Salmonella spp.

Gram-negative, rod-shaped bacilli, more than 2000 strains of Salmonella can cause illness, some strains are more severe than others.

Incubation period

Varies, anywhere from 6 hours to 3 days. Salmonella typhi or S. paratyphi (infection known as typhoid fever) causes symptoms 7-28 days after infection

Symptoms

Include diarrhea, fever, abdominal cramps, and vomiting. S. typhi and S. paratyphi produce typhoid fever with headache, constipation, malaise, chills, and myalgia; with diarrhea uncommon and vomiting not usually severe.

Illness duration

When illness is self-limiting persons usually recover in 4-7 days.

Complications

Reactive arthritis and Reiter's syndrome can occur in patients after acute phase of illness. Other complications are aortic aneurysm within 3 months after infection, ulcerative colitis within one year after infection.

Infective dose

As few as 15-20 cells, much depends on the health or immune functioning of person infected.

Treatments

Supportive care, antibiotics needed when a risk of extra-intestinal spread. Rehydration important; maybe with IV fluids depending on severity. Some strains are antibiotic resistant.

Testing

Stool cultures to identify strain.

Communicability

Communicable throughout course of infection; several days to several weeks; sometimes months; antibiotics can prolong; 1% of infected adults and 5% of infected children excrete organism for over 1 year; some individuals are chronic carriers, may persist for years.

Nationally Notifiable

Salmonellosis is a nationally notifiable disease, physicians and labs should report cases to their local and/ or state health department and possibly the Center's for Disease Control (CDC).