{"id":2078,"date":"2011-03-23T12:47:45","date_gmt":"2011-03-23T17:47:45","guid":{"rendered":"http:\/\/jianmingli.com\/wp\/?p=2078"},"modified":"2011-03-23T14:16:19","modified_gmt":"2011-03-23T19:16:19","slug":"food-borne-illnesses","status":"publish","type":"post","link":"https:\/\/jianmingli.com\/wp\/?p=2078","title":{"rendered":"Food Borne Illnesses"},"content":{"rendered":"

Overview<\/h2><\/span>\n

* CDC estimates that 9.4 million of the illnesses are caused by 31 known foodborne pathogens
\n* 90% of all illnesses due to known pathogens are caused by seven pathogens: <\/p>\n

norovirus, <\/h3><\/span>\n

* is a virus
\n* aka stomach flu
\n* present in feces<\/p>\n

Salmonella <\/h3><\/span>\n

* is a bacteria
\n* present in eggs, poultry, meat, vegetables, fruits<\/p>\n

Campylobacter<\/h3><\/span>\n

* is a bacteria
\n* present in chicken feces<\/p>\n

Toxoplasma<\/h3><\/span>\n

* is a parasite
\n* present in uncooked meats, cat feces<\/p>\n

E. coli O157:H7<\/h3><\/span>\n

* is a bacteria
\n* present mostly in cows
\n* produces Shiga toxin<\/p>\n

Listeria<\/h3><\/span>\n

* is a bacteria
\n* present in raw foods<\/p>\n

Clostridium perfringens<\/h3><\/span>\n

* is a bacteria
\n* present everywhere, especially undercooked meat<\/p>\n

Causes of Food Borne Illnesses<\/h2><\/span>\n

* Bacteria (Salmonella, campylobacter, E coli, listeria, clostridium perfringen)
\n* Viruses (norovirus)
\n* Parasites
\n– Protozoan(toxoplasma)
\n– Worms (tapeworm)
\n* natural toxins (alfatoxin from mold peanuts, tetradotoxin from puff fish, mushroom toxins)
\n* Others such as prions (human mad cow or vCJD)<\/p>\n

Outbreak Investigation: Ten Steps<\/h2><\/span>\n

Step 1: Prepare for Field Work<\/h3><\/span>\n

* Research the disease\/situation
\n* Gather needed supplies\/equipment
\n* Make official and personal travel arrangements
\n* Follow protocol to make local contacts<\/p>\n

Step 2: Establish existence of an outbreak<\/h3><\/span>\n

* Expected number of cases
\n– health records, surveys
\n*Other factors
\n– better reporting<\/p>\n

Step 3: Verify the diagnosis<\/h3><\/span>\n

* Verify diagnostic procedures are correct
\n* Verify no lab errors
\n* Interview patients for
\n– cause
\n– source
\n– spread<\/p>\n

Step 4: Define and identify cases<\/h3><\/span>\n

Define cases<\/h4><\/span>\n

* Case definition (4 components)
\n– clinical information
\n– patient demography
\n– location
\n– time sequence
\n* Case definition example for influenza-like illness
\n– clinical information: fever of 100F orally or 101F rectally, plus coughing
\n– patient demography
\n– location
\n– time sequence: Oct1 to May 31<\/p>\n

Identify cases<\/h4><\/span>\n

* Case types
\n– confirmed
\n– probable
\n– possible
\n* Line listing
\n– ID or case number
\n– clinical info
\n– time
\n– personal info
\n– place
\n– risk factors and possible causes<\/p>\n

Step 5: Describe TPP (Time, Place, Person) Triad<\/h3><\/span>\n

* Time
\n– Epidemic curve or epi curve
\n* Place
\n– spot map
\n* Person
\n– affected population<\/p>\n

Types of descriptive studies<\/h4><\/span>\n

* Case report: for single patient
\n* Case series: for multiple patients
\n* Correlative studies
\n– Time series analysis
\n– Ecologic relations
\n* Cross sectional<\/p>\n

Step 6: Develop Hypothesis or AHE (Agent, Host, Envionment) Triad<\/h3><\/span>\n

* Agent: virus, bacteria, protozoa, fungi, worms
\n* Hypothesis must be testable
\n* Should be based on current knowledge and updated<\/p>\n

Step 7: Evaluate Hypothesis<\/h3><\/span>\n

* Past cases
\n* Observational studies
\n* Cohort
\n– retrospective or history: past to present
\n– prospective: now to future
\n* Case control
\n* Must have lab verification to validate hypothesis<\/p>\n

Calculation<\/h4><\/span>\n

* Cohort table
\n* Attack rate: sick \/ total
\n* Relative risk: exposed attack rate \/ un-exposed attack rate
\n >1.0: positive association
\n = 1.0: no association
\n(need more study on this)<\/p>\n

Step 8: Refine Hypothesis and do Additional Studies<\/h3><\/span>\n

Implement Control and Preventative measures<\/h3><\/span>\n

* Break chain of transmission: any or all within AHE
\n* Interrupt transmission or exposure: quarantine
\n* Reduce susceptibility: immunization, education<\/p>\n

Criteria to draw conclusions<\/h4><\/span>\n

* Temporality
\n* Consistency
\n* Coherence, 1 to 1 relationship
\n* Strength of association
\n* Biological plausibility
\n* Dose\/response<\/p>\n

Step 10: Communicate Findings<\/h3><\/span>\n

* Oracle briefing
\n* Written report<\/p>\n

References<\/h2><\/span>\n

* http:\/\/www.foodborneillness.com\/<\/a><\/p>\n

* Bad Bugs Book<\/a><\/p>\n

* Science Olympia site<\/a><\/p>\n

* Foodborne Infections and Intoxication<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Overview * CDC estimates that 9.4 million of the illnesses are caused by 31 known foodborne pathogens * 90% of all illnesses due to known pathogens are caused by seven pathogens: norovirus, * is a virus * aka stomach flu … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[52],"tags":[],"class_list":["post-2078","post","type-post","status-publish","format-standard","hentry","category-health"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8cRUO-xw","_links":{"self":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2078","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2078"}],"version-history":[{"count":3,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2078\/revisions"}],"predecessor-version":[{"id":2099,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/2078\/revisions\/2099"}],"wp:attachment":[{"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2078"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2078"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jianmingli.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2078"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}