The Impact of GB Virus C co-infection on Mother to Child transmission of Human Immunodeficiency Virus

GB virus C (GBV-C) is a common, apathogenic virus that can inhibit human immunodeficiency virus (HIV) replication in vitro. Persistent coinfection with GBV-C has been associated with improved survival among HIV-infected adults while loss of GBV-C viremia has been associated with poor survival. If GBV-C does inhibit HIV replication, it is possible that GBV-C infection may reduce mother-to-child-transmission (MTCT) of HIV. This study investigated whether maternal or infant GBV-C infection was associated with reduced MTCT of HIV infection. The study population consisted of 1,783 pregnant women from three Bangkok perinatal HIV transmission studies (1992-94, 1996-7, 1999-2004). We tested plasma collected at delivery for GBV-C RNA, GBV-C antibody, and GBV-C viral genotype. If maternal GBV-C RNA was detected, the four- or six-month infant specimen was tested for GBV-C RNA. Rates of MTCT of HIV in GBV-C-infected and GBV-C-uninfected women and infants were compared using multiple logistic regression as were associations with MTCT of GBV-C and prevalence of GBV-C infection. The prevalence of GBV-C infection (i.e. presence of RNA or antibody) was 33% among HIV-infected women and 15% among HIV-uninfected women. Forty-one percent of GBV-C-RNA-positive women transmitted GBV-C to their infants. Only two of 101 (2.0%) GBV-C-RNA-positive infants acquired HIV infection compared to 162 (13.2%) of 1,232 of GBV-C-RNA-negative infants (RR 0.15, p<0.0001). This association remained after adjustment for maternal HIV viral load, antiretroviral prophylaxis, CD4+ count and other covariates. MTCT of HIV was not associated with presence of maternal GBV-C RNA or maternal GBV-C antibody. Maternal receipt of antiretroviral therapy was associated with increased MTCT of GBV-C, as was high GBV-C viral load, vaginal delivery and absence of infant HIV infection. GBV-C infection among women was independently associated with more than one lifetime sexual partner, intravenous drug use and HIV-infection. We observed a higher prevalence of GBV-C infection among HIV-infected compared to HIV-uninfected pregnant women in Thailand, likely due to common risk factors. Antiretroviral therapy appears to increase MTCT of GBV-C. Infant GBV-C acquisition, but not maternal GBV-C infection, was significantly associated with reduced MTCT of HIV. Mechanisms for these later two associations are unknown.

Department dc:contributor.department

Dalla Lana School of Public Health

Year dc:date.issued

2010

Author dc:creator

• Supapol, Wendy C. Bhanich

Advisors dc:contributor.advisor

• Remis, Robert S.
• Millson, Margaret

• HIV
• GBV-C
• vertical transmission
• mother-to-child
• Thailand
• perinatal

Language dc:language.iso

en_ca

Handle dc:identifier.uri

http://hdl.handle.net/1807/19258

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/19258