CD4 and infection: This results from selective testing of those with ODs such that the testing rate is generally higher among those with advanced disease, and from the opportunity to miss those with recent infections even when testing rates are high, leading to a shift in the untested population towards those with less advanced HIV (we estimate that among those untested, the portion with CD4 cell counts higher than 500 was 29.4% in 2003 and 59.3%in 2014).