Salmonellosis epidemiology and demographics

Overview
Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common in the United States. Salmonella has been known to cause illness for over 100 years. They were discovered by a American scientist named Salmon, for whom they are named.

Every year, approximately 40,000 cases of salmonellosis are reported in the United States. Because many milder cases are not diagnosed or reported, the actual number of infections may be thirty or more times greater. There are many different kinds of Salmonella bacteria. Salmonella serotype Typhimurium and Salmonella serotype Enteritidis are the most common in the United States.Salmonellosis is more common in the summer than winter.

Children are the most likely to get salmonellosis. The rate of diagnosed infections in children less than five years old is higher than the rate in all other persons. Young children, the elderly, and the immunocompromised are the most likely to have severe infections. It is estimated that approximately 400 persons die each year with acute salmonellosis.

How common is salmonellosis?
Every year, approximately 40,000 cases of salmonellosis are reported in the United States. Because many milder cases are not diagnosed or reported, the actual number of infections may be thirty or more times greater. Salmonellosis is more common in the summer than winter. Children are the most likely to get salmonellosis. Young children, the elderly, and the immunocompromised are the most likely to have severe infections. It is estimated that approximately 600 persons die each year with acute salmonellosis.

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.

Incidents of salmonellosis
In June 2006, the BBC reported that the Cadbury chocolate manufacturer withdrew a number of products when products contaminated with salmonella caused up to 56 cases of Salmonellosis. The problems had been traced to a leaking pipe at a Cadbury plant in Herefordshire in January 2006, though the announcement was not made until June.

The U.S. Government reported that 16.3% of all chickens were contaminated with salmonella in 2005, and in the late 1990s as many as 20% were contaminated. In the mid to late twentieth century, Salmonella enterica serovar Enteritidis was a common contaminant of eggs. This is much less common now with the advent of hygiene measures in egg production and the vaccination of laying hens to prevent salmonella colonization. Many different salmonella serovars also cause severe diseases in animals other than human beings.

In February 2007, the U.S. FDA issued a warning to consumers not to eat certain jars of Peter Pan peanut butter or Great Value peanut butter due to risk of contamination with 'Salmonella Tennessee'. 

In March 2007, around 150 people were diagnosed with salmonella-poisoning after eating tainted food at a governor's reception in Krasnoyarsk, Russia. Over 1,500 people attended the ball on March 1 and fell ill as a consequence of ingesting salmonella-tainted sandwiches.

In December 2007, about 150 people were sickened by salmonella-tainted chocolate cake produced by a major bakery chain in Singapore. 

Four-Inch Law
The Four-Inch Law refers to a regulation passed by the U.S. Food and Drug Administration in 1975 outlawing the sale of turtles with a carapace length of less than four inches. Exceptions are present for scientific and educational use, export, and private sale.

The law was enacted, according to the FDA, "because of the public health impact of turtle-associated salmonellosis". There had been reported cases of young children placing small turtles in their mouths, which led to the size-based restriction.

Resources
CDC Salmonellosis