2. NOROVIRUS
NORWALK AGENT
• NOROVIRUS, FORMERLY
REFERRED TO AS
NORWALK VIRUS, IS
THE MOST COMMON
CAUSE OF EPIDEMIC
NONBACTERIAL
GASTROENTERITIS IN
THE WORLD.
2/23/2016Dr.T.V.Rao MD 2
3. NOROVIRUS GROUP
• THE NOROVIRUS GROUP WERE
FIRST IDENTIFIED AS THE CAUSE
OF A PRIMARY SCHOOL OUTBREAK
OF VOMITING/DIARRHEA IN
NORWALK, OHIO DURING THE
EARLY 1970'S. THE GROUP
CONSISTS OF RELATED VIRUSES
THAT SHARE SIMILAR SYMPTOMS
AND EPIDEMIOLOGY. THIS VIRUS
GROUP CAUSES VIRAL
GASTROENTERITIS
2/23/2016Dr.T.V.Rao MD 3
4. STRUCTURE OF NOROVIRUS
• THE NOROVIRUSES ARE SMALL,
ROUND, STRUCTURED, NON-
ENVELOPED VIRUSES WHICH ARE 27
TO 32 NM IN DIAMETER. THEIR
GENOME CONSISTS OF A SINGLE 7.5
KB POSITIVE STRAND OF RNA. THE
PROTEIN COAT IS COMPOSED OF A 60
KDA STRUCTURAL PROTEIN. THE
VIRUS IS RESISTANT TO PH LEVELS
BETWEEN 5 TO 10, ACID, ETHER, AND
IS CAPABLE OF SURVIVING
TEMPERATURES OF 60C FOR 30
2/23/2016Dr.T.V.Rao MD 4
5. NORWALK VIRUS
• NORWALK VIRUS - AN INTESTINAL INFECTION CAUSED BY
FECAL CONTAMINATION, MAINLY OCCURRING IN
COUNTRIES WITH POOR SANITATION, AND LESS
FREQUENT IN DEVELOPED COUNTRIES. THE PROBLEM IS
NOT LIFE-THREATENING, BUT CAUSES DIGESTION,
STOMACH PROBLEMS, AND DIARRHOEA. THE VIRUS IS
NAMED AFTER THE PLACE IT WAS FIRST DIAGNOSED IN
1972: NORWALK, OHIO. THE NORWALK VIRUS IS A
MEMBER OF THE CALICIVIRUS FAMILY OF VIRUSES
2/23/2016Dr.T.V.Rao MD 5
6. NORWALK VIRUS CAUSES
• NORWALK VIRUS
SYMPTOMS AND
INFECTIONS ARE OFTEN
CAUSED BY CONTACT
WITH SEWEGE, OR FECAL
CONTACT. IT IS
CONTAGEOUS AND
CONTRACTED FROM
OTHER PEOPLE. PETS AND
2/23/2016Dr.T.V.Rao MD 6
7. SOURCES WHICH CAN SPREAD NORWALK
INFECTIONS
• CONTAMINATED WATER
• •CONTAMINATED FOOD THAT MAY BE
IRRIGATED, FARMED, TREATED OR
WASHED WITH CONTAMINATED WATER
• •PERSON-TO-PERSON ANAL OF FECAL
CONTACT
• •CONTACT WITH FECES
• •CONTACT WITH CHILDREN'S DIAPERS
• •CONTACT WITH SEWAGE
2/23/2016Dr.T.V.Rao MD 7
8. HOW ARE NOROVIRUSES TRANSMITTED?
• NORWALK AND NOROVIRUSES ARE TRANSMITTED PRIMARILY BY THE FECAL-
ORAL ROUTE. HAVING DIRECT CONTACT WITH VOMIT OR FECES FROM AN
INFECTED PERSON AND THEN TRANSFERRING THE VIRUS TO THE MOUTH FROM
THE HANDS PRIMARILY SPREADS THE VIRUSES. SECONDARY PERSON-TO-PERSON
TRANSMISSION THROUGH SHARING FOOD, WATER, AND/OR UTENSILS, OR
CONTACT WITH THE CONTAMINATED ENVIRONMENT IS ALSO POSSIBLE.
TOUCHING A CONTAMINATED DOOR KNOB AND/OR STAIR RAILING AND THEN
TOUCHING YOUR MOUTH IS A POSSIBLE METHOD OF TRANSMISSION. IN SOME
OUTBREAKS, THERE IS EVIDENCE THAT THE VIRUS MAY BE SPREAD BY THE
AIRBORNE ROUTE. THESE VIRUSES ARE VERY CONTAGIOUS AND ONLY A FEW ARE
NEEDED TO CAUSE AN ILLNESS.
2/23/2016Dr.T.V.Rao MD 8
9. TRANSMISSION OF NOROVIRAL INFECTIONS
• THE DISEASE IS TRANSMITTED THROUGH INGESTION OF
CONTAMINATED FOODS AND DRINKS, OR BY CONTACT WITH AN
INFECTED INDIVIDUAL. SHELLFISH FROM WATERS EXPOSED TO RAW
SEWAGE WILL CONCENTRATE VIRUS PARTICLES FROM THE WATER
SINCE THEY ARE FILTER FEEDERS. CONTAMINATED WATER CAN
ALSO INTRODUCE THE VIRUS TO BEVERAGES, ICE, EGGS, FRUITS,
AND SALAD INGREDIENTS. COOKED FOODS MAY ALSO BE
CONTAMINATED THOUGH HANDLING BY AN INFECTED
INDIVIDUAL. THE VIRUS CAN ALSO BE TRANSMITTED THROUGH
CLOSE CONTACT WITH AN INFECTED INDIVIDUAL AND/OR
TOUCHING CONTAMINATED SURFACES
2/23/2016Dr.T.V.Rao MD 9
10. NORWALK VIRUS SYMPTOMS
• •ABDOMINAL CRAMPS AND BLOATING
• •FATIGUE AND NAUSEA, AND SOMETIMES WEIGHT-LOSS
• •DIARRHOEA
• •GREASY STOOLS
• •RED AND BLOODY POOP
• •FOUL-SMELLING STOOLS
• •EXCESSIVE GAS
• •DEHYDRATION
• •DEVELOPING A LACTOSE INTOLERANCE
2/23/2016Dr.T.V.Rao MD 10
11. OTHER CLINICAL MANIFESTATIONS
• LOW-GRADE FEVER
• TACHYCARDIA
• POSSIBLE
HYPOTENSION WITH
VOLUME DEPLETION
2/23/2016Dr.T.V.Rao MD 11
13. NORWALK VIRUS DIAGNOSTIC
TESTS
• SPECIALIZED LABORATORIES
CAN PERFORM STOOL TESTING
FROM AN INFECTED PERSON
AND IDENTIFY EVIDENCE OF
INFECTION BY TESTING BLOOD
FOR ANTIBODY. LABORATORY
STOOL TEST DIAGNOSIS IS
DIFFICULT. DIAGNOSIS IS
OFTEN BASED ON THE
COMBINATION OF SYMPTOMS
AND THE SHORT TIME OF
2/23/2016Dr.T.V.Rao MD 13
14. TREATMENT AND SUPPORT OF NORWALK
INFECTIONS
• INFECTED PEOPLE USUALLY
RECOVER WITHIN A WEEK
WITHOUT SERIOUS OR LONG-
TERM HEALTH EFFECTS.
TREATMENT OPTIONS ARE
LIMITED SINCE NORWALK VIRUS
SYMPTOMS GO AWAY ON THEIR
OWN. IN CASE OF SEVERE
DIARRHEA, DOCTORS SUGGEST
DRINKING MORE WATER AND
FLUIDS TO AVOID
2/23/2016Dr.T.V.Rao MD 14
15. NORWALK VIRUS PREVENTION
• WASHING HANDS AFTER
USING THE TOILET,
CHANGING DIAPERS,
BEFORE EATING OR
PREPARING FOOD
• •USE ALCOHOL-BASED
SANITIZERS WHEN SOAP IS
NOT AVAILABLE
2/23/2016Dr.T.V.Rao MD 15
16. SAFE WATER MAKES LIFE SAFE FROM
NORVOVIRUS
• BE CAREFUL OF FISH OR SHELLFISH
THAT MAY HAVE COME FROM
CONTAMINATED WATER
• •DON'T DRINK WATER FROM SHALLOW
WELLS, LAKES, RIVERS, SPRINGS, PONDS
AND STREAMS UNLESS YOU FILTER IT
OR BOIL THE WATER
• •DON'T SWALLOW WATER WHEN
SWIMMING IN POOLS, LAKES OR
STREAMS
• •USE BOTTLED WATER
2/23/2016Dr.T.V.Rao MD 16
17. PROTECTING FROM NOROVIRUS
• DON'T USE ICE, AND AVOID RAW
FRUITS AND VEGETABLES, EVEN
THOSE YOU PEEL YOURSELF
• •PRACTICE SAFER SEX
• •PEOPLE HANDLING FOOD NEED TO
WASH THEIR HANDS AFTER BOWEL
MOVEMENTS
• •AVOID BAD PLUMBING AND KEEP A
WELL-FUNCTIONING PLUMBING
2/23/2016Dr.T.V.Rao MD 17
18. NEW STRAIN
• IN JANUARY 2013, THE US
CENTERS FOR DISEASE
CONTROL AND PREVENTION
(CDC) REPORTED THAT A NEW
NOROVIRUS STRAIN, GII.4
SYDNEY, WHICH WAS FIRST
DETECTED IN AUSTRALIA, HAD
SPREAD TO THE UNITED
STATES. DURING THE LAST 4
MONTHS OF 2012 2/23/2016Dr.T.V.Rao MD 18
19. NEW STRAIN CAUSES HIGHER MORTALITY
• IN GENERAL, GII.4
STRAINS ARE
ASSOCIATED WITH
HIGHER RATES OF
HOSPITALIZATION
AND DEATH.
2/23/2016Dr.T.V.Rao MD 19
20. ATTENTION OF VIEWERS• I AM THANKFUL TO MANY IN THE WORLD WHO MADE ME TO ACHIEVE MY DESIRED GOALS FASTER THAN I THOUGHT, HAVING
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MORE EMPHASIS ON INFECTIOUS DISEASES AND HOSPITAL ASSOCIATED INFECTION WISH TO BE YOUR PARTNER IN EDUCATING
MANY MILLIONS WHO KNOW WELL THE IMPORTANCE OF INFECTIOUS DISEASES
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• FOR ANY ASSISTANCE ON INFECTION REALTED ISSUES CONTACT ME AT DOCTORTVRAO@GMAIL.COM
• MOB +91 7204113154 2/23/2016Dr.T.V.Rao MD 20
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• DOCTORTVRAO@GMAIL.COM 2/23/2016Dr.T.V.Rao MD 21