Acute HIV infection at travel clinics

Abstract

I read with interest the observational cross-sectional study based on the GeoSentinel surveillance database by Alberto Matteelli and colleagues, showing a low but worrying burden of sexually transmitted infections (STIs) and high proportions of acute HIV infection in travellers seen after or during travel and in immigrant travellers. However, I think that the defi nitions of reported STIs and acute HIV infection are not fully described, which might substantially aff ect these estimates. Most STIs are usually diagnosed on the basis of laboratory testing. Although the authors mention that the case defi nitions of STIs were based on microbiological criteria and clinical judgment, the microbiological criteria, particularly those for acute HIV infection, are not clear. Acute HIV infection, also known as primary HIV infection or acute retroviral syndrome, can be defined as the period (usually a few weeks) between acquisition of HIV and the appearance of detectable anti-HIV antibodies. It can be diagnosed only by showing the presence of p24 antigen or HIV viral RNA. Available point-of-care tests do not reliably detect acute HIV infection. Acute HIV infection often manifests as transient symptoms related to high concentrations of HIV viral replication and the subsequent immune response, but these symptoms (eg, fever, rash, malaise, sore throat) usually mimic other, more prevalent conditions, such as infl uenza, resulting in misdiagnoses. Fever, which Matteelli and colleagues mention, has sensitivity of only 80–88% and specifi city of only 50–56% in the diagnosis of acute HIV infection. Because I don’t know the diagnostic criteria used by the authors for acute HIV infection, it is impossible to comment on underestimation or overestimation of the infection in the study. However, the prevalence in the study population—acute HIV infection was diagnosed in 117 (0·18%) of 64 335 patients seen after travel, nine (0·02%) of 38 287 patients seen during travel, and 25 (0·26%) of 9558 immigrant patients—seems higher than that in patients attending STI clinics in Baltimore, USA (0·02%) or Guangxi, China (0·04%). Patients with acute HIV infection have high viral loads and are maximally contagious, and thus their identifi cation could provide opportunities for behavioural and biomedical interventions, including condom use, early referral, potential treatment, and partner notifi cation to limit further transmission during this period. The high prevalence of acute HIV infection in patients at travel clinics might have important implications for the role of such clinics as frontiers for HIV interventions. However, such conclusions should be made only after further clarifi cation of Matteelli and colleagues’ fi ndings.