Prevention of HTLV-I transmission through the breast milk by a freeze-thawing process.

Fifteen human breast milk samples obtained from mothers seropositive for human T-cell lymphotropic virus type-I (HTLV-I) antigen were kept frozen overnight at -20 degrees. Each milk sample was then co-cultivated with cord lymphocytes obtained from 15 anti-HTLV-I antibody-negative mothers. No HTLV-I antigen-positive cells were detected among the cord lymphocytes subjected to co-cultivation. These results suggest that thawing of frozen breast milk may prevent HTLV-I transmission from mother to child via breast milk.