Seroprevalence of HTLV-1/2 infection among native and immigrant pregnant women in Spain

HTLV-1=2 antenatal screening is not mandatory in European countries. The rapid increase in immigrants coming from areas endemic for HTLV-1 infection has compelled a review of this policy in Spain. From February 2006 to December 2007, a cross-sectional study was carried out in all pregnant women attended at 10 different Spanish hospitals. An enzyme immunoassay (EIA) was used to test serum HTLV-1=2 antibodies; reactive samples were further confirmed by Western blot and=or polymerase chain reaction. A total of 20,518 pregnant women were examined, of whom 18,266 (89%) were native Spaniards. Overall, 946 (4.6%) of the immigrants came from HTLV-1 endemic areas (mainly Central and South America and sub-Saharan Africa). Four samples were EIA seroreactive for HTLV-1=2, two of them in women infected with HTLV-1 coming from endemic areas. The other two women were infected with HTLV-2; one was an immigrant from Bolivia and another was a native Spaniard who admitted prior injection drug use and was HIV-1 positive. The overall HTLV-1=2 seroprevalence was 0.19 per 1000 (95% CI: 0.05-0.49=1000). For HTLV-1, the seroprevalence was 2.11 per 1000 (95% CI: 0.26-7.62=1000) in pregnant women from endemic areas. The seroprevalence of HTLV-1=2 infection is below 0.02% among pregnant women in Spain, and therefore universal screening for HTLV-1=2 infection in antenatal clinics is not warranted. However, HTLV-1=2 screening could be considered in pregnant women coming from endemic areas, in whom the rate of infection is nearly 1000-fold higher than in native Spaniards and are the only group infected with the more pathogenic HTLV-1.