A descriptive epidemiology in syphilis in Tokyo, 2019-2022.

The number of syphilis cases in Tokyo has been found to increase in recent years. We conducted a descriptive epidemiology to elucidate the actual status of syphilis. Data on age, sex, disease stage, and presumed sexual partner of syphilis cases reported in Tokyo were tabulated and analyzed. A total of 9,419 syphilis cases have been reported between 2019 and 2022. There was a particularly sharp rise in the number of reported cases from 2021 to 2022. Comparing 2020 to 2022, the number of syphilis cases among women in their 20s, rapidly increased, more than triple. Furthermore, the number of pregnant women among syphilis cases increased in 2022. Despite the rapid increase in the number of young women with syphilis, there has been no increase in cases of congenital syphilis. One of the reasons may be that syphilis was detected early in pregnancy due to the high antenatal checkup rate in Tokyo. However, the continued incidence of syphilis among young women may increase congenital syphilis in the future. Public health strategy should include educational activities targeting high-risk populations or adolescents, early and appropriate testing, and treatment for preventing progression of syphilis.

Food poisoning outbreak in Tokyo, Japan caused by Staphylococcus argenteus.

Staphylococcus argenteus is a novel species subdivided from Staphylococcus aureus. Whether this species can cause food poisoning outbreaks is unknown. This study aimed to investigate the enterotoxigenic activities of two food poisoning isolates suspected to be S. argenteus (Tokyo13064 and Tokyo13069). The results for phylogenic trees, constructed via whole genome sequencing, demonstrated that both isolates were more similar to a type strain of S. argenteus (MSHR1132) than any S. aureus strain. Moreover, the representative characteristics of S. argenteus were present in both strains, namely both isolates belong to the CC75 lineage and both lack a crtOPQMN operon. Thus, both were determined to be "S. argenteus." The compositions of the two isolates' accessory elements differed from those of MSHR1132. For example, the seb-related Staphylococcus aureus pathogenicity island, SaPIishikawa11, was detected in Tokyo13064 and Tokyo13069 but not in MSHR1132. Both isolates were suggested to belong to distinct lineages that branched off from MSHR1132 lineages in terms of accessory elements. Tokyo13064 and Tokyo13069 expressed high levels of s(arg)eb and produced S(arg)EB protein, indicating that both have the ability to cause food poisoning. Our findings suggest that S. argenteus harboring particular accessory elements can cause staphylococcal diseases such as food poisoning, similarly to S. aureus.

Shedding of Rubella Virus among Infants with Congenital Rubella Syndrome Born in Tokyo, Japan, 2013-2014.

Rubella is usually a mild illness, with febrile rash being its main symptom. However, serious consequences of rubella infection can result when the infection occurs during the early stages of pregnancy. After the occurrence of a rubella outbreak in Japan that was observed from 2012 to 2013, 45 infants were reportedly born with congenital rubella syndrome (CRS). We prospectively followed the 15 CRS cases reported in Tokyo to determine the virus shedding periods by using nested reverse transcriptase-polymerase chain reaction to detect rubella virus genes. Throast swabs were used for virus detection. The virus shedding period was measured from birth until the time when the sample last tested positive followed by 2 consecutive negative samples. Kaplan-Meier method was used to estimate the proportion of cases remaining positive for rubella virus genes over time. The proportion of CRS cases shedding virus dropped steadily after birth, dropping to 33.8% at 6 months and 16.9% at 12 months. Our findings also suggested that the earlier the mother's onset of rubella during pregnancy, the longer the infant remained positive. Based on our findings, we believe that infants with CRS should be monitored for rubella virus shedding until 1 year of age.