Usages of no
B: This one is yours.
Note: the subject marker が is more appropriate than は in this context. The subject of the sentence is たくさんのユダヤ人 (many Jewish people), and in this case, が is typically used because it is introducing new, non-contrastive information.
Using 持って いる suggests that the condition or disease is chronic, whereas かかって いる is neutral with respect to duration.
Note how this sentence shows how the word 事 is the origin of the verb nominalizer 〜こと.