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Norovirus Summary -

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Transmission•Fecal-oral•Ingestion of aerosolized vomitus•Indirect:-exposuretofomites--contaminatedwater or food,Infectiousdose:low, 10particles
Transmission, Exclusion
LabDiagnosis•RT-PCR:Test stool, emesis, environmental samples.Mosteffective with specimens obtained within 48-72 hrs. of infection.•Direct & immune electron microscopy of fecal specimens-early stage of illness•Seroconversion:>4foldrise inIgGantibody titer during acute/convalescent phasesera(acutephase serum drawn within first 5 days, convalescent phase 3-6 weeks later)•Enzyme linkedimmunosorbentassays– single assays of IgA antibody for quickdiagnosis.Notas sensitive.
Calicivirus-5genogroups(GI, II, and IV affect humans) and 30+ genotypes-Sequencingof strains allows linking cases to common source
No specific treatment currently available.Make sure torehydrateand restore electrolyte balance.
Sporadic casesOutbreaks:•Cruise ships, hotels•Nursing homes, long-term care facilities•Restaurants, catered events•Contaminatedwatersupply
Food:•Shellfish (oysters, clams) should be cooked completely.Steaming may not be sufficient.•Fruits, vegetables should be washed thoroughly.
Prevention of initial contamination of food/water sourcesPrevent person-to-person spread
Very common:-5-17% ofall diarrheal-50% of food-borne cases)
Incubation12-48 hrs.
Communicability15-72 hrs. (as long as 3 wks.)
Hardy, ubiquitous,extremely persistent (can withstand extreme conditions)
Food-handlersshould be excluded from work for 3 days after cessation of symptoms, and should be vigilant about washing hands and wearing gloves for 3 weeks.
Exclude:•Isolateinfected members of long-term care or living facilities•Food-handlers(symptomatic)•Health careworkers (symptomatic)
Kaplan Criteria for Diagnosis during outbreaks• Median illness duration of 12-60 hrs.• Incubation period of 24-48 hrs.• More than 50% of people vomiting.• No bacterial agent
Able to survivefreezing,heat(60ºC),10 ppm chlorine
•Disinfect soiled surfaces using 5000 ppm sodium hypochlorite (bleach)•Wash soiled linens/clothes with detergent in hot water•Avoid preparing food while infected•Wash hands (with soap and water) frequently
-Exclusionof health care workers,food workers until symptoms subside + 48hrs-Isolation ofresidents inlong-termcare centers,
GastroEnteritis12-60hrs.Diarrhea, Nausea, Abdominal pain, Vomiting,Myalgia,Fatigue, HeadacheLowfever, Chills
Complications:Severe dehydration is possible and may be fatal to the very young/old.
Examplesof items to disinfect:Doorknobs, faucets, sinks, toilets, commodes, bath rails, phones, counters, chairs (including backs), tables, hand rails, elevator buttons, light switches, mattress covers, aprons, uniforms, linens, bedding and ice machines.Best:Chlorine bleach (sodium hypochlorite -NaOCl)Chlorinebleach concentrations and mixing instructions:- Forstainless steel, food/mouth contact items,toys: 200ppm(parts per million1 Tablespoon of bleach in 1-gallon water (1:250 dilution)- Fornon-porous surfaces, tile floors, counter-tops, sinks,toilets: 1000ppm(parts per million)1/3-cupbleach in 1-gallon water (1:50 dilution)-Forporous surfaces, woodenfloors: 5000ppm(parts per million)1cup bleach plus 2/3-cup bleach in 1-gallon water (1:10 dilution)Contacttime:Leave bleach on surface for 10-20 minutes and then rinse with clean water.Stabilityof chlorine bleach:Openbottles of concentrated chlorine bleach<30days.Diluted chlorine: Replace every day, discard day oldUse in well ventilated areas to avoid respiratory irritation. Do not mix bleach with ammonia or acid (release of chlorine gas or chloraminesOthereffective disinfectants:•Glutaraldehyde(0.5%) or Iodine (0.8%) mixed at the manufacturer’s recommendations.•Aphenolicenvironmental disinfectant (Lysol® orPinesol®)effective, butrequiresa concentration of2-4 xmanufacturer’srecommendation.Highconcentrationsignificanthealth risk tochildren, workers,pets.Useextreme cautionwhen using these products.•OtherEPAapproveddisinfectants: Quaternaryammonia-based disinfectants but in combination with alcohols.EPA’s Registered Antimicrobial Products Effective AgainstNorovirus: food establishments see list belowPersonal Protective Equipment•Disposable gloves, masks, eye protection or face shields, and gown or protective clothing•Environmental cleaning using a more concentrated disinfectant will require a heavier duty glove than a simple non-sterile latex/vinyl glove.SpecificClean-up Procedures:Forcleaning large spills ofvomitusor stool, a two-step process should be used. Put on personal protective equipment before cleanup as specified in the CDC document: pre-cleaningof visible/organic debris with absorbent material (double layer and placed in a plastic bag to minimize exposure to aerosols)2-Then liberallydisinfect area and objects surrounding the contamination with an appropriatedisinfectant(multiple applications may be required).*Ensure appropriate dilution and contact time for the appropriate environmental disinfectant.Hardsurfaces:Disinfect with bleach, rinse with water if food preparation area.Carpet/ Upholstered Furniture:Visible debris should be cleaned with absorbent material (double layer) and placed in a plastic bag to minimize exposure to aerosols -disinfecting with bleach may discolor carpet– steam clean (heat inactivation) 158°F for 5 minutes or 212°F for 1 minute for complete inactivation.Linens/ clothing / textiles:If soiled, vomit or stool should be carefully removed to minimize aerosols. Keep contaminated and uncontaminated clothes separated. Minimize disruption of soiled linens and laundry. Aerosols created may pose a risk for transmission. Wash items in a pre-wash cycle, then use a regular wash cycle using detergent and dried separately from uncontaminated clothing at high temperature greater than 170°F. Ensure segregation of clean and soiled linens/clothing/textiles.SurfacesCorrodible/damageable by bleach:EPA registeredphenolicsolutions (concentrated Lysol® or concentratedPinesol®) mixed at2-4Xthe manufacturer’s recommended concentration.Sick employees:exclude from food preparation and handling cleanequipmentpreferablysend home and stay away for 48 hours after symptoms subsideHand washing:Afterusing the restroom, sneezing, coughing, before and after food preparation, all employees should wash hands with warm running water and soap, using friction for 20 seconds. Hands should be dried with a single-service paper towel or air dryer.Personsinvolved in busing tables, handling of used utensils; cups or any dishes exercise regular thorough hand washing, particularly before eating or handling food or clean utensils.DisinfectionPrecautionsnot all disinfectants shown on EPA list•Product label must contain language stating approval for use in (FDA or USDA) food facilities AND provide appropriate directions for use/application rates in these settings. Consult the manufacturer for further information on approval for use on food contact surfaces and/or in food service facilities. Policies: Cleaning Precautions:Medical equipment used for care ofnorovirusinfected patients, should be either dedicated to that room for the duration of isolation or be thoroughly disinfected upon removal from the room.CleaningProcedures:Routineenvironmental cleaning measures, at proper time intervals, and proper disinfection order, with the recommended concentration and contacttime• For cleaning procedures (i.e. changing water / wash cloths, sequence of cleaning) refer to HICPAC Environmental Infection Control for Healthcare Facilities, 2003 Concerns:Do not shake soiled linens and laundry. Aerosols created may pose a risk for transmission. Soiled linens should be placed directly into a bag at the point of removal.Ensureproper separation of clean and soiled laundry.• Contaminated ice machines must be disinfected.• For protocols see
Disinfection(For non-visibly soiled areas - please refer to specific procedures for large spills)
Clean Up Procedures
Food Service Establishments
Healthcare/Hospital/Nursing Home Facilities
Ice Machines





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Norovirus Summary -