Utilisation of Rapid Tests for Sexually Transmitted Infections: Promises and Challenges

The control of curable STIs in countries with high disease burden has been hampered by the lack of accessible STI laboratory services. Rapid tests that are sensitive, specific and easy to use have the potential to increase the specificity of syndromic management of STIs in symptomatic patients and increase access to screening of asymptomatic infection to prevent the development of long-term complications and to interrupt the chain of transmission of STIs in the population. Although most rapid tests for chlamydia and gonorrhoea have sub-optimal sensitivity, and are neither simple nor affordable, some rapid syphilis tests have been shown to have acceptable performance. These can be deployed to increase access to screening in settings where testing is not previously possible or where laboratory services are inconsistent. With more political commitment and technological advances made possible by increased funding and public and private product development partnerships, there is much optimism in the near future for point of care tests for STIs that can improve patient management and disease control. The WHO estimates that more than 380 million new cases of sexually transmitted chlamydia, gonorrhea, syphilis and trichomoniasis occur worldwide every year (1). An equal or greater number of viral sexually transmitted infections (STIs) such as those caused by herpes simplex virus and human papilloma virus also occur every year but efforts to estimate the annual incidence of these infections on a global basis have been limited. THE NEED FOR STI DIAGNOSTICS Most STIs are asymptomatic but their consequences are serious. Undiagnosed and untreated STIs can lead to long term complications (Table 1). While complications are relatively rare in men, infections in women can lead to pelvic inflammatory disease and tubal infertility, a condition, which, in some societies renders a woman worthless. STIs also cause serious adverse outcomes in pregnancy for both the women and their foetus or infant. Affordable curative therapy is available for the major bacterial STIs. Screening and early treatment are therefore critical for effective patient management to prevent the development of long term complications and to interrupt onward transmission. For infected individuals with symptoms, STI laboratory services are scarce in most high burden countries, requiring patients to travel long distances to access these services.