Infection Dating Tool

This tool enables systematic interpretation of diagnostic test histories into formal plausible infection intervals, using data on "diagnostic delays" (i.e. window periods) of tests, and particular (dated) positive and negative test results. It outputs a detectable infection interval: Earliest Plausible Date of Detectable Infection (EP-DDI), Latest Plausible DDI (LP-DDI) and the midpoint of the interval as an infection time 'point estimate' or Estimated Date of Detectable Infection (EDDI). Detectable infection (for HIV) is by default defined as test conversion on a viral load assay with a detection threshold of 1 RNA copy/ml, but arbitrary reference tests or the exposure event may be used as time-zero. In addition, the tool uses these data to estimate residual risk of infectious donated blood units, using properties of the screening algorithm and incidence in the donor population.

Analytical framework described in: Grebe E, Facente SN, Bingham J, Pilcher CD, Powrie A, Gerber J, Priede G, Chibawara T, Busch MP, Murphy G, Kassanjee R, Welte A on behalf of the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA). Interpreting HIV Diagnostic Histories into Infection Time Estimates: Analytical Framework and Online Tool. bioRxiv 323808; doi: https://doi.org/10.1101/323808.

This release fixes several bugs affecting:

• Only positive or only negative tests reported for a subject
• Identical flags set multiple times on the same result row
• CSV downloads opened in Excel