In paratyphoid fever (synonyms: Gastroenteritis paratyphosa; infection by Salmonella hirschfeldii; infection by Salmonella paratyphi; infection by Salmonella paratyphi A; infection by Salmonella paratyphi B; infection by Salmonella paratyphi C; infection by Salmonella schottmuelleri; paratyphus abdominalis; ICD-10 A01. 1-A01.4) is an infectious disease caused by the serovars Paratyphi A, B and C of the bacterium Salmonella enterica from the family Enterobacteriaceae.
According to the causative agent, typhoid fever can be classified as follows according to ICD-10:
- Paratyphoid A (A01.1)
- Paratyphoid B (A01.2) – two different pathovars.
- Paratyphoid C (A01.3)
- Paratyphoid fever, unspecified (A01.4)
Salmonella enterica paratyphi is a Gram-negative flagellated bacterium that is facultatively anaerobic.
Occurrence: Serovar paratyphi B is distributed worldwide. Serovars Paratyphi A and C are mainly found in warmer countries. Serotype A is often imported from Asia and serotype B from Turkey.
Humans are currently the only relevant reservoir of the pathogen.
The main source of infection is humans, who excrete the pathogen in their stool. Transmission of the pathogen (route of infection) is oral (by mouth) through contaminated food and drinking water. Direct fecal-oral (infections in which pathogens excreted in the stool (fecal) are absorbed through the mouth (oral)) transmission is also possible.
The incubation period (time from infection to onset of disease) is usually 1-10 days.
Duration of illness is usually 4-10 days.
Sex ratio: boys/men are more frequently affected than girls/women.
The incidence (frequency of new cases) is approximately 0.1 cases per 100,000 population per year.
The duration of infectiousness (contagiousness) ranges from the first week after the onset of the disease to several weeks after the end of symptoms. Up to 5% of those affected can become lifelong excretors. The disease leaves a temporary immunity (for about one year).
Course and prognosis: The clinical picture is similar to that of typhoid abdominalis, but is usually milder. Recurrences (relapses) or complications are rare. The prognosis is good.
In Germany, even the suspicion of a paratyphoid infection must be reported in accordance with the Infection Protection Act (IfSG). Persons suspected of having paratyphoid fever are not allowed to work where they come into contact with food. Furthermore, they are not allowed to work in communal facilities.