Key results:
The prevalence rate of STIs among women diagnosed with the syndromic approach was relatively high and showed a positive trend over 11 years for all age groups and symptoms. VD and especially vaginosis was the most common recorded syndrome. Women of childbearing age were the most affected age group.
Limitations:
STIs Surveillance at primary health care level was based on syndromic data and not on biological tests. Since each symptom has multiple potential agents, this study based on syndromic data cannot provide accurate statistics on the frequency of STI pathogens. In fact, according to studies conducted in Tunisia and a prospective observational cohort study in South Africa (6, 7, 20), syndromic approach diagnosis had a low sensitivity and specificity which suggests that the large number of STIs such as VD detected in our study may be largely underestimated and that asymptomatic cases could only be diagnosed by an appropriate biological tests. On the other hand, many cases of VD are not caused by sexually transmitted infections such as cervical ectopy, foreign bodies, retained tampon, vulval dermatitis, non-sexually transmitted infection like some bacterial vaginosis and candida infections (21, 22).
As STIs have the same risk factors as other infections, such as HIV and hepatitis, a contact tracing is needed to investigate cases (23). However, as data collection from the registry of STI surveillance was conducted retrospectively, data available on personal and contact information was not exhaustive to do so.
Interpretation:
• Predominance of STIs among women of childbearing age:
Globally, 2012 and 2016 estimates of the prevalence and incidence of the four curable STIs (chlamydia, gonorrhea, trichomoniasis and syphilis) remain high among women of reproductive age, consistent with our findings (1, 2, 24).
• Predominance of vaginal discharge syndrome:
World estimates have shown that for these four pathogens, Trichomonas Vaginalis is the most frequent in women 5.3% (95% uncertainty interval UI:4.0-7.2) followed by Chlamydia trachomatis 3.8% (95%, UI: 3.3–4.5); gonorrhea 0.9% (95% UI: 0.7–1.1) and syphilis 0.5% (95% UI: 0.4–0.6). The same order of pathogens according to their involvement in STIs was also recorded in the East Mediterranean Region (EMR) with a predominance of Trichomonas Vaginalis: 4.7% (95% UI: 3.3–6.7) followed by Chlamydia trachomatis 3.8% (95% UI: 2.6–5.4); gonorrhea 0.7% (95% UI: 0.5–1.1) and syphilis 0.7% (95% UI: 0.4-1.0) (1, 2, 25).These statistics are relatively consistent with our results. In fact, when excluding vaginosis which are in most cases caused by a non sexually transmetted pathogens “Gardnerella vaginalis” (26), we find that vaginitis (mainly caused by Trichomonas Vaginalis) was the most frequent syndrome followed by pelvic pain and cervicitis (mainly caused by Chlamydia trachomatis and Neisseria gonorrhea) and then by Genital ulceration (syphilis) (Tables 1 and 2). However, our results showed lower prevalence rates than those reported in the literature. This discrepancy could be understood by the low sensitivity of syndromic approach to diagnose STIs leading to an underreporting of cases in our study.
In Tunisia, several studies on the epidemiological characteristics of sexually transmitted infections in women had concluded to a high prevalence of VD and the pathogen Chlamydia trachomatis in those of reproductive age(6, 27). In Morocco, a 1995–2015 study of reported cases of VD showed that the prevalence of Chlamydia trachomatis was 3.8%; IC95%[2.1–6.4] and that of Neisseria gonorrhoeae was 0.37% IC95%[0.14-1] of (15). A 2019 meta-analysis had shown that Tunisia had a higher prevalence of Chlamydia trachomatis than Morocco and Algeria and highlighted strong evidence of a sub-regional difference with the Horn Africa and North Africa (Tunisia, Morocco, Algeria, Sudan) presenting respectively 6 fold and 5 fold higher odds of syphilis infection than Eastern Middle East and North Africa(MENA)(10) .
The predominance of vaginosis among female consulting for vaginal discharge in our study is concordant with the results of a Meta-Analysis published in 2019 which have shown that general population prevalence of bacterial vaginosis is high globally, ranging from 23–29% across regions (Middle East and North Africa: 25%; sub-Saharan Africa: 25%) (28, 29).However, their predominance is not synonymous with their incrimination in STIs, because the most common bacterial vaginosis "Gardnerella vaginalis" is not sexually transmitted bacteria but found naturally in the vagina(26). These vaginosis are endogenous reproductive tract infection resulting from replacement of the normal hydrogen peroxide-producing Lactobacillus sp. in the vagina by high concentrations of anaerobic bacteria, such as Gardnerella vaginalis (30).
• An upward trend in STIs:
Consist with our findings, WHO prevalence estimates of the four curable STIs among women have shown an overall positive trend from 2012 to 2016 globally and especially in the EMR (25).This trend of declared STIs showed that we are not on the right way to reach 2030 goals of eliminating STIs as a public health problem. It could be explained by,first, the change in lifestyle, sexual behavior and other factors such as addiction which is currently a health problem in Tunisia where illicit substance use among college students represents one of the most complicated social problems(31). Secondly,it could also be due to the low sensitivity of the syndromic approach to detect asymptomatic cases that would be potential sources for infections dissemination.
In conclusion, despite a possible underreporting of STIs cases in this study, the results showed a significant increase in their trend over time. This upward trend of STIs may be the result of a failing primary prevention on which we must act.
Generalisability:
To reach the 2030 goal of eliminating STIs in Maghreb countries, several measures should be reinforced. First, a continuous monitoring of STI prevalence and incidence which is fundamental to design, implement and evaluate STI interventions that is why WHO and its partners are looking at options to improve the quality of future estimates and supporting countries to generate their own national estimates (1).Second, additional preventive interventions including behavioral changes in the use of alcohol and substances and a focus on populations at risk such as sex workers. Third, prompt identification, correct treatment and partner tracing to stop the spread of these infections.