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. 2024 Mar 27;19(3):e0298288.
doi: 10.1371/journal.pone.0298288. eCollection 2024.

Rapid resurgence of syphilis in Japan after the COVID-19 pandemic: A descriptive study

Akira Komori  1   2   3 , Hirotake Mori  1 , Wenke Xie  1 , Simon Valenti  1 , Toshio Naito  1
Affiliations

Rapid resurgence of syphilis in Japan after the COVID-19 pandemic: A descriptive study

Akira Komori et al. PLoS One. .

Abstract

Some countries have reported a post-pandemic resurgence in syphilis prevalence, but trend data in the World Health Organization Western Pacific Region (WHO-WPRO), including Japan, are severely lacking. Thus, the present study compares the number of syphilis cases before and after the COVID-19 pandemic in some WHO-WPRO countries. In addition, temporal trends in the number of syphilis cases in Japan pre- and post-pandemic are described. Annual numbers of syphilis cases during the study periods from China, New Zealand, Australia and Japan were compared. Annual trends of the numbers of syphilis cases during the same study periods were examined in Japan. In 2020, the number of syphilis-positive cases decreased in all four countries. In 2021, though, China, Australia and Japan all showed an increase in the numbers of syphilis cases. However, the rate of increase in China (+2.8%) and Australia (+4.8%) was low compared to Japan (+36.0%). The number of syphilis cases in New Zealand in 2021 was 12.6% lower than in 2020. In 2022, the number of cases of syphilis in China was 7.4% lower than in 2021. The increase of syphilis-positive cases was approximately 6.3-fold higher in Japan compared to Australia (+66.2% vs. +10.5%) in 2022. In conclusion, post-pandemic resurgence of syphilis occurred in Australia and Japan, but not in China and New Zealand. The reason for the substantial increase in syphilis-positive cases in Japan remains unclear. Post-pandemic, prevention and control of sexually transmitted infections still require attention.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Trends in the numbers of syphilis cases in WHO-WPRO: China, New Zealand, Australia, and Japan.
The number beside the line graph indicates the actual number of syphilis-positive cases. The vertical line shows the number of syphilis-positive cases, and the horizontal line shows the time of year.
Fig 2
Fig 2. Number of cases of syphilis by age and sex in Japan between 2018–2022.
The vertical line shows the number of syphilis-positive cases, and the horizontal line shows age.
Fig 3
Fig 3. Number of cases of syphilis by sexual preference in Japan: 2018–2022.
Heterosexuals include both men who have sex with women and women who have sex with men. The number beside the bar graph indicates the actual number of syphilis-positive cases.
See this image and copyright information in PMC

References

    1. World Health Organization department news. STIs in 2022: emerging and re-emerging outbreaks. 2 September 2022. https://www.who.int/news/item/02-09-2022-stis-in-2022-emerging-and-re-em.... Accessed: 9 February 2023.
    1. Komori A, Mori H, Naito T. The impact of the COVID-19 pandemic on other infections differs by their route of transmission: A retrospective, observational study in Japan. J Infect Chemother. 2022;28:1700–3. doi: 10.1016/j.jiac.2022.08.022 - DOI - PMC - PubMed
    1. Nazir A, Masood W, Ahmad S, et al.. Rise of syphilis surge amidst COVID-19 pandemic in the USA: A neglected concern. Ann Med Surg (Lond). 2022;80:104239. doi: 10.1016/j.amsu.2022.104239 - DOI - PMC - PubMed
    1. Public Health Agency of Canada. Infectious syphilis and congenital syphilis in Canada, 2021. December 2022. https://www.canada.ca/en/public-health/services/reports-publications/can.... Accessed: 9 February 2023.
    1. National Institute of Infectious Diseases. National institute of infectious diseases home page. https://www.niid.go.jp/niid/en/. Accessed: 17 January 2024. In Japanese.