Genetic relatedness of human immunodeficiency virus-1 (HIV-1) strains in a 12-year-old daughter and her father in a household setting

Modalities of intra-familial transmission of HIV-1 are not always clear. Here we describe an uncommon case of HIV transmission in a family setting, analyzed using clinical, epidemiological and nucleic-acid-based methods, and assess risk factors for intrafamilial transmission of HIV-1 infection. All sequences from the father and the daughter were grouped in the same cluster with a 100 % bootstrap value, which means that the father and his daughter were infected with highly homologous CRF01_AE. The diversity of genetic clones between env and pol genes was insignificant (p > 0.05). Moreover, the results of analysis of drug-resistance-associated mutation positions of the two viral isolates were almost identical, indicating that both were susceptible to the first-line anti-HIV drugs prior to the initiation of antiretroviral treatment (ART), and this presented additional evidence of a high similarity between the two family members’ HIV-1 quasispecies. In this family, HIV-1 isolates from a father and his daughter had very highly genetic relatedness. By combining their clinical histories, we could draw the conclusion that the daughter was probably infected via contact with her father’s blood or other body fluids, but no obvious transmission route was found, suggesting that HIV-1 infection in similar household settings should be taken into consideration whenever the origin of HIV-1 infection cannot be identified.