Due to the common symptoms of COVID-19, patients are similar to influenza-like illness. Therefore, the detection method would be crucial to discriminate between SARS-CoV-2 and influenza virus-infected patients. In this study, CRISPR-Cas12a-based detection was applied for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus, and influenza B virus which would be a practical and attractive application for screening of patients with COVID-19 and influenza in areas with limited resources. The limit of detection for SARS-CoV-2, influenza A, and influenza B detection was 10, 103, and 103 copies/reaction, respectively. Moreover, the assays yielded no cross-reactivity against other respiratory viruses. The results revealed that the detection of influenza virus and SARS-CoV-2 by using RT-RPA and CRISPR-Cas12a technology reaches 96.23% sensitivity and 100% specificity for SARS-CoV-2 detection. The sensitivity for influenza virus A and B detections was 85.07% and 94.87%, respectively. In addition, the specificity for influenza virus A and B detections was approximately 96%. In conclusion, the RT-RPA with CRISPR-Cas12a assay was an effective method for the screening of influenza viruses and SARS-CoV-2 which could be applied to detect other infectious diseases in the future.

Between 2018 and 2019, the incidence of chikungunya was approximately 15,000 cases across 60 provinces in Thailand. Here, the clinical presentations in chikungunya, emergent pattern, and genomic diversity of the chikungunya virus (CHIKV) causing this massive outbreak were demonstrated. A total of 1,806 sera samples from suspected cases of chikungunya were collected from 13 provinces in Thailand, and samples were tested for the presence of CHIKV RNA, IgG, and IgM using real-time PCR, enzyme-linked immunoassay (ELISA), commercial immunoassay (rapid test). The phylogenetic tree of CHIKV whole-genome and CHIKV E1 were constructed using the maximum-likelihood method. CHIKV infection was confirmed in 547 (42.2%) male and 748 (57.8%) female patients by positive real-time PCR results and/or CHIKV IgM antibody titers. Unsurprisingly, CHIKV RNA was detected in >80% of confirmed cases between 1 and 5 days after symptom onset, whereas anti-CHIKV IgM was detectable in >90% of cases after day 6. Older age was clearly one of the risk factors for the development of arthralgia in infected patients. Although phylogenetic analysis revealed that the present CHIKV Thailand strain of 2018–2020 belongs to the East, Central, and Southern African (ECSA) genotype similar to the CHIKV strains that caused outbreaks during 2008–2009 and 2013, all present CHIKV Thailand strains were clustered within the recent CHIKV strain that caused an outbreak in South Asia. Interestingly, all present CHIKV Thailand strains possess two mutations, E1-K211E, and E2-V264A, in the background of E1-226A. These mutations are reported to be associated with virus-adapted Aedes aegypti. Taken together, it was likely that the present CHIKV outbreak in Thailand occurred as a result of the importation of the CHIKV strain from South Asia. Understanding with viral genetic diversity is essential for epidemiological study and may contribute to better disease management and preventive measures.

This study monitored the long-term immune response to severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infection in patients who had recovered from coronavirus disease (COVID)-19. Anti-nucleocapsid immunoglobulin G (anti-N IgG) titer in serum samples collected at a single (N = 302) or multiple time points (N = 229) 3–12 months after COVID-19 symptom onset or SARS-CoV-2 detection in respiratory specimens was measured by semiquantitative chemiluminescent microparticle immunoassay. The 531 patients (966 specimens) were classified according to the presence or absence of pneumonia symptoms. Anti N IgG was detected in 87.5% of patients (328/375) at 3 months, 38.6% (93/241) at 6 months, 23.7% (49/207) at 9 months, and 26.6% (38/143) at 12 months. The anti-N IgG seropositivity rate was significantly lower at 6, 9, and 12 months than at 3 months (P < 0.01) and was higher in the pneumonia group than in the non-pneumonia/asymptomatic group at 6 months (P < 0.01), 9 months (P = 0.04), and 12 months (P = 0.04). The rate started to decline 6–12 months after symptom onset. Anti-N IgG sample/cutoff index was positively correlated with age (r = 0.192, P < 0.01) but negatively correlated with interval between symptom onset and blood sampling (r =  − 0.567, P < 0.01). These findings can guide vaccine strategies in recovered COVID-19 patients.

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. Supplementary Information The online version contains supplementary material available at 10.1007/s00705-022-05666-6.

Background and ObjectiveCervical cancer is the second most common female genital cancer worldwide. There is strong epidemiological and molecular evidence indicating that human papillomavirus (HPV) infection is a necessary event in the development of cervical intraepithelial lesion and subsequent invasive carcinoma. The aim of this study was to investigate the HPV genotype distribution and prevalence in cervical cancer of Thai women.Materials and MethodsOne hundred fifty-five cervical cancer specimens were enrolled in this study. The HPV genotypes were determined by means of the combined use of a line probe assay (INNO-LiPA) and DNA chip methods.ResultsOf the overall prevalence of HPV in the study group, 83.2% and 11.6% of the cases had single and multiple genotype infections, respectively. The most prevalent genotypes were HPV 16 (51%), followed by HPV 18 (20%), HPV 52 (10.3%), HPV 58 (5.8%), and HPV 33 (4.5%). All HPV genotypes found in this study could be classified as 13 high-risk HPV, 2 low-risk HPV, and 2 additional types. Of the specimens, 94.8% had at least one high-risk HPV genotype infection.ConclusionAs for the potential benefits of commercially available prophylactic vaccines to prevent HPV infection in Thailand, both vaccines (bivalent and quadrivalent) can protect from HPV-related cervical cancer in only approximately 71%. Therefore, screening programs such as routine Papanicolaou test, cytology, and HPV DNA detection are still essential for cervical cancer prevention. Moreover, future generations of HPV vaccines should also include the other most common genotypes and decrease the severe adverse effects reported at the present time.