The results of this study show that the incidence of AIDS/HIV in Chinese population increased year by year from 1999 to 2018,which are consistent with the results of Yong-Chao and Zunyou Wu's study[7, 8]. The rising tendency of morbidity is most pronounced during the period of 2002-2005, the average annual increase was 102.5%. The possible reasons are the abuse of intravenous drug , the increase in the number of homosexual men and infection occurred after irregular blood collection in this time stage[9]. However, since the implementation of the blood donation law in 1998, the transmission of HIV through blood collection and supply has been basically controlled in China. At present, the transmission of HIV is mainly through sexual transmission[10, 11]. The introduction of "four exemptions and one care" policy in 2006 and the implementation of the "six expansion and five strengthening" prevention and control measures in 2011 have also effectively slowed down the rising tendency of AIDS incidence, which is consistent with the results of our study[12-14]. At the same time, a research report on the global AIDS epidemic shows that compared with other countries, the current AIDS epidemic in China is at a low epidemic level[15]. But the relevant studies indicate that the AIDS infected people in China are changing from high-risk population to general population, especially adolescents and the floating population [7, 16]. Adolescents not only have a high incidence of premarital sex but also have multiple sexual partners, leading to a high incidence of sexually transmitted infections among adolescents. According to the survey ,1 out of 7 new HIV infections in the world now occur in adolescence, AIDS has become the second leading cause of death among adolescents worldwide[16]. At the same time, due to the low education level of the floating population, their knowledge, attitudes and behaviors of HIV are limited, and their strong mobility leads to the floating population becoming a bridge for the spread of HIV[9, 17].Therefore, in order to prevent the epidemic of AIDS in the general population, our country should strengthen the sex education, health promotion and health education for the two groups of teenagers and floating population .
Gonorrhea is reported to be the most common sexually transmitted infection in any country in the world[18, 19], with 106 million new cases of gonorrhea in adults worldwide each year and extremely high exposure rates. Not only is it a major cause of pelvic inflammatory disease and infertility in women, it can also increase the sexual transmission and prevalence of HIV.Therefore, the gonorrhea has a significant impact on reproductive health. The epidemic of gonorrhea in China rose rapidly in the 1970s, reached its peak in 1999, and then declined, which is consistent with the results of our study[20]. But our study shows that the incidence of gonorrhea showed a significant decrease in 1999-2012,and then showed a significant increase from 2012 to 2018.The increased trend of the gonorrhea incidence in China from 2012 to 2018 is similar to that of the United States and the United Kingdom in the same years[21].An increase of the gonorrhea incidence at this time stage in China may be due to the expanded coverage of gonorrhea screening,the increased sensitivity of diagnostic methods and the increase in the number of MSM patients[22, 23]. Although this study indicates that the incidence of gonorrhea in China from 1999 to 2018 shows an overall trend of decline, it is still in the forefront of the notifiable infectious diseases. Especially in 2018 its incidence is 9.58%, ranking fourth[6]. Gonorrhea is currently treated with antibiotics because there is no vaccine that can be prevented. However, neisseria gonorrhoeae has been found to be increasingly resistant to many antibiotics, making the treatment of gonorrhea become a major challenge for clinicians in recent years[11, 19, 24, 25]. Therefore, in order to control the rising trend of gonorrhea epidemic in China, the state not only needs to actively publicize the knowledge related to gonorrhea among high-risk population, so as to enhance the public awareness of prevention and treatment of gonorrhea, but also needs to increase the research and development of gonorrhea related vaccines and drugs.
According to the reports of WHO, 988 000 pregnant women were infected with syphilis in 2016, resulting in over 350 000 adverse birth outcomes including 200 000 stillbirths and newborn deaths[26].It can be seen that syphilis seriously affects the life and health of women who are in childbearing age and of newborns[27]. The results of our study show that the incidence of syphilis in China is on the rise from 1999 to 2018 on the whole, which is contrary to the overall temporal trend of gonorrhea incidence[20]. The trends in the incidence of both sexually transmitted diseases are similar to developed countries. On the one hand, this phenomenon may be due to the increased number of syphilis infection population in MSM of China; On the other hand, it may be because the Government launched a national plan on expanding syphilis screening in 2010, which led to an increase in the number of cases diagnosed as latent syphilis[28, 29]. And the related literature also suggest that syphilis infection rate is higher than AIDS in Chinese MSM population [7]. From the four temporal stages of syphilis incidence, we can learn that syphilis incidence has a downward trend from 1999 to 2003, the rest of time stages presents a steady upward trend. It also suggests that China should pay more attention to the prevention and treatment of syphilis. At the same time, the relevant studies have shown that the majority of Chinese people’s knowledge of syphilis is far lower than the standard of 10-year plan set by the our country, which requires the awareness rate of the general population reaches 90% and that of high-risk population reaches 95% by 2020[27, 28, 30]. Therefore, the country should strengthen the publicity of syphilis prevention knowledge, enhance the prevention and control ability and prevent its further spread.