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Wedding Day Blues (and greens, and oranges, and reds). The Day Before…. Practice wedding dinner activity Groom developed intestinal turbulence jittery nerves or something he ate? No more guy’s night out Have to share the remote control Loss of manly freedom. During the wedding dinner.
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The Day Before…. • Practice wedding dinner activity • Groom developed intestinal turbulence • jittery nerves or something he ate? • No more guy’s night out • Have to share the remote control • Loss of manly freedom
During the wedding dinner • upchuck barf vomit hurl ralph purge puke hork buick spew regurgitate throw up toss your cookies lose your lunch toss a sidewalk pizza tango with the toilet make modern art in the toilet have a technicolor yawn expunge the contents of your stomach • bare your guts to the world become a multicolored organic fountain revisit your breakfast vomit your victuals drive the porcelain bus perform peristaltic pyrotechnics paint the town red.. and green and orange and pink have to say "that tasted better going down than coming up" burp to the ninth power make the janitor get out the ol’ sawdust bucket find out just how acidic your stomach contents are greet your guts pray to the porcelain god UP
A few days later • Other wedding dinner guests wanted to “share the pain” • vomiting • diarrhea (bloody) • porcelain throne - best friend • “Talked to Ralph on the big white phone” • symptoms occurred 1-2 days after the wedding dinner • duration of 1- 4 days
Salmonella Campylobacter Shigella Bacillus Vibrio Listeria Hepatitis A Enterovirus Norovirus Rotavirus Intentional contamination by former spouse/girlfriend Possible Causes of Illness
shellfish chicken eggs chocolate milk fried rice undercooked beef Unpasteurized apple cider lettuce alfalfa sprouts unwashed fruit other food contaminated by foodhandler Most likely food products
Solved by Committee • County food poisoning hotline • complaints about an institution • Epidemiologists (county and state) • track contacts, point of origin, review common patient symptoms, ask for specimens
Solved by Committee • State lab • coordinate all activities and ship out specimens • CDC • identification of causative agent
Specifics • 131 people reported some illness (self reported or contacted by epidemiology) • Food institution voluntarily shut down to review procedures and disinfect • Food institution reopened - people became ill again • Shut down for one month for more thorough cleansing, new carpeting
Specifics • No one food item could be narrowed down • Food institution tried to blame it on the groom - “projectile vomiting, aerosolization of agent” • Food handlers later determined to be ill before the outbreak • CDC determined agent to be Norwalk virus
Evidence for airborne transmission of NLV in a hotel restaurant Epidemiol Infect 124:481-487 • Woman abruptly vomited at her table during dinner • Staff cleaned it up quickly and the meal continued • A few days later several other people started getting various similar symptoms • Reported to health authorities – investigation began • People at the same table 91% ill • 1 table away on both sides 60-69% ill • 2 tables away on either side 40-45% ill • Food service workers – 15% ill – moved between tables • No suspect food products, no previously ill workers • Stools specimens showed 100% match between patients • Aerosolization of vomitus most likely cause!
What are Noroviruses? • Noroviruses are a group of viruses that cause acute gastroenteritis in humans. • The symptoms of norovirus infection include nausea, vomiting, diarrhea, cramping, and low-grade fever. • Noroviruses are transmitted through the fecal-oral route, either by consumption of fecally contaminated food or water, direct person-to-person spread, or environmental and fomite contamination.
Epidemiology • Norwalk virus • 23 million cases/year • 96% of nonbacterial gastroenteritis outbreaks • Crowding and poor sanitation • High attack rates • Low infectious dose
Microbiology • Caliciviridae – small round viruses • 32 nm w/ an amorphous surface and ragged outline • No known reservoir outside of humans • Earlier designations Norwalk virus • Norwalk OH – prototype virus – 11 varieties • Norwalk like viruses – noroviruses • Named for where first detected: Snow Mountain, Hawaii, Montgomery County, Oklahoma, Sapporo, etc
Pathogenesis • Blunting of villi, cytoplasmic vacuolation, and infiltration with mononuclear cells
Specimens • Collected as soon as gastroenteritis diagnosed • Within 48 hours of illness • Stool specimens, ileostomy contents, bowel contents • Relatively stable - 4°C 1 week
Diagnosis • Gastrointestinal viruses • Electron microscopy - EM or IEM • Antigen detection • Serology • Molecular assays – RT-PCR
Electron Microscopy • Viruses easily recognizable • 106 - 107quantity corresponds to active vs asymptomatic infection • Solid Phase immune electron microscopy • EM grid coated with Ab to virus to capture viral particles • Enhances specificity, can type calici and NLV • JCM 33:501-4
Antigen Detection • ELISA • Latex agglutination • Rapid tests also available • Commercial assays available for Adenovirus, Astrovirus, and Norwalk virus • No commercial assays available for other caliciviruses
Serology • Capture IgM assay 62% natural infection, 94% experimental infection • J Virol Methods 24:57-66 • Timing of serum collection important • JCM 37:2983-6 • Capture IgM better for diagnosis • JCM 36:1064-9, J Infect Dis 170:535-42
Molecular Assays • RNA PAGE - silver staining • Restriction enzyme analysis • Dot blot assays = ELISA • PCR - > sensitivity over ELISA • definitive method, most sensitive 102 - 104 particles/ml • inhibitors removed with better processing
Treatment • Gastrointestinal viruses • No specific treatment available • Supportive therapy • Bismuth salicylate may reduce GI symptoms
Prevention and Control • Gastroenteritis viruses • Careful handling of food • Maintain purity of water supply • Handwashing • Improvements in hygiene • Infection control methods for reducing outbreaks
Prevention and Control • Potential vaccine • Intranasally delivered dry powder • Lyophilized virus particles – conformation of the viral capsid • Phase 1 safety trials – immunogenic • Live virus challenge studies forthcoming • Greatest effects on pediatric and geriatric populations
Disinfection! • Doorknobs, faucets, sinks, toilets, commodes, bath rails, phones, counters, chairs (including backs), tables, hand rails, elevator buttons, light switches, keyboards, mattress covers, aprons, uniforms, linens, bedding and ice machines. • Hard surfaces • Carpet / Upholstered Furniture • Linens / clothing / textiles
Food Handler Issues • Food handlers who are ill with gastrointestinal symptoms MUST NOT prepare or serve food for others under any circumstances • Any employee with vomiting or diarrhea must be sent home immediately, unless their symptoms are the result of a non-infectious condition (e.g., pregnancy or Crohn’s Disease). • Employees that have been ill with suspected Norovirus MUST not return to work for a period of 24 hours after symptoms have ended or provides medical documentation that the symptom is from a non-infectious condition.
Cruise Line Data • 10 year span • 208 foodborne outbreaks • 142 confirmed Norovirus infections • Top 5 cruise lines • 39, 30, 25, 17, 12 outbreaks • Several on same boats • Some had to be taken off service for full cleaning • CDC provides info for free
Case Report • BSA National Jamboree Fort AP Hill 2001 • 40,000 campers, 20 subcamps, 600 groups of 40-90 campers • Day 1 medical screening - rashes, vomiting, diarrhea, fever, HA, cough • 6/80 grp A, 15/84 grp B - vomiting, diarrhea • Day 2 6/80 grp C - vomiting, diarrhea • Overall attack rates 10/80 grp A, 26/84 grp B, 22/80 grp C
Case Report • 8 stool samples collected, 6/8 NLV (+) by RT-PCR, confirmed at CDC, genetically identical • Affected campers excluded from camp activities with potential for transmission • water sports, archery, shooting • Affected groups provided with dedicated latrines, washing facilities, drinking water • Shower space reserved for affected members, facilities cleaned with 10% bleach
Case Report • Hand washing stressed for all members of affected groups • Well group members - enteric precautions • Outbreaks lasted 4-9 days • Final evening 36 campers in same subgroup as grp A - vomiting and diarrhea • point source outbreak • Infection control in action! Intervention efforts effective. • MMWR 51:661-3