ChAdOx1 nCoV-19 vaccine-associated thrombocytopenia: three cases of immune thrombocytopenia after 107 720 doses of ChAdOx1 vaccination in Thailand.

We reported three cases of immune thrombocytopenia (ITP) that developed within 6 weeks after ChAdOx1 nCoV-19 vaccination. Antiplatelet factor 4 antibodies were undetectable in all three cases. Therefore, vaccine-induced immune thrombotic thrombocytopenia was very unlikely. Other potential causes of thrombocytopenia were excluded. Their clinical presentations, severity of thrombocytopenia and outcomes were varied. Only one ITP case, an 80-year-old man, received ITP treatments and achieved complete response after 2 weeks of eltrombopag. An 84-year-old man had spontaneous complete remission, and a 55-year-old woman had partial platelet recovery without ITP treatments. Among 107 720 Thais administered the ChAdOx1 vaccine between 16 March and 10 May 2021, these three ITP cases resulted in an estimated risk of ITP of at least one per 36 000 doses, which was approximately similar to the risk of ITP after measles-mumps-rubella immunization. This raises the concern of an increased risk of ITP after ChAdOx1 vaccination.

Real-world data of Helicobacter pylori prevalence, eradication regimens, and antibiotic resistance in Thailand, 2013-2018.

BACKGROUND AND AIM: Helicobacter pylori is a class I carcinogen. Nowadays, the problem of antibiotic resistance is increasing worldwide. The latest prevalence rates of infection and resistant status in Thailand vary or are out of date. Our aims are to identify the current prevalence and antibiotic resistance patterns in Thailand and to suggest regimens for treatment-naive and -resistant patients. METHODS: This descriptive retrospective study was conducted, using a urea breath test, on patients in King Chulalongkorn Memorial Hospital between 2013 and 2017. They were categorized into the diagnostic group and posttreatment group. Specimens from some patients were cultured to identify the antibiotic-resistant pattern. RESULTS: There were 1894 patients included in our study. The prevalence of H. pylori infection in dyspeptic patients was 28.4%. Of 1258 patients, 1165 (92.61%) responded to initial treatment. The 95 patients who failed to respond could respond to second-line treatment of longer period, at higher doses, or using other antibiotics (success rate 68.42%). There were 21.43, 14.29, and 10.71% of patients resistant to ciprofloxacin, metronidazole, and clarithromycin, respectively. However, no patients resistant to amoxicillin, tetracycline, and levofloxacin were found. CONCLUSION: The prevalence of H. pylori infection in Thailand has increased slightly. Initial regimens (triple therapy or sequential therapy or quadruple therapy) can be effective for the eradication of H. pylori infection, with a success rate of > 90%. For patients who failed to respond to initial triple therapy, using a longer duration of triple therapy or changing to quadruple therapy could be a good alternative. The resistance rates of amoxicillin, metronidazole, levofloxacin, and tetracycline are declining, but those of clarithromycin and ciprofloxacin are increasing.