Objective: We previously developed a multiassay algorithm (MAA) to identify recent HIV infection that includes the BED-capture enzyme immunoassay, an avidity assay based on the Genetic Systems HIV-1/HIV-2 + O enzyme immunoassay, CD4 cell count, and HIV viral load. We used this MAA to evaluate the association between recent maternal HIV infection and in-utero transmission of HIV.
Methods: Plasma samples were collected at delivery from 2561 HIV-infected women in the postexposure prophylaxis of infants-Malawi trial. The MAA described above was used to identify women with recent HIV infection. Logistic regression models assessed association between recent HIV infection and in-utero HIV transmission (defined as a positive infant HIV DNA test at birth).
Results: Seventy-three women were identified as recently infected using the MAA. Those women were younger and had lower parity than women who were identified as not recently infected using the MAA (P < 0.0001 for age and parity). The frequency of in-utero HIV transmission was 17.8% among women identified as recently infected, compared with 6.7% among women identified as not recently infected (13/73 vs. 166/2488, P = 0.001). In a multivariate model, three factors were independently associated with in-utero HIV transmission: recent infection [adjusted odds ratio (AOR): 2.49, 95% confidence interval (CI): 1.30–4.78, P = 0.006], log10 HIV viral load at delivery (AOR: 2.01, 95% CI: 1.60–2.51, P < 0.0001), and younger age (per 10 year increase, AOR: 0.66, 95% CI: 0.43–0.93, P = 0.02).
Conclusion: Results obtained using a MAA suggest that recent maternal HIV acquisition is strongly associated with in-utero HIV transmission, independent of HIV viral load at delivery.
aDepartment of Epidemiology, Johns Hopkins University Bloomberg School of Public Health
bDepartment of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland
cDepartment of Statistics and Biostatistics and Institute for Health, Healthcare Policy and Aging Research, Rutgers University, Piscataway, New Jersey
dLaboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
eDepartment of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
fDepartment of Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
gDepartments of Global Health, Medicine, and Pediatrics, University of Washington, Seattle, Washington, USA
hInstitut National de la Santé et de la Recherche Médicale, INSERM U1018, CESP, Villejuif
iHôpital Ambroise-Paré, Assistance Publique- Hôpitaux de Paris, Boulogne
jUniversity of Versailles, Guyancourt, France
kClinical Sciences, Family Health International, Durham, North Carolina
lPediatric, Adolescent, and Maternal AIDS Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Rockville, Maryland
mEpidemiology Branch, Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA.
Correspondence to Susan H. Eshleman, MD, PhD, Professor, Department of Pathology, The Johns Hopkins University School of Medicine, Ross Bldg., Room 646, 720 Rutland Ave., Baltimore, MD 21205, USA. Tel: +1 410 614 4734; fax: +1 410 502 9244; e-mail: firstname.lastname@example.org
Received 25 February, 2011
Revised 21 April, 2011
Accepted 9 May, 2011