translation.en: After an incubation period of, usually, 2–3 weeks, disease symptoms may appear but more frequently they do not.
translation.mt: Wara perjodu ta’ inkubazzjoni ta’ , ġeneralment, 2– 3 ġimgħat, is-sintomi tal-marda jistgħu jitfaċċaw i żd a ħafna drabi dawn ma jitfaċċawx.