Routine screening

Prevalence of BBV: geographic distribution

The risk of introducing infection into the laboratory can be minimized by screening patients for infectious agents where indicated by medical history and physical examination. The risk of infectious agent transmission in ART procedures varies in different populations and geographical regions; a risk assessment should be carried out according to the prevalence of disease in the specific patient population, bearing in mind the possibility of ‘silent’ infection prior to detectable seroconversion. Figures 15.1–15.4 illustrate the current geographic distribution for infections due to HIV/AIDS, HBV and HCV.

National and international guidelines in many countries now recommend that patients presenting for ART procedures should undergo routine testing for Hepatitis B and C annually; screening for HIV-1 and HIV-2 should be carried out within 3–6 months of starting treatment to allow for the lag time to seroconversion. Human T-cell lymphotrophic virus (HTLV-I and HTLV-II) has a low prevalence in Western countries, with HTLV-I principally endemic in Japan, Central Africa, the Caribbean and Malaysia, and HTLV-II prevalent in Central America and the southern USA. Screening for these viruses prior to blood or organ donation is now mandatory in some countries; guidelines for HTLV-I and HTLV-II patient screening prior to ART procedures should be adapted to local regulations and epidemiology. Routine screening for genital infections, i.e.