HIVST does not replace provider-administered testing. Individuals with a reactive self-test result should receive further testing from a trained provider using the full national testing algorithm.

• HIVST can replace risk screening tools* to optimize testing among those presenting at health facilities. * Risk screening tools, provider- or self-administered, typically comprise questions designed to identify individuals with elevated HIV risk factors, such as their practices, symptoms or other characteristics. Tools are generally used to prompt testing among those who would otherwise not be offered testing (screening in) or to stop testing people who would otherwise be offered testing (screening out). WHO does not advise the use of screening-out tools. WHO has recommended HIVST since 2016, and more than 100 countries have policies and are implementing HIVST. A range of self-testing approaches can be implemented and are recommended, ranging from use in the community, in pharmacies, online, in facilities and through network-based testing services. These strategies need to be supported and scaled up. Wherever self-tests are distributed it is important that key information and messages are delivered by providers and communities when questions or challenges arise

Self-testing refers to a process whereby people collect their own specimen using a simple rapid test and then perform the test and interpret their results when and where they want. WHO recommends a range of self-testing approaches which can improve access to and uptake of testing services, including those for pregnancy (40), HIV (11), HCV (41), syphilis and COVID-19 (42) (see for example, Figure 5.1). New dual self-tests, which can detect syphilis and HIV infection at the same time, are also recommended (43). See Box 5.8 for a summary of self-testing recommendations. Self-testing has been consistently shown to be safe, acceptable, and effective in increasing the number of people tested, diagnosed with and treated. While efforts to optimize linkage are important, studies have consistently shown that linkage rates following self-testing continue to be high and comparable to standard testing (44-46). The empowering nature of self-testing has also enabled people, including partners and people with limited contact with the health system, to access testing along with onward prevention, care and treatment services. Self-tests could be distributed through pharmacies, vending machines, pick-up from a local store, distribution by peers, community-based distribution, online ordering, mail delivery and facility-based distribution. Self-testing can enable greater flexibility for clients and health services, particularly as part of simplified implementation of PrEP and PEP services (3). A range of support tools can be utilized to support self-testing implementation (47), including virtual interventions and artificial intelligence (48). Evidence has shown that both blood-based and oral fluid-based self-tests are acceptable, and different users have different preferences (49-60). There is currently no evidence that there are differences in user uptake when offering either blood-based or oral fluid-based self-tests. There are currently a range of affordable WHO prequalified self-tests that can be accessed: https:// extranet.who.int/prequal/vitro-diagnostics/prequalification-reports/whopr.