Norovirus Infection

April 15, 2010

Marcy McMillian

Effie Boothe

What is norovirus?

• Also known as– Norwalk-like virus– Caliciviruses (family Caliciviridae)– Small round structured viruses

• Viral infection– Not improved with antibiotics– Live only in human host

• Most common cause of gastroenteritis outbreaks

Symptoms

• Nausea• Vomiting• Diarrhea• Abdominal cramping• Incubation 10-50 hours• Duration 1-2 days

How is norovirus spread?

• Found in stool or vomitus

• Infection spreads by– Consuming contaminated food or liquids– Touching contaminated surfaces or objects– Person-to-person contact

• Day care centers and nursing homes more vulnerable to both spread and effects of illness

Treatment

No vaccine or antibiotic available

Supportive care--fluids--rest

Hospitalization may occur in vulnerable groups

IV rehydration may be indicated

Outbreak Data

Enteric Outbreaks 2005-2010N=255

0

10

20

30

40

50

60

2005 2006 2007 2008 2009 2010

# o

f o

utb

reak

s

year

Norovirus

All other outbreaks

* *

* Preliminary data

Norovirus by Transmission Mode

Unknown12%

Foodborne37%

Person-to-Person

51%

Norovirus by Setting

Other25%

Hospital7%

8%29%

Restaurant31%

School/DaycareLTCF

Norovirus Outbreaks 2005-2010N=112

0

5

10

15

20

25

30

2005 2006 2007 2008 2009 2010

# o

f o

utb

reak

s

year

LTCF

All other outbreaks

* *

* Preliminary data

Median Number ill from Norovirus Outbreaks by Year

0

10

20

30

40

50

60

2005 2006 2007 2008 2009 2010

LTCF

Med

ian

# i

ll

year

All other settings

* ** Preliminary data

Hospitalizations by Setting

LTCF63%

Other13%

Restaurant12%

Retirement Community

9%

Prison3%

Prevention and Control

Prevention and control of norovirus

• Frequent handwashing

• Wash fruits/vegetables, steam oysters

• Cohort patients

• Disinfect using bleach-based cleaner

• Exclude food workers and HCWs for 48 hrs after symptoms end

TDOH response to norovirus

• Evaluation of trends

• CDC recommendations

• Laboratory capacity for identification increased

…additional TDOH responses

• Statewide annual review

• Fact sheet for long term care facilities

• Development of viral gastroenteritis fact sheet for Tennessee HDs

Conclusions

• Norovirus is a serious illness

• Illness can spread quickly in congregate settings

• Important to educate LTCF and other partners about prevention and control

Thank You!

• Effie Boothe: Effie.Boothe@tn.gov

• Marcy McMillian: Marcy.McMillian@tn.gov

615-741-7247