Mother-to-child transmission of HIV in Australia and other high-income countries: Trends in perinatal exposure, demography and uptake of prevention strategies

Molecular epidemiology to aid virtual elimination of HIV transmission in Australia

The Global UNAIDS 95/95/95 targets aim to increase the percentage of persons who know their HIV status, receive antiretroviral therapy, and have achieved viral suppression. Achieving these targets requires efforts to improve the public health response to increase access to care for those living with HIV, identify those yet undiagnosed with HIV early, and increase access to prevention for those most at risk of HIV acquisition. HIV infections in Australia are among the lowest globally having recorded significant declines in new diagnoses in the last decade. However, the HIV epidemic has changed with an increasing proportion of newly diagnosed infections among those born outside Australia observed in the last five years. Thus, the current prevention efforts are not enough to achieve the UNAIDS targets and virtual elimination across all population groups. We believe both are possible by including molecular epidemiology in the public health response. Molecular epidemiology methods have been crucial in the field of HIV prevention, particularly in demonstrating the efficacy of treatment as prevention. Cluster detection using molecular epidemiology can provide opportunities for the real-time detection of new outbreaks before they grow, and cluster detection programs are now part of the public health response in the USA and Canada. Here, we review what molecular epidemiology has taught us about HIV evolution and spread. We summarize how we can use this knowledge to improve public health measures by presenting case studies from the USA and Canada. We discuss the successes and challenges of current public health programs in Australia, and how we could use cluster detection as an add-on to identify gaps in current prevention measures easier and respond quicker to growing clusters. Lastly, we raise important ethical and legal challenges that need to be addressed when HIV genotypic data is used in combination with personal data.

Timing of HIV diagnosis relative to pregnancy and postpartum HIV care continuum outcomes among Latin American women, 2000 to 2017

BACKGROUND

HIV incidence among women of reproductive age and vertical HIV transmission rates remain high in Latin America. We, therefore, quantified HIV care continuum barriers and outcomes among pregnant women living with HIV (WLWH) in Latin America.

METHODS

WLWH (aged ≥16 years) enrolling at Caribbean, Central and South America network for HIV epidemiology (CCASAnet) sites from 2000 to 2017 who had HIV diagnosis, pregnancy and delivery dates contributed. Logistic regression produced adjusted odds ratios (aOR) and 95% confidence intervals (CI) for retention in care (≥2 visits ≥3 months apart) and virological suppression (viral load <200 copies/mL) 12 months after pregnancy outcome. Cumulative incidences of loss to follow-up (LTFU) postpartum were estimated using Cox regression. Evidence of HIV status at pregnancy confirmation was the exposure. Covariates included pregnancy outcome (born alive vs. others); AIDS diagnosis prior to delivery; CD4, age, HIV-1 RNA and cART regimen at first delivery and CCASAnet country.

RESULTS

Among 579 WLWH, median postpartum follow-up was 4.34 years (IQR 1.91, 7.35); 459 (79%) were HIV-diagnosed before pregnancy confirmation, 445 (77%) retained in care and 259 (45%) virologically suppressed at 12 months of postpartum. Cumulative incidence of LTFU was 21% by 12 months and 40% by five years postpartum. Those HIV-diagnosed during pregnancy had lower odds of retention (aOR = 0.58, 95% CI: 0.35 to 0.97) and virological suppression (aOR = 0.50, 95% CI: 0.31 to 0.82) versus those HIV-diagnosed before.

CONCLUSION

HIV diagnosis during pregnancy was associated with poorer 12-month retention and virological suppression. Young women should be tested and linked to HIV care earlier to narrow these disparities.