There is no transitive disease, no ill omen, no ghoul. Note: The majority of scholars interpret this to mean that these things in and of themselves do not transmit or cause harm through supernatural or hidden means but that Allah is ultimately in control and any fearful superstition around these is false. (Using translation from Muslim 2222a)
قَالَ رَسُولُ اللهِ ﷺ لَا عَدْوَى وَلَا طِيَرَةَوَلَا غُولَ