Environmental Engineering Reference
In-Depth Information
unsafe source, (3) inadequate cooking, (4) poor personal hygiene on the part of
foodhandlers, and (5) contaminated equipment.
An analysis of 1,586 foodborne outbreaks reported to the CDC from 1977
through 1984 most frequently implicated fish and shellfish in 24.8 percent of the
outbreaks; beef and pork in 23.2 percent; turkeys and chickens in 9.8 percent;
potato, chicken, and other salads in 8.8 percent; and other foods in 5 percent.
39
In the most recent summary of foodborne outbreak surveillance in the United
States, a total of 6,647 outbreaks were reported during 1998 to 2002, causing
128,370 persons to become ill.
40
Atlhough this was in increase in the number
of outbreaks compared to previous summaries, enhanced surveillance was likely
responsible for much of the increase. Bacterial pathogens caused 55 percent of
both outbreaks and cases, with
Salmonella
serotype Enteritidis accounting for
the largest number of outbreaks and outbreak-related cases. During this same
time period, infection with
Listeria monocytogenes
caused the most deaths. Viral
pathogens caused 33 percent of outbreaks and 41 percent of cases, and the propor-
tion of outbreaks attributed to viruses increased 26 percent from 1998 to 2002.
40
The factors most commonly associated with these outbreaks were described as
follows:
The most commonly reported contamination factor that contributed to FBDOs food-
borne disease outbreaks was “bare-handed contact by handler/worker/preparer.” For
outbreaks caused by bacterial pathogens “raw product/ingredient contaminated by
pathogens from animal or environment” was the most commonly reported con-
tamination factor. The most commonly reported proliferation factor was “allowing
foods to remain at room or warm outdoor temperature for several hours”; the most
common survivability factor was “insufficient time and/or temperature during initial
cooking/heat processing
40
.”
Poultry
Campylobacter jejuni
is a common contaminant in poultry-processing plants and
is frequently found in conjunction with
Salmonella
. Contaminated chicken has
been found to be the source or vehicle of over 50 percent of
C. jejuni
enteritis
cases.
41
Campylobacter
may also be also found in raw milk and contaminated
water.
Salmonella
outbreaks have been related to the use of raw or undercooked
eggs.
42
The incidence of
Salmonella enterica
infection and the number of out-
breaks has increased dramatically in the United States since the 1970s.
43
Shell
eggs are the major vehicle for
Salmonella enterica
infection in humans; eggs
are contaminated internally by transovarial transmission from the laying hen.
The FDA now recommends that all products containing eggs are fully cooked
or made with a pasteurized liquid egg product. Contaminated feed is believed to
cause animal infection leading to contamination of meat and poultry products.
Between 1963 and 1975, there were 651 reported outbreaks of salmonel-
losis, with 38,811 cases in the United States. Poultry, meat (beef, pork), and
eggs were the three most common vehicles. Eggs were not incriminated in
