title: Risk of HTLV-I infection in Japanese women who are last in birth order.
abstract: The percentage of last-born women among pregnant women who were seropositive for human T-lymphotropic virus type I (HTLV-I) significantly exceeded that among HTLV-I seronegative women (119/258 (46.1%): 89/251 (35.4%); P < 0.05). The findings suggest that last-born women are susceptible to HTLV-I infection. At least two possible interpretations of this birth-order effect are: (i) these last-born women were born to mothers who, on the average, were older than those of early-born women and, as a consequence, were more likely to have been seropositive and to have passed on HTLV-I to their daughters; (ii) husband-to-wife transmission of HTLV-I requires time to occur, so last-born women are more likely than early-born women to become infected.
authors.forename: M
authors.initials: M
authors.lastname: Umemoto
authors.forename: H
authors.initials: H
authors.lastname: Take
authors.forename: K
authors.initials: K
authors.lastname: Kusuhara
authors.forename: K
authors.initials: K
authors.lastname: Kuraya
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001722:Birth Order; D005260:Female; D015490:HTLV-I Infections / Q000097:blood / Q000453:epidemiology* / Q000635:transmission*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000097:blood / Q000382:microbiology; D012307:Risk Factors