Genital colonization by Actinomyces israelii and serologic immune response to the bacterium after five years use of the same copper intra-uterine device. 
An increased risk of developing genital actinomycosis has been found with long-term use of IUDs.  In this study a group of women who had used their IUDs for 60 +/- 6 months was compared with a group having worn their IUDs for 36 +/- 6 months.  None of the women examined had symptoms of genital infection.  No significant differences could be found in colonization frequency of A. israelii on the IUDs or in humoral antibody response to the bacterium.