The diagnostics landscape
Nearly half of people living with HIV are not aware of their status. Most countries use rapid HIV diagnostic tests quite widely and many countries are now also introducing self-testing to reach even more people with HIV tests and to close the diagnostic gap.
In addition to tests for screening and confirming HIV infection, there are several other types of HIV diagnostic tools. CD4 tests are used to monitor the immune response of people living with HIV by measuring CD4 T-cells in the blood. Viral load tests monitor the effectiveness of treatment by measuring the amount of HIV in the blood.
There are also HIV tests that are used for epidemiological surveillance purposes. One example is an HIV incidence assay — a test that can determine whether an HIV infection is recent (i.e., from within the past year) to help estimate HIV incidence (the number of new HIV infections in a population).
Gaps & challenges
While diagnostic tools exist for all of these purposes — screening, confirming, self-testing, CD4 count, viral load monitoring, incidence testing — some are too expensive or complex for wide use in resource-poor areas that do not have fully equipped laboratories or trained staff.
Rapid diagnostic tests for HIV are widely available and require only a saliva swab or blood from a finger stick. However, early infant diagnosis remains a challenge, and many CD4 and viral load tests are expensive and not widely enough available outside larger population centres or in resource-limited settings.
At the beginning of 2015, an estimated 36.9 million people around the world were living with the human immunodeficiency virus (HIV). The virus has killed some 34 million people and contributes to cycles of poverty and underdevelopment in low- and middle-income countries. Sub-Saharan Africa is home to the vast majority of HIV infections, about 25.8 million, and to 70% of the two million new infections globally in 2014.
HIV compromises the function of the immune system, meaning untreated patients eventually become susceptible to a wide range of diseases that healthy individuals can usually resist. Tuberculosis, a particularly common co-infection among people living with HIV, is the leading cause of AIDs-related deaths (approximately one in three).
There is currently no cure for HIV, but antiretroviral therapy (ART) can be used to help control the virus and prevent onward transmission. As of mid-2015, approximately 15.8 million – less than half of people living with HIV – were receiving ART globally. This is partly a result of the fact that an estimated 47% of people with HIV have not been diagnosed.
The global health community has set ambitious targets for the post-2015 era, with the goal of eliminating AIDs by 2030. The ‘90-90-90’ targets—90% of people living with HIV know their status, 90% of those diagnosed are receiving sustained ART and 90% of those receiving ART have successful viral suppression—have been set for 2020. Achieving them will require a significant scale-up of global and national HIV/AIDs control and prevention measures.
FIND has several projects underway with partners in support of better diagnostic tools for HIV, including: i) support for advancing new tools and guidance for estimating HIV incidence; ii) quality assurance of rapid diagnostic tests for HIV; and iii) strengthening laboratory capacity to use new and existing tools for HIV diagnosis, treatment monitoring and surveillance.
In April 2015, FIND and partners announced the launch of a 90-minute molecular HIV test that can be used to diagnose HIV in infants with equipment that many countries are already using for the diagnosis of tuberculosis. In December 2014, FIND and partners announced the launch of a test for the rapid measurement of HIV-1 viral load also run on the same equipment as that used for an existing TB diagnostic test.