Increased cervical Chlamydia trachomatis and syphilis infections in Japanese females of reproductive age in the late 2010s: Possible cause

Abstract

From 2000 to 2019, Japan's reproductive-age population gradually declined by 24%. In comparison, the Chlamydia trachomatis infection rate increased from 2016, with the syphilis infection rate increasing more sharply from 2014. Since 2013, the numbers of foreign tourists to Japan have also increased. From 2011 to 2018, the rate of increase in tourists was 5.02 times, while the rate of increase in syphilis patients was higher at 22.4 times. The lack of a one-to-one relationship between foreign tourists and syphilis cases suggests that cases of syphilis were transmitted to others. Although the prevalence of syphilis in the tourists' home countries (Korea in 2014 and China in 2013) was 20-30 times higher than that in Japan, the Japanese sex industry did not discriminate against foreign tourists, leading to increased STI infections in Japanese female sex workers. Indeed, from 2017 to 2018, a history of working in the sex industry for six months was identified as a risk factor for syphilis. The rise in Chlamydia trachomatis infections has lagged behind that of syphilis by two years, with the rate of increase lower. We suspect the difference in increasing rates of syphilis and chlamydial infections is due to the different methods of infection: syphilis can be transmitted by light physical contact, such as a kiss, whereas chlamydia requires close sexual contact, such as oral sex or sexual intercourse. Regardless, examinations and infection control are necessary to prevent the spread of STIs in Japan due to inbound tourists.

Syphilis and nephrotic syndrome: A case report and literature review

“…Nephrotic syndrome is a known but rare complication of secondary syphilis [1] , and the occurrence rate, risk factors, and timing of occurrence are unknown. In Japan, the incidence rate of syphilis has recently risen [2] , and the chances of encountering syphilis are potentially increasing. Here, we report a case of nephrotic syndrome that improved with appropriate treatment.…”

From novel coronavirus disease 2019 pandemic to sexually transmitted infection concerns: Japan's multifaceted birth rate dilemma

“…1,2 Notably, in Japan, while the reported cases of genital chlamydia infection had been on a decline since 2002, the number of reported cases in 2021 reached 30,003, marking the highest in the past 15 years 3 Despite Japan's efforts to enhance sexual health through measures like free or low-cost STI testing and treatment, the recent surge in infections, juxtaposed with the previously noted decline attributed to a decrease in the reproductive-age population, underscores the notable insufficiency of current infection control interventions. 4 Importantly, it is estimated that 10%-15% of women infected with chlamydia develop pelvic inflammatory disease leading to tubal damage, which is known as approximately 30% of infertility causes, 5 and considering that the number of births in Japan in 2022 was 777,747, the lowest since records began in 1899, highlighting a critical decline in birth rates, early interventions are imperative. 6 Of note, addressing STIs involves concerns related to privacy within couples or partnerships, such as determining the source of the infection and complicating independent management by those directly infected.…”