Results of 1-year screening of donors in The Netherlands for human T-lymphotropic virus (HTLV) type I: significance of Western blot patterns for confirmation of HTLV infection

Transfusion. 1994 Oct;34(10):877-80. doi: 10.1046/j.1537-2995.1994.341095026973.x.


Background: Between January 1993 and January 1994, Dutch blood banks screened approximately 674,000 volunteer donors for the presence of antibodies to human T-lymphotropic virus type I (HTLV-I).

Study design and methods: Confirmatory testing was performed on samples from 870 different anti-HTLV-I-reactive donors (0.13% of the total tested).

Results: According to the authors' Western blot (WB) interpretation criteria, 15 (0.002%) donors tested HTLV-I-positive in the WB; 201 tested negative, and 654 (75% of donors reacting on enzyme-linked immunosorbent assay) tested indeterminate. Fresh samples from 234 of 870 anti-HTLV-reactive donors were tested for HTLV-I and type II (HTLV-II) DNA by polymerase chain reaction: all 15 WB-positive donors tested positive for HTLV-I DNA; 206 WB-indeterminate and 13 WB-negative donors tested negative for HTLV-I and -II DNA. Application of the manufacturer's (World Health Organization-based) guidelines for WB interpretation would have resulted in the misclassification of 48 (23%) of 206 polymerase chain reaction-negative donors as HTLV-I/II-positive. Risk factors were present in 14 of 15 HTLV-I-infected donors: 8 had a partner from an HTLV-I-endemic area, 4 were from HTLV-I-endemic countries, and 2 had received blood transfusions.

Conclusion: HTLV-I and -II infection is rare among Dutch blood donors. HTLV screening will prevent few cases of HTLV-related disease, but it will prevent a further spread of the virus by transfusion. In a low-risk population, conservative guidelines for WB interpretation unnecessarily generate an excess of false-positive results.

MeSH terms

  • Blood Donors*
  • Blotting, Western
  • DNA, Viral / blood
  • Deltaretrovirus Infections / blood*
  • Deltaretrovirus Infections / prevention & control*
  • HTLV-I Antibodies / blood
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 2 / genetics
  • Humans
  • Mass Screening
  • Netherlands
  • Polymerase Chain Reaction


  • DNA, Viral
  • HTLV-I Antibodies