We read with interest the report by Giulieri et al1 on professional exposures to patients with acute primary human immunodeficiency virus (HIV) infection (PHI) with high viral load and a positive P24 antigen test result but no detectable antibodies. The authors warned about the limits of the rapid HIV test, which does not include p24 antigen detection. We recently experienced these limits.
According to European and Swiss recommendations,2,3 24-hour rapid HIV testing (Determine HIV-1/2 Ac; Abbott Diagnostics, Abbott Park, Illinois) was available in emergency departments in hospitals of our network through routine onsite laboratories. A fourth-generation test, including antibodies and p24 antigen testing (AxSYM HIV, Ag/Ab Combo; Abbott Diagnostics), was then performed within 24 hours or, at the latest, on the following working day by a specialized central laboratory closed at night and during weekends.