there are three serovars of the species of S. enterica that cause paratyphoid: S. Paratyphi A, S. Paratyphi B (S. schottmuelleri and S. pullorum), and S. Paratyphi C (S. hirschfeldii).
they are transmitted by means of contaminated water or food via faecal-oral route
-
travellers should be vaccinated with typhoid vaccine which also protects against paratyphoid B.
owners of tropical fish should ensure scrupulous cleaning of aquariums to eliminate potential S. Paratyphi B organisms.
there are about 16 million cases a year, which result in about 25,000 deaths worldwide
unlike S. typhi, the reservoir for S. paratyphi may include domestic animals as well as humans.