Genetic diversity of HIV-1 in western Kenya: subtype-specific differences in mother-to-child transmission.

Abstract

BACKGROUND:

Little is known about the impact of HIV-1 group M subtypes on mother-to-child transmission (MTCT) of HIV-1 in African settings where multiple HIV-1 group M subtypes are co-circulating.

OBJECTIVE:

To assess the role of subtype variation on MTCT.

METHODS:

HIV-1-infected women attending an antenatal clinic in western Kenya were enrolled for a prospective study (1996-2000) of MTCT. HIV-1 subtype analysis of p24gag and gp41env identified potential recombinants, and their role in MTCT was determined.

RESULTS:

Among 414 women for whom HIV-1 subtype and HIV transmission status were available, MTCT occurred in 80 (19.3%). MTCT rates were higher among women with subtype D compared with subtype A in either the gp41 region [31.6 versus 16.1%, relative risk (RR) 2.0, P=0.002] or p24 region (29.9 versus 18.0%, RR 1.7, P=0.02). Discordant subtype combinations were identified in 103 of the women (25.9%), and were associated with higher rates of MTCT (28.2 versus 17.0%, RR 1.7, P=0.01). In multivariate analysis, women with subtype combinations D/D, D/A, and A/D had an increased risk of MTCT (adjusted odds ratios 3.5, 2.5, 6.2; P=0.005, 0.05, and 0.0003, respectively) compared with A/A women after adjustment for maternal HIV viral load, placental malaria infection, episiotomy or perineal tear, and low birthweight.

CONCLUSION:

MTCT appears to be more common among mothers infected with subtype D compared with subtype A. Such differences in MTCT frequency may be caused by altered cellular tropism for placental cell types.

• Authors: Chunfu Yang, Ming Li, Robert D Newman, Ya-Ping Shi, John Ayisi, Anna M van Eijk, Juliana Otieno, Ambrose O Misore, Richard W Steketee, Bernard L Nahlen, Renu B Lal
• Journal: AIDS (London, England) (AIDS) Vol. 17 Issue 11 Pg. 1667-74 (Jul 25 2003) ISSN: 0269-9370 [Print] England
• PMID: 12853749 (Publication Type: Journal Article)

Chemical References

• HIV Core Protein p24
• HIV Envelope Protein gp41
• RNA, Viral

Topics

• Female
• HIV Core Protein p24 (genetics)
• HIV Envelope Protein gp41 (genetics)
• HIV Infections (transmission, virology)
• HIV-1 (classification, genetics)
• Humans
• Infectious Disease Transmission, Vertical
• Kenya
• Logistic Models
• Mutation
• Pregnancy
• Pregnancy Complications, Infectious (virology)
• Prospective Studies
• RNA, Viral (analysis)
• Risk Factors
• Viral Load