Prevalence and associating factors of long COVID in pediatric patients during the Delta and the Omicron variants.

Introduction: The number of pediatric COVID-19 infections is increasing; however, the data on long COVID conditions in children is still limited. Our study aimed to find the prevalence of long COVID in children during the Delta and Omicron waves, as well as associated factors. Methods: A single-center prospective cohort study was conducted. We included 802 RT-PCR-confirmed COVID-19 pediatric patients in the Delta and Omicron periods. Long COVID was defined as having symptoms for ≥3 months after infection. Parents and/or patients were interviewed by phone. Multivariable logistic regression was performed to find associated factors with long COVID. Results: The overall prevalence of long COVID was 30.2%. The Delta period had more prevalence than the Omicron (36.3% vs. 23.9%). Common symptoms for patients 0-3 years' old were loss of appetite, rhinorrhea, and nasal congestion. Conversely, patients 3-18 years' old had hair loss, dyspnea on exertion, rhinorrhea, and nasal congestion. However, there was no significant negative impact on daily life. Most symptoms improved after a 6-month follow-up. Factors associated with long COVID-19 conditions were infection during the Omicron period (adjusted OR: 0.54; 95% CI: 0.39-0.74, P < 0.001), fever (adjusted OR: 1.49, 95% CI: 1.01-2.20, P = 0.04) and rhinorrhea (adjusted OR: 1.47, 95% CI: 1.06-2.02, P = 0.02). Conclusion: Infection during the Omicron wave has a lower prevalence of long COVID. The prognosis is often favorable, and most symptoms gradually become less. However, pediatricians may schedule appointments to surveil long COVID in children with fever or rhinorrhea as an initial symptom.

Prevalence, risk factors, and vaccine effectiveness of COVID-19 infection in thai children, adolescents, and young adults in the omicron era.

Background and objectives: The study of prevalence, risk factors, and vaccine effectiveness (VE) in children, adolescents, and young adults during the Omicron era has been limited, making this the objectives of the study. Methods: A prospective, test-negative case-control study was conducted on patients aged 0-24 years old classified as patients under investigation (PUI) from January to May 2022. PUI with positive RT-PCR within 14 days were classified as cases, whilst PUI with negative RT-PCR in 14 days were controls. Univariate and multivariate analyses determined risk factors; VE was calculated using [1-adjusted odds ratio (OR)] × 100. Results: The final analyses included 3,490 patients with a PUI infection rate of 45.6%. Heterologous vaccination regimens, including inactivated vaccines, viral vectors, and mRNA were utilized during the study period. A total of 2,563 patients (73.5%) had received at least 2 vaccine doses, regardless of regimen. Male gender and household infections were independent risk factors for the development of infection, with an adjusted OR of 1.55 and 1.45, respectively. Underlying comorbidities and obesity were not significantly associated with the development of infection. Patients with underlying comorbidities were more likely to have at least moderate severity of infection with the adjusted OR of 3.07. Age older than 11 years was associated with lower infection risk and development of at least moderate infection with adjusted OR of 0.4 and 0.34, respectively. Vaccinated participants also had a lower risk of developing at least moderate infection: adjusted OR of 0.40. The adjusted VE of any vaccination regimen for infection prevention for one, two, three, or more than four doses was 21.8%, 30.6%, 53.5%, and 81.2%, respectively. The adjusted VE of any vaccination regimen for prevention of at least moderate severity of the disease for one, two, three, or more than four doses was 5.7%, 24.3% 62.9%, and 90.6%, respectively. Conclusion: Disease prevalence among PUI was substantially high during the Omicron wave. A two-dose vaccination regimen does not appear sufficient to ensure protection against infection.

Real-life effectiveness of COVID-19 vaccine during the Omicron variant-dominant pandemic: how many booster doses do we need?

The surge in coronavirus disease 2019 (COVID-19) caused by the Omicron variants of the severe acute respiratory syndrome coronavirus 2 necessitates researches to inform vaccine effectiveness (VE) and other preventive measures to halt the pandemic. A test-negative case-control study was conducted among adults (age ≥18 years) who were at-risk for COVID-19 and presented for nasopharyngeal real-time polymerase chain reaction testing during the Omicron variant-dominant period in Thailand (1 January 2022-15 June 2022). All participants were prospectively followed up for COVID-19 development for 14 days after the enrolment. Vaccine effectiveness was estimated and adjusted for characteristics associated with COVID-19. Of the 7971 included individuals, there were 3104 cases and 4867 controls. The adjusted VE among persons receiving 2-dose, 3-dose, and 4-dose vaccine regimens for preventing infection and preventing moderate-to-critical diseases were 33%, 48%, 62% and 60%, 74%, 76%, respectively. The VE were generally higher among those receiving the last dose of vaccine within 90 days compared to those receiving the last dose more than 90 days prior to the enrolment. The highest VE were observed in individuals receiving the 4-dose regimen, CoronaVac-CoronaVac-ChAdOx1 nCoV-19-BNT162b2 for both preventing infection (65%) and preventing moderate-to-critical diseases (82%). Our study demonstrated increased VE along with an increase in number of vaccine doses received. Current vaccination programmes should focus on reducing COVID-19 severity and mandate at least one booster dose. The heterologous boosters with viral vector and mRNA vaccines were highly effective and can be used in individuals who previously received the primary series of inactivated vaccine.

Outcomes of young children hospitalized with acute wheezing.

BACKGROUND: Wheezing in preschool children is a common symptom. OBJECTIVE: The study aimed to determine an incidence of recurrent wheezing among young children who had been hospitalized with acute wheezing after 12 months. Factors associated with recurrent wheezing were explored. METHODS: A longitudinal study was conducted among 236 children, aged between 6 months and 5 years, who were hospitalized with acute wheezing in 4 hospitals located in Bangkok and adjacent provinces, Thailand. Demographics, house environments and clinical characteristic data were collected at entry. Serum specific IgE levels against common food and inhalant allergens and serum 25-hydroxyvitamin D (25OHD) concentrations were measured. RESULTS: At entry, the mean age was 24.4 months (SD = 15.7 months). Of 236 hospitalized children with acute wheezing, ninety-four cases (39.8%) were the first wheezing episode of life. By laboratory results, 197 (83.5%) and 56 (23.7%) children were atopic and had vitamin D insufficiency respectively. There were 195 cases completely followed for 12 months. One-year risk of emergency visits and hospitalization due to recurrent wheezing were 49.7% and 23.1% respectively. By multivariable analysis, being the second born child or more, vitamin D insufficiency, "ever wheeze", and allergic rhinitis were significantly associated with recurrent wheezing within 12 months with adjusted odds ratios of 2.5 (95% confidence interval: 1.3-5.3), 2.3 (95% confidence interval: 1.1-4.4), 1.9 (95% confidence interval: 1.2-3.5), and 1.6 (95% confidence interval: 1.3-2.9) respectively. CONCLUSIONS: Being the second born child or more, vitamin D insufficiency, ever wheeze, and allergic rhinitis were significant risks of recurrent wheezing.

Development and validation of the predictive score for pediatric COVID-19 pneumonia: A nationwide, multicenter study.

BACKGROUND: Due to the possibility of asymptomatic pneumonia in children with COVID-19 leading to overexposure to radiation and problems in limited-resource settings, we conducted a nationwide, multi-center study to determine the risk factors of pneumonia in children with COVID-19 in order to create a pediatric pneumonia predictive score, with score validation. METHODS: This was a retrospective cohort study done by chart review of all children aged 0-15 years admitted to 13 medical centers across Thailand during the study period. Univariate and multivariate analyses as well as backward and forward stepwise logistic regression were used to generate a final prediction model of the pneumonia score. Data during the pre-Delta era was used to create a prediction model whilst data from the Delta one was used as a validation cohort. RESULTS: The score development cohort consisted of 1,076 patients in the pre-Delta era, and the validation cohort included 2,856 patients in the Delta one. Four predictors remained after backward and forward stepwise logistic regression: age < 5 years, number of comorbidities, fever, and dyspnea symptoms. The predictive ability of the novel pneumonia score was acceptable with the area under the receiver operating characteristics curve of 0.677 and a well-calibrated goodness-of-fit test (p = 0.098). The positive likelihood ratio for pneumonia was 0.544 (95% confidence interval (CI): 0.491-0.602) in the low-risk category, 1.563 (95% CI: 1.454-1.679) in the moderate, and 4.339 (95% CI: 2.527-7.449) in the high-risk. CONCLUSION: This study created an acceptable clinical prediction model which can aid clinicians in performing an appropriate triage for children with COVID-19.

Epidemiological and Clinical Characteristics of Pediatric COVID-19 in the Tertiary Care System in Thailand: Comparative Delta and pre-Delta Era.

Background: Few studies had focused on the epidemiological and clinical characteristics of pediatric COVID-19 (SARS-CoV-2) during Delta and pre-Delta eras in Asia, despite it being a pandemic. Objective: To study the epidemiological and clinical characteristics of three waves of pediatric COVID-19 infections in a tertiary-care setting in Thailand. Methods: This retrospective study reviewed all PCR-confirmed pediatric (0-18 years of age) COVID-19 infections between January 13, 2020, and October 31, 2021, in a tertiary care system in Thailand. Results: 1,019 patients, aged 0.02 - 18 years, 552 (54.2%) male, and 467 (45.8%) female, with a median age of 9.2 years, were enrolled. Asymptomatic cases accounted for 35.7%, of which 106 (18.9%) had abnormal chest X-ray findings. Most cases were classified as having mild clinical symptoms, with only 8 (0.8%) and 4 (0.4%) developing a severe and critical illness, respectively. There were no deaths. The Delta variant appeared more transmissible than previous ones, but we did not see any difference in disease severity. Upper respiratory tract symptoms were predominant, while few cases had lower respiratory tract involvement. The sensitivity and specificity of dyspnea symptoms to predict radiologically confirmed pneumonia were 14% and 95%, respectively, with a likelihood ratio of 3.37. The overall prognosis was good, with only 13 (1.3 %) needing respiratory support. All cases showed clinical improvement with a decent recovery. Conclusion: Pediatric COVID-19 during the Delta variant predominance era generally appeared more transmissible but benign. One-fifth of cases had pneumonia, but few cases needed respiratory support. Prevention remains important for disease control.

A randomized controlled study comparing the efficacy of soap versus soap-plus-microwave disinfection for irrigation device in children with acute rhinosinusitis.

BACKGROUND: Nasal irrigation is an effective component of sino-nasal disease management. Nonetheless, bacterial contamination is worrisome. OBJECTIVE: To study bacterial colonization incidence using squeeze-bottle nasal irrigation devices, after disinfection with soap or soap-plus-microwave technique, in pediatric acute rhinosinusitis. METHODS: A randomized, prospective, controlled study was conducted on acute rhinosinusitis children, aged 2-15 years. Each participant was randomized into a soap-cleaning or soap-plus- microwave group. For a two-week period, participants irrigated their nostrils with NSS twice daily and cleaned the bottle after each use. In the end, bottles were sent to a microbiological laboratory for bacterial identification. RESULTS: The mean 5S Score and satisfaction score gradually improved in both groups with no significant differences between groups. Bacterial identification frequency in the soap group was slightly higher than in the soap-plus-microwave one, without statistical significance. For safety and tolerability, all participants reported 100% adherence to nasal irrigation. The soap-plus-microwave group reported more minor adverse outcomes than the soap-cleaning one. No thermal deformation of irrigation bottles was observed. CONCLUSIONS: Regular cleaning of nasal irrigation devices is needed to minimize bacterial contamination. Only soap or soap plus microwave disinfection appeared simple and safe for disinfection. Both techniques can equally minimize the rate of bacterial contamination. Although no gross thermal deformation at optimal power and duration, chemical irritants after high power or long microwave durations may be a concern.

An epidemiological study of pediatric COVID-19 in the era of the variant of concern.

BACKGROUND: There were limited epidemiological data of pediatric COVID-19 in Asia outside China, especially during the era of the variants of concern such as the Delta and Alpha variants. The objective was to describe the clinical epidemiology of pediatric COVID-19 in a tertiary care center in Thailand from April to August 2021. The identification of risk factors for the development of pneumonia in these children was also performed. METHODS: This retrospective cohort study was conducted by retrospective chart review of all children aged 0-15 years admitted to Thammasat University Hospital care system during the study period. The risk factors for the development of pneumonia were analyzed using logistic regression. RESULTS: A total of 698 children were included for analysis, of which 52% were male. The mean age of the cohort was 7.2 + 4.5 years old. Radiographic pneumonia was identified in 100 children (14.3%) and a total of 16 children (2.3%) were diagnosed with severe and critical diseases. The mortality rate was 0.1%. Children younger than 1 year and children with comorbidity were at higher risk of developing pneumonia (Adjusted odds ratios 2.99 (95% confidence interval (CI): 1.56-5.74) and 2.32 (95% CI: 1.15-4.67), respectively). CONCLUSION: In the era of the variants of concern, the proportion of children with severe and critical diseases remained low. However, prudence must be taken in caring for younger children and children with comorbidity.

Comparing real-life effectiveness of various COVID-19 vaccine regimens during the delta variant-dominant pandemic: a test-negative case-control study.

Data on real-life vaccine effectiveness (VE), against the delta variant (B.1.617.2) of the severe acute respiratory syndrome coronavirus 2 among various coronavirus disease 2019 (COVID-19) vaccine regimens are urgently needed to impede the COVID-19 pandemic. We conducted a test-negative case-control study to assess the VE of various vaccine regimens for preventing COVID-19 during the period when the delta variant was the dominant causative virus (≥ 95%) in Thailand (25 July 2021-23 Oct 2021). All individuals (age ≥18 years) at-risk for COVID-19, presented for nasopharyngeal real-time polymerase chain reaction (RT-PCR) testing, were prospectively enrolled and followed up for disease development. Vaccine effectiveness was estimated with adjustment for individual demographic and clinical characteristics. Of 3353 included individuals, there were 1118 cases and 2235 controls. The adjusted VE among persons receiving two-dose CoronaVac plus one BNT162b2 booster was highest (98%; 95% confidence interval [CI] 87-100), followed by those receiving two-dose CoronaVac plus one ChAdOx1 nCoV-19 booster (86%; 95% CI 74-93), two-dose ChAdOx1 nCoV-19 (83%; 95% CI 70-90), one CoronaVac dose and one ChAdOx1 nCoV-19 dose (74%; 95% CI 43-88) and two-dose CoronaVac (60%; 95% CI 49-69). One dose of CoronaVac or ChAdOx1 nCoV-19 had a VE of less than 50%. Our study demonstrated the incremental VE with the increase in the number of vaccine doses received. The two-dose CoronaVac plus one BNT162b2 or ChAdOx1 nCoV-19 booster regimens was highly effective in preventing COVID-19 during the rise of delta variant.

LACHT syndrome (Mardini-Nyhan association) with tracheal stenosis in a Thai newborn.

LACHT syndrome, or Mardini-Nyhan association, is an ultra-rare disorder, diagnosed solely by the clinical characteristics of lung agenesis, complex cardiac defects, and thumb anomalies. Only 12 patients have been reported worldwide, and here, we report a new clinical diagnosis of LACHT syndrome. Our patient was a male full-term newborn with left lung agenesis, congenital heart defects including ventricular septal defect, right-sided aortic arch, with aberrant left subclavian artery and Kommerell diverticulum, as well as left preaxial polydactyly and hemivertebra. Our patient appears to be the second LACHT syndrome case to also suffer from tracheal stenosis, which has only been reported once before in conjunction with this syndrome. In light of this, tracheal stenosis may be a phenotype for LACHT syndrome.

A randomized controlled study comparing the efficacy of nasal saline irrigation devices in children with acute rhinosinusitis.

OBJECTIVE: To evaluate the efficacy of positive-pressure nasal irrigation devices in children with acute sinusitis, in addition to bacterial colonization of the irrigation device. METHOD: We performed a randomized, prospective, controlled study of 80 children with acute sinusitis, aged between 3 and 15 years. Participants were randomly separated into two groups, where one group was treated using a squeezable bottle and the other group treated using a syringe. All patients were instructed to use a 1.25% buffered hypertonic solution for nasal irrigation twice daily for 2 weeks, in addition to amoxicillin-clavulanic acid. During this period, all participants recorded a 5S score, satisfaction score, any side effects and use of antihistamines. Parents were instructed to clean the device with soap after each use. After this period, the nasal irrigation devices were sent to a microbiological laboratory for bacterial identification. RESULTS: At the 2-week follow-up, improvement in both 5S and satisfaction scores were observed in both groups compared to baseline, which were significantly higher in the group treated with the squeezable bottle compared to the syringe. Few complaints were reported, and side effects were equal in both groups. The overall rate of bacterial contamination for both treatments was approximately 80%, but this did not translate into higher rates of infection amongst patients. CONCLUSIONS: The use of a squeezable bottle for nasal irrigation in children with acute sinusitis was associated with further improvements in 5S and satisfaction scores compared to syringe use, and there were no significant differences in bacterial contamination between methods.

Effect of allergic rhinitis and asthma on the quality of life in young Thai adolescents.

BACKGROUND: Despite an increasing recognition that both asthma and allergic rhinitis are serious health disorders in Thailand, their combined effects on patients' quality of life in the Thai population has not been reported. OBJECTIVE: The study aimed to evaluate the impacts of allergic rhinitis and asthma on the quality of life of young adolescents in Thailand. METHODS: A total of 1,440 pupils, aged 12-14 years, were randomly recruited from 4 schools located in Bangkok and Pathum Thani Province. Allergic rhinitis and asthmatic symptoms were identified by the International Study of Asthma and Allergies in Childhood (ISAAC) written questionnaire. The Pediatric Quality of Life Inventory (PedsQL) questionnaire was used to evaluate their quality of life. RESULTS: There were 1,230 completed questionnaires for analysis. The prevalence of allergic rhinitis alone, asthma alone and diseases co-occurrence was 32.8%, 7.2%, and 12.7% respectively. Pupils with respiratory allergy had significantly lower PedsQL mean scores than healthy pupils, for all dimensions (p < 0.006). The greatest reduction of the PedsQL mean score was for emotional functioning. Among pupils with allergic rhinitis, those who were also affected with asthma had significantly lower mean scores, for all quality of life domains (all p < 0.001). Compared to allergic rhinitis, asthma significantly reduced PedsQL mean scores in almost all domains (p < 0.001), except for physical health. CONCLUSIONS: Allergic rhinitis and asthma have a significant influence on the quality of life in young Thai adolescents, in particular regarding emotional functioning. Asthma has stronger negative effects on life quality than allergic rhinitis, especially regarding psychosocial health.

Incidence of recurrent wheezing in under 5-year-old human bocavirus infection during one year follow-up.

BACKGROUND: Human bocavirus (HBoV) is a newly identified virus that can cause acute wheezing in young children. The present study aimed to evaluate the incidence and factors associated with recurrent wheezing during 1 year after HBoV lower respiratory tract infection (LRI). MATERIAL AND METHOD: Children younger than 5 years old who were admitted to King Chulalongkorn Memorial Hospital between February 1, 2006 and September 30, 2008 due to LRI were recruited. Their nasopharyngeal aspirates were evaluated for respiratory virus by polymerase chain reaction (PCR) assays. Those who had positive PCR for HBoV and had no underlying diseases were studied. Their clinical presentations were evaluated and their clinical data about recurrent wheezing as well as pulmonary function tests were followed-up for 1 year. RESULTS: Fifteen patients with HBoV-LRI were regularly followed-up. Seven patients (47%) had co-infection with other respiratory viruses. Generalized wheezing was the most common lung sign detected in 73% of cases (11 cases) and 36% (4 cases) of them responded well to bronchodilators. During one year follow-up, serial pulmonary function tests were normal in all cases and most patients were doing well. However 27% of HBoV infected patients (4 cases) developed recurrent wheezing associated with respiratory tract infections. Two of them had to be re-hospitalized. Compared to patients without recurrent wheezing, eosinophil count tended to be higher in those with recurrent wheezing and isolated HBoV infected patients tended to develop recurrent wheezing more than those with co-infection. CONCLUSION: Acute wheezing is a common presenting lung sign in HBo V-LRI. Although the pulmonary function tests of all patients were normal, more than a quarter of patients suffered from recurrent wheezing during one-year follow-up.