Marriage patterns among HTLV-I seropositive women in Japan

A significantly higher percentage of asymptomatic HTLV-I seropositive pregnant women in the Kagoshima prefecture were married to men who were also born in that prefecture compared with seronegative women [138/166(83.1%), 221/306 (72.2%); P < 0.01]. A significantly higher percentage of the fathers of the seropositive women were born in the Kagoshima prefecture compared with the fathers of the seronegative women [152/166 (91.6%), 235/306 (76.8%); P < 0.01]. Additionally, a significantly higher seropositivity was found among pregnant women born in the Kagoshima prefecture who were married to men born in that prefecture compared with men born in other prefectures [5.8% (138/2374), 3.4% (28/819); P < 0.01]. Women born in other prefectures had a significantly lower seropositivity irrespective of the birthplace of their spouse [2.9% (12/418); P < 0.05, 3.0% (7/234)]. These findings indicate that HTLV-I seropositive women and their mothers chose their husbands from a smaller geographic region than seronegative women. This marriage pattern within an HTLV-I seropositive group may be one of the factors sustaining the present seroprevalence of HTLV-I.