اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْبَرَصِ وَالْجُنُونِ وَالْجُذَامِ وَمِنْ سَيِّئِ الْأَسْقَامِ
Transliteration
Allahumma inni a'udhu bika minal-barasi wal-jununi wal-judhami wa min sayyi'il-asqam
English meaning
O Allah, I seek refuge in You from leprosy, madness, elephantiasis, and evil diseases.
When is it recited?
Can be recited anytime, especially during times of epidemic.
Source
Abu Dawud, Witr 32, 1554