Missed opportunities for HIV diagnosis in Mexico City: unveiling the sex gap.

Background: Women in Mexico are not considered a key population for acquiring HIV and are often not perceived at risk by themselves or their physicians. This limited risk perception can delay testing and contribute to advanced HIV disease. We aimed to determine the frequency of missed opportunities for HIV diagnosis (MOHD) in a tertiary center in Mexico City and compare characteristics between men and women. Methods: We conducted a retrospective observational study using standardized questionnaires administered to adults newly enrolled in care at a tertiary HIV Clinic between 2013 and 2023. MOHD was defined as a healthcare encounter for HIV related symptoms in which diagnosis was not made within 30 days and or the patient attended at least two medical consultations before diagnosis. We described sociodemographic characteristics, the proportion of MOHD, and advanced HIV defined as baseline CD4 < 200 cells or an AIDS defining condition. Comparisons were made by sex, proportions were stratified by age group, and logistic regression identified factors associated with MOHD. Results: Of 1,332 questionnaires, 619 individuals reported symptoms and sought medical care before diagnosis; 320 (51.6 percent) met MOHD criteria, including 39 women and 281 men. MOHD was more frequent in women than men (67.2 percent vs. 50.1 percent, Conclusions: In this cohort, missed opportunities for HIV diagnosis were common and occurred more frequently among women than men. Women experienced longer delays to diagnosis and higher rates of advanced disease. These findings highlight persistent gaps in timely HIV diagnosis among women.