Retrospective cohort study on HIV-1 intrafamilial transmission infector

Objective To study the transmission rate and influence factors of human immunodeficiency virus type 1 (HIV-1) among the family members with unknown infector.Methods An average 8 years retrospective follow-up was conducted among 487 persons in 117 families with HIV-1 infected members.Results Among 117 families,39 persons were infected with HIV-1,the intrafamilial transmission rate was 33.3%.The HIV-1 infection rate was 22.8% (49/215) for family members with transmission factors,and no family member without transmission factors was found to be infected by HIV.Both the spousal transmission and mother-to-child transmission (MTCT) resulted in higher intrafamilial transmission rate (47.8% 32/67 for familial transmission,40.9% 27/66 for MTCT,and 16.5% 19/115 for spousal transmission).Intrafamilial transmission rates of HIV by wife and husband carriers were 38.5% (37/96) and 9.5% (2/21),respectively.The intrafamilial transmission rate was higher in familes with younger wife infector and long time existense of spousal transmission risk factor.The MTCT was not influenced by the time of MTCT factor existence.Conclusion The intrafamilial transmission rate of HIV-1 was obtained for families with unrecognized infector.