Figure 2 Biases in antenatal clinic (ANC) sample. (A) Ratio of percentage of women attending ANCs who are HIV+ and percentage of all HIV+ women, assuming that the probability of women being included in the ANC sample depends on stage of HIV (solid line) and the fraction of HIV cases in late stage of infection (tertiary stage or full‐blown AIDS) (dashed line). (B) Percentage of women attending ANC who are HIV+ (dashed line) and percentage of all women HIV+ (solid line), assuming that the probability of being included in the ANC sample depends on sexual activity group.