Multiple policies with a bunch of CS preventive and control measures were conducted at the same period (2010–2020), which involved integrating the syphilis screening with health education, the standard treatment for pregnant women and the follow-up of infants of CS patients, alongside supportive strategies from the government. These policies targeted at elimintating MTCT of syphilis and turned out to be effective in Guangdong Province, as evidenced by the significant difference in CS notification rate before and after the implementation. The CS new cases would be fewer in the following year.
Particularly, at the provincial level, the notification rate of CS rose from 72.69 to 128.55/ 100,000 livebirths in the pre-program period, reflecting the heavy disease burden which the re-emergence brought.[1] Also, some researchers believed that the upgrade of the national reporting system for infectious diseases which reduced underreporting partially contributed to the increase [31]. After implementing the CS control measures, Guangdong Province showed 95.52% of decline in CS notification rate from 2012 to 2020. The significant change in slope and level demonstrated the effectiveness that these core measures contributed to.
In terms of the regional level, it was not surprising to find the most severe CS epidemic in PRD, the region with the highest GDP [32]. It was a consensus decades ago that the developed regions tended to suffer a heavier disease burden of CS[33] and urban citizens were more vulnerable than rural ones because of their more frequent high-risk sexual behaviour[34]. However, a clear decreasing trend in CS notification rate of PRD was witnessed since 2007 and it became the region with the lowest CS notification rate in 2015, 3 years after the implementation. Digging into the reason of this progress, we discovered that PRD owned over 60% of GDP and 70% of top-tier hospitals over the province[35, 36], implying the abundant medical resources and the great capacity to prevent and control the disease. For instance, Shenzhen, one of the most developed cities in the province, launched the Program of Prevention of Mother-to-Child Transmission of Syphilis in Shenzhen (PPSS) in 2002, which involved free syphilis test for pregnant women, treatment for positive individuals and 18 months’ follow-up for their babies[37]. It cost almost 2800 million Yuan in total (around 431.7 million US dollars) [38] and resulted in a 91.3% decrease in CS notification rate from 2002 to 2011[39]. Therefore, since the epidemic of PRD had already been controlled before 2012, presenting a constant downward trend, insignificant change in slope was detected. However, the progress cannot be neglected because of its nearly fastest among all the regions and the lowest notification rate after 2015. Moreover, the CS case is predicted to be 48.
These all indicated that the measures they took earlier were sustainably effective and long-term rewarding.
In contrast, two less-developed regions (East & west wings and North ecological development zone) both had a rising trend of CS notification rate before the implementation. This could presumably bring a heavier disease burden as they possessed fewer medical resources and poorer public health capacity than PRD. In line with Guangdong province Statistic Bureau [32], the north ecological development zone had the lowest GDP and pregnancy screening rate and the fewest hospitals but the highest mortality rate of newborns among all the three regions, followed by East & west wings. These suggested its weak capacity to prevent and control the CS.
Additionally, recent research found that pregnant women in underdeveloped regions had a higher risk of contracting syphilis. This was because that their husbands who might be ‘return migrants’ from urban to rural areas, possibly had untreated syphilis or high-risk sexual behaviour due to the lack of awareness of the disease. It was thus likely that they transmitted the disease to their wife, leading to the occurrence of CS[40]. In this study, the north ecological development zone had the highest net emigration[41], implying a large number of migrant returnees. This should have explained why its CS notification rate was higher than the east & west wings, where the population mobility was less active. LMICs such as Tanzania[42], Mozambique[43] and Nepal [44] have also identified this phenomenon as a potential source of additional CS cases. However, the situation in both two regions started to improve when the preventive and control measures were launched and ended up with a low-level epidemic trend. This proved that the measures worked effectively not only in developed regions but also the resource-constrained settings.
However, CS is still endemic in many other LMICs, accounting for the most cases globally[12]. These countries also faced similar challenges with two underdeveloped regions in our study, such as limited medical resources, the weak public health capacity and the large number of migrants, as previously mentioned [12, 45]. WHO pointed out that there was a lack of guidelines for health service providers in LMICs to prevent this disease. Given that Guangdong Province already had control CS epidemic even in its underdeveloped regions through preventive and control measures, it is possible to generalize them in countries facing the same barriers as Guangdong.
Specifically, the dominant interventions that Guangdong conducted, in particular, providing syphilis-related health education to pregnant women, large-scale screening, standard treatment, as well as the follow-up or the referral of infected mother and their infants, have been already considered as cost-effective by WHO[12]. However, a series of supporting measures from the government was the fundamental of the implementation. It addressed improving the surveillance system, assuring finical subsidy, strengthening the capacity building and so on. To be detailed, the regular supervision was conducted following the order of “provincial-municipal-county level”. The central government allocated particular subsidy to CS control every year in accordance with the number of people in need[46]. All above were referred as “governance commitment” that was called for by WHO [12]. Hence, if countries with CS epidemic could carry out all these measures above, a positive result could be rewarded in the end.
The generalization of these measures would also be considered as part of international cooperation, which is of great importance for global CS elimination. Additionally, more problems would be also found out when localizing, which can help them to remove obstacles and get closer to the CS elimination eventually.