Comparison of sampling methods to measure HIV RNA viral load in female genital tract secretions

Abstract

Problem: How does menstrual cup (MC) compare to other genital sampling methods for HIV RNA recovery?

Method of study: We compared HIV RNA levels between MC, endocervical swab (ECS), and ECS-enriched cervicovaginal lavage (eCVL) specimens in 51 HIV-positive, antiretroviral therapy-naive women at enrollment, 3 and 6 months, with order rotated by visit. Paired comparisons were analyzed with McNemar's exact tests, signed-rank tests, and an extension of Somer's D for pooled analyses across visits.

Results: MC specimens had the highest proportion of quantifiable HIV VL at enrollment and month 3, but more MC specimens (n=12.8%) were insufficient for testing, compared with ECS (2%, P=0.006) and eCVL (0%, P<0.001). Among sufficient specimens, median VL was significantly higher for MC (2.62 log₁₀ copies/mL) compared to ECS (1.30 log₁₀ copies/mL, P<0.001) and eCVL (1.60 log₁₀ copies/mL, P<0.001) across visits.

Conclusion: MC may be more sensitive than eCVL and CVS, provided insufficient specimens are reduced.

Keywords: cervicovaginal lavage; endocervical swab; female genital tract sampling; genital HIV viral load; menstrual cup.