Placental infection of hepatitis B virus among Thai pregnant women: Clinical risk factors and its association with fetal infection.

OBJECTIVES: To identify the risk factors of placental and fetal infections among HBsAg-positive women. METHODS: A prospective cohort study involving HBsAg-positive pregnant women was conducted. Maternal risk factors, including serum HBeAg status, anti-HBcIgM, and HBV-DNA levels, were determined. Placental infection was identified by PCR and confirmed by DNA sequencing. Fetal infection was defined as a positive umbilical cord blood HBV-DNA at birth. RESULTS: A total of 96 HBsAg-positive women were enrolled in the study. The prevalence of placental infection was high (44 of 96; 45.8%) among HBsAg-positive women. The major risk factors for placental infection were high maternal viral load and the presence of HBeAg. Fetal infection was detected in one quarter of HBsAg-positive women (25 of 95; 25.3%). The risk of fetal infection was strongly associated with placental infection (78.3%), high maternal viral load, and the presence of HBeAg. There was no significant difference in perinatal outcomes between the groups with and without placental infection. Data on rates of chronic HBV infection in infants after fetal infection were not available. CONCLUSION: A significant association between maternal measures of viral replication and placental and fetal infection was demonstrated. These findings suggest that transplacental infection prior to birth may be a mechanism contributing to the higher rates of newborn prophylaxis failure in women with a high viral load.

Distribution of norovirus and sapovirus genotypes with emergence of NoV GII.P16/GII.2 recombinant strains in Chiang Mai, Thailand.

Norovirus (NoV) and sapovirus (SaV) are recognized as the causative agents of acute gastroenteritis, and NoV is one of the leading pathogens reported worldwide. This study reports on the distribution of NoV and SaV genotypes in children hospitalized with acute gastroenteritis in Chiang Mai, Thailand, from January 2015 to February 2017. From a total of 843 stool samples, 170 (20.2%) and 16 (1.9%) were identified as having NoV and SaV infections, respectively. Two samples (0.2%) were positive for both NoV and SaV. Of these, NoV GII.4 (57.2%) was the dominant genotype, followed by GII.2, GII.3, GII.17, GII.6, GII.7, GII.13, GII.14, GII.15, GII.21, GI.6, and GI.5. Among the NoV GII.4 variants, Sydney 2012 was the dominant variant during the period 2015-2016, while the other variants detected in this study were Asia 2003 and New Orleans 2009. Interestingly, an increase of NoV GII.2 was observed in 2016 and 2017. Characterization of partial RNA-dependent RNA polymerase and VP1 nucleotide sequences of GII.2 strains revealed that more than half of the GII.2 strains circulating in 2016 and 2017 were recombinant strains of GII.P16/GII.2. For SaV, the majority of strains belonged to GI.1 (55.6%) and GI.2 (33.3%), while GII.5 accounted for 11.1%. In conclusion, this study demonstrates the diversity of NoV and SaV, and the emergence of NoV GII.P16/GII.2 recombinant strains in 2016 and 2017 in Chiang Mai, Thailand.

Molecular epidemiology and genetic diversity of human parechoviruses in children hospitalized with acute diarrhea in Thailand during 2011-2016.

Little is known about human parechovirus (HPeV) infection in Thailand. The genotype distribution of HPeV strains in children admitted to hospitals with acute gastroenteritis was investigated using polymerase chain reaction (PCR) and nucleotide sequencing of the VP1 region as the detection and genotype identification methods, respectively. Of a total of 2,002 stool samples, 49 (2.4%) were positive for HPeV. Of these, HPeV-1 was the most predominant genotype (40.8%), followed by HPeV-3 (16.3%) and HPeV-14 (16.3%), while HPeV-5, -6, -2, -4, and -8 strains were less frequently detected, at 10.2%, 8.2%, 2%, 2%, and 2%, respectively. HPeV infections were detected throughout the year with the biannual peaks of infection in the rainy (Jun-Jul-Aug) and winter (Nov-Dec-Jan) months in Thailand. Based on VP1 amino acid sequence alignment, the arginyl-glycyl-aspartic acid (RGD) motif was found in HPeV-1, -2, -4, and -6 strains. Additionally, an amino acid insertion at the N-terminus of VP1 was observed in HPeV-4 and HPeV-5 strains. Phylogenetic analysis revealed that small clades of HPeV-1 and HPeV-3 strains emerged in 2016 and 2015, respectively, and dominated in the year of their emergence. The HPeV strains detected in Thailand in this study were most closely related to reference strains from Asia and Europe. The evolutionary rate of HPeV strains was 2.87 × 10-4 (95% highest posterior density (HPD) 0.10-6.14 × 10-4) substitutions/site/year. These findings provide information about the genetic diversity and evolutionary dynamics of HPeV genotypes circulating in pediatric patients with acute gastroenteritis in Thailand.

Characterization of Erythromycin and Tetracycline Resistance Genes of Streptococcus gallolyticus Subspecies pasteurianus Strains Isolated from Patients with Septicemia and Bacteremia in Thailand.

BACKGROUND: Streptococcus gallolyticus subspecies (subsp.) pasteurianus, previously known as Streptococcus bovis biotype II/2, has been described as a causative agent of endocarditis, neonatal sepsis, meningitis, bacteremia, and colorectal carcinoma in humans. The aim of this study was to characterize the erythromycin and tetracycline resistance genes of S. gallolyticus subsp. pasteurianus strains isolated from patients with septicemia and bacteremia in Thailand. METHODS: The clinical isolates of Streptococcus gallolyticus were identified by using conventional biochemical tests, PCR, and sodA gene sequence analysis. The erythromycin and tetracycline susceptibilities were determined by disk diffusion and agar dilution methods, while the resistance genes were identified by nucleotide sequence analysis. RESULTS: From a total of 108 blood cultures, 36 (33%) were identified as S. gallolyticus subsp. pasteurianus with the nucleotide sequence identities of partial sodA gene with the reference strains ranging from 98.1 to 100%. Of these, 25 (69.4%) contained erythromycin resistance genes and erm(B) was the most predominant gene (30.6%), followed by erm(T) (19.4%) and mef(A) (5.6%). In addition, erm(B) was also detected in combination with lnu(B) (8.3%), erm(T) and mef(A) (2.8%), and mef(A) and lnu(B) (2.8%). It was interesting to note that lnu(B) was detected for the first time in S. gallolyticus subsp. pasteurianus in this study. For tetracycline resistance genes, tet(L) and tet(M) were detected at 13.9% and 11.1%, respectively. However, tet(M) in combination with tet(L) was detected most commonly at 69.4% and with tet(L) and tet(O) at 5.6%. CONCLUSIONS: A number of erythromycin and tetracycline resistance genes were detected in S. gallolyticus subsp. pasteurianus strains circulating in Thailand.

Increasing predominance of G8P[8] species A rotaviruses in children admitted to hospital with acute gastroenteritis in Thailand, 2010-2013.

Rotavirus A is a well-known etiological cause of acute gastroenteritis in infants and young children worldwide. In this study, we investigated the prevalence and distribution of RVA genotypes circulating in children with acute gastroenteritis in Thailand from 2010 to 2013. A total of 1,032 fecal specimens were collected from children with an age range from neonatal to 15 years of age and tested for RVA by RT-PCR. Of these, 184 (17.8%) were positive for RVA. The highest detection rate of RVA was found in children aged between 12 and 24 months. The G1P[8] genotype was identified as the most dominant genotype (57.6%), followed by G2P[4] (12.5%), G8P[8] (10.4%), G9P[8] (7.1%), G3P[8] (4.9%), G1P[4] (2.2%), G2P[8] (1.7%), and mixed-infections of G1 and G3 in combination with P[8] (0.5%). In addition, the uncommon human rotavirus strains G4P[6] (1.1%), G9P[19] (0.5%), G12P[4] (0.5%), and G12P[6] (0.5%) were also detected in this study. Interestingly, the unusual G8P[8] strains were detected at a relatively high frequency, and phylogenetic analysis revealed that these G8 strains were genetically closely related to bovine and bovine-like human G8 rotavirus strains reported previously from Thailand, Japan, Vietnam, India and Taiwan. These G8P[8] strains displayed the DS-1-like genotype constellation of G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2 (in the order VP7-VP4-VP6-VP1-VP2-VP3-NSP1-NSP2-NSP3-NSP4-NSP5/6, respectively). Overall, the data indicated a high degree of diversity of RVA genotypes, with the emergence of several uncommon RVA strains in children with acute gastroenteritis in Thailand.

Differences in viral load among human respiratory syncytial virus genotypes in hospitalized children with severe acute respiratory infections in the Philippines.

BACKGROUND: Human respiratory syncytial virus (HRSV) is a leading viral etiologic agent of pediatric lower respiratory infections, including bronchiolitis and pneumonia. Two antigenic subgroups, HRSV-A and B, each contain several genotypes. While viral load may vary among HRSV genotypes and affect the clinical course of disease, data are scarce regarding the actual differences among genotypes. Therefore, this study estimated and compared viral load among NA1 and ON1 genotypes of HRSV-A and BA9 of HRSV-B. ON1 is a newly emerged genotype with a 72-nucleotide duplication in the G gene as observed previously with BA genotypes in HRSV-B. FINDINGS: Children <5 years of age with an initial diagnosis of severe or very severe pneumonia at a hospital in the Philippines from September 2012 to December 2013 were enrolled. HRSV genotypes were determined and the viral load measured from nasopharyngeal swabs (NPS). The viral load of HRSV genotype NA1 were significantly higher than those of ON1 and BA9. Regression analysis showed that both genotype NA1 and younger age were significantly associated with high HRSV viral load. CONCLUSIONS: The viral load of NA1 was higher than that of ON1 and BA9 in NPS samples. HRSV genotypes may be associated with HRSV viral load. The reasons and clinical impacts of these differences in viral load among HRSV genotypes require further evaluation.

SAffold viruses in pediatric patients with diarrhea in Thailand.

Saffold virus (SAFV) is a newly discovered human virus which is classified into the genus Cardiovirus of the family Picornaviridae. A total of 608 fecal specimens collected during January 2012 to December 2013 from children with diarrhea in Chiang Mai, Thailand were investigated for SAFV by RT-nested PCR and sequence analysis. Of these, nine out of 608 (1.5%) were positive for SAFVs and four genotypes were identified, SAFV1, SAFV2, SAFV3, and SAFV4. SAFV mono-infection was found in five cases (CMH-S038-12, CMH-S071-12, CMH-S102-12, CMH-N029-12, and CMH-S048-13), while co-infection with other viruses causing diarrhea was observed in four cases (CMH-S021-12, CMH-S115-12, CMH-N048-13 and CMH-N103-13). This study provides more information about the genetic background of SAFV circulating in pediatric patients with diarrhea in Thailand.

Human G3P[4] rotavirus obtained in Japan, 2013, possibly emerged through a human-equine rotavirus reassortment event.

Two novel G3P[4] rotavirus strains were detected from children with acute diarrhea in Sendai, Japan, identified as a G3-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 genotype constellation by whole-genome sequence analysis. The VP7 gene of the two strains displayed the highest nucleotide sequence identity (91 %) and showed a close genetic relationship (99 % bootstrap value) to an equine rotavirus reported in India. The other gene segments were related to human group A rotaviruses. This report suggests a possible reassortment event between human and equine rotaviruses.

Molecular characterization of norovirus variants and genetic diversity of noroviruses and sapoviruses in Thailand.

Norovirus (NoV) and Sapovirus (SaV) have been reported as a common cause of acute gastroenteritis worldwide. For a decade, surveillances of NoV and SaV have been conducted continually in Thailand. To monitor the epidemiological situation and to determine the genetic variation of NoV and SaV in Chiang Mai, Thailand, 567 samples collected from pediatric patients hospitalized with acute gastroenteritis were examined during 2007, and 2010-2011 by semi-nested RT-PCR and nucleotide sequencing methods. NoV was detected at 15.9%. Phylogenetic analysis revealed multiple NoV genotypes, GI/14 (1.1%), GII/1 (1.1%), GII/2 (1.1%), GII/3 (4.4%), GII/4 (65.6%), GII/6 (10.0%), GII/7 (2.2%), GII/12 (4.4%), GII/13 (3.3%), GII/16 (5.7%), and unclassified genotype (1.1%), circulating in this area. Among these, NoV GII/4 was the most prevalent genotype with a predominance of GII/4 2009 over other variants, 1996, 2006a, and 2006b. For SaV, the prevalence was 1.2% which was much lower than those of NoV and only SaV GI/1 was detected. This study highlights the epidemiology of NoV and SaV and genetic diversity of viruses circulating in pediatric patients hospitalized with acute gastroenteritis in Chiang Mai, Thailand.

Hepatitis B virus genotypes associated with pregnant women in Northern Thailand.

BACKGROUND: Mother-to-child transmission of hepatitis B virus (HBV) is the major route of transmission causing persistent infection. The prevalence of HBV infection and HBV genotypes found in different geographical areas varies from country to country. Therefore, this study was conducted to identify the HBV genotypes in HBV-infected pregnant women in Northern Thailand. METHODS: Stored blood samples that were collected from 145 HBsAg-positive pregnant women who gave birth at Maharaj Nakorn Chiang Mai Hospital, Chiang Mai, Thailand from 2017 to 2020 were analyzed. The partial nucleotide sequence of the S gene of HBV was amplified by nested PCR and sequenced. All sequences were analyzed phylogenetically together with the reference strains to define the HBV genotypes. RESULTS: A total of 31 blood samples from 145 HBsAg-positive pregnant women were positive for HBV by nested PCR. The detected HBV strains were identified as presumptive subgenotypes C1 (77.4%; 24/31), B9 (9.7%; 3/31), C2 (3.2%; 1/31), B2 (3.2%; 1/31), B4 (3.2%; 1/31), and presumptive B4/C2 recombinant subgenotype (3.2%; 1/31). CONCLUSIONS: The findings revealed that presumptive subgenotype C1 was the most common subgenotype circulating in pregnant women in Northern Thailand and accounted for 77.4% of cases, followed by presumptive subgenotypes B9, C2, B2, and B4. Furthermore, this study reported, for the first time in Thailand, the HBV genotypes and presumptive subgenotypes, particularly subgenotype B9 circulating in pregnant women.

Diverse genotypes of norovirus genogroup I and II contamination in environmental water in Thailand during the COVID-19 outbreak from 2020 to 2022.

Noroviruses (NoVs) are the most significant viral pathogens associated with waterborne and foodborne outbreaks of nonbacterial acute gastroenteritis in humans worldwide. This study aimed to investigate the prevalence and diversity of NoVs contaminated in the environmental water in Chiang Mai, Thailand. A total of 600 environmental water samples were collected from ten sampling sites in Chiang Mai from July 2020 to December 2022. The presence of NoV genogroups I (GI), GII, and GIV were examined using real-time RT-PCR assay. The genotype of the virus was determined by nucleotide sequencing and phylogenetic analysis. The results showed that NoV GI and GII were detected at 8.5% (51/600) and 11.7% (70/600) of the samples tested, respectively. However, NoV GIV was not detected in this study. NoV circulated throughout the year, with a higher detection rate during the winter season. Six NoV GI genotypes (GI.1-GI.6) and eight NoV GII genotypes (GII.2, GII.3, GII.7, GII.8, GII.10, GII.13, GII.17, and GII.21) were identified. Among 121 NoV strains detected, GII.17 was the most predominant genotype (24.8%, 30 strains), followed by GII.2 (21.5%, 26 strains), GI.3 (17.4%, 21 strains), and GI.4 (16.5%, 20 strains). Notably, NoV GII.3, GII.7, GII.8, and GII.10 were detected for the first time in water samples in this area. This study provides insight into the occurrence and seasonal pattern of NoV along with novel findings of NoV strains in environmental water in Thailand during the COVID-19 outbreak. Our findings emphasize the importance of further surveillance studies to monitor viral contamination in environmental water.

Emergence of norovirus GII/4 2006a and 2006b variants in hospitalized children with acute gastroenteritis in Thailand.

BACKGROUND: Norovirus (NoV) is recognized as a significant cause of acute gastroenteritis in infants and young children worldwide. This study investigated the prevalence of NoV infection in hospitalized children with gastroenteritis in Chiang Mai, Thailand in 2006. METHODS: A total of 156 fecal specimens were collected from children with diarrhea admitted to McCormick Hospital in 2006. All fecal specimens were examinedffor NoV by RT-PCR and the genotypes were identified by sequence analysis. RESULTS: A high prevalence of NoV infection was detected (20.5%, 32/156). NoV GII/4 was the most predominant genotype with a prevalence of 87.5% (28/32), while GII/3, GII/6, GII/12, and GII/15 were less common (3.1% each). Among GII/4 strains, 2006b variant (75%, 21/28) emerged as the leading strain and dominated over the Hunter'04-like variant, which was the most common strain in the previous season of 2005. In addition, the 2003, 2004, and 2006a variants were also detected. NoV infections were most commonly observed in the rainy season in Thailand. CONCLUSIONS: This study demonstrated the emergence of GII/4 2006b variants as the major pathogen causing acute gastroenteritis among infants and children at the age of less than 5 years old who admitted to hospital in Chiang Mai, Thailand in 2006. Additionally, other GII/4 variants of 2003, 2004, and 2006a were also reported.

Possible Association between Genetic Diversity of Hepatitis B Virus and Its Effect on the Detection Rate of Hepatitis B Virus DNA in the Placenta and Fetus.

Background: The prevalence of HBV infection and HBV genotypes varies from country to country, and the role of HBV genotypes in the presence of HBV in the placenta and fetus has never been explored. This study was conducted to (1) identify HBV genotypes, and their frequencies, that infected Northern Thai pregnant women; (2) evaluate the association between HBV genotypes and the detection rate of HBV DNA in the placenta and fetus; (3) evaluate the association between specific mutations of the HBV genome and HBV DNA detection in placental tissue; and (4) identify the mutation of the HBV genome that might occur between maternal blood, placenta, and cord blood. Methods: Stored samples of the maternal blood, placental tissue, and cord blood that were collected from 145 HBsAg-positive pregnant Thai women were analyzed to identify HBV DNA. Results: Approximately 25% of infected mothers had fetal HBV DNA detection, including cases with concomitant HBV DNA detection in the placenta (77.3%). A total of 11.7% of cases with placental detection had no HBV DNA detection in the maternal blood, indicating that the placenta could be a site of HBV accumulation. Of the 31 HBV-positive blood samples detected by nested PCR, the detected strains were subgenotype C1 (77.4%), subgenotype B9 (9.7%), and subgenotype C2, B2, B4, and recombinant B4/C2 (3.2% for each). Genotype B had a trend in increased risk of placental HBV DNA detection compared to genotype C, with a relative risk of 1.40 (95% CI: 1.07-1.84). No specific point mutation had a significant effect on HBV DNA detection in placental tissue. Mutation of C454T tended to enhance HBV DNA detection in placental tissue, whereas T400A tended to have a lower detection rate. No mutation was detected in different sample types collected from the same cases. Conclusions: HBV DNA detection in the fetus was identified in approximately 25% of HBV-positive mothers, associated with the presence of HBV in the placenta in most cases. The placenta could possibly be a site of HBV accumulation. Subgenotype C1 was the most common subgenotype, followed by subgenotype B9. HBV genotype B possibly had a higher trend in intrauterine detection than HBV genotype C. Mutation is unlikely to occur during intrauterine exposure.

Epidemiology and associated factors for hospitalization related respiratory syncytial virus infection among children less than 5 years of age in Northern Thailand.

BACKGROUND: Respiratory syncytial virus (RSV) is often the main problem in young children that require hospitalization. The objective of this study was to identify factors associated with RSV-related hospitalizations in young children less than five years old. METHODOLOGY: A retrospective study was conducted for acute respiratory tract infection (ARTI) at a tertiary care hospital from January 2017 to December 2021 by using binary logistic regression analysis to detect the associated factors with RSV-related hospitalizations in children. RESULTS: RSV-related hospitalization was detected in 293 of 410 (71.46 %) cases of RSV infection, most of which appeared in the rainy months of August to November. The most common symptoms and signs were 81.5 % rhinorrhea, 70.7 % cough, 68.5 % sore throat, 68.3 % sputum production, and 66.8 % fever. Factors associated with RSV-related hospitalization were age less than or equal to 2 years (aOR = 4.62, 95 % CI = 1.86-11.44), preterm birth (aOR = 2.61, 95 % CI = 1.05-6.10), patients with underlying disease (aOR = 3.06, 95 % CI = 1.21-10.34), and the presenting symptoms with sputum production (aOR = 16.49, 95 % CI = 3.80-71.55). Laboratory blood tests, low levels of hematocrit (aOR = 9.61, 95 % CI = 1.09-84.49) was the associated factor for hospitalization with RSV infection (p < 0.05). CONCLUSIONS: Factors associated with RSV-related hospitalizations in children were age less than or equal to two years, preterm birth, underlying disease, symptoms of sputum production. The low level of hematocrit was also associated with RSV-related hospitalizations in these children.

Predominance of ON1 and BA9 genotypes of human respiratory syncytial virus in children with acute respiratory infection in Chiang Mai, Thailand, 2020-2021.

BACKGROUND: Human respiratory syncytial virus (hRSV) is an important cause of acute respiratory infection, especially in children. Few studies have investigated molecular epidemiology of hRSV infection in Thailand. The aims of this study were to investigate the prevalence and genotype diversity of hRSV in children with acute respiratory infection (ARI) in Thailand. METHODS: A total of 383 nasopharyngeal swabs collected from children with ARI from October 2020 to September 2021 were screened for hRSV and nucleotide sequences of the hypervariable region 2 (HVR2) of G gene of the detected hRSV were analysed. RESULTS: Of 383 nasopharyngeal swabs, 104 (27.2 %) were positive for hRSV, of which 51 (49.0 %), 43 (41.3 %), and 10 (9.6 %) were hRSV-A, hRSV-B, and untypeable strains, respectively. All hRSV-A and hRSV-B were ON1 genotype and BA9 genotype, respectively. Most of the hRSV strains were detected in the cool months, November 2020 to February 2021. Phylogenetic analysis of the HVR2 sequence of G gene revealed three clusters of hRSV-A (ON1 genotype) and two clusters of hRSV-B (BA9 genotype). The hRSV-A strains in cluster 1 and 3 were closely related to the hRSV-A reference strains reported previously from other regions of Thailand whereas those in cluster 2 were closely related to the hRSV-A reference strains reported previously from Europe and Africa. For the hRSV-B strains, both clusters 1 and 2 were closely related to the hRSV-B reference strains reported previously from Europe, Australia, and Taiwan. The predicted N- and O-linked glycosylation sites were found along the length of HVR2 of G protein, mostly in the hRSV-B strains. CONCLUSIONS: The ON1 and BA9 were the only two hRSV genotypes that were co-predominant and solely detected in this study. The findings indicated that the ON1 and BA9 are the only two hRSV genotypes currently circulating in children with ARI in northern Thailand.

Characteristics of Respiratory Syncytial Virus Infection in Hospitalized Children Before and During the COVID-19 Pandemic in Thailand.

OBJECTIVES: This study compared the epidemiological and clinical manifestations of patients hospitalized with respiratory syncytial virus (RSV) infection before and during the coronavirus disease 2019 (COVID-19) pandemic at a tertiary care hospital in Chiang Mai Province, Thailand. METHODS: This retrospective observational study utilized data from all cases of laboratory-confirmed RSV infection at Maharaj Nakorn Chiang Mai Hospital from January 2016 to December 2021. Differences in the clinical presentation of RSV infection before (2016 to 2019) and during (2020 to 2021) the COVID-19 pandemic were analyzed and compared. RESULTS: In total, 358 patients hospitalized with RSV infections were reported from January 2016 to December 2021. During the COVID-19 pandemic, only 74 cases of hospitalized RSV infection were reported. Compared to pre-pandemic levels, the clinical presentations of RSV infection showed statistically significant decreases in fever on admission (p=0.004), productive cough (p=0.004), sputum (p=0.003), nausea (p=0.03), cyanosis (p=0.004), pallor (p<0.001), diarrhea (p<0.001), and chest pain (p<0.001). Furthermore, vigilant measures to prevent the spread of COVID-19, including lockdowns, also interrupted the RSV season in Thailand from 2020 to 2021. CONCLUSIONS: The incidence of RSV infection was affected by the COVID-19 pandemic in Chiang Mai Province, Thailand, which also changed the clinical presentation and seasonal pattern of RSV infection in children.

Diversity of human astrovirus genotypes circulating in children with acute gastroenteritis in Thailand during 2000-2011.

Human astrovirus (HAstV) is one of the causative agents of acute gastroenteritis in children worldwide. The objective of this study was to elucidate the molecular epidemiology and genotypic diversity of HAstV circulating in pediatric patients admitted to hospital with diarrhea in Thailand during the year 2000-2011, except for 2004, 2006, and 2009. A total of 1,022 fecal specimens were tested for HAstV by reverse transcription polymerase chain reaction (RT-PCR). HAstV was detected at 1.4% (14 of 1,022). All HAstV strains detected in this study were characterized further by nucleotide sequencing and phylogenetic analysis. Analysis of 348 bp partial capsid nucleotide sequences revealed that HAstV strains detected were HAstV-1 (1a, 1b, and 1d) (8 strains), HAstV-2 (2c) (3 strains), HAstV-3 (1 strain), and HAstV-5 (2 strains). HAstV-1, the most predominant genotype was detected initially in 2002 and circulated continuously up to 2011. HAstV-2 was detected in year 2001, and 2007 and grouped into a 2c lineage. HAstV-3 was found only in 2000 and HAstV-5 was found in the year 2001. The findings indicate that a wide variety of HAstV strains continue to circulate in children admitted to hospital with acute gastroenteritis in Thailand over a decade. The data provide an epidemiological overview of HAstV infection and HAstV genotype distribution in Thailand.

Detection and molecular characterization of cosavirus in adults with diarrhea, Thailand.

Human cosavirus (HCoSV) is a newly discovered virus in Picornaviridae family. At present it is not clear whether HCoSV is associated with diseases, including gastroenteritis in humans, as epidemiological data is limited. Epidemiological surveillance of HCoSV was conducted on 150 fecal specimens collected from children and 150 samples from adults with diarrhea in Thailand by RT-PCR screening. HCoSV was found in a single adult specimen and not in any of the fecal specimens from children. This represents the first report of HCoSV infection in patients with diarrhea in Thailand. Extensive epidemiological surveillance of novel viruses associated with diarrhea in other populations may provide a better understanding of the distribution, genetic diversity, and association of the viral agents associated with acute gastroenteritis in humans.

A wide variety of diarrhea viruses circulating in pediatric patients in Thailand.

BACKGROUND: Viral gastroenteritis has been recognized as one of the most common illnesses that affects infants and young children all over the world. A wide variety of viruses associated with the disease are continually being reported. To investigate the epidemiological situation of diarrhea virus infection in Chiang Mai, Thailand, surveillance was conducted during January to December 2007. METHODS: A total of 160 fecal specimens collected from pediatric patients admitted to the hospital with acute gastroenteritis were tested for the presence of group A, B, and C rotaviruses, norovirus, sapovirus, astrovirus, adenovirus, Aichi virus, enterovirus, bocavirus, and human parechovirus by RT-multiplex PCR. RESULTS: Of 160 fecal specimens tested, 85 (53.1%) were positive for diarrhea viruses. Of these, group A rotavirus was the predominant with a prevalence of 27.5%, followed by norovirus GII (11.9%), sapovirus (3.1%), enterovirus (2.5%), human parechovirus (1.9%), and norovirus GI, astrovirus, adenovirus (each 0.6%). Mixed-infections of 2 or 3 viruses were observed in 7 (4.4%) patients. However, none of groups B and C rotaviruses and Aichi virus were detected in this study. Monthly distribution analysis revealed that all those diarrhea viruses were detected continually throughout the year at a low level of infection except for group A rotavirus and norovirus infections which appeared to peak in a cool season in January-March and December, respectively. CONCLUSIONS: This surveillance revealed a wide variety of diarrhea viruses currently circulating in pediatric patients with acute gastroenteritis in Chiang Mai, Thailand.

Awareness and Attitudes Toward HIV Self-Testing in Northern Thailand.

Human Immunodeficiency Virus self-testing (HIVST) was recently introduced in Thailand, but little is known about receptivity among its residents. Because Human Immunodeficiency Virus (HIV) testing is a critical component of HIV prevention, it is important to understand how HIVST is perceived among potential users. The purpose of this study was to examine awareness and attitudes toward HIVST among adults in Northern Thailand. A convenience sample of 403 adult residents of the Sanpatong district, Chiang Mai Province, was interviewed using a structured questionnaire in 2019. Awareness of HIVST was low (14%), as was the overall HIVST negative attitude score (6.44; possible range of 0-14). The odds of being aware of HIVST were more than twice as high for those with more education compared to those with less (AOR = 2.29, 95% CI: 1.22-4.30), and roughly half as high for those who expressed HIV stigma compared to those who did not (AOR = 0.49, 95% CI: 0.26-0.91). Holding negative attitudes towards HIVST also was associated with lower education and expressing HIV stigma, but these relationships disappeared in multivariate analysis. Findings may be used by local health organizations to tailor HIVST education efforts.