Control of COVID-19 in China likely reduced the burden of multiple other infectious diseases.

Dear Editor

We read with great interest the analyses that suggested the control measures for COVID-19 likely reduced the infections of tuberculosis and influenza, but not the infections of human immunodeficiency virus and hepatitis C virus, possibly because these four diseases are transmitted through different routes.1, 2, 3 In theory, the similar effects could be observed on multiple infectious diseases in China, because China also implemented strict and costly measures, such as lockdown of cities, mass restriction of travelling and gathering, mass isolation, mass mask wearing, and mass disinfection, for the control of COVID-19 caused by SARS-CoV-2 in 2020. Here we provided data to test this theoretical inference that is important for calculating the benefits of the strict and costly measures for combating the COVID-19 pandemic.

Over 30 important infectious diseases were listed as Class A or B infectious diseases in China. The numbers of new cases of these diseases are reported monthly at the official website of National Health Commission of China (http://www.nhc.gov.cn/jkj/s3578/new_list.shtml). We collected these numbers of the years 2010−2020 from this official website. We excluded the numbers of the pandemic H1N1 subtype influenza, hepatitis D, human infection with H7 subtype avian influenza, and COVID-19, because these diseases were not listed as Class A or B infectious diseases in all the years 2010−2020. We also excluded the numbers of plague, severe acute respiratory syndrome (SARS), human infection with H5 subtype avian influenza, poliomyelitis, and diphtheria, because of low incidences of these diseases (<10 cases/year or <21 cases during the years 2010−2020).

We analyzed the numbers of the remaining 26 infectious diseases listed in Fig. 1 , and statistical significance was calculated throughout using the T test compared with the averages of the years 2010−2019, if not specified.

Fig. 1

Changes in the annual new cases of 26 infectious diseases in China over time compared with the relevant averages during the years 2010−2019. HFRS, hemorrhagic fever with renal syndrome; NM-meningitis, Neisseria meningitidis meningitis; UV-hepatitis, unclassified viral hepatitis; BA-dysentery, bacillary and amoebic dysentery; AIDS, acquired immune deficiency syndrome. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

The total new cases of these 26 major infectious diseases declined significantly by ∼16.4% in China in 2020 (P<0.05) (Fig. 1A). The incidences of the five infectious diseases mainly transmitted through oral or nasal routes (IDMTTONRs), including scarlet fever, typhoid & paratyphoid, pulmonary tuberculosis, hemorrhagic fever with renal syndrome, and hepatitis E, declined significantly by 24.0 − 71.5% in 2020 (P<0.05 by the T test) (Fig. 1B). The incidences of two other IDMTTONRs, hepatitis A and Neisseria meningitidis meningitis, declined in 2020 significantly, as compared with the numbers of the years 2012−2019 (P<0.05 by the T test) (Fig. 1B). Pertussis, which is also an IDMTTONR, increased significantly in its incidence in China during the years 2010−2019 (P<0.05 by the Mann-Kendall test), sharing the same resurging trend with many other countries. The incidence declined significantly in 2020 by 56.9 − 85.1% compared with the incidences in the years 2017−2019 (Fig. 1C).

The incidences of rabies, neonatal tetanus, malaria, bacillary and amoebic dysentery, and unclassified viral hepatitis declined by 28.7 − 57.7% in 2020 compared with the year 2019 (Fig. 1D). These changes possibly resulted from some reasons that existed before 2020, because they declined significantly during the years 2010−2019 (P<0.05 by the Mann-Kendall test).

The incidences of measles, Japanese encephalitis, cholera, schistosomiasis, and Dengue fever changed greatly during the years 2010−2019, and the incidences of these diseases all declined in 2020, although not significantly in statistics (Fig. 1E).

The incidences of the infectious diseases mainly transmitted sexually, through blood, or from domestic animals, including AIDS, gonorrhea, syphilis, hepatitis B, hepatitis C, brucellosis, leptospirosis, and anthrax, increased by from −9.9% to 34.3% without statistical significance (P>0.05) (Fig. 1F and Fig. 1G). The incidence of AIDS increased significantly during the years 2010−2019 (P<0.05 by the Mann-Kendall test), and this incidence kept relatively high in 2020 (Fig. 1F).

Together, changes of the incidences of the above 26 infectious diseases supported the theoretical inference that the strict and costly measures for the control of COVID-19 in China likely reduced significantly new cases of multiple IDMTTONRs, and they likely did not reduce new cases of infectious diseases mainly transmitted sexually, through blood, or from domestic animals. This is important for calculating the costs and benefits of the COVID-19 control measures and making rational decisions for pandemic control.

An analysis on the same topic was published using the data of two (2019−2020) or five (2016−2020) years, with the same conclusion on the IDMTTONRs and the contrary conclusion on infectious diseases mainly transmitted sexually, through blood, or from domestic animals. By contrast, this report employed the data of 11 years (2010−2020), and therefore, this report revealed the longer trends of the analyzed diseases and excluded more confounding factors in making conclusions.

Funding

This work was supported by the High-Level Talent Fund of Foshan University (No. 20210036).

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.