英语语法分析

That deals with both symptoms and infectivity.

这种方式既要对付症状也要顾及传染性。

The infectivity is quantified by counting the number of infective centers such as plaques pocks and foci.

应用计算感染点数目来确定其传染性，如蚀斑，痘疱及病杜数。

Luban says it's unclear whether this increased infectivity helped drive the outbreak to epidemic proportions.

鲁邦表示，尚不清楚这种增加的传染性是否会导致传染比例暴增。