Environmental Engineering Reference
In-Depth Information
For other, more severe infections such as
Listeria
, the degree of underreporting
was estimated to be much lower.
3
Hauschild and Bryan,
35
in an attempt to establish a better basis for estimating
the number of people affected, compared the number of cases initially reported
with either the number of cases identified by thorough epidemiologic investiga-
tions or the number estimated. They found that for 51 outbreaks of bacterial,
viral, and parasitic disease (excluding milk), the median ratio of estimated cases
to cases initially reported to the local health authority, or cases known at the
time an investigating team arrived on the scene, was 25 to 1. On this basis
and other data, the annual food- and waterborne disease cases for 1974 to 1975
were estimated to be 1,400,000 to 3,400,000 in the United States and 150,000 to
300,000 in Canada. The annual estimate for the United States for 1967 to 1976
was 1,100,000 to 2,600,000.
35
The authors acknowledge that the method used
to arrive at the estimates is open to criticism. However, it is believed that the
estimates come closer to reality than the present CDC reporting would indicate,
particularly to the nonprofessional. The estimates would also serve as a truer basis
for justifying regulatory and industry program expenditures for water- and food-
borne illness prevention, including research and quality control. The total number
of foodborne illnesses in the United States has been estimated at 5˜million, with
a total cost of $1 billion to $10 billion per year.
32
FOODBORNE DISEASE OUTBREAK SURVEILLANCE
Between 1938 and 1956, 4,647 foodborne outbreaks with 179,773 cases and 439
deaths were reported to the PHS CDC. In 1967, 273 outbreaks were reported,
with 22,171 cases and 15 deaths.
Another analysis of foodborne illnesses based on 1969 and 1970
CDC/Department of Health, Education, and Welfare (DHEW) information
reported 737 outbreaks with 52,011 cases. It was found that 33.0 percent of the
outbreaks occurred at restaurants, cafeterias, and delicatessens; 39.1 percent at
homes; 8.7 percent at schools; 5.2 percent at camps, churches, and picnics; and
14 percent at other places. However, 48 percent of the
cases
were at schools
and 28 percent at restaurants, cafeterias, and delicatessens.
36
Bryan, in a summary of foodborne diseases in the United States from 1969
to 1973, reported 1,665 outbreaks with 92,465 cases.
37
During this same period
it was found that food service establishments accounted for 35.2 percent of the
outbreaks; homes 16.5 percent; food-processing establishments 6.0 percent; and
unknown places 42.1 percent.
In 1982, 656 foodborne outbreaks with 19,380 cases and 24 deaths were
reported to the U.S. PHS CDC.
38
The most frequently isolated bacterial pathogens
were
Salmonella
,
Staphylococcus aureus, Clostridium perfringens, Campylobac-
ter jejuni, Clostridium botulinum
, hepatitis A virus, and Norwalk virus. The latter
two viruses accounted for 21 outbreaks and 5,325 cases. The most common
contributing factors were (1) improper holding temperature, (2) food from an
