Je was op zoek naar: 性是最普遍的感染途径 (Chinees (Vereenvoudigd) - Engels)

性是最普遍的感染途径。
the most common vector for infection is sex.

科威特情况显然是最普遍的一种情况，很方便当作一个范例。
the kuwaiti situation, being, obviously, the most common one, is a convenient one to use as an example.