Inadvertent Platelet Transfusion from Monkeypox Virus-Infected Donor to Recipient, Thailand, 2023.

In Thailand, platelet product from a blood donor was transfused to a recipient who had dengue. Two days later, the donor was confirmed to have monkeypox virus infection. Monkeypox virus DNA was undetectable in recipient specimens up to 2 weeks after transfusion. The recipient remained asymptomatic at 4 weeks of monitoring.

Machine Learning-Assisted Real-Time Polymerase Chain Reaction and High-Resolution Melt Analysis for SARS-CoV-2 Variant Identification.

Since the declaration of COVID-19 as a pandemic in early 2020, multiple variants of the severe acute respiratory syndrome-related coronavirus (SARS-CoV-2) have been detected. The emergence of multiple variants has raised concerns due to their impact on public health. Therefore, it is crucial to distinguish between different viral variants. Here, we developed a machine learning web-based application for SARS-CoV-2 variant identification via duplex real-time polymerase chain reaction (PCR) coupled with high-resolution melt (qPCR-HRM) analysis. As a proof-of-concept, we investigated the platform's ability to identify the Alpha, Delta, and wild-type strains using two sets of primers. The duplex qPCR-HRM could identify the two variants reliably in as low as 100 copies/µL. Finally, the platform was validated with 167 nasopharyngeal swab samples, which gave a sensitivity of 95.2%. This work demonstrates the potential for use as automated, cost-effective, and large-scale viral variant surveillance.

Molecular characterisation and tracking of severe acute respiratory syndrome coronavirus 2 in Thailand, 2020-2022.

The global COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in China in December 2019. To date, there have been approximately 3.4 million reported cases of COVID-19 and over 24,000 deaths in Thailand. In this study, we investigated the molecular characteristics and evolution of SARS-CoV-2 in Thailand from 2020 to 2022. Two hundred sixty-eight SARS-CoV-2 isolates, collected mostly in Bangkok from COVID-19 patients, were characterised by partial genome sequencing. Moreover, the viruses in 5,627 positive SARS-CoV-2 samples were identified as viral variants - B.1.1.7 (Alpha), B.1.617.2 (Delta), B.1.1.529 (Omicron/BA.1), or B.1.1.529 (Omicron/BA.2) - by multiplex real-time reverse transcription polymerase chain reaction (RT-PCR) assays. The results revealed that B.1.36.16 caused the predominant outbreak in the second wave (December 2020-January 2021), B.1.1.7 (Alpha) in the third wave (April-June 2021), B.1.617.2 (Delta) in the fourth wave (July-December 2021), and B.1.1.529 (Omicron) in the fifth wave (January-March 2022). The evolutionary rate of the viral genome was 2.60 × 10-3 (95% highest posterior density [HPD], 1.72 × 10-3 to 3.62 × 10-3) nucleotide substitutions per site per year. Continued molecular surveillance of SARS-CoV-2 is crucial for monitoring emerging variants with the potential to cause new COVID-19 outbreaks.

SARS-CoV-2 Transmission from Human to Pet and Suspected Transmission from Pet to Human, Thailand.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been the cause of human pandemic infection since late 2019. SARS-CoV-2 infection in animals has also been reported both naturally and experimentally, rendering awareness about a potential source of infection for one health concern. Here, we describe an epidemiological investigation of SARS-CoV-2 infection in 639 cats and 224 dogs throughout multiple waves of COVID-19 outbreaks in Thailand. To indicate the potential source of infection, we performed SARS-CoV-2 genomic sequencing of samples obtained from pets and contacted humans, combined with in-depth interviews to support the epidemiological investigation. In the tested animals, SARS-CoV-2 RNA was present in 23 cases (19 cats and 4 dogs). Whole-genome sequencing of selected samples showed various SARS-CoV-2 variants of concern, which included the original European lineage (B.1), Alpha (B.1.1.7), Delta (B.1.617), and Omicron (BA.2). Among SARS-CoV-2-positive pets, 34.78% had evidence of contact with infected humans. Together with genomic analysis and an overlapping timeline, we revealed evidence of viral transmission from infected humans as the primary source, which spread to household cats via an undefined mode of transmission and most likely circulated between cohoused cats and caretakers within the weeks before the investigation. The SARS-CoV-2 surface glycoprotein (spike gene) obtained from caretakers of individual cats contained sequence signatures found in the sequences of infected cats, indicating possible exposure to the virus excreted by cats. Although pet-to-human transmission of SARS-CoV-2 is considered relatively rare, our study provides suspected episodes of human infection from animals that were initially infected through contact with infected humans.

Effects of boosted mRNA and adenoviral-vectored vaccines on immune responses to omicron BA.1 and BA.2 following the heterologous CoronaVac/AZD1222 vaccination.

The coronavirus 2019 omicron variant has surged rapidly and raises concerns about immune evasion even in individuals with complete vaccination, because it harbors mutations. Here we examine the capability of booster vaccination following CoronaVac/AZD1222 prime to induce neutralizing antibodies (NAbs) against omicron (BA.1 and BA.2) and T-cell responses. A total of 167 participants primed with heterologous CoronaVac/AZD1222 for 4-5 months were enrolled, to receive AZD1222, BNT162b2, or mRNA-1273 as a third dose. Reactogenicity was recorded. Immunogenicity analyses of severe acute respiratory syndrome coronavirus 2-binding antibodies were measured using enzyme-linked immunosorbent assay. The NAb titers against omicron BA.1 and BA.2 were determined using the focus reduction neutralization test (FRNT50) and total interferon-γ responses were measured to observe the T-cell activation. A substantial loss in neutralizing potency to omicron variant was found at 4-5 months after receiving the heterologous CoronaVac/AZD1222. Following booster vaccination, a significant increase in binding antibodies and neutralizing activities toward delta and omicron variants was observed. Neutralization to omicron BA.1 and BA.2 were comparable, showing the highest titers after boosted mRNA-1273 followed by BNT162b2 and AZD1222. In addition, individuals boosted with messenger RNA (mRNA) vaccines develop a T-cell response to spike protein, whereas those boosted with AZD1222 did not. Reactogenicity was mild to moderate without serious adverse events. Our findings demonstrated that mRNA booster vaccination is able to overcome waning immunity to provide antibodies that neutralize omicron BA.1 and BA.2, as well as a T-cell response.

Detection of SARS-CoV-2-specific antibodies via rapid diagnostic immunoassays in COVID-19 patients.

BACKGROUND: Efficient monitoring and control of coronavirus disease 2019 (COVID-19) require access to diagnostic tests, and serological diagnostic testing is desirable. In the current study, antibodies were investigated in patients recently diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: Cross-sectional data were obtained from 245 patients in whom SARS-CoV-2 infection had been confirmed via real-time reverse transcriptase-polymerase chain reaction between March and October 2020. Serum samples were acquired between 2 and 60 days following the onset of COVID-19 symptoms or the first detection of SARS-CoV-2 in asymptomatic patients. All specimens were tested simultaneously using an IgM/IgG rapid diagnostic test (RDT), IgG nucleocapsid protein-based chemiluminescent microparticle immunoassay (CMIA), IgG, and IgA spike protein-based enzyme-linked immunosorbent assays (ELISAs). Blood donor samples obtained in 2018 were used as negative controls. RESULTS: The sensitivity and specificity of the RDT IgG were compared with the IgG immunoassays as standards. The RDT IgG exhibited 97.5% sensitivity and 89.4% specificity compared with a CMIA IgG, 98.4% sensitivity, and 78.8% specificity compared with an ELISA IgG. IgM, IgG, and IgA seropositivity rates were low between 1 and 2 weeks after COVID-19 symptom onset or the detection of SARS-CoV-2 RNA. IgM seropositivity rate began decreasing after 4 weeks, whereas IgG and IgA seropositivity rate remained at appreciable levels over the 8-week study period. No cross-reactivity with seasonal coronaviruses was detected. CONCLUSIONS: IgG RDT alone or combined with molecular diagnostic tests may be useful for identifying recent SARS-CoV-2 infection.

Genetic diversity and evolution of enterovirus A71 subgenogroup C1 from children with hand, foot, and mouth disease in Thailand.

Enterovirus A71 (EV-A71) can cause hand, foot, and mouth disease (HFMD) in children and may be associated with severe neurological complications. There have been numerous reports of increased incidence of EV-A71 subgenogroup C1 (EV-A71 C1) infections associated with neurological diseases since the first occurrence in Germany in 2015. Here, we describe 11 full-length genome sequences of 2019 EV-A71 C1 strains isolated from HFMD patients in Thailand from 2019 to early 2020. The genetic evolution of 2019 EV-A71 C1 was traced in the outbreaks, and the emergence of multiple lineages was detected. Our results demonstrated that 2019 EV-A71 C1 from Thailand emerged through recombination between its nonstructural protein gene and those of other EV-A genotypes. Bayesian-based phylogenetic analysis showed that the 2019 EV-A71 C1 Thai strains share a common ancestor with variants in Europe (Denmark and France). The substitution rate for the 2019 EV-A71 C1 genome was estimated to be 4.38 × 10-3 substitutions/(site∙year-1) (95% highest posterior density interval: 3.84-4.94 × 10-3 substitutions/[site∙year-1]), approximating that observed between previous EV-A71 C1 outbreaks. These data are essential for understanding the evolution of EV-A C1 during the ongoing HFMD outbreak and may be relevant to disease outcomes in children worldwide.

Quantity and Quality of Antibodies After Acellular Versus Whole-cell Pertussis Vaccines in Infants Born to Mothers Who Received Tetanus, Diphtheria, and Acellular Pertussis Vaccine During Pregnancy: A Randomized Trial.

BACKGROUND: The blunting effect of pertussis immunization during pregnancy on infant antibody responses induced by whole-cell pertussis (wP) vaccination is not well-defined. METHODS: This randomized controlled trial (NCT02408926) followed term infants born to mothers vaccinated with tetanus, diphtheria, and acellular pertussis (Tdap) vaccine during pregnancy in Thailand. Infants received either acellular pertussis (aP)- or wP-containing vaccine at 2, 4, 6, and 18 months of age. A comparison group comprised wP-vaccinated children born to mothers not vaccinated during pregnancy. Antibodies against pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin (PRN) were evaluated using commercial enzyme-linked immunosorbent assays. Functionality of antibodies against Bordetella pertussis was measured using Bordetella pertussis growth inhibition assay. RESULTS: After maternal Tdap vaccination, 158 infants vaccinated with aP-containing vaccines possessed higher antibody levels (P < .001) against all tested B. pertussis antigens postpriming compared to 157 infants receiving wP-containing vaccines. At 1 month postbooster, only anti-FHA and anti-PRN antibodies were still significantly higher (P < .001) in the aP group. Significantly higher anti-PT and anti-FHA (P < .001), but not anti-PRN immunoglobulin G, were observed among 69 wP-vaccinated infants born to control mothers compared with wP-vaccinated infants of Tdap-vaccinated mothers after primary and booster vaccination. The antibody functionality was higher in all wP-vaccinated infants at all times. CONCLUSIONS: Maternal Tdap vaccination inhibited more pertussis-specific responses in wP-vaccinated infants compared to aP-vaccinated infants, and the control group of unvaccinated women had highest PT-specific responses, persisting until after the booster dose. Antibody functionality was better in the wP groups. CLINICAL TRIALS REGISTRATION: NCT02408926.Infant whole-cell pertussis (wP) vaccine responses are blunted after maternal Tdap vaccination. Pertussis antibody titers are higher in acellular pertussis (aP)- than wP-vaccinated infants of immunized mothers, yet quality of antibodies, measured as serum-mediated bacterial growth inhibition, is better after wP than aP vaccination.

The History of Enterovirus A71 Outbreaks and Molecular Epidemiology in the Asia-Pacific Region.

Enterovirus A71 (EV-A71) is one of the common causative pathogens for hand foot and mouth disease (HFMD) affecting young children. HFMD outbreak can result in a substantial pediatric hospitalization and burden the healthcare services, especially in less-developed countries. Since the initial epidemic of predominantly EV-A71 in California in 1969, the high prevalence of HFMD in the Asia-pacific region and elsewhere around the world represents a significant morbidity in this age group. With the advent of rapid and accurate diagnostic tools, there has been a dramatic increase in the number of laboratory-confirmed EV-A71 infection over the past two decades. The population, cultural, and socioeconomic diversity among countries in the Asia-Pacific region all influence the transmission and morbidity associated with HFMD. This review summarizes the current state of epidemiology of EV-A71 in Asia-Pacific countries based on the most recent epidemiological data and available information on the prevalence and disease burden. This knowledge is important in guiding the prevention, control and future research on vaccine development of this highly contagious disease of significant socioeconomic implications in public health.

Enterovirus A71 Infection, Thailand, 2017.

An outbreak of hand, foot and mouth disease among children in Thailand peaked in August 2017. Enterovirus A71 subgenogroup B5 caused most (33.8%, 163/482) cases. Severe disease (myocarditis and encephalitis) was observed in 1 patient. Coxsackievirus A6 was detected in 6.0% (29/482) of patients, and coxsackievirus A16 was detected in 2.7% (13/482) of patients.