Diagnosis and Infection Control of Recent Epidemic-related Viral Infections

Abstract

Since May 2023, COVID-19 was changed to a Category 5 infectious disease under the Infectious Disease Control Law, and various viral infections became prevalent. In 2023, an influenza epidemic dominated by influenza A/H3 was observed. Respiratory syncytial virus infections were previously more common in the winter and are now more common in the spring and summer. Contact and droplet precautions in addition to standard precautions are needed to prevent nosocomial RSV infection. Human metapneumovirus and RSV infections were simultaneously common in Japan from early May in 2023. Nosocomial infections caused by human metapneumovirus are reported in nursing homes, psychiatric hospitals, and welfare facilities. A relatively large outbreak of hand-foot-and-mouth disease is expected to occur in 2022. In 2023, enterovirus 71 was the most prevalent virus, and several other coxsackie viruses (A6, A10, and A16) were detected in cases of hand-foot-and-mouth diseases. Herpangina is an acute viral pharyngitis characterized by fever and blistering rash of the oral mucosa. It is prevalent during summer, especially among children. A rapid increase in the number of patients with herpangina was observed in May 2023. Contact and droplet precautions are recommended to prevent the spread of hand-foot-and-mouth disease and herpangina. Because of the declining measles vaccination rates due to the COVID-19 pandemic, measles outbreaks have been reported in various countries worldwide. In 2023 and 2004, measles was also reported in Japan. Airborne precautions are required to prevent the spread of measles.