[Show abstract][Hide abstract] ABSTRACT: Human rotavirus A (RVA) is the major infectious virus causing acute watery diarrhea in children, especially those younger than 5years of age, and is a major public health problem in Thailand. Outbreaks of this virus have been reported worldwide. Besides the common genotypes, unusual genotypes providing evidence of inter-species transmission have also been described. Therefore, the aim of this study was to investigate the prevalence and genotypes of RVA in Thailand. A total of 688 samples were collected from children who were hospitalized with acute diarrhea in Chumphae Hospital in Khon Kaen and Chulalongkorn Hospital in Bangkok. RVA was detected using one-step RT-PCR and the genotypes were evaluated by sequencing. Overall, 204 of the 688 samples (30%) were positive for RVA. Nine genotypes were identified: three common in humans (G1P [53%], G2P [18%], G3P [12%]), one feline-like (G3P [1%]), four porcine-like (G4P [0.5%], G5P [0.5%], G9P [0.5%], G12P [1.5%]), and one bovine-like (G8P [13%]) genotype. The variation in virus genotypes and the animal-like genotypes detected in this study suggested that a high diversity of RVA types is circulating in the Thai population. Therefore, continuous molecular epidemiological monitoring of RVA is essential and has implications for the national vaccination program.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 01/2016; 37:129-136. DOI:10.1016/j.meegid.2015.11.011 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Enterovirus D68 (EV-D68) was associated with severe lower respiratory tract infection and neurological abnormalities including acute myelitis and cranial nerve dysfunction. To determine whether the increased incidence of EV-D68 also occurs in Southeast Asia, we retrospectively tested specimens collected from Thai pediatric patients less than five years of age presented with acute respiratory tract infections between 2012 and 2014. Reverse transcription-polymerase chain reaction (RT-PCR) and nucleotide sequencing of the 5'UTR/VP2 region were used to identify EV-D68. We also examined the epidemiological pattern of EV-D68 since 2009 when it was first identified in Thailand and compiled clinical manifestations of children with confirmed EV-D68 infection. From the total of 837 samples, 5 samples (0.6%) were confirmed positive for EV-D68. All patients presented viral pneumonia and required hospitalization. Phylogenetic analysis of the VP4/VP2 regions revealed that EV-D68 strains circulating in Thailand during the past three years were closely related to the strains reported in Japan, United Kingdom, China, and France. Continued surveillance of probable EV-D68-associated severe respiratory tract infection and the development of rapid diagnostic test for EV-D68 are essential in assisting awareness and facilitating disease prevention and control.
Japanese journal of infectious diseases 11/2015; DOI:10.7883/yoken.JJID.2015.352 · 1.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Journal of Medical Virology 08/2015; DOI:10.1002/jmv.24368 · 2.35 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Tuberculosis, a re-emerging public health problem, is uncommon in infancy. Two healthy completely immunized infants presenting with manifestations compatible with osteoarticular infection required surgical debride-ment. The cultures of the specimens were positive for M. tuberculosis (MTB) complex comprised multiple subspecies. One case was misdiagnosed as a Bacillus Calmette-Guerin (BCG) related osteomyelitis by a polymerase chain reaction (PCR) based on detection of genes at the region of difference 1. Genome extraction and PCR using the rimM gene and sequences analysis against MTB and BCG control samples confirmed that both specimens were infected by M. tuberculosis. The lesions were successfully healed within one year. Surgical debridement of suspected lesions is warranted in infants as a definitive treatment and to obtain tissues for further evaluation. Microbiological cultures only confirm nonspecific MTB complex infection. PCR kits may yield a false positive result. Identification of the pathogen by DNA extraction and sequence analysis should be recommended.
[Show abstract][Hide abstract] ABSTRACT: The majority of hepatitis C virus (HCV) infection results in chronic infection, which can lead to liver cirrhosis and hepatocellular carcinoma. Global burden of hepatitis C virus (HCV) is estimated at 150 million individuals, or 3% of the world's population. The distribution of the seven major genotypes of HCV varies with geographical regions. Since Asia has a high incidence of HCV, we assessed the distribution of HCV genotypes in Thailand and Southeast Asia. From 588 HCV-positive samples obtained throughout Thailand, we characterized the HCV 5' untranslated region, Core, and NS5B regions by nested PCR. Nucleotide sequences obtained from both the Core and NS5B of these isolates were subjected to phylogenetic analysis, and genotypes were assigned using published reference genotypes. Results were compared to the epidemiological data of HCV genotypes identified within Southeast Asian. Among the HCV subtypes characterized in the Thai samples, subtype 3a was the most predominant (36.4%), followed by 1a (19.9%), 1b (12.6%), 3b (9.7%) and 2a (0.5%). While genotype 1 was prevalent throughout Thailand (27-36%), genotype 3 was more common in the south. Genotype 6 (20.9%) constituted subtype 6f (7.8%), 6n (7.7%), 6i (3.4%), 6j and 6m (0.7% each), 6c (0.3%), 6v and 6xa (0.2% each) and its prevalence was significantly lower in southern Thailand compared to the north and northeast (p = 0.027 and p = 0.030, respectively). Within Southeast Asia, high prevalence of genotype 6 occurred in northern countries such as Myanmar, Laos, and Vietnam, while genotype 3 was prevalent in Thailand and Malaysia. Island nations of Singapore, Indonesia and Philippines demonstrated prevalence of genotype 1. This study further provides regional HCV genotype information that may be useful in fostering sound public health policy and tracking future patterns of HCV spread.
PLoS ONE 05/2015; 10(5):e0126764. DOI:10.1371/journal.pone.0126764 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Bufavirus (BuV) was initially discovered in fecal samples from children with acute diarrhea. In this study, we determined the prevalence, distribution, and genotype(s) of BuV in Thailand. A total of 1,495 diarrheal and 741 non-diarrheal stool specimens were collected and analyzed. A portion of the NS1 gene of BuV was amplified by nested RT-PCR. Phylogenetic analysis was performed to classify the BuV strains found. We detected bufavirus (BuV) in diarrheal (4/1495; 0.27 %) but not in non-diarrheal specimens (0/726). All four strains belonged to BuV genotype 1. BuV could be detected in adults and children, but its role in causing acute diarrhea remains unclear.
Archives of Virology 05/2015; 160(7). DOI:10.1007/s00705-015-2441-z · 2.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in developing countries are associated with contaminated food or water. Although Thailand is non-endemic for HEV, sporadic infections may occur from zoonotic transmission. Individuals between 7 months to 69 years (mean age = 32.8) from predominantly Islamic Narathiwat (n = 305) and swine farm-dense Lop Buri (n = 416) provinces were screened for anti-HEV and anti-HAV antibodies by commercial enzyme-linked immunosorbent assay and automated chemiluminescent micro-particle immunoassay, respectively. Seroprevalence and relative antibody titers were analyzed according to age groups. HAV IgG antibody positive rates in Lop Buri and Narathiwat residents were 39.9% and 58%, respectively (p < 0.001). Greater than 90% of individuals >50 years old in both provinces possessed anti-HAV IgG. In contrast, seroprevalence for anti-HEV IgG was much higher in Lop Buri (37.3%) than in Narathiwat (8.9%) (p< 0.001). Highest anti-HEV IgG prevalence was found among 21-30 year-olds (50%) in Lop Buri and 41-50 year-olds (14.1%) in Narathiwat. In summary, fewer individuals possessed anti-HEV IgG in Narathiwat where most residents abstained from pork and fewer swine farms are present. Therefore, an increased anti-HEV IgG seroprevalence was associated with the density of swine farm and possibly pork consumption. Adults were more likely than children to have antibodies to both HEV and HAV.
PLoS ONE 04/2015; 10(4). DOI:10.1371/journal.pone.0126184 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Serum hepatitis C virus (HCV) core antigen (HCVcAg) concentrations correlate with HCV RNA levels in HCV monoinfected patients. Data in HCV/HIV coinfected patients are still limited. We aim to compare the use of HCVcAg measurement with respect to HIV status, HCV genotypes, interferon-lambda-4 (IFNL4) polymorphism and clinical parameters.
We analyzed an untreated cohort of 104 patients with HCV monoinfection and 85 patients with HCV/HIV coinfection. Serum HCVcAg was measured by a commercial chemiluminescent microparticle immunoassay. The presence of IFNL4 polymorphism ss469415590 was identified by real-time PCR.
log10 HCVcAg levels were significantly correlated with corresponding log10 HCV RNA levels (r = 0.889, p < 0.001), but not with ALT levels and liver stiffness. The correlation between HCV RNA and HCVcAg was particularly high in coinfected patients and those with high viremia. Mean log10 HCVcAg concentration was significantly higher in coinfected patients than in monoinfected patients. Patients harboring the TT/TT genotype of ss469415590 had significantly higher levels of log10 HCVcAg than those with the non-TT/TT genotype. HCVcAg levels were similar across HCV genotypes.
HCVcAg concentrations had an excellent correlation with HCV RNA levels, particularly in HCV/HIV-coinfected individuals and might be associated with IFNL4 polymorphism. HCVcAg testing could be used as an alternative to HCV RNA assays in resource-limited settings.
[Show abstract][Hide abstract] ABSTRACT: Acute haemorrhagic conjunctivitis outbreaks are often attributed to viral infection. In 2014, an unprecedented nationwide outbreak of infectious conjunctivitis occurred in Thailand, which affected >300 000 individuals over 3 months. To identify and characterize the virus responsible for the epidemic, eye swab specimens from 119 patients were randomly collected from five different provinces. Conserved regions in the enteroviral 5′-UTR and adenovirus hexon gene were analysed. Enterovirus was identified in 71·43% (85/119) of the samples, while no adenovirus was detected. From enterovirus-positive samples, the coxsackievirus A24 variant (70·59%, 84/119) and echovirus (0·84%, 1/119) were identified. Additional sequencing of full-length
genes and subsequent phylogenetic analysis revealed that these clinical isolates form a new lineage cluster related to genotype IV-C5. In summary, the coxsackievirus A24 variant was identified as an aetiological agent for the recent acute haemorrhagic conjunctivitis outbreak in Thailand.
Epidemiology and Infection 03/2015; 143(14):1-7. DOI:10.1017/S0950268815000643 · 2.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: To report clinical outcomes and viral genotypes of acute symptomatic hepatitis E virus (HEY) infection in Thailand. Methods: Forty patients with acute symptomatic HEY infection were recruited during 2009-2013. Clinical, demographic and laboratory data were collected. Diagnosis was accomplished by detection of anti-HEY IgM and/or HEY RNA in the serum or stool. HEY genotypes were classified by direct sequencing of RT-PCR products and phylogenetic analysis. Results: The high risk group, comprising immune-compromised, liver cirrhosis and very elderly (>80 years) patients (17 cases), had higher levels of serum alkaline phosphatase at presentation compared with the low risk group. Two fatal cases resulted from acute hepatitis E in the high risk group. Initial clinical presentation did not show statistically significant differences. In six cases (6/40), the virus could tic detected in scrum or stool by RT-PCR and sequencing. Upon molecular characterization, the viruses were classified as HEV genotype 3f and were in the same cluster as Thai swine REV. Conclusions: Our data showed that acute HEY infection has various clinical presentations and outcomes. Higher levels of serum alkaline phosphatase were observed in high risk patients. All isolated viruses were identified as HEY genotype 3f possibly originating from swine.
Asian Pacific Journal of Tropical Medicine 09/2014; 7(9):709-14. DOI:10.1016/S1995-7645(14)60121-8 · 0.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: An age distribution shift in diphtheria cases during a 2012 outbreak in northeastern of Thailand suggests adults are increasingly at risk for infection in Thailand. Data regarding immunity against diphtheria among the adult Thai population is limited. We review a 2012 diphtheria outbreak in Thailand and conducted a nationwide seroepidemiological survey to determine the prevalence of diphtheria antibodies among Thai adults in order to inform immunization programs. A total of 41 confirmed cases, 6 probable cases and 101 carriers of diphtheria were reported from northeastern and upper southern Thailand. The diphtheria outbreak in northeastern Thailand occurred among adults aged > or =15 years; sporadic cases occurred among children from upper southern Thailand. We conducted a seroepidemiological survey of 890 Thai adults from 4 age groups (20-29, 30-39, 40-49 and 50-59 years) in 7 different geographical areas of Thailand (Chiang Mai, Ratchaburi, Chon Buri, Nakhon Si Thammarat, Phitsanulok, Khon Kaen and Songkhla). Diptheria toxin antibody levels were measured with a commercially available ELISA test. The seroprotection rate ranged from 83% to 99%, with the highest in eastern Thailand (Chon Buri, 99%) and the lowest in northern Thailand (Chiang Mai, 83%). Diphtheria antibodies declined with increasing age. We recommend one doseof diphtheria-tetanus toxoid (dT) vaccine once after 20 years of age in order to boost the antibody and revaccinations every 10 years to prevent future outbreaks.
The Southeast Asian journal of tropical medicine and public health 09/2014; 45(5):1132-41. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Unlabelled:
Timely antibiotic initiation for acute pyelonephritis (APN) can prevent renal complications. We investigated whether urine heparin binding protein (UHBP), a cytokine released from activated neutrophils, was a useful diagnostic tool for APN. Febrile children with presumed APN were prospectively enrolled between January and September 2013, and divided into two groups based on urine cultures. UHBP levels were measured at enrollment in all children and 1 month after antibiotic treatment in children with APN. UHBP levels in children with APN at baseline and 1 month versus controls were 47.0 ± 8.4 and 16.6 ± 3.8 vs. 15.0 ± 2.9 ng/mL, respectively (p < 0.001). Test performance characteristics were calculated against a gold standard of positive urine cultures and compared with leukocyte esterase (LE) and nitrite measured by dipsticks and pyuria by microscopy. The sensitivity and specificity for UHBP levels ≥34 ng/mL were 100 and 100 %. Spearman's rank coefficient was used to assess the associations between routine laboratory tests and UHBP levels. Significant positive correlations were found with pyuria grade (Spearman's rho = 0.62; p < 0.001), neutrophil count (rho = 0.38; p = 0.03), and platelet count (rho = 0.39; p = 0.03).
UHBP is a valid adjunctive diagnostic tool for aiding clinicians in making rapid treatment decisions for APN.
European Journal of Pediatrics 06/2014; 174(1). DOI:10.1007/s00431-014-2362-y · 1.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hand, foot, and mouth disease (HFMD) and herpangina are common infectious diseases caused by several genotypes of human enterovirus species A and frequently occurring in young children. This study was aimed at analyzing enteroviruses from patients with these diseases in Thailand in 2012. Detection and genotype determination of enteroviruses were accomplished by reverse transcription-polymerase chain reaction and sequencing of the VP1 region. Enterovirus-positive samples were differentiated into 17 genotypes (coxsackievirus A4 (CAV4), A5, A6, A8, A9, A10, A12, A16, A21, B1, B2, B4, B5, echovirus 7, 16, 25 and Enterovirus 71). The result showed CAV6 (33.5%), followed by CAV16 (9.4%) and EV71 (8.8%) as the most frequent genotypes in HFMD, CAV8 (19.3%) in herpangina and CAV6 (1.5%) in influenza like illness. Enterovirus infections were most prevalent during July with 34.4% in HFMD, 39.8% in herpangina and 1.6% in ILI. The higher enterovirus infection associated with HFMD and herpangina occurred in infants over one year-old. This represents the first report describing the circulation of multiple enteroviruses in Thailand.
PLoS ONE 06/2014; 9(6):e98888. DOI:10.1371/journal.pone.0098888 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Human parainfluenza virus (HPIV) is a common cause of upper and lower respiratory illness in infants and young children. In order to classify the HPIV isolates circulating in the central part of Thailand, 650 samples obtained from the lower respiratory tract of patients from two hospital pediatric wards during 2010 to 2013, were analyzed for the presence and types of HPIVs by multiplex semi-nested PCR of hemagglutinin-neuraminidase (HN) gene. The results showed that 4.8% of the samples were positive for HPIV, among which 0.5%, 2.5% and 1.5% were positive for HPIV-1, HPIV-3, and HPIV-4, respectively, and none were positive for HPIV-2. A phylogenetic tree constructed from 31 HPIV HN gene sequences compared to those in GenBank showed greater than 80% identity to other reference strains. Prevalence of HPIV infection and phylogenetic characteristics of the circulating HPIVs may help explain the impact of HPIVs infection in Thai children.
The Southeast Asian journal of tropical medicine and public health 05/2014; 45(3):610-21. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Rapid tests are widely used to detect rotavirus A; however, pediatricians are concerned whether the rapid test can still accurately detect the virus. Therefore, this study evaluated the performance of the rotavirus rapid test by comparing it to the one-step RT-PCR method.
Seven hundred fifty-five stool samples were collected from children with acute diarrhea. All samples were processed immediately after arrival with the SD BIOLINE rota rapid test and one-step RT-PCR method.
The detection rates of rotavirus A were 40.79% and 41.91% for the rapid test and one-step RT-PCR, respectively. The rapid test had 93.57% sensitivity and 96.17% specificity. Most of the different genotypes of rotavirus A were detected with the SD rapid test.
Although the rapid test is able to quickly give results, we found that it has high false positive and negative rates. Thus, other highly sensitive methods such as one-step RT-PCR are still required for true diagnosis.
[Show abstract][Hide abstract] ABSTRACT: Emergence of viruses belonging to the coronavirus family has been widespread in the past, causing respiratory infections in humans, such as severe acute respiratory syndrome (SARS). This study investigated the prevalence of human coronavirus (HCoV) and characterized the molecular viral genetics. We collected 1,254 samples from patients diagnosed with respiratory infection in southern Thailand from July 2009 to January 2011 and screened for HCoV by RT-PCR and genotyped by BLAST analysis of nsp12 gene. Phylogenetic analysis was performed based on S gene sequences. Thirty-five of 1,254 samples were positive for HCoV. Viral genotyping revealed 4 genotypes with HCoV-OC43 being the predominant genotype. Viral prevalence and genotype distribution were not in accordance with seasonal distribution. Phylogenetic analysis and deduced amino acid sequences of the S gene showed amino acid variations in each genotype. The S gene sequence of HCoV-OC43 genotype indicated that it resulted from recombination between subgenotypes B and C. Viral genetics analysis disclosed genetic variations of HCoV and additionally, it can provide information suitable for monitoring and prevention of the emergence and re-emergence of various types of coronavirus.
The Southeast Asian journal of tropical medicine and public health 03/2014; 45(2):326-36. · 0.72 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Influenza A virus is a major cause of influenza pandemics and can infect several host species including humans and animals. The objective of this study was to develop a one-step reverse transcription loop-mediated isothermal amplification assay (LAMP) for the detection of genetically diverse influenza A viruses from both human and animal hosts. First, a set of two inner and two outer primers were designed based on the conserved region of the matrix (M) gene of influenza A viruses. The amplification reaction was optimized at 63 o C for 60 min and performed in a simple heat block. The amplicons could be visualized either by gel electrophoresis or by visual analysis upon addition of SybrGreen. The developed LAMP assay was tested with 50 influenza A isolates including H1N1, H1N2, H3N2, H5N1 and H7N4 from swine, avian and human hosts. In sensitivity test, the assay detection capability was ten times more sensitive than conventional RT-PCR and comparable to real time RT-PCR. In summary, this assay is a rapid, simple and sensitive assay suitable for less-equipped laboratories and thus can be utilized in the field as a screening test.
[Show abstract][Hide abstract] ABSTRACT: This study has identified diverse and re-assorted group A rotavirus (RVA) strains by sequence and phylogenetic analysis of the 11 genomic segments. The 22 cases investigated in this study were collected from children with diarrhea between 2008-2011. The RVA genomic constellations identified in this study were identified as G1-P-I1-R1-C1-M1-A1-N1-T1-E1-H1 22.7% (5/22); G2-P-I2-R2-C2-M2-A2-N2-T2-E2-H2 27.3% (6/22); G3-P-I1-R1-C1-M1-A1-N1-T1-E1-H1 18.2% (4/22); G3-P-I3-R3-C3-M3-A3-N3-T3-E3-H6 4.6% (1/22); G9-P-I1-R1-C1-M1-A1-N1-T1-E1-H1 9.1% (2/22); G12-P-I1-R1-C1-M1-A1-N1-T1-E1-H1 4.6% (1/22) and G12-P-I1-R1-C1-M1-A1-N1-T1-E1-H1 13.6% (3/22). Two RVA strains, possessing a complete AU-1-like genomic backbone, showed reassortment for genes 3 and 11, revealing possible zoonotic reassortment events between human and canine strains. In addition, one of the analyzed strains revealed a G12 specificity for VP7 in combination with a porcine-like P VP4 and a complete Wa-like constellation. Continuous surveillance of rotavirus strains and their evolution may be useful for understanding the emergence of novel strains through interspecies genome re-assortment between human and animal viruses.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 11/2013; 21. DOI:10.1016/j.meegid.2013.11.020 · 3.02 Impact Factor