英语翻译as of dec 31,2009,beijing have reported only 10799 cases

英语翻译
as of dec 31,2009,beijing have reported only 10799 cases of influenza A(H1N1) infection,indicate that 相当比例的influenza A(H1N1) infection cant confirmed by influenza surveillance network lab,and 1 laboratory confirmed cases of influenza A(H1N1) infection actually represents 176 (90% 区间:153 204),because 一定比例的patients without any clinical symptoms,the part of symptoms patients have 流感样 symptoms,but not all of cases with 流感样symptoms sampling by doctor,therefore,the reported of influenza A(H1N1) cases cant reflect the epidemic all,it's only tip of the iceberg

参考一下吧,顺序来
第二行开头indicate改为indicating,现在分词作
伴随状语
相当比例的a large proportion of
cant confirmed改为can't be confirmed,是被动式
区间interval
一定比例 和相当比例差不多,也可以改为certain numbers of之类的,意译一下
patients without any clinical symptoms改为patients are without any clinical symptoms
后面一段应该是这样的(从你的意思推测,此处应断句了)
Some of the symptoms patients have are flu symptoms,but not all of the cases with flu symptoms are sampled by doctor.Therefore,the reported A(H1N1) cases can't fully reflect the intensity of the epidemic.They're only the tip of the iceberg .