Norovirus Dr Bhakti Vasant Public Health Physician - Metro South Public Health Unit - Brisbane South PHN
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
Metro South Public Health Unit
Norovirus
Dr Bhakti Vasant
Public Health Physician
Source of image:
http://www.hillingdontimes.co.uk/news/11808717.Four_wards_closed_as_Hillingdo
n_Hospital_fights_norovirus_outbreak/
Outline
• Background
• Epidemiology
• At risk groups
• Symptoms
• Diagnosis
• Transmission
• Treatment
Source of image:
https://www.cdc.gov/norovirus/index.html
• Prevention
Background • Norovirus is a very contagious virus • Can infect anyone but spreads rapidly in institutional settings • Risk for the elderly • Leading cause of endemic diarrhoeal disease • Leading cause of foodborne disease • Causes half of all gastroenteritis outbreaks worldwide Acknowledgement: Dr Kari Jarvinen, Hall AJ. Noroviruses: The perfect human pathogens? The journal of infectious diseases 2012; 11(1): 1622–1624
Background • Rapid and prolific shedding in faeces / vomitus • Constantly evolving • Evokes limited immunity • Most people fully recover • Presents infection control challenges Source: Hall AJ. Noroviruses: The perfect human pathogens? The journal of infectious diseases 2012; 11(1): 1622–1624
Background: The guidelines Source: Australian Government Department of Health and Ageing. Guidelines for the public health management of gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL: http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdf
Epidemiology Worldwide: • Most common cause of epidemic gastroenteritis • Account for >90% of viral gastro outbreaks • 50% of all-cause outbreaks worldwide • Up to 200,000 deaths in children
Source of image: CDC. Available from: https://www.cdc.gov/norovirus/images/quick-stats- lg.jpg
Epidemiology Australia: • Estimated 1.8 million cases (95% CI 1.4 – 2.3 million cases) • Most common in late winter to early summer • Affects all age groups Source of text: Dolin R and Treanor JJ. Noroviruses and Sapoviruses (Caliciviruses). From: Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases, Updated Edition.
At risk groups of severe disease • Young children • The elderly • Immunocompromised people Source of text: Dolin R and Treanor JJ. Noroviruses and Sapoviruses (Caliciviruses). From: Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases, Updated Edition. Source of image: https://www.uq.edu.au/news/ article/2017/03/one-four- elderly-australian-women- has-dementia
Facilities at risk of outbreaks Closed settings • Hospitals • Residential aged care facilities • Cruise ships • Schools • The military Source: Dolin R and Treanor JJ. Noroviruses and Sapoviruses (Caliciviruses). From: Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases, source of image: https://agedcare.health.gov.au/
Symptoms
• Acute onset vomiting
• Watery, non-bloody diarrhoea with abdo cramps
• Nausea
• Some people may have low-grade fever,
headaches and myalgias (body aches)
Source of text: https://www.cdc.gov/norovirus/hcp/clinical-overview.html , source of image:
http://www.independent.co.uk/life-style/norovirus-treatment-symptoms-winter-vomiting-bug-outbreak-definition-avoid-
sickness-a8098786.htmlSuspected case of norovirus
1. Three or more loose stools or bowel movements in a 24
hour period that are different from normal AND / OR
2. Two or more episodes of vomiting in a 24 hour period
Source: Australian Government Department of Health and Ageing. Guidelines for the public health management of
gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL:
http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdfSuspected gastroenteritis outbreak
• “Two or more associated cases of diarrhoea and
/ or vomiting in a 24 hour period”
(excluding cases which have a known cause, e.g. bowel disease,
alcohol or pregnancy)
Source: Australian Government Department of Health and Ageing. Guidelines for the public health management of
gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL:
http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdfDiagnosis Confirmed cases of norovirus must meet the suspected case definition along with a positive laboratory test from one of the following: • Detection of human norovirus by antigen detection • Detection of human norovirus by nucleic acid assays • Visualisation of norovirus by electron microscopy Source: Australian Government Department of Health and Ageing. Guidelines for the public health management of gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL: http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdf
Specimens to collect
• Faecal
• Vomitus
• Testing of faecal specimens
• Microscopy, culture and sensitivity
• Viruses (esp norovirus)
• Parasites
Source of text: Australian Government Department of
Health and Ageing. Appendix 3: collection of clinical
specimens in an outbreak. Available from URL:
http://www.health.gov.au/internet/publications/publishing.
nsf/Content/cda-cdna-norovirus.htm-l~cda-cdna-
norovirus.htm-l-app3, source of image:
https://www.healthdirect.gov.au/stool-testsComplications • Dehydration • Acute kidney injury • Serum potassium loss cardiovascular instability • Malnutrition • Hospitalisation and death Source: Source: Dolin R and Treanor JJ. Noroviruses and Sapoviruses (Caliciviruses). From: Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases , Mattner F. Risk groups for clinical complications of norovirus infections: an outbreak investigation. Clinical Microbiology and Infection 2006; 12(1): 69 – 74
Transmission: Vomiting Larry • https://youtu.be/sLDSNvQjXe8 Source of image: https://www.npr.org/sections/health-shots/2013/01/04/168608466/as-norovirus-rages-a-robot- named-vomiting-larry-gets-a-closeup
Transmission Person to Person • Faecal-oral route • Ingestion of aerosolised vomitus • Indirect: fomites, contaminated environmental surfaces Foodborne • Contaminated by infected food handlers • Upstream (Distribution syst): contaminated water Waterborne outbreaks • Recreational / drinking water contamination Acknowledgement: Dr Kari Jarvinen, Australian Government Department of Health and Ageing. Guidelines for the public health management of gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL: http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdf
Period of shedding and infectivity
• Did not extend >72 hours after symptoms onset
in human volunteers
• One study of RACF outbreak found that
symptoms lasted 3–4 days and median
excretion time for norovirus was 8.6 days
• Prolonged shedding can occur
Source: Australian Government Department of Health and Ageing. Guidelines for the public health management of
gastroenteritis outbreaks due to norovirus or suspected viral agents in Australia. Available from URL:
http://www.health.gov.au/internet/main/publishing.nsf/content/cda-cdna-norovirus.htm/$File/norovirus-guidelines.pdfTransmission Source of image: https://www.cdc.gov/norovirus/images/vital-signs-transmission-lg.jpg
Transmission: why does norovirus spread
so rapidly?
1. Low infectious dose (≥18 viral particles)
• Copious viral shedding
• ≤5 billion infectious doses in each gram of faeces
2. Environmentally stable
• Survives freezing and heating
• Resistant to many common disinfectants
• Can persist on surfaces for up to 2 weeks
3. Many ways of spread
Source: Hall AJ. Noroviruses: The perfect human pathogens? The journal of
infectious diseases 2012; 11(1): 1622–1624Treatment • Supportive measures only • Oral fluid replacement • Rarely intravenous fluids • Symptomatic treatment of headache and myalgia • Anti-nausea medication Source of text: Dolin R and Treanor JJ. Noroviruses and Sapoviruses (Caliciviruses). From: Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases, Updated Edition.
Prevention of person-to-person outbreaks in RACFs • Infection control policies • Exclusion of infected staff until 48 hours after symptoms cease • Limited movement of residents, staff and visitors • Daily environmental cleaning and use of appropriate disinfectants • Effective handwashing • Personal protective equipment Source: Australian Government Department of Health and Ageing. Appendix 3: collection of clinical specimens in an outbreak. Available from URL: http://www.health.gov.au/internet/publications/publishing.nsf/Content/cda-cdna- norovirus.htm-l~cda-cdna-norovirus.htm-l-app3, Greig JD, Lee MB. Enteric outbreaks in long-term care facilities and recommendations for prevention: a review. Epidemiology and Infection 2009; 137: 145–155
Prevention of foodborne outbreaks in RACFs
• Safe food handling
• Temperature controls for foods
• Appropriate environmental cleaning and
disinfection
• Exclusion of infected staff until 48 hours after
symptoms cease
Source: Australian Government Department of Health and Ageing. Appendix 3: collection of clinical specimens in an
outbreak. Available from URL: http://www.health.gov.au/internet/publications/publishing.nsf/Content/cda-cdna-
norovirus.htm-l~cda-cdna-norovirus.htm-l-app3, Greig JD, Lee MB. Enteric outbreaks in long-term care facilities and
recommendations for prevention: a review. Epidemiology and Infection 2009; 137: 145–155Conclusions • Norovirus is highly infectious • Constantly evolving • A risk for elderly residents of aged care facilities • Presents infection control challenges • Prevention and control are important
Acknowledgement • Dr Kari Jarvinen • Dr Gayle Pollard • Metro South Public Health Unit
Contact email: Bhakti.Vasant@health.qld.gov.au Source of image: http://www.powerpointhintergrund.com/uploads/thank-you-background-powerpoint-22.jpeg
You can also read
