DURING April-May 1998, a total of 11 states reported an increase in
cases of Salmonella serotype Agona infections; as
of June 8, a total of 209 cases have been reported and at least 47 persons
have been hospitalized, representing an eightfold increase over the median
number of cases reported in those states during 1993-1997. The states reporting
increases were Illinois (49 cases), Indiana (30), Ohio (29), New York (24),
Missouri (22), Pennsylvania (20), Michigan (15), Iowa (eight), Wisconsin (six),
Kansas (four), and West Virginia (two). This report summarizes the outbreak
investigation by local, state, and federal public health officials, which
implicated Millville brand plain Toasted Oats cereal manufactured by Malt-O-Meal,
Inc. as the cause of illness.
Among 162 patients in this outbreak for whom information was available,
85 (52%) were female. Most cases occurred in children and the elderly (47%
in persons aged <10 years and 21% in persons aged >70 years). Most illnesses
began in May.
Officials in the 11 state health departments, in collaboration with
CDC, conducted a matched case-control study comparing persons with cases of S. Agona infection in April and May with well household
members (controls); conditional linear logistic regression was used to examine
the relation between consumption of cereal and illness. As of June 8, information
from 55 households has been analyzed; 46 (84%) of these 55 households shopped
at an Aldi supermarket. During the 3 days before onset of illness, 31 (66%)
of 47 patients and 32 (36%) of 89 household controls consumed Millville brand
plain Toasted Oats cereal purchased at an Aldi supermarket (matched odds ratio=22;
p=0.003). This association remained significant when controlled for age (p<0.05).
When average daily consumption of Millville brand plain Toasted Oats cereal
purchased from an Aldi supermarket was categorized into three groups (no consumption, ≤1
cup, and >1 cup), a significant dose response relation was found (p=0.003).
Culture of an open box of Millville brand plain Toasted Oats cereal
obtained from the home of a case-patient yielded Salmonella Agona at CDC. The pulsed-field gel electrophoresis (PFGE) pattern
of this isolate was indistinguishable from the predominant PFGE pattern among
outbreak-associated clinical isolates. The Food and Drug Administration (FDA)
isolated Salmonella Agona from two separate composite
samples from unopened boxes. Clinical isolates were susceptible to all antimicrobial
agents tested (i.e., ampicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin).
The Minnesota Department of Health, the Minnesota Department of Agriculture,
FDA, and CDC are collaborating in the investigation of the Malt-O-Meal, Inc.
plant that manufactured the implicated cereal to determine the source of contamination.
At this plant on the same production line, multiple brands of plain Toasted
Oats are manufactured at different times. Malt-O-Meal has issued a voluntary
recall of all plain Toasted Oats cereal produced on the same production line.
Investigation is ongoing to determine whether other plain Toasted Oats cereal
brands produced by the same company were contaminated. Cases of Salmonella Agona infection occurring during the same time have now
been reported in California (11), Washington (nine), New Jersey (five), Tennessee
(three), Oklahoma (three), Idaho (two), Maryland (two), Minnesota (two), Nebraska
(one), and Connecticut (one). These cases are being investigated to determine
possible links to this outbreak. CDC recommends that consumers not eat plain
Toasted Oats cereal produced by Malt-O-Meal until further investigation has
identified the scope, magnitude, and cause of the contamination. Questions
about plain Toasted Oats cereals manufactured by Malt-O-Meal should be directed
to the company, telephone (800) 590-1810.
State and local health depts. Office of Regulatory Affairs, and Center
for Food Safety and Applied Nutrition, Food and Drug Administration. Foodborne
and Diarrheal Diseases Br, Div of Bacterial and Mycotic Diseases, National
Center for Infectious Diseases, CDC.
Salmonella Agona is one of approximately 2000 Salmonella serotypes that can cause illness in humans.
An estimated 2-4 million cases of salmonellosis occur in the United States
each year, resulting in ≥500 deaths.1 Approximately 40,000 of
these infections are culture confirmed, serotyped, and reported to CDC by
state health departments.1Salmonella
infections usually resolve in 5-7 days and do not require antibiotic treatment.
Persons with severe diarrhea may require rehydration with intravenous fluids.
Antibiotics are required when infection spreads from the intestinal tract. Salmonella Agona is an uncommon serotype of Salmonella, accounting for approximately 1.5% of human isolates reported
to the Public Health Laboratory Information System (PHLIS).2 Like
most other Salmonella serotypes, Salmonella Agona is found in a variety of animal reservoirs including
poultry, cattle, pigs, and animal feed. The first reported U.S. outbreak of Salmonella Agona infections was traced to animal feed made
with contaminated imported fishmeal in 19723; other outbreaks have
been attributed to dried milk4 and to a commercial peanut-flavored
snack.5 This outbreak represents the first time a commercial cereal
product has been implicated in a Salmonella outbreak,
although an infant cereal product was implicated in an outbreak of Salmonella senftenberg in the United Kingdom.6Salmonella spp. are relatively resistant to desiccation and can survive
for long periods in dry environments such as cereal.7
Timely communication among the states and CDC about unexplained local
increases in Salmonella Agona infections, and the
relative rarity of this serotype, led to the identification of this multistate
outbreak. Electronic national laboratory-based reporting of Salmonella infections facilitated prompt recognition of the extent
of the outbreak. Cooperative investigations among federal, state, and local
agencies, coordination by CDC, electronic reporting through PHLIS, and the
rapid identification of related isolates using PulseNet (the national network
of public health laboratories that perform DNA "fingerprinting" on foodborne
bacteria) are critical components in the recognition and investigation of
multistate foodborne outbreaks.
References 7 available.
Multistate Outbreak of. JAMA. 1998;280(5):411. doi:10.1001/jama.280.5.411