SheldonAround 50 percent of the men have human papillomavirus (HPV) which often goes undetected and is easily passed on during unprotected sex。
Of the group, around six percent of men yearly contract a new HPV 16 infection, the virus most well known for causing cervical cancer in women and also causing cancers in men。
While the majority of the nearly 200 known types of HPV cause no symptoms in most people, some cause warts while others lead to cancers of the genitals and throat。
The study further reinforces calls for a male HPV vaccination program to be rolled out worldwide to nip the infection in the bud。
Professor Anna Giuliano of the H Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, found 32,000 cases of cancers in men and women in the USA in 2009 were attributable to HPV infection。
It also found anogenital warts were the most common result of HPV, with 205 cases per 100,000 diagnosed every year in the USA。
In addition to the diseases HPV causes directly in men, the virus is readily transmitted from men to women putting them at greater risk。
The study found men who had more than one lover were more prone to catching the virus。
The chances of cancer-causing (oncogenic) HPV infection was 2.4 times higher from men who had had 50 or more female partners compared with no partners or just one partner and 2.6 times higher for men who had at least three male anal sex partners compared with no recent partners。
The average duration of HPV infection was seven and a half months for any HPV and 12 months for the cancer-causing HPV type 16.
HPV also causes 80 percent of cervical cancer cases. The findings are published online in the Journal Lancet。
约50%的男性都感染有乳头瘤病毒(HPV)，该病毒往往被男性忽视，性行为时若未采取保护措施很容易传染给他人。
其中感染了该病毒的约6%的男性每年会感染HPV16这种变异病毒品种。HPV16会引发女性子宫癌，也会在男性身上造成一系列癌症病变。
HPV有约莫200种变体，其中大部分都不会对大众产生危害，然而其中一些会造成病毒疣，有的甚至引发阴茎癌和咽喉癌。
这项研究进一步呼吁在全世界范围内对男性注射HPV疫苗的卫生项目，防止感染扩大严重化。
位于佛罗里达坦帕的H?李?墨菲特癌症中心和研究机构成员安娜?朱利亚诺发现2009年全美约有三万二千多癌症病例是由HPV感染导致的。
该研究还发现肛门-生殖器疣也主要是由HPV造成的，在美国一万例确诊中就有205例是因感染了该病毒。
HPV除了能直接造成男性疾病外，还能通过性行为传播给女性，使其致病几率加大。
该研究还发现性伴侣超过一人的感染该病毒的几率更大。
女伴累计超过50人的男性感染致癌HPV的几率是没有女伴或只有一名女伴的2.4倍，而至少拥有三名男性性伴侣的男性比没有男伴的男性高2.6倍。
一般HPV感染平均持续时间为7.5个月，而致癌的HPV16则长达12个月
80%的子宫癌是由HPV引发的。这些研究结果发表在医学期刊《柳叶刀》上。
