Salmonelloses

Salmonelloses

Diseases caused by Salmonella. These include enteritis and septicemia with or without enteritis. Salmonella typhi, S. paratyphi A, B, and C, and occasionally S. cholerae suis cause particular types of septicemia called typhoid and paratyphoid fever, respectively; while all other types may cause enteritis or septicemia, or both together.

Typhoid fever has an incubation period of 5–14 days. It is typified by a slow onset with initial bronchitis, diarrhea or constipation, a characteristic fever pattern (increase for 1 week, plateau for 2 weeks, and decrease for 2–3 weeks), a slow pulse rate, development of rose spots, swelling of the spleen, and often an altered consciousness; complications include perforation of the bowel and osteomyelitis. Typhoid fever leaves the individual with a high degree of immunity. Vaccination with an oral vaccine gives an individual considerable protection for about 3 years. The only effective antibiotic is chloramphenicol. See Antibiotic, Immunity, Vaccination

Paratyphoid fever has a shorter course and is generally less severe than typhoid fever. Vaccination is an ineffective protective measure.

Enteric fevers, that is, septicemias due to types of Salmonella other than those previously mentioned, are more frequent in the United States than typhoid and paratyphoid fever but much less frequent than Salmonella enteritis. In children and in previously healthy adults, enteric fevers are most often combined with enteritis and have a favorable outlook. The organisms involved are the same as those causing Salmonella enteritis. Chloramphenicol or ampicillin are used in treatment. However, resistant strains have been observed. See Drug resistance

Inflammation of the small bowel due to Salmonella is one of the most important bacterial zoonoses. The most frequent agents are S. typhimurium, S. enteritidis, S. newport, S. heidelberg, S. infantis, and S. derby. The incubation period varies from 6 h to several days. Diarrhea and fever are the main symptoms; the intestinal epithelium is invaded, and early bacteremia is probable. Predisposed are persons with certain preexisting diseases (the same as for enteric fevers), very old and very young individuals, and postoperative patients. Antimicrobial treatment serves only to prolong the carrier state and has no effect on the disease.