High frequency of primary mutations associated with antiretroviral drug resistance in recently diagnosed HIV-infected children.

Introduction: The aim of our study was to analyse the frequency of primary mutations associated with HIV drug resistance in a population of children born to HIV-infected mothers.

Design: A prospective study included newly HIV-diagnosed children treated at two public paediatric hospitals.

Patients And Methods: Clinical and antiretroviral therapy (ART) data were collected in mother-child pairs. HIV-1 subtyping and ART resistance mutations were assayed in children by sequencing a region of HIV pol gene.

Results: A total of 67 children were enrolled: 22 less than 12 months of age, 20 between 1 and 5 years and 25 between 6 and 14 years. Six (9.0%) children had viral strains with at least one primary mutation associated with resistance to reverse transcriptase and protease inhibitors. A significantly (P = 0.019) higher frequency of resistance (22.7%, n = 5/22) was found among children aged < 12 months. Fourteen children (20.9%) had a subtype B HIV-1 strain and 53 (79.1%) had an inter-subtype B/F recombinant variant.

Discussion: A high percentage of recently diagnosed infants were found to carry primary ART resistance mutations. Limited options for ART of HIV-infected children might lead to increased HIV-associated morbidity and mortality. Thus, consideration should be given to mandatory screening for primary ART resistance before initiating therapy for infants aged < 12 months in countries where HIV mother-to-child transmission is still present, such as in Argentina. This will allow for the rationalized and individualized use of drugs and will contribute to the increased cost-effectiveness of local health systems.