Fluctuation in SARS-CoV-2 Environmental Surface Contamination Levels in Homes Where Patients With COVID-19 Stayed for Recuperation.

Introduction Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) often occurs among family members. Elucidating where viable SARS-CoV-2 virions, and not just residual viral RNA, are present in the house is necessary to prevent the further spread of the coronavirus disease 2019 (COVID-19). We aimed to evaluate the environmental surface contamination levels of both SARS-CoV-2 RNA and viable viruses in the homes of housebound patients with COVID-19. Methods Environmental samples were collected from the households of three patients in April and July 2022 when the number of new COVID-19 cases in Japan was reported to be approximately 50,000 and 200,000 cases per day, respectively. For each case, samples were obtained from 19-26 household sites for seven consecutive days. SARS-CoV-2 RNA was examined in 455 samples through reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and RT-qPCR-positive samples were subjected to plaque assay to detect viable viruses. Results Among the 455 samples, 63 (13.8%) that were collected from patients' pillows and comforters, doorknobs, chairs, and refrigerators tested positive by RT-qPCR. The maximum detection rate of SARS-CoV-2 RNA-positive samples in each case ranged from 20.0% to 57.7% on days 1 to 3. The detection rate gradually decreased to 0-5.3% as the days elapsed. Although all RT-qPCR-positive samples were examined, no viable viruses were detected in these samples. Conclusions Although environmental contamination of SARS-CoV-2 RNA was observed in the homes of housebound patients with COVID-19, no viable viruses were isolated. This suggests that the indirect transmission risk from fomites was low.

SARS-CoV-2 Contamination on Healthy Individuals' Hands in Community Settings During the COVID-19 Pandemic.

Introduction Hand hygiene is an infection control measure for COVID-19 in our daily lives; however, the contamination levels of SARS-CoV-2 in the hands of healthy individuals remain unclear. Thus, we aimed to evaluate SARS-CoV-2 contamination levels by detecting viral RNA and viable viruses in samples obtained from the hands of 925 healthy individuals. Methods Swab samples were collected from the palms and fingers of healthy participants, including office workers, public officers, university students, university faculty and staff, and hospital staff between December 2022 and March 2023. The collected swab samples were analyzed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for SARS-CoV-2 RNA detection. Viral RNA-positive samples were subjected to plaque assay to detect viable viruses. Results We collected 1,022 swab samples from the hands of healthy participants. According to the criteria for data collection, 97 samples were excluded, and 925 samples were analyzed using RT-qPCR. SARS-CoV-2 RNA was detected in three of the 925 samples. The viral RNA detection rate was 0.32% (3/925), and the viral RNA copy numbers ranged from 5.0×103 to 1.7×105 copies/mL. The RT-qPCR-positive samples did not contain viable viruses, as confirmed by the plaque assay results. Conclusions The detection rate of SARS-CoV-2 RNA from the hands of healthy individuals was extremely low, and no viable viruses were detected. These results suggest that the risk of contact transmission via hands in a community setting is extremely rare.

Current perspectives of viral hepatitis.

Viral hepatitis represents a major danger to public health, and is a globally leading cause of death. The five liver-specific viruses: Hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus, each have their own unique epidemiology, structural biology, transmission, endemic patterns, risk of liver complications, and response to antiviral therapies. There remain few options for treatment, in spite of the increasing prevalence of viral-hepatitis-caused liver disease. Furthermore, chronic viral hepatitis is a leading worldwide cause of both liver-related morbidity and mortality, even though effective treatments are available that could reduce or prevent most patients' complications. In 2016, the World Health Organization released its plan to eliminate viral hepatitis as a public health threat by the year 2030, along with a discussion of current gaps and prospects for both regional and global eradication of viral hepatitis. Today, treatment is sufficiently able to prevent the disease from reaching advanced phases. However, future therapies must be extremely safe, and should ideally limit the period of treatment necessary. A better understanding of pathogenesis will prove beneficial in the development of potential treatment strategies targeting infections by viral hepatitis. This review aims to summarize the current state of knowledge on each type of viral hepatitis, together with major innovations.