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Public Health and Epi > Lecture 25 Biological Hazards II- Campylobacter spp & Listeria spp > Flashcards

Lecture 25 Biological Hazards II- Campylobacter spp & Listeria spp Flashcards

1
Q

What are the top 5 pathogens contributing to domestically acquired foodborne illnesses?

A
  • Noroviruses
  • Salmonella, nontyphoidal
  • Clostridium perfringens
  • Campylobacter spp.
  • Staphylococcus aureus
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2
Q

What are the top 5 pathogens that contribute to domestically acquired foodborne illnesses resulting in HOSPITALIZATION?

A
  • Salmonella, nontyphoidal
  • Norovirus
  • Campylobacter spp.
  • Toxoplasma gondii
  • E. coli O157
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3
Q

What are the top 5 pathogens contributing to domestically acquired foodborne illnesses resulting in DEATH?

A
  • Salmonella, nontyphoidal
  • Toxoplasma gondii
  • Listeria monocytogenes
  • Norovirus
  • Campylobacter spp.
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4
Q

What is Campylobacter jejuni?

A
  • Non-spore forming, G-ve rod with curved- to Sshaped morphology
  • Many strains display motility (cock screw)
  • 7 organisms in genus, almost all human illness is
    caused by 2 organsims:
  • C. jejuni- common ~90% (occasionally invasive)
  • C. coli- uncommon
  • Worldwide distribution
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5
Q

Mortality in campylobacteriosis is seen mainly in:

A

immunocompromised
Rarely among otherwise healthy people

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6
Q

Who is most likely to get campylobacteriosis?

A
  • Children < 5 and people 15-29 years (mainly
    males) old more likely to get infection than
    are others
    a. Highest rate infants 6 -12 months old
  • People with weak immune systems
    a. Individuals with HIV/AIDS get infected 40 times more
    often
  • Rarely, babies can be infected in utero, causing miscarriages or stillbirths
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7
Q

Where is campylobacteriosis most commonly found?

A

Commonly found in GI tract of wild and domestic ruminants, swine, dogs, cats, fowl and rodents

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8
Q

This is a infection source of campylobacteriosis?

A

Surface water may be infection source due to fecal runoff or contamination by birds

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9
Q

Why are birds more likely to have higher infection rates of campylobacter?

A

Due to higher body temperature, infection rates can be
90-100% in birds (prefers 107.5ºF)

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10
Q

Poultry operations have been associated with what in terms of campylobacter?

A
  • Resistance to antibiotics has been associated with use in
    poultry operations.
  • Use of fluoroquinolones was removed over concerns
    of resistance transfer to humans
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11
Q

Campylobacter sources of infection include:

A
  • Normal gut microflora of food-producing animals
  • Food Sources
    a. Improperly handled or undercooked poultry
    b. Raw milk and cheeses from unpasteurized milk
    c. Contaminated water
  • Contaminated poultry carcass carries 100-100,000
    Campylobacter cells
    a. only 500 needed to cause infection
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12
Q

What are some causes of food or water contaminations of campylobacter?

A
  • Campylobacter spreads from bird to bird through common water source or contact with infected feces
  • Campylobacter can transfer to meat at slaughter
  • In 2005, Campylobacter present on 47% of raw chicken breasts tested through FDA Retail Food program
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13
Q

Chicken flocks infected with campylobacter will show..

A

no signs of illness

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14
Q

What are some causes of food or water contamination that lead to infection of campylobacter?

A
  • Milk can become contaminated if the cow has an udder
    infection with Campylobacter or the milk is contaminated with manure
  • Surface water and mountain streams can become
    contaminated from feces of cows or wild birds
  • Travelers to developing countries are also at risk of acquiring Campylobacter infection
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15
Q

As little as (blank) campylobacter cells can cause disease.

A

500

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16
Q

What is the incubation period and duration of campylobacteriosis?

A
  • Incubation period - 2 to 5 days
  • Duration - 2 to 10 days
17
Q

Most cases of campylobacteriosis are…

A

self-limiting

18
Q

What are the clinical signs of campylobacteriosis?

A
  • Major signs: Fever, diarrhea, abdominal cramps, and vomiting
  • Other symptoms often include abdominal pain, nausea, headache, and muscle pain
19
Q

What are some complications of campylobacteriosis?

A
  • Include bacteremia and infection of various organ systems, such as
    meningitis, hepatitis, cholecystitis, and pancreatitis
    a. ~ 1.5 cases of bacteremia occur per 1,000 cases
  • Autoimmune disorders are a potential long-term complication;
    Guillain-Barré syndrome (GBS).
    a. ~ 1 case of GBS per 2,000 cases, typically 2 to 3 weeks post infection
    b. Antigens present on C. jejuni similar to those in nervous tissues in humans, leading to the autoimmune reaction.
20
Q

How do you diagnose campylobacteriosis?

A
  • Isolation and growth requires special incubation
    conditions since the organism is microaerophilic
  • Fecal samples inoculated directly onto selective
    media, or enriched to increase recovery
  • To limit growth of competing organisms, media used for
    cultivation usually are supplemented with blood and
    antimicrobial agents
  • Isolation from food is difficult, because the bacteria are
    usually present in very low numbers.
21
Q

How do you properly prevent infection of campylobacteriosis?

A

Wash hands with soap:
- before preparing food
- after handling raw foods of animal origin
- after contact with animals (particularly kittens
and puppies)
- carefully and frequently (individuals with diarrhea)

Prevent cross contamination (separate)

Do NOT drink unpasteurized milk or untreated surface water

Cook poultry to 165 F

22
Q

What is Listeria monocytogenes?

A
  • G+, rod-shaped, facultative
  • 13 serotypes
23
Q

Listeria monocytogenes is considered a?

A

Reportable disease

24
Q

Listeria monocytogenes is considered an?

A

Important cause of death from foodborne illness

25
Q

Describe listeria monocytogene in the environment.

A
  • Ubiquitous in environment and can be found in moist environments, soil, and decaying vegetation
  • Persistent in food-manufacturing environments
  • Can grow at refrigeration temperatures
  • ~3°C/37.4°F
  • Salt-tolerant
26
Q

What is the reservoir of Listeria?

A

Domestic and wild mammals, birds, and man

27
Q

Where can you find listeria?

A
  • May be free living (not only able to survive but to grow) in water, mud, silage and other crops, and sewage.
28
Q

How long can listeria survive?

A

Can survive months to years in soil

29
Q

What is one way Listeria can be spread?

A
  • Widely distributed by farming techniques and spreading of manure
  • Can contaminate vegetables, animal feed or water and may be transmitted to people and animals.
30
Q

What are the two forms of listeriosis?

A
  • Non-invasive GI illness
  • More serious invasive form
31
Q

Describe the non-invasive GI illness of listeria.

A
  • Fever, muscle aches,
    and nausea or
    diarrhea
  • Often self-limiting in
    healthy people
32
Q

Describe the invasive form of listeria.

A
  • May cause septicemia
    and meningitis
  • Pregnant women
    more susceptible to
    infection, and
    although they
    generally recover,
    their babies usually
    don’t survive
33
Q

What is the mortality rate of listeria?

A
  • Severe form- case-fatality rate 15% - 30%
  • with meningitis, case-fatality rate up to 70%
  • with septicemia, 50%
  • in perinatal/neonatal infections, more than 80%
34
Q

What is the incubation period of listeria?

A
  • Infective dose varies with the strain and susceptibility of the host, and the food matrix involved
  • Gastroenteritis form: 9-48 hrs
  • Severe, invasive form: 2-6 weeks
35
Q

What are some common food sources of listeria?

A
  • Raw milk
  • Raw, smoked fish and other seafood
  • Meat, including deli meats
  • Cheeses, especially soft cheeses
  • Ice cream
  • Raw vegetables and fruits
36
Q

Why is listeria a problem in the food industry?

A

It can grow in refrigerated temperatures

37
Q

How is listeria diagnosed and treated?

A
  • Culture from tissue, blood, cerebrospinal fluid, or another normally sterile site (e.g., placenta or fetus) needed for diagnosis
  • Stool cultures not helpful, since some healthy humans may be intestinal
    carriers
  • Methods of analyzing foods complex and time-consuming (5 to 7 days)
  • Treatment consists of antimicrobial therapy
  • Ampicillin, with or without gentamicin (both will cross the blood brain barrier)
38
Q

How do you control/prevent listeria?

A

Do NOT drink raw milk or cheeses made with raw milk

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