In this study, we found that the availability of CT laboratory testing was still poor in different hospitals in China. In 2018, only one fifth (496/2450) of hospitals in Shandong reported STD cases, which meant that a few hospitals could provide related laboratory testing and STD clinical services. Among those provided STD clinical services, more than half could not provide antigen testing for CT, more than four fifths could not provide PCR testing, and more than two fifths could provide neither antigen nor PCR testing, indicating that GCTI cases in those hospitals were not correctly diagnosed and reported, which meant that a large number of GCTI cases were not screened and reported, and the real situation of GCTI epidemic in China may be largely underestimated according to surveillance data of case reporting.
We supposed that GCTI case reporting was largely related to laboratory testing for CT provided in hospitals. To confirm the hypothesis, we compared the proportion of different kind of hospitals reported GCTI cases with that of hospitals provided laboratory testing for CT, and found that they were completely consistent as expected. In other words, the reported incidence of GCTI is determined by the availability of laboratory testing and can not reflect the real disease burden of GCTI in China.
We found that antigen testing was more available than PCR in Shandong province, although its sensitivity is as low as 65%-75༅.[28] The advantages of convenient operation, cheap and available reagents and rapid reporting make it an attractive option in primary hospitals and counterbalance the impact of its lower sensitivity. PCR testing, with sensitivity and specificity as high as 97% and 100% respectively,[29, 30] was strongly recommended for diagnosis of CT,[31–33] but was seldom used in Chinese hospitals.
From the point of view of programmes supervisors for STD control, we suppose that one of the main reasons for the low availability of GCTI testing is lack training of medical staffs, which leads to inadequate knowledge of the disease and low awareness of GCTI screening. A survey showed that only 21.2% of general practitioners were able to provide correct follow-up guidance for patients with GCTI.[34] Another reason is expensive equipments needed and complicated process for PCR testing. Cost-benefit analysis may affect decision making of hospitals. We found that PCR testing was more available among general western medicine hospitals than specialized dermatological hospitals and maternal and child health hospitals because PCR was widely used as an auxiliary diagnosis for various infectious diseases including CT.[35–37] Lastly, GCTI is not included in 39 statutory infectious diseases,[38] and CT screening and reporting are routinely requested in pointed STD monitoring sites rather than all medical institutions in China. CT screening is not given priority in some medical institutions.
Some efforts are needed to improve the situation of GCTI control in Shandong province as well as in China. First, the governments need to attach great importance to initiate CT screening plans among sexually active and high-risk groups, especially among women under 30 years old, female sex workers and man who have sex with man. National Chlamydia Screening Programmes (NCSP) was rolled out between 2003 and 2008 in England, which resulted in a large increase of chlamydia diagnoses and reporting from 2008 onwards at first and a reduction in numbers of infections then.[17, 39] Second, urine testing for CT by PCR or ligase chain reaction (LCR) needs to be promoted in tertiary and secondary hospitals. One of the main reasons for the poor availability of PCR tests for GCTI is inconvenient swab specimen collection. Urine testing has a high sensitivity and specificity as well as using swab specimens.[40] Third, effective referral service and laboratory outsourcing service are suggested to be introduced among primary hospitals where CT testing are unavailable. Fourth, ad hoc survey rather than passive case reporting is recommended for GCTI surveillance in order of avoiding underestimation of the epidemic situation.
There are some limitations in the study. First, the investigation was conducted in a province of China, and generalization of the results and referring of the conclusion should be careful. Second, many factors may affect reporting and estimation of CT prevalence beside availability of CT testing, and more issues concerning GCTI control are need to be addressed in China in further studies.