HTLV-1 infection in japan, Hawaii, and California : the effect of immigration from endemic southwestern Japan

一些研究已经证明，在一到两代人内，非流行地区的移民中HTLV-1血清阳性率下降。我们假设性传播的减少是由于被低流行率的宿主人口同化。并对22名日裔美国人（JA）HTLV-1+女性（病例）和一组长崎的80名日本人（JN）HTLV-1+女性（对照）进行家族研究。JA女性比JN女性年龄大（中位年龄50 vs. 33）：JA女性从献血人群中招募，JN女性从产后护理诊所招募。JA妇女的文化程度高于JN妇女。JA女性的抗体滴度略高（中位数1/64 vs. 1/16），但调整年龄后差异不显著。截至本报告时，已通过PCR进行病毒载量分析，等待计算机分析。问卷调查数据显示，75（90%）的JN和20（90%）的JA妇女曾母乳喂养的母亲，两组有类似的母乳喂养的持续时间。JA妇女目前的性伴侣之间的HTLV-1血清阳性率没有差异（2/11，18%）与尼泊尔女性的伴侣相比（4/20，20%），两组一生中的男性性伴侣中位数均为2个。（p<0.05）更多的JN妇女比JA妇女报告说，他们的当前或以前的性伴侣来自流行区（九州、四国或冲绳）：31/32（97%）vs. 6/12（50%）。避孕套的使用率较高的JN妇女，27（33%）通常或总是使用避孕套与他们的当前的伴侣，相比之下，只有3（18%）的17 JA妇女与当前的伴侣。我们的结论是，移民相关的HTLV-1血清阳性率下降可能是由于减少性接触的移民妇女从HTLV-1流行区的男子。地方病妇女和移民妇女的母乳喂养暴露情况相似。

Several studies have documented declining HTLV-1 seroprevalence among immigrants to non-endemic areas within one or two generations. we hypothesized a decrease in sexual transmission due to assimilation into the low-prevalence host population. and performed family studies of 22 Japanese-American (JA) HTLV-1+ women (cases) to a group of 80 Japanese (JN) HTLV-1+ women in Nagasaki (controls). The JA women were older than the JN women (median age 50 vs. 33) : JA women were enrolled from blood donor population, and JN women from postnatal care clinic. Educational level of JA women was higher than that of JN women. Antibody titers were slightly higher in the JA women (median 1/64 vs. 1/16), but the difference was not significant after adjustment for age. By the time of this report, the viral load analysis by PCR was done, waiting for computer analysis. Questionnaire data revealed that 75 (90%) of JN nad 20 (90%) of JA women had been breast-fed by their mothers, and both groups had similar duration of breast-feeding. There was no difference in HTLV-1 seroprevalence among current sexual partners of the JA women (2/11,18%) compared to partners of JN women (4/20,20%), Both groups had a median of 2 lifetime male sexual partners.Significantly (p<.05) more JN women than JA women reported that their current of previous sexual partner was from an endemic area (Kyushu, Shikoku or Okinawa) : 31/32 (97%) vs. 6/12 (50%). Condom usage was higher in the JN women, with 27 (33%) using a condom usually or always with their current partner, comared to only 3 (18%) of the 17 JA women with a current parther. We conclude that the immigration-related decline in HTLV-1 seroprevalence may be due to reduced sexual exposure of immigrant women to men from HTLV-1 endemic areas. Breast-feeding exposure was similar in endemic and immigrant women.