| Clinical
Features |
Fever, abdominal cramps, and diarrhea
(sometimes bloody). Occasionally can establish localized infection
(e.g., septic arthritis) or progress to sepsis. |
| Etiologic
Agent |
Enterobacteriaceae of the genus
Salmonella, a gram-negative rod-shaped bacilli. Approximately
2000 serotypes cause human disease. |
| Incidence |
An estimated 1.4 million cases occur
annually in the United States; of these, approximately 30,000
are culture-confirmed cases reported to CDC. |
| Sequelae |
Estimated >500 fatal cases each
year; 2% of cases are complicated by chronic arthritis. |
| Transmission |
Contaminated food, water, or contact
with infected animals. |
| Risk
Groups |
Affects all age groups. Groups
at greatest risk for severe or complicated disease include
infants, the elderly, and persons with compromised immune
systems. |
| Surveillance |
National surveillance is conducted
through the public health laboratories for culture-confirmed
cases and through the National Notifiable Diseases Surveillance
System (NNDSS). Active laboratory- and population-based surveillance
is conducted in FoodNet sites. |
| Trends |
Half of salmonellosis cases are
caused by 2 serotypes: S. Enteritidis (SE) and S.
Typhimurium (ST). The proportion of salmonellosis caused by
SE increased markedly from 1980 to 1995, but has decreased
22% since 1996. The incidence of ST decreased 24% since 1996,
but an increasing proportion of isolates show resistance to
multiple antimicrobial agents. S. Newport has increased 32%
from 1996 to 2001 to become the third most frequent serotype,
with many isolates resistant to >9 antimicrobial drugs. |
| Challenges |
Identifying unrecognized major sources
of Salmonella infections. Assuring adequate supply
of serotyping reagents; controlling SE infections through
changes in the egg industry and education of food service
workers and consumers; and developing effective education
methods and materials to prevent reptile-associated salmonellosis. |
| Opportunities |
Improving detection of dispersed
outbreaks through use of statistical outbreak detection algorithms
and providing this capability to state health departments;
training state health department personnel in Salmonella
serotyping; and encouraging judicious use of antimicrobial
agents in veterinary medicine. |
|
December 2003
|
