Typhoid fever is caused by a systemic infection with Salmonella enterica subspecies enterica serovar Typhi (Salmonella Typhi). Paratyphoid fever, caused by infection with Salmonella enterica serovar Paratyphi A or B, is similar to typhoid fever. 5 The 2 diseases are often indistinguishable.
https://immunisationhandbook.health.gov.au/vaccine-preventable-diseases/typhoid-fever