- Educate providers and the public about
transmission and prevention of non-typhoidal Salmonella.
- Educate providers and laboratories to report non-typhoidal
Salmonella infections from any site to the local health
department in the patient's county of residence within one week of
diagnosis.
- Educate laboratories to submit all non-typhoidal Salmonella
isolates to the Office of Laboratory Services for serotyping and
pulsed field gel electrophoresis (PFGE).
- Conduct an appropriate investigation as follows:
- For sporadic cases: Complete the
Supplemental Enteric Disease Case Report Follow-up Form and attach
it to the yellow card. Laboratory results, including antimicrobial
susceptibilities, should also be attached. Use of the Supplemental
Enteric Disease Case Report Follow-up Form will prompt the local
health department to complete an appropriate investigation, to
include: 1) a three-day food history; 2) history of exposure to
animals, including reptiles, during the incubation period; 3)
identification of high-risk persons or symptomatic individuals for
further investigation; and 4) identification of specific behaviors
that may be associated with Salmonella infection. Use an
incubation period of six to 72 hours.
- For small outbreaks (three or more epi-linked
cases): Do not wait for serotype results to begin the
epidemiological investigation as in 4a above. Consider using a
slightly longer incubation period, such as six to 96 hours in some
cases of non-typhoidal salmonellosis; consult the Infectious Disease
Epidemiology Program (IDEP) at 1-800-423-1271. Take special care to
assure that isolates are rapidly sent to the OLS for serotyping and
PFGE.
- For large outbreaks (five or more epi-linked
cases): Consult IDEP immediately at 1-800-423-1271. Take special
care to assure that isolates are rapidly sent to OLS for serotyping
and PFGE.
- For extra-intestinal infection: Take
special care to assure that isolates are sent to OLS. Document a
general investigation using the Supplemental Enteric Disease Case
Report Follow-up Form as a guide, and use an incubation period of
three to four weeks. Replace the "Open-ended Food History"
with a usual 24-hour food history.
- Identify other cases including probable cases
(symptomatic persons who are epidemiologically linked to a
culture-confirmed case), and investigate completely as in 4 above.
- Identify household contacts or close contacts of
culture-confirmed cases. Culture the stools of any household or close
contacts who are involved in food handling, direct patient care, or
care of young children or the elderly in institutional settings.
- If the case works or attends a day care facility:
- Interview the manager/operator and check
attendee records to identify suspect cases that occurred within the
past month.
- Provide educational information to the
manager/operator and staff regarding proper food handling and hand
washing, especially after changing diapers.
- Collect stool samples from all symptomatic
staff members and children or attendees who have been ill in the
previous two months.
- Do a sanitary inspection if there are any other
suspected cases.
- Instruct the manager/operator to notify the
local health department if new cases of diarrhea occur. Call or
visit once a week for two weeks to verify surveillance and if
appropriate hygienic measures are being carried out.
- Exclude symptomatic individuals who are
involved in direct care of infants.
- Exclude asymptomatic employees
with questionable hygienic habits.
- Exclude symptomatic attendees.
- If the case is a food handler:
- Conduct a sanitary inspection of the facility.
Interview the manager/operator and check attendee records to
identify suspect cases that occurred the previous month. Ask if
there have been any complaints from any patrons during the past
month.
- Collect stool samples from all symptomatic
individuals who have been ill the previous month.
- Exclude symptomatic individuals who are
involved in food handling. Exclude asymptomatic individuals with
questionable hygienic habits.
- Excluded food handlers should only return to
work after two consecutive negative stool cultures are collected 24
hours apart. If antibiotics are given, the initial culture should be
taken at least 48 hours after the last dose.
- If the case works at a health care or residential
care facility:
- Identify any abnormal incidence of diarrheal
illness within the past month. If so, identify any common source
outbreaks or sources of exposure.
- Conduct a sanitary inspection of the facility.
- Exclude symptomatic individuals who are
involved with the elderly, immunocompromised, and institutionalized
patients until two negative stool samples are taken 24 hours apart
and at least 48 hours after the last dose of antibiotics are taken.
Reduce the risk of disease through the education of
the general public to:
- Practice good hand washing as a primary means
of preventing person-to-person transmission.
- Practice proper food handling, including
thorough cooking of eggs, meat, and poultry, washing of fruits and
vegetables prior to consumption, and avoidance of
cross-contamination.
- Avoid unsafe foods such as unpasteurized milk,
cheese, juice, and cider.
- Practice proper handling of animals, including
reptiles.
- Maintain foods at the proper temperature prior
to serving.
Reduce the risk of secondary cases by:
- Determining whether the infected individual is
employed as a food handler, health care worker, or daycare worker
and excluding appropriately to prevent further transmission of
illness.
- Identifying infected household contacts who are
involved in food handling, direct patient care, or care of children
or elderly people in institutional settings; and managing
appropriately to prevent further transmission.
- Identifying symptomatic epidemiologically
linked persons and investigating as probable cases of Salmonella.
- Identifying and investigating outbreaks at the
earliest possible time so that control measures can be instituted
rapidly.
- Determine the incidence of salmonellosis in West
Virginia.
- Identify demographic characteristics of persons
with salmonellosis.
- Identify behavioral risk factors associated with
salmonellosis.
- Facilitate outbreak identification and
investigation by obtaining serotype and pulsed field gel
electrophoresis on all isolates.
- Determine the antimicrobial resistance profile of
non-typhoidal Salmonella isolates in West Virginia.
While most cases of non-typhoidal Salmonella
are sporadic, this bacteria can cause large and dramatic outbreaks due to
contamination of commercial food products. Multi-state, and even
international outbreaks, have been described with this pathogen. Smaller
clusters occur frequently due to person-to-person transmission,
contamination of foods during preparation or handling, or temperature
abuse of foods. Outbreaks are most commonly reported from foods of animal
origin; however, large outbreaks have also been associated with tomatoes,
cantaloupes, sprouts, grain products, and even non-chlorinated public
water supplies. Approximately 40,000 cases of salmonellosis are reported
to CDC out of an estimated 1.4 million cases occurring in the United
States every year. An estimated 1,000 persons die from salmonellosis every
year in the U.S.
Non-typhoidal Salmonella Gastroenteritis
Infection with non-typhoidal Salmonella
almost always results in an acute self-limited gastroenteritis that is
completely indistinguishable from other causes of gastroenteritis caused
by other bacterial pathogens. In most cases, diarrhea is moderate in
severity and without blood. Fever, abdominal cramping, nausea, vomiting,
and chills are frequently reported. Headache, myalgias, and other systemic
symptoms may also occur.
Diarrhea usually lasts three to seven days. After
resolution of acute symptoms, mean duration of carriage of non-typhoidal Salmonella
strains in the stool is four to five weeks. Some studies suggest that
antimicrobial therapy may increase the duration of carriage.
Mortality from non-typhoidal Salmonella is
estimated at 0.4% of outbreak-associated cases; however, the case-fatality
rate in hospitals and nursing homes is 70-fold higher.
Bacteremia and Vascular Infection
Any Salmonella serotype can cause bacteremia.
Bacteremia occurs in about 1-4% of immunocompetent individuals with non-typhoidal
salmonellosis; and in a much higher proportion of individuals with AIDS. Salmonella
may infect the heart (endocarditis) or atherosclerotic plaque or
aneurysms. When a vascular site is infected, blood cultures may be
repeatedly positive for Salmonella.
Extra-intestinal Infection
In addition to intra-vascular sites, Salmonella
can set up an infection almost anywhere in the body. Common sites include
bones and joints, the central nervous system, lungs, spleen, urinary
system, genital sites, including testes or ovaries, the hepatobiliary
system, etc.
Chronic Carriage
After resolution of non-typhoidal salmonellosis,
mean duration of carriage in the stool is four to five weeks. Long-term
(> one year) carriage occurs in about one percent of persons with non-typhoidal
salmonellosis. Long-term carriage is more frequent in older women and in
persons with biliary abnormalities or concurrent Schistosoma
infection.
The pathogen is a gram-negative bacteria in the
family Enterobacteriaciae. Based on genetic similarity, all Salmonella
are classified in a single species: S. choleraesuis. Salmonella
are further subdivided into seven subgroups or subspecies. The seven
subspecies can be further serotyped into 2,300 serovars. Serotypes have
enormous epidemiological importance, and so for simplicity are often used
as the species name (though this is not taxonomically correct).
In addition, a new strain of Salmonella
typhimurium (DT 104) has emerged with resistance to five
antimicrobials – ampicillin, chloramphenicol, streptomycin,
sulfonamides, and tetracyclines. Infection with this strain is associated
with greater morbidity and mortality than susceptible strains. DT 104 has
been associated with contact with farm animals or meat products.
Non-typhoidal Salmonella are found in the
gastrointestinal tracts of domesticated and wild animals, including
poultry, swine, cattle, rodents, dogs, cats, birds (including pet ducks
and chicks), reptiles (including iguanas, snakes, and turtles), insects,
and human carriers.
Some serotypes have been specifically associated
with reptiles. Serotype S. enteritidis has been specifically
associated with eggs and poultry, but has also been associated with an
outbreak traced to reptile exposure.
Salmonella is transmitted through the
ingestion of food and water contaminated with human or animal waste.
Contaminated raw vegetables or fruits have also been implicated in some
recent outbreaks. Transmission through the fecal-oral route is important,
especially from persons who have diarrhea or who are incontinent.
Non-typhoidal Salmonella: six to 72 hours
Extra-intestinal infection: probably about three to
four weeks
As long as bacilli appear in the stool during
illness and usually several days to several weeks thereafter. One percent
of adults and five percent of infants and toddlers excrete Salmonella
for over one year after infection.
Outbreak recognition and investigation requires
timely and complete epidemiological investigation (risk factors, food
history, history of exposure to animals, etc.) paired with timely and
complete laboratory investigation (serotyping and pulsed field gel
electrophoresis). With the use of modern laboratory techniques, outbreaks
may be defined as three or more epi-linked cases infected with Salmonella
of the same serotype and PFGE pattern.
Community-based outbreaks have been linked to
individual food handlers, improper preparation of eggs, meats and poultry
dishes, and exposure to iguanas or other animals. Contaminated water has
rarely been implicated in community-based outbreaks involving
non-chlorinated public water supplies. National and international
outbreaks have been associated with widespread distribution of
contaminated commercial food products, vegetables, fruits, cereals, and
meats.
Clinical Description
An illness of variable severity manifested by
diarrhea, abdominal pain, nausea, headache, and sometimes vomiting. Some
serotypes may cause bloody diarrhea and invasive disease. Asymptomatic
infections may occur, and the organism may cause extra-intestinal
infections.
Laboratory Criteria for Diagnosis
Isolation of non-typhoidal Salmonella from a
clinical specimen.
Case Classification
Probable: a clinically compatible case that
is epidemiologically linked to a confirmed case.
Confirmed: a case that is laboratory
confirmed.
Comment
If laboratory confirmed, it is considered a
confirmed case that should be reported to the local health department in
the patient's county of residence within one week of the diagnosis.
The Office of Laboratory Services accepts isolates
for serotyping and pulsed field gel electrophoresis. Cary Blair Transport
Media is used for transporting stool cultures for Salmonella
testing and can be ordered from the lab (1 box = 12 vials). Take special
care to assure that all isolates are rapidly sent for serotyping and PFGE
to West Virginia Office of Laboratory Services, 167 11th Avenue, South
Charleston, WV 25303.
Share these prevention messages:
- Wash hands well after using the toilet, cleaning
the toilet, after changing diapers, and after handling soiled towels
or linens.
- Wash hands well before, during, and after fixing
food.
- Thoroughly cook all foods from animal sources,
especially chicken, beef, pork, meat dishes, and eggs.
- After preparing raw meat, thoroughly wash and
rinse all utensils, bowls, counters, and hands.
- Use a separate cutting board to prepare raw
meats. Use a clean plate for cooked meat. Never return cooked meat to
the same plate used for raw meat.
- Marinade or BBQ sauce used on raw meat should not
be used on cooked meat.
- Do not eat raw or partially cooked eggs, as in
eggnog or homemade ice cream. Use pasteurized egg products from the
grocery store for these purposes.
- Cook eggs until the yolks are hard.
"Sunny-side up" and "over easy" eggs may be a
source of Salmonella infection.
- Thoroughly rinse or wash fruits and vegetables
that will be eaten raw.
- Avoid the use of untreated manure as a fertilizer
for fruits and vegetables.
- Drink only pasteurized milk and milk products.
- Keep food at proper refrigeration temperatures.
- Wash hands after handling pets, pet toys, pet
feces, pet beds, and pet cages.
- Keep pets out of food-preparation areas.
- Do not clean pet or reptile cages in the kitchen
sink or in the bath tub.
- Iguanas or other reptiles should not be allowed
to roam the house.
- Do not let children handle reptiles without
supervision.
- Reptiles should not be kept in child care
centers.
- Households with children under age five, pregnant
women, and persons with depressed immune systems, such as AIDS, should
not have reptiles.
- Before traveling to developing countries, educate
yourself about safe food and water ("boil it, cook it, peel it,
or forget it"), and check with your travel clinic about the
necessary immunizations.
- Re-hydration and electrolyte replacement.
- Antibiotics may prolong the carrier state and may
lead to resistant strains or more severe infections.
- However, infants under the age of two months,
the elderly, the debilitated, those with sickle cell disease,
persons infected with HIV, or patients with high fever or
manifestations of extra-intestinal infection should be given
antibiotic therapy.
- Ampicillin or amoxicillin is usually
recommended when antibiotics must be administered; however, check
antimicrobial susceptibilities to identify inappropriate agents.
- Antimicrobial therapy is recommended for Salmonella
gastroenteritis occurring in patients with an increased risk of
invasive disease, including infants younger than three months of age
and persons with malignant neoplasms, hemoglobinopathies, HIV
infection, or other immunosuppressive illnesses or therapy.
- Ampicillin, amoxicillin,
trimethoprim-sulfanathoxazole (TMP-SMX), cefotaxime, or ceftriaxone is
recommended for susceptible strains in patients for whom therapy is
indicated.
- Proportion of investigations with complete
demographic information.
- Proportion of investigations with complete
information on high-risk occupations.
- Proportion of confirmed cases with known non-typhoidal
Salmonella serotype.
- Proportion of confirmed cases with antibiotic
susceptibility profile.
- Proportion of cases with complete risk factor
investigation including a three-day food history.
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