Page 104 - Journal of Special Operations Medicine - Spring 2014

An Ongoing Series

Salmonella Infections Including Typhoid Disease

Mark W. Burnett, MD

ABSTRACT
It is estimated that more than 20 million cases of Sal- been banned by the U.S. Food and Drug Administration
monella enterica serotype Typhi and 6 million cases of since 1975 in an attempt to curtail nontyphoidal Salmo-
paratyphoid disease occur worldwide annually, with ty- nella infection among pet owners.
phoid disease alone causing more than 200,000 deaths.
The clinical manifestations, diagnosis, treatment, and The clinical manifestations of nontyphoidal Salmonella
vaccination guidelines are discussed. infections can run from asymptomatic disease to blood-
stream infections that can lead to osteomyelitis, menin-
Keywords: Salmonella, typhoid disease, vaccination gitis, and brain abscesses. More commonly, these types
of infections cause fever, abdominal cramping, and
gastroenteritis.
Background
The enteric fevers—Salmonella serotypes Typhi, para-
Salmonella are gram-negative bacilli that can cause a typhi A, B, and C—are all transmitted from human to
wide-range of illness in humans. Although likely a disease human through fecal-oral ingestion, primarily through
of antiquity, it was not until 1829 that the French Physi- ingestion of contaminated food or water from some-
cian Pierre Louis coined “typhoid” to describe an illness one who has been acutely infected. Salmonella serotype
that he thought was “like typhus.” Although Salmonella Typhi can also be spread from asymptomatic carri-
enterica serotype Typhi, or “typhoid fever,” is only one of ers, the final result of a minority of acute infections. A
more than 2500 Salmonella serotypes that have been iso- well-known historical example of the chronic carrier
lated, it has likely been an infection of military relevance was that of Mary Mallon, given the nickname of “Ty-
and importance for centuries. Typhoid infections cause phoid Mary,” a housekeeper and cook who spread ty-
widespread disease in the Developing World and their im- phoid bacilli and infected dozens in New York City in
portance should be understood by the Special Operations the early 1900s. The clinical aspect of typhoid disease
medical provider. is highlighted by fever, abdominal tenderness, anorexia,
constipation, headache, and lethargy. Physical examina-
tion findings can include “rose spots” (Figure 1) across
Clinical
the lower chest and upper abdomen, which are caused
Nontyphoidal Salmonella infections can be transmit- by bacterial emboli to the skin. Untreated, fever at tem-
ted to humans from consuming improperly prepared peratures to 103°–104°C can persist for months, and
or stored food from animals—poultry and their eggs the disease carries a 20% mortality rate. Paratyphoid
and unpasteurized dairy products are common culprits. disease symptoms are generally less severe, and the dis-
Widespread outbreaks have occurred during this century ease carries a negligible mortality rate.
in the United States, spread from food-processing plants
in products as diverse as farm-grown produce, to peanut
butter and chicken pot pies. Water, especially that con- Diagnosis
taminated by feces from infected reptiles, or even han- The diagnosis of Salmonella can be made by cultures
dling reptiles themselves can cause disease. Baby turtles of stool, urine, and blood and by rose spots, if pres-
have been shown to be Salmonella “super-spreaders,” ent. None of these cultures is close to 100% sensitive;
such that the sale of turtles less than 4 inches in size has multiple cultures will improve the chances of a positive

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