Piyarat Suntarattiwong | Rangsit University (original) (raw)

Papers by Piyarat Suntarattiwong

Research paper thumbnail of Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants

PubMed, Aug 1, 2011

Background: Respiratory syncytial virus (RSV) and influenza infections are among the leading caus... more Background: Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published. Material and method: The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR). Results: Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between July and October (42-76%). RSV patients were more likely to present with higher temperature than the negative RT-PCR patients (p = .031). Oseltamivir was prescribed in 7.7% of influenza infections. Intravenous antibiotics were prescribed in 69.2%, 56.7% and 60.7% of the influenza, RSV and negative group respectively (p = .736). Percentages of patients requiring mechanical ventilation were 3.8, 6.7 and 6.3% among the influenza, RSV and negative group respectively (p = .861). Three patients died: 2 from RSV and 1 from the negative group. All three fatality cases had existing co-morbidity. Conclusion: A high proportion of RSV was detected in infants hospitalized with LRTI especially during July to October. High proportion of antibiotic prescription and relatively low rate of oseltamivir treatment were identified. Surveillance data and the availability of a rapid and reliable viral diagnostic test may help guide treatment, thereby improve outcome of this vulnerable population.

Research paper thumbnail of Influenza-Associated Medical Visits Prevented by Influenza Vaccination in Young Children in Thailand, 2012–2014

Journal of the Pediatric Infectious Diseases Society, Jul 24, 2020

Despite recommendations, few children aged 6-35 months in Thailand receive seasonal influenza vac... more Despite recommendations, few children aged 6-35 months in Thailand receive seasonal influenza vaccination. Using previously estimated incidence and vaccine effectiveness data from the period 2012-2014, we estimate that up to 121 000 medical visits could be prevented each year with 50% coverage and expanded recommendations to children aged <5 years.

Research paper thumbnail of Immunogenicity and Reactogenicity of mRNA BNT162b2 COVID-19 Vaccine among Thai Adolescents with Chronic Diseases

Vaccines

Adolescents with underlying diseases are at risk of severe COVID-19. The immune response of BNT16... more Adolescents with underlying diseases are at risk of severe COVID-19. The immune response of BNT162b2 may be poor among immunocompromised adolescents. We aim to describe immunogenicity of mRNA BNT162b2 among adolescents who are immunocompromised or have chronic diseases. We recruited adolescents 12–18 years of age; group A impaired-immunity (post-transplantation, cancer, on immunosuppressive drugs) and group B chronic diseases. A two-dose regimen of BNT162b2 was given. Immunogenicity was determined by surrogate virus neutralization test (sVNT) and IgG against receptor-binding domain (RBD). From August to October 2021, 312 adolescents, with a median age (IQR) of 15 years (13.7–16.5), were enrolled (group A 100, group B 212). The geometric means (GMs) of sVNT (% inhibition) against Delta strain and anti-RBD IgG (BAU/mL) after the 2nd dose among group A were: post-transplantation recipients 52.9 (95% CI 37.7–74.2) and 233.6 (95% CI 79–690.6); adolescents with cancer 62.3 (95% CI 29.2–13...

Research paper thumbnail of Influenza virus seroincidence in a cohort of healthy and high-risk children enrolled in infancy, Bangkok, Thailand

International Journal of Infectious Diseases, 2019

Influenza virus seroincidence in a cohort of healthy and high-risk children enrolled in infancy,

Research paper thumbnail of Predictors for influenza vaccination among Thai pregnant woman: The role of physicians in increasing vaccine uptake

Influenza and Other Respiratory Viruses, 2019

BackgroundPhysician recommendation and attitudes and beliefs of pregnant women toward influenza a... more BackgroundPhysician recommendation and attitudes and beliefs of pregnant women toward influenza and vaccination may influence vaccine uptake during pregnancy. We examined how physician recommendation and health beliefs of pregnant women may jointly affect influenza vaccination during pregnancy.MethodsThai pregnant women aged ≥18 years and >13 gestational weeks attending antenatal care (ANC) clinics, and ANC physicians were recruited during May‐August 2015. Women and physicians, linked using unique identifiers, provided data on demographic, health and work history, knowledge, attitudes, and beliefs toward influenza and vaccination, based on Health Belief Model constructs. Physicians also provided data on their practices in recommending influenza vaccination during pregnancy. Prevalence ratios for the association between knowledge, attitudes and beliefs of pregnant women, physician recommendation and documented receipt of vaccination within 30 days of the visit were calculated.Resu...

Research paper thumbnail of Pertussis surveillance in a children hospital in Bangkok, Thailand

International Journal of Infectious Diseases, 2019

To investigate the incidence, clinical characteristics and cost associated with pertussis in Thai... more To investigate the incidence, clinical characteristics and cost associated with pertussis in Thai children with persistent cough. Methods: A prospective study was conducted among children aged 0-18 years with persistent cough for 7 days with at least one of the following: paroxysm, inspiratory whooping, or post-tussive emesis. Nasopharyngeal swabs were obtained and tested for pertussis real time polymerase chain reaction (RT-PCR). Results: 19.6% of children (28 out of 143) had pertussis confirmed by RT-PCR, 75% of cases occurred in children who were too young to complete their primary series of vaccine. Paroxysm and post-tussive emesis were the most consistent clinical features, identified in 96% and 93% of cases, respectively, whooping was found in only 18%. Pertussis cases were more likely to have household cough contact (64% versus 30%, p < 0.001), be hospitalized (79% versus 58%, p = 0.048) and experience protracted duration of cough (47 vs. 20 days, p < 0.001) compare to their counterpart. Conclusion: Pertussis in Thai children is not infrequent and the common age group is young infant before completion of primary series of pertussis vaccine at six months of age, underline the importance of maternal pertussis immunization.

Research paper thumbnail of Nevirapine Concentrations During the First Month of Life and Maternal Efavirenz Washout in High-Risk HIV-Exposed Infants Receiving Triple Antiretroviral Prophylaxis

Pediatric Infectious Disease Journal, 2018

Background: Triple-drug infant antiretroviral prophylaxis containing nevirapine (NVP) is increasi... more Background: Triple-drug infant antiretroviral prophylaxis containing nevirapine (NVP) is increasingly used to prevent HIV transmission among neonates at high risk of HIV infection. Our aim was to describe NVP concentration from birth through the first month of life. Methods: High-risk HIV-exposed neonates were enrolled in a prospective cohort in Thailand. High-risk neonates defined as maternal HIV RNA >50 copies/mL before delivery or mother received antiretroviral treatment for <12 weeks before delivery. Neonates received zidovudine (4 mg/kg) and lamivudine (2 mg/kg) twice daily, plus NVP (4 mg/kg) once daily (no lead-in) from birth to 6 weeks of life. Infant plasma samples were collected at 1, 2, 14 or 2, 7, 28 days of life. NVP trough concentrations (C 24) were estimated using a population pharmacokinetic model and target C 24 was ≥0.1 mg/L. "Washout" efavirenz (EFV) concentrations were assessed in infants whose mother received EFV-based antiretroviral treatment. Results: A total of 48 infants were included: 25 (52%) were male and 12 (25%) were preterm (gestational age 34-37 weeks). Median (interquartile range) predicted NVP C 24 were 1.34 mg/L (1.13-1.84), 2.24 (2.00-2.59), 2.78 (2.61-3.12), 2.20 (1.86-2.44) and 0.81 (0.58-0.98) on days 1, 2, 7, 14 and 28 of life, respectively. NVP C 24 was not significantly different between term and preterm infants. All infants maintained NVP C 24 ≥0.1 mg/L. EFV via placental transfer remained detectable in infants up to 7 days of life. Conclusions: NVP 4 mg/kg daily from birth provided adequate prophylactic concentrations during the first month of life in high-risk HIV-exposed neonates.

Research paper thumbnail of Tolerability of trivalent inactivated influenza vaccine among pregnant women, 2015

BMC pregnancy and childbirth, Jan 23, 2018

Thailand recommends influenza vaccination among pregnant women. We conducted a cohort study to de... more Thailand recommends influenza vaccination among pregnant women. We conducted a cohort study to determine if the prevalence of adverse events following immunization (AEFIs) with influenza vaccine among Thai pregnant women was similar to that often cited among healthy adults. Women who were ≥17 gestational weeks and ≥18 years of age were recruited. Demographic and health history data were collected using structured questionnaires. Women were provided with symptom diary, ruler to measure local reaction(s), and thermometer to measure body temperature. AEFIs were defined as any new symptom/abnormality occurring within four weeks after vaccination. The diaries were abstracted for frequency, duration, and level of discomfort/inconvenience of the AEFIs. Serious adverse events (SAEs) and the likelihood of AEFIs being associated with vaccination were determined using standard definitions. Among 305 women enrolled between July-November 2015, median age was 29 years. Of these, 223 (73%) were in...

Research paper thumbnail of Cost-effectiveness of inactivated seasonal influenza vaccination in a cohort of Thai children ≤60 months of age

PLOS ONE, 2017

Background Vaccination is the best measure to prevent influenza. We conducted a cost-effectivenes... more Background Vaccination is the best measure to prevent influenza. We conducted a cost-effectiveness evaluation of trivalent inactivated seasonal influenza vaccination, compared to no vaccination, in children 60 months of age participating in a prospective cohort study in Bangkok, Thailand. Methods A static decision tree model was constructed to simulate the population of children in the cohort. Proportions of children with laboratory-confirmed influenza were derived from children followed weekly. The societal perspective and one-year analytic horizon were used for each influenza season; the model was repeated for three influenza seasons (2012-2014). Direct and indirect costs associated with influenza illness were collected and summed. Cost of the trivalent inactivated seasonal influenza vaccine (IIV3) including promotion, administration, and supervision cost was added for children who were vaccinated. Quality-adjusted life years (QALY), derived from literature, were used to quantify health outcomes. The incremental cost-effectiveness ratio (ICER) was calculated as the difference in the expected total costs between the vaccinated and unvaccinated groups divided by the difference in QALYs for both groups. Results Compared to no vaccination, IIV3 vaccination among children 60 months in our cohort was not cost-effective in the introductory year (2012 season; 24,450 USD/QALY gained),

Research paper thumbnail of Therapeutic Drug Monitoring of Lopinavir in Human Immunodeficiency Virus-Infected Children Receiving Adult Tablets

Pediatric Infectious Disease Journal, 2010

Optimal treatment of acute bronchiolitis is currently unclear. In a double-blind study, we found ... more Optimal treatment of acute bronchiolitis is currently unclear. In a double-blind study, we found no significant differences between inhaled epinephrine and nasal decongestant in hospitalized infants with acute bronchiolitis regarding length of hospitalization, need for oxygen supplementation, or intravenous fluids and clinical score. Nasal decongestant is as effective as inhaled epinephrine in acute bronchiolitis.

Research paper thumbnail of Feasibility and Performance of Self-Collected Nasal Swabs for Detection of Influenza Virus, Respiratory Syncytial Virus, and Human Metapneumovirus

The Journal of Infectious Diseases, 2021

Background We assessed performance of participant-collected midturbinate nasal swabs compared to ... more Background We assessed performance of participant-collected midturbinate nasal swabs compared to study staff-collected midturbinate nasal swabs for the detection of respiratory viruses among pregnant women in Bangkok, Thailand. Methods We enrolled pregnant women aged ≥18 years and followed them throughout the 2018 influenza season. Women with acute respiratory illness self-collected midturbinate nasal swabs at home for influenza viruses, respiratory syncytial viruses (RSV), and human metapneumoviruses (hMPV) real-time RT-PCR testing and the study nurse collected a second midturbinate nasal swab during home visits. Paired specimens were processed and tested on the same day. Results The majority (109, 60%) of 182 participants were 20–30 years old. All 200 paired swabs had optimal specimen quality. The median time from symptom onsets to participant-collected swabs was 2 days and to staff-collected swabs was also 2 days. The median time interval between the 2 swabs was 2 hours. Compared...

Research paper thumbnail of Comparison of incidence and cost of influenza between healthy and high-risk children <60 months old in Thailand, 2011-2015

PloS one, 2018

Thailand recommends influenza vaccination for children aged 6 months to <36 months, but invest... more Thailand recommends influenza vaccination for children aged 6 months to <36 months, but investment in vaccine purchase is limited. To inform policy decision with respect to influenza disease burden and associated cost in young children and to support the continued inclusion of children as the recommended group for influenza vaccination, we conducted a prospective cohort study of children in Bangkok hospital to estimate and compare influenza incidence and cost between healthy and high-risk children. Caregivers of healthy children and children with medical conditions ('high-risk') aged <36 months were called weekly for two years to identify acute respiratory illness (ARI) episodes and collect illness-associated costs. Children with ARI were tested for influenza viruses by polymerase chain reaction. Illnesses were categorized as mild or severe depending on whether children were hospitalized. Population-averaged Poisson models were used to compare influenza incidence by ri...

Research paper thumbnail of Effect of intensive hand washing education on hand washing behaviors in thai households with an influenza-positive child in urban Thailand

Asia-Pacific journal of public health / Asia-Pacific Academic Consortium for Public Health, 2012

This study assessed the effect of intensive education on self-reported frequency of hand washing ... more This study assessed the effect of intensive education on self-reported frequency of hand washing (FHW), measured quality of hand washing (QHW), and measured scores of knowledge, attitude, and practice (KAP) after 7 days and 90 days home-based intensive education of participants (aged >7 years) in households with a influenza-positive child. The authors provided intensive hand washing education using interactive participation including individual training, self-monitoring diary, provision of soap, and so on. There were significant improvements on FHW and QHW on day 7, control group (n(1) = 135) reported 3.9 hand washing episodes/day, whereas the intervention group (n(2) = 140) reported 5.7 episodes/day; control group (n(1) = 164) obtained a 3.2 measured quality score, whereas the intervention group (n(2) = 166) obtained a score of 6.4. Pre-education and 90 days post-education, FHW significantly improved by 2 episodes/day and QHW increased by 3 scores/episode. Knowledge of influenza...

Research paper thumbnail of The Serial Intervals of Seasonal and Pandemic Influenza Viruses in Households in Bangkok, Thailand

American journal of epidemiology

The serial interval (SI) of human influenza virus infections is often described by a single distr... more The serial interval (SI) of human influenza virus infections is often described by a single distribution. Understanding sources of variation in the SI could provide valuable information for understanding influenza transmission dynamics. Using data from a randomized household study of nonpharmaceutical interventions to prevent influenza transmission in Bangkok, Thailand, over 34 months between 2008 and 2011, we estimated the influence of influenza virus type/subtype and other characteristics of 251 pediatric index cases and their 315 infected household contacts on estimates of household SI. The mean SI for all households was 3.3 days. Relative to influenza A(H1N1)pdm09 (3.1 days), the SI for influenza B (3.7 days) was 22% longer (95% confidence interval: 4, 43), or about half a day. The SIs for influenza viruses A(H1N1) and A(H3N2) were similar to that for A(H1N1)pdm09. SIs were shortest for older index cases (age 11-14 years) and for younger infected household contacts (age ≤15 year...

Research paper thumbnail of Modes of Transmission of Influenza B Virus in Households

PLoS ONE

Introduction While influenza A and B viruses can be transmitted via respiratory droplets, the imp... more Introduction While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei “aerosols” in transmission is controversial. Methods and Findings In Hong Kong and Bangkok, in 2008–11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a positive rapid influenza diagnostic test result, subjects were randomly allocated to one of three household-based interventions: hand hygiene, hand hygiene plus face masks, and a control group. Index cases plus their household contacts were followed for 7–10 days to identify secondary infections by reverse transcription polymerase chain reaction (RT-PCR) testing of respiratory specimens. Index cases with RT-PCR-confirmed influenza B were included in the present analyses. We used a mathematical model to make inferences on the modes of transmission, facilitated by apparent differences in clinical p...

Research paper thumbnail of Aerosol transmission is an important mode of influenza A virus spread

Nature Communications

Influenza A viruses are believed to spread between humans through contact, large respiratory drop... more Influenza A viruses are believed to spread between humans through contact, large respiratory droplets and small particle droplet nuclei (aerosols), but the relative importance of each of these modes of transmission is unclear. Volunteer studies suggest that infections via aerosol transmission may have a higher risk of febrile illness. Here we apply a mathematical model to data from randomized controlled trials of hand hygiene and surgical face masks in Hong Kong and Bangkok households. In these particular environments, inferences on the relative importance of modes of transmission are facilitated by information on the timing of secondary infections and apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We find that aerosol transmission accounts for approximately half of all transmission events. This implies that measures to reduce transmission by contact or large droplets may not be sufficient to control influenza A virus trans...

Research paper thumbnail of Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2011

Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospita... more Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published. The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR). Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between Jul...

Research paper thumbnail of Influenza vaccination coverage and effectiveness in young children in Thailand, 2011-2013

Influenza and Other Respiratory Viruses, 2014

Since 2009, Thailand has recommended influenza vaccine for children aged 6 months through 2 years... more Since 2009, Thailand has recommended influenza vaccine for children aged 6 months through 2 years, but no estimates of influenza vaccine coverage or effectiveness are available for this target group. During August 2011-May 2013, high-risk and healthy children aged ≤36 months were enrolled in a 2-year prospective cohort study. Parents were contacted weekly about acute respiratory illness (ARI) in their child. Ill children had combined nasal and throat swabs tested for influenza viruses by real-time reverse transcription-polymerase chain reaction. Influenza vaccination status was verified with vaccination cards. The Cox proportional hazards approach was used to estimate hazard ratios. Vaccine effectiveness (VE) was estimated as 100% x (1-hazard ratio). During 2011-2013, 968 children were enrolled (median age, 10·3 months); 948 (97·9%) had a vaccination record and were included. Of these, 394 (41·6%) had ≥1 medical conditions. Vaccination coverage for the 2011-2012 and 2012-2013 seasons was 29·3% (93/317) and 30·0% (197/656), respectively. In 2011-2012, there were 213 ARI episodes, of which 10 (4·6%) were influenza positive (2·3 per 1000 vaccinated and 3·8 per 1000 unvaccinated child-weeks). The VE was 55% (95% confidence interval [CI], -72, 88). In 2012-2013, there were 846 ARIs, of which 52 (6·2%) were influenza positive (1·8 per 1000 vaccinated and 4·5 per 1000 unvaccinated child-weeks). The VE was 64% (CI, 13%, 85%). Influenza vaccination coverage among young children in Thailand was low, although vaccination was moderately effective. Continued efforts are needed to increase influenza vaccination coverage and evaluate VE among young children in Thailand.

Research paper thumbnail of Modes of Transmission of Influenza B Virus in Households

PLoS ONE, 2014

While influenza A and B viruses can be transmitted via respiratory droplets, the importance of sm... more While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;aerosols&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; in transmission is controversial. In Hong Kong and Bangkok, in 2008-11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a positive rapid influenza diagnostic test result, subjects were randomly allocated to one of three household-based interventions: hand hygiene, hand hygiene plus face masks, and a control group. Index cases plus their household contacts were followed for 7-10 days to identify secondary infections by reverse transcription polymerase chain reaction (RT-PCR) testing of respiratory specimens. Index cases with RT-PCR-confirmed influenza B were included in the present analyses. We used a mathematical model to make inferences on the modes of transmission, facilitated by apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We estimated that approximately 37% and 26% of influenza B virus transmission was via the aerosol mode in households in Hong Kong and Bangkok, respectively. In the fitted model, influenza B virus infections were associated with a 56%-72% risk of fever plus cough if infected via aerosol route, and a 23%-31% risk of fever plus cough if infected via the other two modes of transmission. Aerosol transmission may be an important mode of spread of influenza B virus. The point estimates of aerosol transmission were slightly lower for influenza B virus compared to previously published estimates for influenza A virus in both Hong Kong and Bangkok. Caution should be taken in interpreting these findings because of the multiple assumptions inherent in the model, including that there is limited biological evidence to date supporting a difference in the clinical features of influenza B virus infection by different modes.

Research paper thumbnail of Patient-Based Transcriptome-Wide Analysis Identify Interferon and Ubiquination Pathways as Potential Predictors of Influenza A Disease Severity

PLoS ONE, 2014

Background: The influenza A virus is an RNA virus that is responsible for seasonal epidemics worl... more Background: The influenza A virus is an RNA virus that is responsible for seasonal epidemics worldwide with up to five million cases of severe illness and 500,000 deaths annually according to the World Health Organization estimates. The factors associated with severe diseases are not well defined, but more severe disease is more often seen among persons aged .65 years, infants, pregnant women, and individuals of any age with underlying health conditions. Methodology/Principal Findings: Using gene expression microarrays, the transcriptomic profiles of influenza-infected patients with severe (N = 11), moderate (N = 40) and mild (N = 83) symptoms were compared with the febrile patients of unknown etiology (N = 73). We found that influenza-infected patients, regardless of their clinical outcomes, had a stronger induction of antiviral and cytokine responses and a stronger attenuation of NK and T cell responses in comparison with those with unknown etiology. More importantly, we found that both interferon and ubiquitination signaling were strongly attenuated in patients with the most severe outcomes in comparison with those with moderate and mild outcomes, suggesting the protective roles of these pathways in disease pathogenesis.

Research paper thumbnail of Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants

PubMed, Aug 1, 2011

Background: Respiratory syncytial virus (RSV) and influenza infections are among the leading caus... more Background: Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published. Material and method: The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR). Results: Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between July and October (42-76%). RSV patients were more likely to present with higher temperature than the negative RT-PCR patients (p = .031). Oseltamivir was prescribed in 7.7% of influenza infections. Intravenous antibiotics were prescribed in 69.2%, 56.7% and 60.7% of the influenza, RSV and negative group respectively (p = .736). Percentages of patients requiring mechanical ventilation were 3.8, 6.7 and 6.3% among the influenza, RSV and negative group respectively (p = .861). Three patients died: 2 from RSV and 1 from the negative group. All three fatality cases had existing co-morbidity. Conclusion: A high proportion of RSV was detected in infants hospitalized with LRTI especially during July to October. High proportion of antibiotic prescription and relatively low rate of oseltamivir treatment were identified. Surveillance data and the availability of a rapid and reliable viral diagnostic test may help guide treatment, thereby improve outcome of this vulnerable population.

Research paper thumbnail of Influenza-Associated Medical Visits Prevented by Influenza Vaccination in Young Children in Thailand, 2012–2014

Journal of the Pediatric Infectious Diseases Society, Jul 24, 2020

Despite recommendations, few children aged 6-35 months in Thailand receive seasonal influenza vac... more Despite recommendations, few children aged 6-35 months in Thailand receive seasonal influenza vaccination. Using previously estimated incidence and vaccine effectiveness data from the period 2012-2014, we estimate that up to 121 000 medical visits could be prevented each year with 50% coverage and expanded recommendations to children aged <5 years.

Research paper thumbnail of Immunogenicity and Reactogenicity of mRNA BNT162b2 COVID-19 Vaccine among Thai Adolescents with Chronic Diseases

Vaccines

Adolescents with underlying diseases are at risk of severe COVID-19. The immune response of BNT16... more Adolescents with underlying diseases are at risk of severe COVID-19. The immune response of BNT162b2 may be poor among immunocompromised adolescents. We aim to describe immunogenicity of mRNA BNT162b2 among adolescents who are immunocompromised or have chronic diseases. We recruited adolescents 12–18 years of age; group A impaired-immunity (post-transplantation, cancer, on immunosuppressive drugs) and group B chronic diseases. A two-dose regimen of BNT162b2 was given. Immunogenicity was determined by surrogate virus neutralization test (sVNT) and IgG against receptor-binding domain (RBD). From August to October 2021, 312 adolescents, with a median age (IQR) of 15 years (13.7–16.5), were enrolled (group A 100, group B 212). The geometric means (GMs) of sVNT (% inhibition) against Delta strain and anti-RBD IgG (BAU/mL) after the 2nd dose among group A were: post-transplantation recipients 52.9 (95% CI 37.7–74.2) and 233.6 (95% CI 79–690.6); adolescents with cancer 62.3 (95% CI 29.2–13...

Research paper thumbnail of Influenza virus seroincidence in a cohort of healthy and high-risk children enrolled in infancy, Bangkok, Thailand

International Journal of Infectious Diseases, 2019

Influenza virus seroincidence in a cohort of healthy and high-risk children enrolled in infancy,

Research paper thumbnail of Predictors for influenza vaccination among Thai pregnant woman: The role of physicians in increasing vaccine uptake

Influenza and Other Respiratory Viruses, 2019

BackgroundPhysician recommendation and attitudes and beliefs of pregnant women toward influenza a... more BackgroundPhysician recommendation and attitudes and beliefs of pregnant women toward influenza and vaccination may influence vaccine uptake during pregnancy. We examined how physician recommendation and health beliefs of pregnant women may jointly affect influenza vaccination during pregnancy.MethodsThai pregnant women aged ≥18 years and >13 gestational weeks attending antenatal care (ANC) clinics, and ANC physicians were recruited during May‐August 2015. Women and physicians, linked using unique identifiers, provided data on demographic, health and work history, knowledge, attitudes, and beliefs toward influenza and vaccination, based on Health Belief Model constructs. Physicians also provided data on their practices in recommending influenza vaccination during pregnancy. Prevalence ratios for the association between knowledge, attitudes and beliefs of pregnant women, physician recommendation and documented receipt of vaccination within 30 days of the visit were calculated.Resu...

Research paper thumbnail of Pertussis surveillance in a children hospital in Bangkok, Thailand

International Journal of Infectious Diseases, 2019

To investigate the incidence, clinical characteristics and cost associated with pertussis in Thai... more To investigate the incidence, clinical characteristics and cost associated with pertussis in Thai children with persistent cough. Methods: A prospective study was conducted among children aged 0-18 years with persistent cough for 7 days with at least one of the following: paroxysm, inspiratory whooping, or post-tussive emesis. Nasopharyngeal swabs were obtained and tested for pertussis real time polymerase chain reaction (RT-PCR). Results: 19.6% of children (28 out of 143) had pertussis confirmed by RT-PCR, 75% of cases occurred in children who were too young to complete their primary series of vaccine. Paroxysm and post-tussive emesis were the most consistent clinical features, identified in 96% and 93% of cases, respectively, whooping was found in only 18%. Pertussis cases were more likely to have household cough contact (64% versus 30%, p < 0.001), be hospitalized (79% versus 58%, p = 0.048) and experience protracted duration of cough (47 vs. 20 days, p < 0.001) compare to their counterpart. Conclusion: Pertussis in Thai children is not infrequent and the common age group is young infant before completion of primary series of pertussis vaccine at six months of age, underline the importance of maternal pertussis immunization.

Research paper thumbnail of Nevirapine Concentrations During the First Month of Life and Maternal Efavirenz Washout in High-Risk HIV-Exposed Infants Receiving Triple Antiretroviral Prophylaxis

Pediatric Infectious Disease Journal, 2018

Background: Triple-drug infant antiretroviral prophylaxis containing nevirapine (NVP) is increasi... more Background: Triple-drug infant antiretroviral prophylaxis containing nevirapine (NVP) is increasingly used to prevent HIV transmission among neonates at high risk of HIV infection. Our aim was to describe NVP concentration from birth through the first month of life. Methods: High-risk HIV-exposed neonates were enrolled in a prospective cohort in Thailand. High-risk neonates defined as maternal HIV RNA >50 copies/mL before delivery or mother received antiretroviral treatment for <12 weeks before delivery. Neonates received zidovudine (4 mg/kg) and lamivudine (2 mg/kg) twice daily, plus NVP (4 mg/kg) once daily (no lead-in) from birth to 6 weeks of life. Infant plasma samples were collected at 1, 2, 14 or 2, 7, 28 days of life. NVP trough concentrations (C 24) were estimated using a population pharmacokinetic model and target C 24 was ≥0.1 mg/L. "Washout" efavirenz (EFV) concentrations were assessed in infants whose mother received EFV-based antiretroviral treatment. Results: A total of 48 infants were included: 25 (52%) were male and 12 (25%) were preterm (gestational age 34-37 weeks). Median (interquartile range) predicted NVP C 24 were 1.34 mg/L (1.13-1.84), 2.24 (2.00-2.59), 2.78 (2.61-3.12), 2.20 (1.86-2.44) and 0.81 (0.58-0.98) on days 1, 2, 7, 14 and 28 of life, respectively. NVP C 24 was not significantly different between term and preterm infants. All infants maintained NVP C 24 ≥0.1 mg/L. EFV via placental transfer remained detectable in infants up to 7 days of life. Conclusions: NVP 4 mg/kg daily from birth provided adequate prophylactic concentrations during the first month of life in high-risk HIV-exposed neonates.

Research paper thumbnail of Tolerability of trivalent inactivated influenza vaccine among pregnant women, 2015

BMC pregnancy and childbirth, Jan 23, 2018

Thailand recommends influenza vaccination among pregnant women. We conducted a cohort study to de... more Thailand recommends influenza vaccination among pregnant women. We conducted a cohort study to determine if the prevalence of adverse events following immunization (AEFIs) with influenza vaccine among Thai pregnant women was similar to that often cited among healthy adults. Women who were ≥17 gestational weeks and ≥18 years of age were recruited. Demographic and health history data were collected using structured questionnaires. Women were provided with symptom diary, ruler to measure local reaction(s), and thermometer to measure body temperature. AEFIs were defined as any new symptom/abnormality occurring within four weeks after vaccination. The diaries were abstracted for frequency, duration, and level of discomfort/inconvenience of the AEFIs. Serious adverse events (SAEs) and the likelihood of AEFIs being associated with vaccination were determined using standard definitions. Among 305 women enrolled between July-November 2015, median age was 29 years. Of these, 223 (73%) were in...

Research paper thumbnail of Cost-effectiveness of inactivated seasonal influenza vaccination in a cohort of Thai children ≤60 months of age

PLOS ONE, 2017

Background Vaccination is the best measure to prevent influenza. We conducted a cost-effectivenes... more Background Vaccination is the best measure to prevent influenza. We conducted a cost-effectiveness evaluation of trivalent inactivated seasonal influenza vaccination, compared to no vaccination, in children 60 months of age participating in a prospective cohort study in Bangkok, Thailand. Methods A static decision tree model was constructed to simulate the population of children in the cohort. Proportions of children with laboratory-confirmed influenza were derived from children followed weekly. The societal perspective and one-year analytic horizon were used for each influenza season; the model was repeated for three influenza seasons (2012-2014). Direct and indirect costs associated with influenza illness were collected and summed. Cost of the trivalent inactivated seasonal influenza vaccine (IIV3) including promotion, administration, and supervision cost was added for children who were vaccinated. Quality-adjusted life years (QALY), derived from literature, were used to quantify health outcomes. The incremental cost-effectiveness ratio (ICER) was calculated as the difference in the expected total costs between the vaccinated and unvaccinated groups divided by the difference in QALYs for both groups. Results Compared to no vaccination, IIV3 vaccination among children 60 months in our cohort was not cost-effective in the introductory year (2012 season; 24,450 USD/QALY gained),

Research paper thumbnail of Therapeutic Drug Monitoring of Lopinavir in Human Immunodeficiency Virus-Infected Children Receiving Adult Tablets

Pediatric Infectious Disease Journal, 2010

Optimal treatment of acute bronchiolitis is currently unclear. In a double-blind study, we found ... more Optimal treatment of acute bronchiolitis is currently unclear. In a double-blind study, we found no significant differences between inhaled epinephrine and nasal decongestant in hospitalized infants with acute bronchiolitis regarding length of hospitalization, need for oxygen supplementation, or intravenous fluids and clinical score. Nasal decongestant is as effective as inhaled epinephrine in acute bronchiolitis.

Research paper thumbnail of Feasibility and Performance of Self-Collected Nasal Swabs for Detection of Influenza Virus, Respiratory Syncytial Virus, and Human Metapneumovirus

The Journal of Infectious Diseases, 2021

Background We assessed performance of participant-collected midturbinate nasal swabs compared to ... more Background We assessed performance of participant-collected midturbinate nasal swabs compared to study staff-collected midturbinate nasal swabs for the detection of respiratory viruses among pregnant women in Bangkok, Thailand. Methods We enrolled pregnant women aged ≥18 years and followed them throughout the 2018 influenza season. Women with acute respiratory illness self-collected midturbinate nasal swabs at home for influenza viruses, respiratory syncytial viruses (RSV), and human metapneumoviruses (hMPV) real-time RT-PCR testing and the study nurse collected a second midturbinate nasal swab during home visits. Paired specimens were processed and tested on the same day. Results The majority (109, 60%) of 182 participants were 20–30 years old. All 200 paired swabs had optimal specimen quality. The median time from symptom onsets to participant-collected swabs was 2 days and to staff-collected swabs was also 2 days. The median time interval between the 2 swabs was 2 hours. Compared...

Research paper thumbnail of Comparison of incidence and cost of influenza between healthy and high-risk children <60 months old in Thailand, 2011-2015

PloS one, 2018

Thailand recommends influenza vaccination for children aged 6 months to <36 months, but invest... more Thailand recommends influenza vaccination for children aged 6 months to <36 months, but investment in vaccine purchase is limited. To inform policy decision with respect to influenza disease burden and associated cost in young children and to support the continued inclusion of children as the recommended group for influenza vaccination, we conducted a prospective cohort study of children in Bangkok hospital to estimate and compare influenza incidence and cost between healthy and high-risk children. Caregivers of healthy children and children with medical conditions ('high-risk') aged <36 months were called weekly for two years to identify acute respiratory illness (ARI) episodes and collect illness-associated costs. Children with ARI were tested for influenza viruses by polymerase chain reaction. Illnesses were categorized as mild or severe depending on whether children were hospitalized. Population-averaged Poisson models were used to compare influenza incidence by ri...

Research paper thumbnail of Effect of intensive hand washing education on hand washing behaviors in thai households with an influenza-positive child in urban Thailand

Asia-Pacific journal of public health / Asia-Pacific Academic Consortium for Public Health, 2012

This study assessed the effect of intensive education on self-reported frequency of hand washing ... more This study assessed the effect of intensive education on self-reported frequency of hand washing (FHW), measured quality of hand washing (QHW), and measured scores of knowledge, attitude, and practice (KAP) after 7 days and 90 days home-based intensive education of participants (aged >7 years) in households with a influenza-positive child. The authors provided intensive hand washing education using interactive participation including individual training, self-monitoring diary, provision of soap, and so on. There were significant improvements on FHW and QHW on day 7, control group (n(1) = 135) reported 3.9 hand washing episodes/day, whereas the intervention group (n(2) = 140) reported 5.7 episodes/day; control group (n(1) = 164) obtained a 3.2 measured quality score, whereas the intervention group (n(2) = 166) obtained a score of 6.4. Pre-education and 90 days post-education, FHW significantly improved by 2 episodes/day and QHW increased by 3 scores/episode. Knowledge of influenza...

Research paper thumbnail of The Serial Intervals of Seasonal and Pandemic Influenza Viruses in Households in Bangkok, Thailand

American journal of epidemiology

The serial interval (SI) of human influenza virus infections is often described by a single distr... more The serial interval (SI) of human influenza virus infections is often described by a single distribution. Understanding sources of variation in the SI could provide valuable information for understanding influenza transmission dynamics. Using data from a randomized household study of nonpharmaceutical interventions to prevent influenza transmission in Bangkok, Thailand, over 34 months between 2008 and 2011, we estimated the influence of influenza virus type/subtype and other characteristics of 251 pediatric index cases and their 315 infected household contacts on estimates of household SI. The mean SI for all households was 3.3 days. Relative to influenza A(H1N1)pdm09 (3.1 days), the SI for influenza B (3.7 days) was 22% longer (95% confidence interval: 4, 43), or about half a day. The SIs for influenza viruses A(H1N1) and A(H3N2) were similar to that for A(H1N1)pdm09. SIs were shortest for older index cases (age 11-14 years) and for younger infected household contacts (age ≤15 year...

Research paper thumbnail of Modes of Transmission of Influenza B Virus in Households

PLoS ONE

Introduction While influenza A and B viruses can be transmitted via respiratory droplets, the imp... more Introduction While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei “aerosols” in transmission is controversial. Methods and Findings In Hong Kong and Bangkok, in 2008–11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a positive rapid influenza diagnostic test result, subjects were randomly allocated to one of three household-based interventions: hand hygiene, hand hygiene plus face masks, and a control group. Index cases plus their household contacts were followed for 7–10 days to identify secondary infections by reverse transcription polymerase chain reaction (RT-PCR) testing of respiratory specimens. Index cases with RT-PCR-confirmed influenza B were included in the present analyses. We used a mathematical model to make inferences on the modes of transmission, facilitated by apparent differences in clinical p...

Research paper thumbnail of Aerosol transmission is an important mode of influenza A virus spread

Nature Communications

Influenza A viruses are believed to spread between humans through contact, large respiratory drop... more Influenza A viruses are believed to spread between humans through contact, large respiratory droplets and small particle droplet nuclei (aerosols), but the relative importance of each of these modes of transmission is unclear. Volunteer studies suggest that infections via aerosol transmission may have a higher risk of febrile illness. Here we apply a mathematical model to data from randomized controlled trials of hand hygiene and surgical face masks in Hong Kong and Bangkok households. In these particular environments, inferences on the relative importance of modes of transmission are facilitated by information on the timing of secondary infections and apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We find that aerosol transmission accounts for approximately half of all transmission events. This implies that measures to reduce transmission by contact or large droplets may not be sufficient to control influenza A virus trans...

Research paper thumbnail of Clinical and epidemiological characteristics of respiratory syncytial virus and influenza virus associated hospitalization in urban Thai infants

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2011

Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospita... more Respiratory syncytial virus (RSV) and influenza infections are among the leading cause of hospitalized lower respiratory tract infections (LRTI) in children especially among those younger than 1 year of age. Few descriptions of these 2 important viruses in Thai children less than 1 year of age have been published. The authors conducted a prospective study of children 1-12 months old hospitalized at a pediatric tertiary-care hospital in Bangkok with LRTI during the period December 2007 to August 2009. Respiratory specimens were tested for influenza A/B virus and RSV using a reverse-transcriptase polymerase chain reaction (RT-PCR). Twenty-six (7.3%) had RT-PCR positive for influenza and 104 (29.4%) for RSV from 354 infants. Clinical diagnoses included pneumonia (73.4%), bronchiolitis (17.55%), croup (6.5%) and bronchitis (2.5%) and were similar among groups except the proportion of croup was significantly lower in RSV (p = .018). The proportion of RSV infection was highest between Jul...

Research paper thumbnail of Influenza vaccination coverage and effectiveness in young children in Thailand, 2011-2013

Influenza and Other Respiratory Viruses, 2014

Since 2009, Thailand has recommended influenza vaccine for children aged 6 months through 2 years... more Since 2009, Thailand has recommended influenza vaccine for children aged 6 months through 2 years, but no estimates of influenza vaccine coverage or effectiveness are available for this target group. During August 2011-May 2013, high-risk and healthy children aged ≤36 months were enrolled in a 2-year prospective cohort study. Parents were contacted weekly about acute respiratory illness (ARI) in their child. Ill children had combined nasal and throat swabs tested for influenza viruses by real-time reverse transcription-polymerase chain reaction. Influenza vaccination status was verified with vaccination cards. The Cox proportional hazards approach was used to estimate hazard ratios. Vaccine effectiveness (VE) was estimated as 100% x (1-hazard ratio). During 2011-2013, 968 children were enrolled (median age, 10·3 months); 948 (97·9%) had a vaccination record and were included. Of these, 394 (41·6%) had ≥1 medical conditions. Vaccination coverage for the 2011-2012 and 2012-2013 seasons was 29·3% (93/317) and 30·0% (197/656), respectively. In 2011-2012, there were 213 ARI episodes, of which 10 (4·6%) were influenza positive (2·3 per 1000 vaccinated and 3·8 per 1000 unvaccinated child-weeks). The VE was 55% (95% confidence interval [CI], -72, 88). In 2012-2013, there were 846 ARIs, of which 52 (6·2%) were influenza positive (1·8 per 1000 vaccinated and 4·5 per 1000 unvaccinated child-weeks). The VE was 64% (CI, 13%, 85%). Influenza vaccination coverage among young children in Thailand was low, although vaccination was moderately effective. Continued efforts are needed to increase influenza vaccination coverage and evaluate VE among young children in Thailand.

Research paper thumbnail of Modes of Transmission of Influenza B Virus in Households

PLoS ONE, 2014

While influenza A and B viruses can be transmitted via respiratory droplets, the importance of sm... more While influenza A and B viruses can be transmitted via respiratory droplets, the importance of small droplet nuclei &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;aerosols&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; in transmission is controversial. In Hong Kong and Bangkok, in 2008-11, subjects were recruited from outpatient clinics if they had recent onset of acute respiratory illness and none of their household contacts were ill. Following a positive rapid influenza diagnostic test result, subjects were randomly allocated to one of three household-based interventions: hand hygiene, hand hygiene plus face masks, and a control group. Index cases plus their household contacts were followed for 7-10 days to identify secondary infections by reverse transcription polymerase chain reaction (RT-PCR) testing of respiratory specimens. Index cases with RT-PCR-confirmed influenza B were included in the present analyses. We used a mathematical model to make inferences on the modes of transmission, facilitated by apparent differences in clinical presentation of secondary infections resulting from aerosol transmission. We estimated that approximately 37% and 26% of influenza B virus transmission was via the aerosol mode in households in Hong Kong and Bangkok, respectively. In the fitted model, influenza B virus infections were associated with a 56%-72% risk of fever plus cough if infected via aerosol route, and a 23%-31% risk of fever plus cough if infected via the other two modes of transmission. Aerosol transmission may be an important mode of spread of influenza B virus. The point estimates of aerosol transmission were slightly lower for influenza B virus compared to previously published estimates for influenza A virus in both Hong Kong and Bangkok. Caution should be taken in interpreting these findings because of the multiple assumptions inherent in the model, including that there is limited biological evidence to date supporting a difference in the clinical features of influenza B virus infection by different modes.

Research paper thumbnail of Patient-Based Transcriptome-Wide Analysis Identify Interferon and Ubiquination Pathways as Potential Predictors of Influenza A Disease Severity

PLoS ONE, 2014

Background: The influenza A virus is an RNA virus that is responsible for seasonal epidemics worl... more Background: The influenza A virus is an RNA virus that is responsible for seasonal epidemics worldwide with up to five million cases of severe illness and 500,000 deaths annually according to the World Health Organization estimates. The factors associated with severe diseases are not well defined, but more severe disease is more often seen among persons aged .65 years, infants, pregnant women, and individuals of any age with underlying health conditions. Methodology/Principal Findings: Using gene expression microarrays, the transcriptomic profiles of influenza-infected patients with severe (N = 11), moderate (N = 40) and mild (N = 83) symptoms were compared with the febrile patients of unknown etiology (N = 73). We found that influenza-infected patients, regardless of their clinical outcomes, had a stronger induction of antiviral and cytokine responses and a stronger attenuation of NK and T cell responses in comparison with those with unknown etiology. More importantly, we found that both interferon and ubiquitination signaling were strongly attenuated in patients with the most severe outcomes in comparison with those with moderate and mild outcomes, suggesting the protective roles of these pathways in disease pathogenesis.