Phylogenetic analysis revealed that 15 (55.6%) isolates belonged to genotype 1A, while 12 (44.4%) isolates to IIIA genotype. The results suggest that both genotypes IA and IIIA are almost equally prevalent in northern India. A significant difference was observed with respect to the mean liver-function profile between the IgM anti-HAV-positive and the IgM anti-HAV-negative (includes hepatitis B (153), hepatitis C (57), hepatitis E (153) and unclassified (136)) cases. There is a need for further research on HAV transmission and genotype distribution in Indian sub-continent. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]