**8. Screening**

The social and financial burdens imposed by chlamydia are quite numerous. For this reason, some states such as the UK, Australia, the Netherlands, and Sweden have established a national chlamydia screening program. Each of these programs aimed to reduce the transmission of infection and its overall prevalence in the community with different strategies [71, 72]. Such a program should cover all sexually active individuals who are at an age where clinical intervention can alter long-term outcomes [73]. Evidence supports that screening should be available to those under 25 years old [74]. Studies on the subject have shown that because it is less invasive and easier, the postal screening method, in which people take samples on their own instead of the traditional way in the medical setting, increases screening rates [75, 76]. As Hoenderboom et al. points out, these samples may not be blood, but urine or vaginal swab samples [77].

Despite different opinions on the cost-effectiveness of screening programs, some authors argue that the screening program in the UK should be supported in this respect as well [78–80]. Retrospective studies of the chlamydia screening program in Sweden have shown that even in the first phase, the number of new cases has decreased. However, this reduction was achieved by using a more precise testing method, such as PCR, instead of more traditional methods such as culture. It was therefore concluded that faster, easier and more sensitive methods should be used for the diagnosis of chlamydia [37, 80]. Some other studies reported that the number of chlamydia infections was higher than expected, so screening should be done regardless of the estimated prevalence [81, 82]. In addition, several studies report that the prevalence of infection is high in adolescents and young women due to both their biological and behavioral predispositions, so a screening program should be established for at least 15–24 years of age [83]. All this evidence shows that it is important to establish screening programs to cover all sexually active individuals and to repeat tests for possible recurrent infections at regular intervals in order to prevent the spread of chlamydia and possible morbidity in the community by treating infected people in a timely manner. For such a screening program to be successful, noninvasive screening methods must be used. In this way, more people will be reached and the real incidence in the population will be determined, the measures to be taken for the control of the infection will be planned in a healthier way and the society will be made aware of the risk factors through prevention campaigns [84].

Recently, Huai and colleagues published a meta-analysis to estimate the prevalence of chlamydia infection worldwide and found that rates varied widely in the regions they studied, with the lowest prevalence in Southeast Asia. The authors then concluded, based on previous studies on the cost-effectiveness of screening programs, that it is critical to establish *Chlamydia trachomatis* screening programs using different guidelines in Latin America and Africa [85].

The US Preventive Services Task Force also recommends routine *Chlamydia* screening for sexually active young women to prevent consequences of undiagnosed and untreated chlamydial infection and has made the following recommendations: [86, 87].

