Pregnancy and birth outcomes among young women living with perinatally acquired HIV in Thailand and Vietnam.

We conducted a retrospective cohort study of pregnancy and infant outcomes in 670 adolescents and young adult women with perinatally acquired HIV (AYAPHIV), aged 15-24 years, in Thailand and Vietnam. Between January 2013 and December 2018, there were 52 pregnancies, for an incidence of 2.49 (95% CI 1.90-3.27) per 100 person-years. The median age at pregnancy was 17.7 years (IQR 16.8-18.9). Pregnant AYAPHIV had been on cART for a lifetime median of 9.8 years (IQR 7.3-12.4). At the time of conception, the median CD4 was 521 cells/mm3 (IQR 213-760), and 76% had HIV RNA ≤400 copies/ml. Of the 51 pregnancies with available outcomes, 90% resulted in live singleton births at a median gestational age of 38 weeks (IQR 37-39); 77% of mothers (n = 27/35) had HIV RNA ≤400 copies/ml at delivery. Among infants with available data, 50% (n = 21/42) were male and 29% (n = 12/42) were reported to be low birthweight (<2,500gm); none (n = 0/41) were breastfed. One infant was diagnosed with HIV. Our findings emphasize that efforts to strengthen reproductive health education, including contraception, pregnancy-related psychosocial support services, and prevention of vertical HIV transmission interventions, in our region are needed for adolescents with perinatally acquired HIV as they transition to young adults.

Incidence of healthcare-associated urinary tract infections in Thai children.

BACKGROUND: Urinary tract infection is one of the commonest types of healthcare-associated infections. There are currently limited data regarding the incidence and characteristics of healthcare-associated urinary tract infections (HA-UTIs) in children. This study was conducted to determine the incidence of HA-UTIs and their characteristics and associated risk factors. METHODS: A case-control study was performed from 2016 to 2020 on children under 15 years old who were diagnosed with HA-UTI. Patients who had HA-UTI were compared with non-UTI patients. The incidence rate of HA-UTIs was calculated and reported as events per 1000 patient days. Potential associated risk factors were analyzed using multivariate logistic regression. RESULTS: Eighty cases and 80 controls were included in the study. The incidence of HA-UTIs was 0.32 events per 1000 patient days. The median time to UTI was 18 days. The most common causative organism was Escherichia coli (43.2%) and the rates of third-generation cephalosporin resistance and carbapenem resistance were 75.6% and 4.9%, respectively. Admission longer than 7 days (OR = 21.61, 95% CI: 6.30-74.11; p < 0.001), neurogenic bladder (OR = 26.24, 95% CI: 3.77-182.87; p < 0.001), mechanical ventilation (OR = 3.60, 95% CI: 1.23-10.54; p = 0.019), and immunosuppressants (OR = 2.59; 95% CI: 1.01-6.60; p = 0.047) were the risk factors significantly associated with HA-UTIs. CONCLUSIONS: The incidence of HA-UTIs was low in this single-center experience. Identifying patients with the risk factor is imperative for preventing the development of HA-UTIs.

Acceptance and outcome of interventions in a meropenem de-escalation antimicrobial stewardship program in pediatrics.

BACKGROUND: Prospective audit and feedback is a method that allows the antimicrobial stewardship program (ASP) team to interact with attending physicians to tailor antibiotic therapy, including de-escalation, as appropriate. This study aimed to evaluate the acceptance and outcomes of ASP de-escalation recommendations in children who received meropenem. METHODS: A prospective cohort study was conducted in children aged 1 month to 18 years who received meropenem in a tertiary-care teaching hospital. The ASP team gave recommendation between 72 and 120 h after initiating meropenem therapy. Acceptance of de-escalation recommendations among primary physicians was evaluated within 24 h of recommendation. Outcomes included clinical success rate on the 7th day and incidence rate of acquisition of carbapenem-resistant gram-negative bacteria (CR-GNB) within 30 days. RESULTS: From March to December 2019, 217 children with a median (interquartile range) age of 2.1 (0.6, 9.5) years received meropenem. The ASP team gave recommendations in 127 (58.5%) of cases for continuation of meropenem therapy and 90 (41.5%) of cases for de-escalation. The overall acceptance of ASP de-escalation recommendations was 57.8% (95%CI: 46.9-68.1%). Clinical success rates were 85.2% in the accepted group compared to 77.5% in the rejected group (P = 0.06). The incidence rate of acquisition of CR-GNB within 30 days after treatment was 5.8% in the accepted group and 15.8% in the rejected group (P = 0.03). CONCLUSIONS: About half of the recommendations to de-escalate meropenem prescriptions were accepted through the ASP intervention. Carbapenem-resistant gram-negative bacteria acquisitions was less likely in the de-escalation group. A robust de-escalation strategy 72 h following carbapenem initiation should be encouraged to combat multidrug-resistant organisms.

Behavioral problems in perinatally HIV-infected young children with early antiretroviral therapy and HIV-exposed uninfected young children: prevalence and associated factors.

Although behavioral problems have been observed in children and adolescents with perinatally-acquired HIV infection (PHIV), behavioral information regarding younger PHIV children are scarce. This study aims to identify behavioral problems in PHIV and HIV-exposed uninfected (HEU) children and to evaluate factors associated with such problems. A prospective study of PHIV and HEU young children was conducted. Behavioral problems were assessed with the Child Behavior Checklist (CBCL) at baseline and 12 months later among children aged 18-60 months old. The Patient Health Questionnaire-9 and the Parenting Styles & Dimensions Questionnaire identified primary caregivers' symptoms of depression and parenting styles, respectively, at both visits. Chi-squared analyses were used to compare the prevalence of behavioral problems between groups. Factors associated with behavioral problems were analyzed by logistic regression. From 2016 to 2017, 121 children (41 PHIV and 80 HEU) were assessed with no significant differences in prevalence of Total, Internalizing, Externalizing, and Syndrome scales problems between PHIV and HEU at both visits (p > 0.5). Primary caregivers' depression and lower education in addition to authoritarian and permissive parenting styles were significantly related to child behavioral problems. Family-centered care for families affected by HIV, including positive parenting promotion, mental health care, and education are warranted.

Antimicrobial prescription patterns in a tertiary-care pediatric unit in Thailand.

BACKGROUND: Antimicrobial resistance is one of the greatest public health threats worldwide. The improper prescription of antibiotics is one factor that promotes antibiotic resistance. Access to antimicrobial surveillance data is essential when assessing the pattern and appropriateness of antimicrobial prescriptions in hospitals and for the establishment of an antimicrobial stewardship program. This study aimed to describe the rate of antimicrobial use and the pattern of prescriptions in a tertiary care pediatric unit in Thailand. METHODS: A point prevalence survey on antimicrobial use was conducted monthly between January and June 2016, using standardized tools. The survey included all inpatient pediatric beds and identified all children receiving antimicrobial treatment on the day of the survey. RESULTS: The study included 644 children, 43.3% of whom received antimicrobial treatment during hospitalization. In general wards, the rate of antimicrobial prescriptions was 37.2%; in oncology wards it was 47.0%; in intensive care units it was 38.7%, and in surgical wards it was 67.7%. Meropenem was the most prescribed antimicrobial in the general wards (24.5%) and intensive care units (28.6%), whereas antipseudomonas was the most commonly prescribed antimicrobial in the oncology ward (26.6%). For the surgical ward, the most prescribed antimicrobial was third-generation cephalosporin for both prophylaxis and treatment (39.0%). The most common reason for antimicrobial use was the treatment of infections. CONCLUSIONS: Nearly half of hospitalized children received at least one antimicrobial. This was comparable with other pediatric tertiary care centers, although the high use of meropenem was different. This study provides important baseline information on antimicrobial use in a large tertiary-care pediatric unit and could lead to a nationwide survey in the future.

Gaps in the elimination of congenital syphilis in a tertiary care center in Thailand.

BACKGROUND: The World Health Organization has set a goal to eliminate mother-to-child transmission of syphilis to a target of <50 cases per 100 000 live births. This study aimed to determine the rate of congenital syphilis and identify gaps in prevention. METHODS: A retrospective chart review was conducted in a tertiary care center in Bangkok, Thailand. The study included all pregnant women with positive syphilis serology and their infants. All congenital syphilis cases were categorized according to Centers for Disease Control criteria. RESULTS: From 2013 to 2017, 69 syphilis-infected pregnant women were included, with 30 congenital syphilis cases. The rate of congenital syphilis was 115 cases (95% CI 78-164) per 100 000 live births. The median (interquartile range) maternal age was 21 (18-32) years and 12 (17%) women had human immunodeficiency virus co-infection. Regarding maternal treatment, 28 (41%) women had inadequate treatment due to 13 cases (19%) of late or no antenatal care, six cases (8%) of recent infection near delivery, five cases (7%) of failure of treatment provision, and four (6%) others. There were three syphilitic stillbirths who were prematurely born to untreated pregnant women and 67 live births (one set of twins) of which 27 met definitions of probable congenital syphilis. They received complete treatment with penicillin and had non-reactive rapid plasma reagin within the first 6 months of life, with the exception of one who had non-reactive rapid plasma reagin at the age of 7 months. CONCLUSIONS: Congenital syphilis remains a problem in our setting. Nearly half of pregnant women who had syphilis had inadequate treatment. There is an urgent need to strengthen diagnosis and the treatment cascade of syphilis during antenatal care.

Efficacy of chlorhexidine patches on central line-associated bloodstream infections in children.

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) are important hospital-acquired infections. Chlorhexidine-impregnated dressings (also known as chlorhexidine patches, CHG patches) are reported to decrease CLABSIs in adults. This study aims to determine the efficacy of CHG patches in reducing CLABSIs in children. METHODS: An open-label randomized controlled trial was conducted in children aged 2 months to 18 years, requiring a short-term catheter. Patients were randomized into two groups, allocated to receive CHG patches or standard transparent dressings. Care of the catheter was in accordance with Asia Pacific Society of Infection Control (APSIC) recommendations. Central-line-associated bloodstream infections were defined using National Healthcare Safety Network surveillance criteria. RESULTS: From April 2017 to April 2018, 192 children were enrolled. There were 108 CHG patch catheters and 101 standard dressing catheters, contributing to 3,113 catheter days. The median duration of catheter dwelling was 13 days, with an interquartile range (IQR) of 8-20 days. Half were placed at the jugular vein and 22% at the femoral vein. There were 23 CLABSI events. Incidence rates for CHG patches and standard dressings were 7.98 (95% confidence interval (CI), 4.25-13.65) and 6.74 (95% CI, 3.23-12.39) per 1,000 catheter days, respectively (incidence rate ratio 1.18; 95% CI, 0.52-2.70). The CLABSI pathogens were 15 Gram-negative bacteria, six Gram-positive bacteria, and two Candida organisms. Catheter colonization of CHG patches and standard dressings were 2.02 (95% CI, 0.42-5.91) and 3.07 (95% CI, 1.00-7.16) per 1,000 catheter days, respectively. Only local adverse effects occurred in 6.8% of the participants. CONCLUSIONS: In our setting, there was no difference in CLABSI rates when the chlorhexidine patch dressings were compared with the standard transparent dressings. Strengthening of CLABSI prevention bundles is mandatory.

Clinical Features and Survival Outcomes of Invasive Aspergillosis in Pediatric Patients at a Medical School in Thailand.

BACKGROUND: Invasive aspergillosis (IA) is a severe infection in immunocompromised patients. Recently, serum galactomannan has been widely used for diagnosis and voriconazole as an antifungal agent. The objective of this study is to describe clinical features and survival outcomes of IA. MATERIAL AND METHOD: A retrospective chart review of IA in patients younger than 18 years old at King Chulalongkorn Memorial Hospital, Thailand, was conducted. Clinical definitions were based on criteria oft he European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) 2008. RESULTS: Between January 2006 and December 2012, 40 cases of invasive aspergillosis were identified, classified as proven (8 patients, 20%), probable (28, 70%), and possible IA (4, 10%). Median age of patients was 10 years (range, 42 days-17 years). The most common underlying disease was hematologic malignancy (60%). The major risk factor was neutropenia (65%) with median duration of 21 days (range, 4-58 days). The most common site of infection was in the lungs (80%). The most common computed tomography chest finding was nodules (71%). An air crescent sign was seen only in 11% and a halo sign was found only in 7% of patients. Serum galactomannan was positive in 78% of patients with median value of 1.34 (range 0.5-5.6). Only seven patients (17%) had microbiological confirmation, of which were Aspergillus flavus (4 cases) and Aspergillus fumigates (3 cases). Antifungal therapy included voriconazole (23 patients, 58%), amphotericin B (12, 30%), liposomal amphotericin B (3, 8%), caspofungin (1, 2%) and itraconazole (1, 2%). Two deaths related to angioinvasive complications of aspergillosis (pulmonary hemorrhage and rupture mycotic aneurysm) were reported The 3-month and 12- month survival rates after diagnosed IA were 73.7% and 56.7%, respectively. The major cause of death was new episode of sepsis found in 11 cases (52%). CONCLUSION: The 1-year survival rate was poor; however, cause of death is related to complications of the immunocompromised state not from IA.

CHARACTERIZATION OF CLINICAL AND BIOLOGIC MANIFESTATIONS OF CHIKUNGUNYA AMONG CHILDREN IN AN URBAN AREA, THAILAND: A RETROSPECTIVE COHORT STUDY.

Chikungunya virus (CHIKV), transmitted by Aedes mosquitoes, has reemerged in Southeast Asia since 2019. A retrospective review of CHIKV cases was conducted. Children commonly presented with high-grade fever, rash, arthralgia, and lymphopenia. Neurological manifestations or shock occurred in 20% of hospitalized children. These findings indicate the need for increased vigilance for CHIKV alongside dengue in travelers from Southeast Asia with suspected mosquito-borne viral infections.

Prevalence and Risk Factors of Healthcare-Associated Infections among Hospitalized Pediatric Patients: Point Prevalence Survey in Thailand 2021.

BACKGROUND: Healthcare-associated infections (HAIs) pose a grave threat to patient safety, morbidity, and mortality, contributing to antimicrobial resistance. Thus, we estimated the point prevalence, risk factors, types, and pathogens of HAIs in hospitalized pediatric patients. METHODS: A point prevalence survey (PPS) of HAIs in hospitalized pediatric patients < 18 years old was conducted from March to May 2021. Outcomes, risk factors, and types of HAIs associated with HAIs in 41 hospitals across Thailand were collected. RESULTS: The prevalence of HAIs was 3.9% (95% CI 2.9-5.0%) (56/1443). By ages < 1 month, 1 month-2 years, 2-12 years, and 12-18 years, the prevalence of HAIs was 4.2%, 3.3%, 4.1%, and 3.0%, respectively (p = 0.80). Significant independent risk factors were extended hospital length of stay (LOS) and central venous catheter (CVC) use. Compared to an LOS of <4 days, LOSs of 4-7 days, 8-14 days, and >14 days had adjusted odds ratios (aORs) of 2.65 (95% CI 1.05, 6.68), 5.19 (95% CI 2.00, 13.4), and 9.03 (95% CI 3.97, 20.5), respectively. The use of a CVC had an aOR of 2.45 (95% CI 1.06-5.66). Lower respiratory tract infection (LRTI) was the most common HAI type (46.4%: 26/56). The highest prevalence of HAIs was predominantly observed in LRTI diagnoses, with the highest among these in the <1 month age category at 2.3% (17/738). CONCLUSION: The prevalence of HAIs in hospitalized pediatric patients was 3.9%. Extended LOS and use of CVC were HAI risk factors. A strategy for reducing LOS and reviewing insertion indications or the early planned removal of a CVC was implemented. The surveillance of HAIs stands as a cornerstone and fundamental component of IPC, offering invaluable insights that enhance hospital IPC interventions aimed at preventing HAIs.

Pharmacokinetics of Generic Pediatric Dolutegravir Dispersible Tablet in Thai Young Children Living With HIV Weighing Below Twenty Kilograms.

INTRODUCTION: Dolutegravir (DTG) dispersible tablet (DTG-DT) is a pediatric-friendly formulation. We aimed to describe the pharmacokinetics and virologic responses of generic DTG-DT in children weighing <20 kg. METHODS: Children living with HIV-1 and <7 years of age weighing 6 to <20 kg were eligible. A generic 10-mg scored DTG-DT was administered to children using 3 weight bands (WB): WB1 (6 to <10 kg), WB2 (10 to <14 kg) and WB3 (14 to <20 kg), at doses of 20 mg (higher than World Health Organization recommendation of 15 mg), 20 mg and 25 mg, respectively. Steady-state intensive pharmacokinetics (PK) was performed in fasting condition with blood sampling at predose and 1, 2, 3, 4, 6 and 24 hours postdose. DTG PK parameters were estimated using a noncompartmental analysis, and DTG trough concentrations (C 24 ) and 24-hour area under the concentration-time curve were calculated. Comparisons were made with ODYSSEY and IMPAACT 2019. And 90% effective concentration of 0.32 mg/L was used as a reference individual DTG C 24 concentration. RESULTS: From August 2021 to March 2023, 29 Thai children with a median (interquartile range) age of 3.2 (1.5-4.8) years were enrolled; 8 in WB1, 9 in WB2 and 12 in WB3. All children were treatment experienced and 59% had HIV RNA <200 copies/mL. Overall geometric mean (coefficient of variation percentage) DTG C 24 was 1.0 (46%) mg/L [WB1, 0.9 (53%); WB2, 0.9 (27%); WB3, 1.2 (51%)]. Geometric mean (coefficient of variation percentage) 24-hour area under the concentration-time curve was 83.2 (24%) mg h/L [WB1, 84.3 (31%); WB2, 76.9 (16%); WB3, 87.6 (25%)]. At weeks 24 and 48, 90% and 92% of participants had plasma HIV RNA <200 copies/mL. CONCLUSIONS: Generic DTG-DT provided adequate drug exposure in children weighing 6 to <20 kg. The exploratory dose of DTG 20 mg for children weighing 6 to <10 kg showed similar PK parameters to World Health Organization doses in the other WB.

Effective and safe transfer of maternal antibodies persisting two months postpartum following maternal immunization with different doses of recombinant pertussis-containing vaccines.

INTRODUCTION: Recombinant acellular pertussis (ap) vaccines containing genetically inactivated pertussis toxin (PTgen) and filamentous hemagglutinin (FHA) with or without tetanus (TT) and diphtheria (DT) vaccines (Td) were found safe and immunogenic in non-pregnant and pregnant women. We report here maternal antibody transfer and safety data in mothers and neonates. METHODS: This is the follow up of a phase 2 trial in 2019 among 400 pregnant women who randomly received one dose of recombinant pertussis-only vaccine containing 1 µg PTgen and 1 µg FHA (ap1gen), or Td combined with ap1gen (Tdap1gen), or with 2 µg PTgen and 5 µg FHA (Tdap2gen), or with 5 µg PTgen and 5 µg FHA (TdaP5gen, Boostagen®, BioNet, Thailand) or chemically-inactivated acellular pertussis comparator (Tdap8chem, Boostrix™, GSK, Belgium), either in the second or third trimester of gestation. IgG against PT, FHA, TT and DT were assessed by ELISA, PT-neutralizing antibodies (PTNA) by Chinese Hamster Ovary cell assay and safety outcomes at delivery in mothers and at birth. RESULTS: Anti-PT and anti-FHA geometric mean concentration (GMC) ratio between infants at birth and mothers at delivery was above 1 in all groups. PT GMC in infants at birth were ≥30 IU/mL in all groups with the highest titers in infants found in TdaP5gen group at birth (118.8 [95% CI 93.9-150.4]). At 2 months, PT GMC ratio to Tdap8chem (98.75% CI) was significantly higher for TdaP5gen (2.6 [1.7-4.0]) and comparable for other recombinant vaccines. No difference in PTNA titers at birth was observed between all groups nor between time of vaccination. Adverse events were comparable in all vaccine groups. CONCLUSIONS: BioNet licensed (TdaP5gen and Tdap2gen) and candidate vaccines (Tdap1gen and ap1gen) when given to pregnant women in the second or third trimester of gestation are safe and have induced passive pertussis immunity to infants.

Neurological complications associated with influenza in hospitalized children.

BACKGROUND: Influenza is a known respiratory and potential neurotropic virus. This study aimed to determine the prevalence and outcomes of influenza-related neurological complications among hospitalized children. METHODS: All medical records of hospitalized children aged <18 years old diagnosed with influenza at a tertiary care hospital in Bangkok were retrospectively reviewed. Influenza infection was confirmed by rapid antigen or reverse transcription polymerase chain reaction tests. Neurological characteristics and clinical outcomes were analyzed using the Pediatric Cerebral Performance Category Scale. RESULTS: From 2013 to 2018, 397 hospitalized children with a median age of 3.7 years (interquartile range [IQR]: 1.6-6.9) were included. The prevalence of neurological complications, including seizure or acute encephalopathy, was 16.9% (95% confidence interval [CI]: 13.3-20.9). Influenza A and B were identified in 73.1% and 26.9% of the patients, respectively. Among 39 (58.2%) acute symptomatic seizure cases, 25 (37.3%) children had simple febrile seizures, 7 (10.4%) had repetitive seizures, and 7 (10.4%) had provoked seizures with pre-existing epilepsy. For 28 (41.8%) encephalopathy cases, the clinical courses were benign in 20 (29.9%) cases and severe in 8 (11.9%) cases. Ten (14.9%) children needed intensive care monitoring, and 62 (93.5%) fully recovered to their baselines at hospital discharge. Predisposing factors to the neurological complications included a history of febrile seizure (adjusted odds ratio [aOR]: 20.3; 95% CI: 6.6-63.0), pre-existing epilepsy (aOR: 3.6; 95% CI: 1.3-10.2), and a history of other neurological disorders (aOR: 3.5; 95% CI: 1.2-10.2). CONCLUSIONS: One fifth of hospitalized children with influenza had neurological complications with a favorable outcome. Children with pre-existing neurological conditions were at higher risk for developing neurological complications.

Point prevalence survey of antibiotic use among hospitalized patients across 41 hospitals in Thailand.

Objectives: To describe the antibiotic use among hospitalized patients in Thailand. Methods: A standardized cross-sectional point prevalence survey (PPS) modified from the WHO PPS protocol was conducted in 41 selected hospitals in Thailand. All inpatients who received an antibiotic at 9 a.m. on the survey date were enrolled. The total number of inpatients on that day was the denominator. Results: Between March and May 2021, a total of 8958 inpatients were enumerated; 4745 inpatients received antibiotics on the day of the survey and there were 6619 prescriptions of antibiotics. The prevalence of antibiotic use was 53.0% (95% CI 51.1%-54.0%), ranging from 14.3% to 73.4%. The antibiotic use was highest among adults aged >65 years (57.1%; 95% CI 55.3%-58.9%). From 6619 antibiotics prescribed, 68.6% were used to treat infection, 26.7% for prophylaxis and 4.7% for other or unknown indications. Overall, the top three commonly used antibiotics were third-generation cephalosporins (1993; 30.1%), followed by first-generation cephalosporins (737; 11.1%) and carbapenems (703; 10.6%). The most frequently used antibiotics for community-acquired infections were third-generation cephalosporins (36.8%), followed by ß-lactam/ß-lactamase inhibitors (11.8%) and carbapenems (11.3%) whereas for the patients with hospital-acquired infections, the most common antibiotics used were carbapenems (32.7%), followed by ß-lactam/ß-lactamase inhibitors (15.7%), third-generation cephalosporins (11.7%) and colistin (11.7%). The first-generation cephalosporins were the most commonly used antibiotics (37.7%) for surgical prophylaxis. Seventy percent of the patients received surgical prophylaxis for more than 1 day post surgery. Conclusions: The prevalence of antibiotic use among hospitalized patients in Thailand is high and one-quarter of these antibiotics were used for prophylaxis. The majority of surgical prophylaxis was inappropriately used for a long duration post operation. Therefore, it is recommended that local guidelines should be developed and implemented.

Immunogenicity of BNT162b2 in children 6 months to under 5 years of age with previous SARS-CoV-2 infection, in the era of Omicron predominance.

Background: Children 6 months to < 5 years old are recommended to receive 3-dose regimen of BNT162b2. Children previously infected with Omicron variant of SARS-CoV-2 develop immunity from natural infection, therefore may require fewer doses of vaccine. Objective: To compare immunogenicity of 1- or 2-dose BNT162b2 in healthy children post COVID-19 with 3-dose BNT162b2 in COVID-naïve children. Methods: Children aged 6 months to < 5 years who developed COVID-19 during the Omicron-predominant period were enrolled; Group A 3-6 months(N = 40) and Group B > 6 months(N = 40) prior to vaccination. Participants in Group A and B received 2-dose BNT162b2 intramuscularly 1 month apart. COVID-naïve children were enrolled as a control group (N = 40) and received 3-dose BNT162b2 at month 0,1,3. Neutralizing antibody against Omicron variant(BA.2.75 and BA.4/5) was determined by pseudovirus assays(pVNT) as reported by neutralization dilution for 50%inhibition (ID50) at 28 days after the 1st and 2nd dose. Results: From October-November 2022, 120 children with a median age of 2.8 years (IQR 1.6-4.0) were enrolled. The median duration since COVID-19 to vaccination was 4.4 months(IQR 3.8-5.4) in Group A and 7.9 months(7.0-8.5) in Group B. In Group A, the geometric means(GMs) of pVNT-BA.2.75 ID50 were 553 (95%CI 338-906) and 753(516-1098) after 1 and 2 doses, respectively, and the GMs of pVNT-BA.4/5 ID50 were 1936(1402-2673) and 1885(1414-2512), respectively. In Group B, the GMs of pVNT-BA.2.75 ID50 were 1383(1100-1742) and 1419 (1104-1823), and the GMs of pVNT-BA.4/5 ID50 were 2627(2048-3367) and 2056(1546-2735), respectively. Meanwhile in COVID-naïve group, the GMs of pVNT-BA.2.75 and pVNT-BA.4/5 ID50 were 158(98-255) and 59(31-114) after the 3rd dose, respectively. The geometric mean ratio(GMR) of pVNT-BA.2.75 ID50 after 1 dose in Group A and B compared with after 3 doses in COVID-naïve group were 3.50 (1.93-6.34) and 8.74 (4.79-15.95), respectively. The GMR of pVNT-BA.2.75 ID50 after 1 dose in Group B compared with Group A was 2.50 (1.45-4.31). Conclusions: Children previously infected with SARS-CoV-2 Omicron variant, developed robust neutralizing antibody response against Omicron variant after single-dose BNT162b2. Children with an interval of > 6 months since COVID-19 infection developed higher neutralizing antibody response compared to those with a 3-to-6-month interval.

Long COVID and Hybrid Immunity among Children and Adolescents Post-Delta Variant Infection in Thailand.

This study aimed to assess long COVID, and describe immunogenicity against Omicron variants following BNT162b2 vaccination. A prospective cohort study was conducted among children (aged 5-11) and adolescents (aged 12-17) who had SARS-CoV-2 infection from July to December 2021 (Delta predominant period). Long COVID symptoms were assessed by questionnaires at 3 months after infection. Immunogenicity was evaluated by using a surrogate virus-neutralizing antibody test (sVNT) against the Omicron variant. We enrolled 97 children and 57 adolescents. At 3 months, 30 children (31%) and 34 adolescents (60%) reported at least one long COVID symptom, with respiratory symptoms prevailing (25% children and 32% adolescents). The median time from infection to vaccination was 3 months in adolescents and 7 months in children. At 1 month following vaccination, in children who received one-dose and two-dose BNT162b2 vaccines, the median (IQR) sVNT against Omicron was 86.2% inhibition (71.1-91.8) and 79.2% inhibition (61.5-88.9), respectively (p = 0.26). Among adolescents who received one-dose and two-dose BNT162b2 vaccines, the median (IQR) sVNT against Omicron was 64.4% inhibition (46.8-88.8) and 68.8% inhibition (65.0-91.2) (p = 0.64). Adolescents had a higher prevalence of long COVID than children. Immunogenicity against the Omicron variant after vaccination was high and did not vary between one or two doses of the vaccine in either children or adolescents.

Good performance of syphilis rapid diagnostic test kits among young key populations in Thailand.

BACKGROUND: The prevalence of syphilis is increasing among adolescents and young adults (AYAs) globally. Use of syphilis rapid diagnostic treponemal tests (RDTs) may improve test coverage and same-day treatment. This study aims to determine sensitivity and specificity of two syphilis RDTs. METHODS: A cross-sectional study was conducted in men who have sex with men and transgender women aged 15-24 years attending a sexual health clinic in Bangkok. Syphilis RDTs used were Determine Syphilis TP and Bioline Syphilis 3.0, using whole blood from finger pricks and venipuncture. Treponemal pallidum electrochemiluminescence assay was used as standard reference. RESULTS: From February to July 2022, 200 AYAs with a mean age 21.1 (SD2.1) years were enrolled, including 50 (25.0%) living with HIV. Prevalence of syphilis was 10.5% (95%CI 6.6-15.6), which was higher among AYAs living with HIV (22.0%) compared with AYAs unaffected by HIV (6.7%). Sensitivities of Determine Syphilis TP and Bioline Syphilis 3.0 were 85.7% (95%CI 63.7-97.0) and 66.7% (95%CI 43.0-85.4), respectively. Specificity of both RDTs was 100% (95%CI 98.0-100.0). Performance of RDTs was similar for both specimens. CONCLUSIONS: Syphilis RDTs have high sensitivity and specificity in diagnosing syphilis. It should be considered for use in sexual health clinics with high syphilis prevalence to initiate treatment promptly.

Case Report: Simple Nodular Cutaneous Leishmaniasis Caused by Autochthonous Leishmania (Mundinia) orientalis in an 18-Month-Old Girl: The First Pediatric Case in Thailand and Literature Review.

We report an autochthonous case of simple, localized cutaneous leishmaniasis in a healthy 18-month-old girl from southern Thailand. The patient presented with a solitary chronic cutaneous nodular lesion on her left cheek for approximately 1 year. Histopathological dissection of the cheek skin biopsy demonstrated remarkably nodular and interstitial infiltrates of lymphocytes and histiocytes full of intracellular oval-shaped amastigotes, consistent with cutaneous leishmaniasis. The Leishmania promastigotes were also cultured successfully from the lesion biopsy and were designated with the WHO code MHOM/TH/2021/CULE5. Using internal transcribed spacer 1-specific polymerase chain reaction, the parasite DNA was demonstrated in both saliva and lesion biopsy. Based on the BLASTn and phylogenetic analysis, the parasite was identified as Leishmania orientalis, clustered in the Mundinia subgenus. The patient responded well to a 6-week course of oral itraconazole, without recurrence. To our knowledge, this is the fourth case of autochthonous leishmaniasis resulting from L. orientalis and the youngest patient of leishmaniasis ever reported in Thailand. More importantly, we also demonstrate the clinical course of the lesion according to the timeline before and after treatment, which can help physicians better understand and provide an accurate diagnosis with appropriate treatment of this emerging parasitic disease.

Outcomes among Thai children with risk conditions hospitalized for pneumococcal disease (invasive or non-bacteraemic pneumonia): A multi-centre, observational study.

Objective: To describe the risk condition status and clinical outcomes among Thai children hospitalized with pneumococcal disease. Methods: In this retrospective analysis, children with invasive pneumococcal disease (IPD) or x-ray-confirmed non-bacteraemic pneumococcal pneumonia (NBPP) were identified from nine hospitals in Thailand between 2010 and 2019. Data on risk factors and outcomes were extracted from medical records. Results: In total, 413 cases were identified: 319 IPD and 94 NBPP. Overall, 133 (32.2%) patients were admitted to intensive care units and 11/406 (2.7%) died. Twenty-seven percent of IPD cases had at-risk conditions and 15% had high-risk conditions. Most IPD cases (32.9%) occurred in children aged 2-4 years, and most NBPP cases (28.7%) occurred in infants aged 0-11 months. Of 51 Streptococcus pneumoniae isolates collected, 41 (80%) were pneumococcal 13-valent conjugate vaccine serotypes. Only 5.1% of children had received a pneumococcal vaccine. Conclusions: Most children with IPD and NBPP did not have high-risk or at-risk conditions, while 42% had at-risk or high-risk conditions for pneumococcal disease. Very few children in the cohort had received any type of pneumococcal vaccine. Increasing the availability of pneumococcal conjugate vaccines should be considered to reduce the burden of pneumococcal disease among children in Thailand.

A phase 2 randomized controlled dose-ranging trial of recombinant pertussis booster vaccines containing genetically inactivated pertussis toxin in pregnant women.

INTRODUCTION: Despite a decrease in infections caused by Bordetella pertussis due to COVID-19 pandemic, booster vaccination of pregnant women is still recommended to protect newborns. Highly immunogenic vaccines containing genetically inactivated pertussis toxin (PTgen) and filamentous hemagglutinin (FHA) may generate comparable anti-PT antibody concentrations, even at lower doses, to chemically inactivated acellular pertussis vaccines (Tdapchem) shown effective for maternal immunization. METHODS: This phase 2 randomized, observer-blind, active-controlled non-inferiority trial was conducted in healthy Thai pregnant women randomly assigned to receive one dose of low-dose recombinant pertussis-only vaccine containing 1 µg PTgen and 1 µg FHA (ap1gen), or tetanus, reduced-dose diphtheria combined with ap1gen (Tdap1gen), or combined with 2 µg PTgen and 5 µg FHA (Tdap2gen), or with 5 µg PTgen and 5 µg FHA (TdaP5gen, Boostagen®) or comparator containing 8 µg of chemically inactivated pertussis toxoid, 8 µg FHA, and 2.5 µg pertactin (Boostrix™, Tdap8chem). Blood was collected at Day 0 and Day 28 post-vaccination. The non-inferiority of the study vaccines was assessed based on anti-PT IgG antibody levels on Day 28 pooled with results from a similarly structured previous trial in non-pregnant women. RESULTS: 400 healthy pregnant women received one dose of vaccine. Combined with data from 250 non-pregnant women, all study vaccines containing PTgen were non-inferior to comparator vaccine (Tdap8chem). Both ap1gen and TdaP5gen vaccines could be considered to have superior immunogenicity to Tdap8chem. Local and systemic solicited reactions were similar among all vaccine groups. CONCLUSIONS: Vaccine formulations containing PTgen were safe and immunogenic in pregnant women. The ap1gen vaccine, with the lowest cost and reactogenicity, may be suitable for use in pregnant women when diphtheria and tetanus toxoids are not needed. This study is registered in the Thai Clinical Trial Registry (www. CLINICALTRIALS: in.th), number TCTR20180725004.