▁and ▁the ▁question ▁began ▁to ▁be ▁research ed ▁again . ▁ ▁Several ▁studies ▁have ▁been ▁carried ▁out ▁to ▁determine ▁whether ▁B L V ▁causes ▁disease ▁in ▁humans , ▁testing ▁mostly ▁farm ▁workers ▁who ▁drink ▁raw ▁milk ▁from ▁inf ected ▁c ows . ▁Some ▁long ▁term ▁studies ▁may ▁be ▁necessary , ▁as ▁there ▁appears ▁to ▁be ▁a ▁correlation ▁in ▁instances ▁of ▁cancer ▁among ▁but ch ers ▁and ▁sla ugh ter house ▁workers . ▁In ▁ 2 0 1 4 , ▁research ers ▁discovered ▁the ▁presence ▁of ▁B L V ▁positive ▁cells ▁in ▁the ▁human ▁breast ▁t issue ▁in ▁a ▁sample ▁of ▁US ▁women , ▁and ▁a ▁case - control ▁study ▁published ▁in ▁ 2 0 1 5 ▁suggested ▁that ▁expos ure ▁to ▁B L V ▁is ▁associated ▁with ▁breast ▁cancer , ▁also ▁in ▁US ▁women . ▁ ▁A ▁later ▁study ▁of ▁Australian ▁women ▁detected ▁retro trans cribed ▁B L V ▁DNA ▁in ▁breast ▁t issue ▁of ▁ 4 0 / 5 0 ( 8 0 %) ▁of ▁women ▁with ▁breast ▁cancer ▁versus ▁ 1 9 / 4 6 ( 4 1 %) ▁of ▁women ▁with ▁no ▁history ▁of ▁breast ▁cancer , ▁indicating ▁an ▁age - ad just ed ▁odd s ▁ratio ▁and ▁confidence ▁interval ▁of ▁ 4 . 7 2 ( 1 . 7 1 - 1 3 . 0 5 ). ▁These ▁results ▁cor ro bor ate ▁the ▁find ings ▁of ▁the ▁previous ▁study ▁of ▁US ▁women ▁with ▁an ▁even ▁higher ▁odd s ▁ratio ▁for ▁the ▁Australian ▁population . ▁Most ▁recently ▁a ▁case