Foodborne 101

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Foodborne 101

• Danae Bixler, MD, MPH
• Infectious Disease Epidemiology Program

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Included

• Clinical syndromes
• Basic epidemiology reservoir and infectious
  dose
• Implications for investigation
• Mechanics of a WVEDSS investigation

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Not Included

• Information on food borne illness
• Manifesting as neurological disease botulism,
  mushroom poisoning, Guillan-Barre syndrome, etc.
• Manifesting as systemic disease Listeria,
  Brucella, Vibrio vulnificus, Salmonella typhi,
  hepatitis A and E

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Using WVEDSS to Investigate Foodborne Illness

• Problems
• Entry of laboratory studies
• HTML
• Paper
• OLS line listing
• Entry of restaurant information
• Use activity list
• High risk (daycare, foodhandler, healthcare)
• Promise
• Provider data clearly demarcated
• Data rapidly available for analysis

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Clinical Data
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Gastroenteritis

• Vomiting predominant symptom
• (/-) diarrhea
• (/-) fever

• Viral gastroenteritis
• Rotavirus (infant)
• Norovirus and related viruses (older child and
  adult
• Food poisoning due to pre-formed toxins
  Staphylococcus aureus, Bacillus cereus
• Heavy metals

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Non-inflammatory Diarrhea

• Acute watery diarrhea
• Usually no fever
• No dysentery

• Can be caused by any pathogen, but especially
• Enterotoxigenic E coli
• Giardia
• Vibrio cholerae
• Enteric viruses
• Cryptosporidium
• Cyclospora cayetanensis

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Inflammatory Diarrhea

• Invasive gastroenteritis
• (/-) Fever
• (/-) Bloody stool

• Shigella
• Campylobacter
• Salmonella
• Enteroinvasive E coli
• Enterohemorrhagic E coli
• Vibrio parahemolyticus
• Yersinia enterocolitica
• Entamoeba histolytica

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Persistent Diarrhea

• Diarrhea with duration gt 7-14 days

• Cyclospora cayatenensis
• Cryptosporidium
• Entamoeba histolytica
• Giardia lamblia

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Salmonellosis
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Cryptosporidiosis
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Giardiasis
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Laboratory Studies
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Salmonellosis (Salmonella spp.)1997 Case
Definition

• Clinical description
• An illness of variable severity commonly
  manifested by diarrhea, abdominal pain, nausea,
  and sometimes vomiting. Asymptomatic infections
  may occur, and the organism may cause
  extraintestinal infections.
• Laboratory criteria for diagnosis
• Isolation of 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

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Cryptosporidiosis (Cryptosporidium parvum) 1995
Case Definition

• Clinical description
• An illness caused by the protozoan
  Cryptosporidium parvum and characterized by
  diarrhea, abdominal cramps, loss of appetite,
  low-grade fever, nausea, and vomiting. Infected
  persons may be asymptomatic. The disease can be
  prolonged and life-threatening in severely
  immunocompromised persons.
• Laboratory criteria for diagnosis
• Demonstration of Cryptosporidium oocysts in
  stool, or
• Demonstration of Cryptosporidium in intestinal
  fluid or small-bowel biopsy specimens, or
• Demonstration of Cryptosporidium antigen in stool
  by a specific immunodiagnostic test (e.g.,
  enzyme-linked immunosorbent assay)
• Case classification
• Probable a clinically compatible case that is
  epidemiologically linked to a confirmed case
• Confirmed a case that is laboratory confirmed

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Create New Lab Report
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Enter laboratory information, then click New
Result
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Enter results, then click Submit Changes
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Repeat steps to add more laboratory results
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and repeat
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Results will append to the end of the WVEDSS
Detail Form
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Salmonella Serotype Information
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A laboratory-confirmed case is a confirmed case
(pg 1).
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Shigellosis (Shigella spp) 1997 Case Definition

• Clinical description
• An illness of variable severity characterized by
  diarrhea, fever, nausea, cramps, and tenesmus.
  Asymptomatic infections may occur.
• Laboratory criteria for diagnosis
• Isolation of Shigella 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

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Giardiasis (Giardia lamblia) 1997 Case
Definition

• Clinical description
• An illness caused by the protozoan Giardia
  lamblia and characterized by diarrhea, abdominal
  cramps, bloating, weight loss, or malabsorption.
  Infected persons may be asymptomatic.
• Laboratory criteria for diagnosis
• Demonstration of G. lamblia cysts in stool, or
• Demonstration of G. lamblia trophozoites in
  stool, duodenal fluid, or small-bowel biopsy, or
• Demonstration of G. lamblia antigen in stool by a
  specific immunodiagnostic test (e.g.,
  enzyme-linked immunosorbent assay)
• Case classification
• Probable a clinically compatible case that is
  epidemiologically linked to a confirmed case
• Confirmed a case that is laboratory confirmed

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A probable case, e.g., of Shigellosis is (pg 6
of WVEDSS form / mock case for teaching purposes)
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a case that is epi-linked to a laboratory
confirmed case and should be reported as such
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Risk Factor Investigation
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Basic Salmonella Epidemiology
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Counties Reporting Salmonella Cases as of
4/28/2005(WVEDSS (provisional))
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Selected Risk Factors in Salmonella Cases
Reported to WVEDSS as of 4/28/2005, N22
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Basic Enterohemorrhagic E coli Epidemiology
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Basic Campylobacter Epidemiology
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Confirmed Cases of Campylobacter (WVEDSS as of
4/30/2005(provisional))
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Selected Risk Factors in Campylobacter Cases
Reported to WVEDSS as of 4/30/2005, N12
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Basic Epidemiology the incubation period (when
you look at risk factors)
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Incubation Period - Example
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Incubation Period - Example
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Food History - Salmonellosis
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Food History - Campylobacteriosis
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Basic Shigella Epidemiology
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Basic Giardia Epidemiology
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Giardiasis
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Basic Cryptosporidium Epidemiology
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Cryptosporidium Investigation
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Basic Cyclospora Epidemiology
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Basic Entamoeba Epidemiology
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Demographic Information
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High Risk Occupations / Settings
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Resistance Testing Results (Salmonella and
Shigella)
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Foodborne Investigations

• Case classification
• Confirmed or probable
• Demographics
• High risk settings
• Laboratory confirmation
• Susceptibility testing for Salmonella and
  Shigella
• Use HTML or OLS section
• Risk factor investigation for all diseases
• Detailed food history for Salmonella, E coli
  O157H7, Campylobacter