Smallpox was a systemic disease, officially eradicated since 1979 (WHO), caused by infection with the Variola major virus, whose only reservoir was infected humans.
Listeriosis is a disease caused by Listeria monocytogenes. The disease primarily causes problems in pregnant women, newborns, and adults with a weakened immune system.
Dengue is a mosquito-borne viral disease widely spread in tropical and subtropical regions. It is transmitted by Aedes mosquitoes. Most of the clinical cases present a febrile illness, severe forms include hemorrhagic fevers and shock with fatalities.