What is a Recent Infection Testing Algorithm (RITA)?
A RITA is a combination of laboratory tests and laboratory/clinical information used to classify an HIV infection as recent or long-term infection. To screen out false recent results of individuals on ART or elite controllers, viral load testing can be used in combination with the RTRI for final classification of recent infection status. Persons who test recent on the RTRI should have a blood specimen collected for viral load testing, if possible (see next question). Those who test recent on the RTRI and have a viral load ≥1,000 copies/mL will be considered as a RITA recent case (Figure 2).
Figure 2. Recent Infection Testing Algorithm with Viral Load Testing in Routine HIV Testing Services
UNAIDS and WHO recommend RITAs that may include HIV-1 RNA/DNA or evidence of ARVS using high performance liquid chromatography viral load test to reduce misclassification of false recent infection when used for surveillance. Other clinical (patient monitoring/case surveillance) information including testing history may be useful to help reduce false recent results.