Clinical utility of HIV standard genotyping among antiretroviral-naive individuals with unknown duration of infection.

In clinical settings, we have found a high rate of human immunodeficiency virus (HIV) drug resistance among antiretroviral-naive patients for whom the duration of infection was unknown. These high rates were most likely the result of both transmitted resistance and informal antiretroviral use, and they suggest that routine resistance testing among antiretroviral-naive patients would be a cost-effective clinical practice.