Public Health Follow-up of Sporadic Enteric Disease Notifications

Applicable to:

Description: A revised version of the public health follow-up of sporadic enteric disease notifications which is mainly conducted by population health units and OzFoodNet, Department of Health.

Public Health Follow-up of Sporadic Enteric Disease Notifications

This Operational Directive describes the course of action to be undertaken by staff of Public Health Units (PHU) and/or the OzFoodNet Unit within the Communicable Disease Control Directorate for the public health management of sporadic cases of notifiable enteric infections. Clusters or outbreaks of enteric infection, especially those occurring in the Perth metropolitan area, are generally investigated by OzFoodNet, with assistance from PHUs, as required.

This document should be read in conjunction with Guidelines for exclusion of people with enteric infections and their contacts from work, school and child-care settings (OD 0303/10). 

1.         BACKGROUND

Enteric infections comprise around one–fifth of all infectious disease notifications in WA. Campylobacteriosis and salmonellosis are most common, accounting for over three-quarters of enteric disease notifications.  Appropriate public health management of sporadic enteric disease cases is important in preventing the transmission, and reducing the impact, of these infections. 

2.         CONTROL MEASURES

The table below summarises the public health follow-up required for sporadic cases of notifiable enteric infections and their contacts, and identifies the responsible organisation and the response timeframe.

Disease
(incubation period)

Public health follow-up for cases

Public health follow-up for contacts

Organisation responsible

Response time

Botulism
(12-36 hours)

Identify source and stop further consumption of contaminated food.

Identify people who have eaten source food & are at risk of developing disease.

OFN, CDCD in collaboration with FU

On day of notification

Haemolytic uraemic syndrome (HUS) caused by enteric infections
(N/A)

Interview to identify risk factors.

Maintain surveillance for further cases.

N/A

OFN, CDCD

Within 1 working day of notification

Listeria infection
(3-70 days)

Interview to identify risk factors.

Maintain surveillance for further cases.

N/A

OFN, CDCD

Within 1 working day of notification

Salmonella Enteritidis
infection
(1-7 days)

Interview to ascertain where infection acquired. If Australian-acquired, identify risk factors.

Ensure enteric precautions and exclusions.*

N/A

OFN, CDCD

Within 7 working days of notification

Shiga-/Vero-toxigenic
E. coli (STEC/VTEC) infection
(2-10 days)

Interview to identify risk factors.

Ensure enteric precautions, exclusions and clearance specimens for high risk cases*.

N/A

OFN, CDCD

Within 1 working day of notification

Vibrio parahaemolyticus infection
(4-30 hours)

Interview to ascertain where infection acquired. If Australian-acquired, identify risk factors.

Ensure enteric precautions and exclusions*.

N/A

OFN, CDCD

Within 2 working days of notification

Cholera (Vibrio cholerae 01/0139) presumptive toxin positive
(Hours to 5 days)

Interview to ascertain where infection acquired (see Appendix 1). If Australian-acquired, refer to OFN to identify risk factors.

Ensure enteric precautions, exclusions and clearance specimens for high risk cases*.

N/A

PHU

On day of notification

Hepatitis A
(15-50 days)

See Operational Directive (OD 0228/09) Management of Hepatitis A.

PHU

Within 1 working day of notification

 

Disease
(incubation period)

Public health follow-up for cases

Public health follow-up for contacts

Organisation responsible

Response time

Hepatitis E
(26-42 days)

Interview to ascertain where infection acquired. If Australian-acquired, refer to OFN to identify risk factors.

Ensure enteric precautions and exclusions for high risk cases*.

N/A

PHU

Within 2 working days of notification

Paratyphoid
(Salmonella Paratyphi)
(1-10 days)

Interview to ascertain where infection acquired (see Appendix 1). If Australian-acquired, refer to OFN to identify risk factors.

Ensure enteric precautions, exclusions and clearance specimens for high risk cases*.

Ensure enteric precautions, exclusions and clearance specimens for high risk contacts*

PHU

On day of notification

Shigella dysenteriae infection
(1-3 days)

Interview to ascertain where infection acquired (see Appendix 1). If Australian-acquired, refer to OFN to identify risk factors.

Ensure enteric precautions, exclusions and clearance specimens for high risk cases*.

N/A

PHU

On day of notification

Typhoid (Salmonella Typhi)
(3-60 days)

Interview to ascertain where infection acquired (see Appendix 1). If Australian-acquired, refer to OFN to identify risk factors.

Ensure enteric precautions, exclusions and clearance specimens for high risk cases*.

Ensure enteric precautions, exclusions and clearance specimens for high risk contacts*

PHU

On day of notification

Yersinia infection

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Cryptosporidium infection

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Salmonella species, not listed above

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Shigella species, not listed above

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Campylobacter infection

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Rotavirus

Generally only clusters or outbreaks investigated, by OFN with assistance from PHU as required.

Notes:    *refer to Guidelines for exclusion of people with enteric infections and their contacts from work, school and child-care settings (OD 0303/10). High risk cases include health care, residential care and child care workers, food handlers, young children in child care and people who are faecally incontinent.

FU = Food Unit, Environmental Health Directorate
OFN, CDCD = OzFoodNet, located within Communicable Disease Control Directorate
PHU = Public Health Unit
N/A = Not applicable

3.         PROCEDURE FOR PUBLIC HEALTH MANAGEMENT OF SPORADIC ENTERIC DISEASE NOTIFICATIONS

General procedures

  • Confirm that the case meets the case definition for notification and is entered on the Western Australian Notifiable Infectious Disease Database (WANIDD) within 24 hours of receipt, if not already on the database.  Update the notification record in WANIDD if additional information is available.  Case definition manuals are available in all PHUs, or individual disease definitions are listed on the Department of Health Public Health website, in the section ‘Infectious diseases A to Z for health professionals’ http://www.public.health.wa.gov.au/2/243/3/infectious_diseases_az_for_health_professionals.pm
  • Refer to table in section 3 above to decide whether OFN or the PHU is responsible for public health management of the case, and the appropriate response time.
  • If a PHU is responsible, the case should be followed up by the PHU in the area where the case resides, or for non-residents the PHU area where the case received medical attention.
  • Prior to proceeding with case follow-up, the CDCD/PHU staff member should advise the notifying medical practitioner of their intention to contact the case.  This is necessary as electronic laboratory notification to CDCD often occurs before the medical practitioner becomes aware of the positive result.  Hence, the patient may not have been informed of their diagnosis.  In the event that the notifying medical practitioner or appropriate delegate (e.g. practice nurse) is unavailable, CDCD/PHU staff should continue with the follow-up investigation in the interest of minimising disease transmission.
  • Implement appropriate public health interventions for case and contacts as documented in the table in section 3 above, in collaboration with the notifying medical practitioner and local government officers, as appropriate.
  • During public health follow-up, update WANIDD with information collected, including date of onset, travel history, clinical history, whether cases or contacts are high risk and when follow-up is complete.
  • If there is cluster or outbreak of a locally acquired enteric infection, CDCD and/or PHU staff will investigate, as appropriate. In the Perth metropolitan area, CDCD will generally lead outbreak investigations. In country areas, the PHU should lead, with advice from CDCD.

Cholera, Shigella dysenteriae, typhoid and paratyphoid

  • Cholera: for Vibrio cholerae O1 or O139 to meet the case definition, the isolate must be toxin positive.  However, as toxin testing can take some time, public health follow-up should commence presumptively once the organism is identified as serotype O1 or O139.
  • Cases
    • Use the questionnaire included in Appendix 1.  Interview the case or, if this is not possible, interview their carer or doctor.  For “high risk” cases of typhoid, paratyphoid, Shigella dysenteriae infection orcholera, use the appropriate letters in Appendices 2 and 3 to assist with collection of clearance specimens.
  • Contacts
    • For high risk contacts of typhoid and paratyphoid only, use the letter in Appendix 4 to assist with collection of clearance specimens.
    • For low risk contacts of typhoid, paratyphoid cholera, and Shigella dysenteriae infection, use the letter in Appendix 5 to assist with public health management.

Hepatitis A

  • For guidance on public health management, see OD 0228/09, Management of Hepatitis A.

4.         MORE INFORMATION

For more information contact OzFoodNet staff at the Communicable Disease Control Directorate (08 9388 4811 / 08 9388 4872) or the appropriate Public Health Unit with contact details listed at http://www.public.health.wa.gov.au/3/280/3/contact_details.pm.

5.         REFERENCES

1.   Heymann DL (ed).  Control of Communicable Diseases Manual 2008 (19th Edition).  American Public Health Association.

2.   Communicable Disease Control Network Australia (CDNA). Surveillance Case Definitions for the Australian National Notifiable Diseases Surveillance System: 1 January 2004 to 1 July 2013. http://www.health.gov.au/internet/main/publishing.nsf/Content/cdna-casedefinitions.htm

6.         APPENDICES

Appendix 1:   Typhoid / Paratyphoid /Cholera / Shigella dysenteriae Questionnaire.
Appendix 2:   Typhoid / Paratyphoid specimen collection for clearance letter (high risk cases).
Appendix 3:   Cholera /Shigella dysenteriae specimen collection for clearance letter (high risk cases).
Appendix 4:   Typhoid / Paratyphoid specimen collection for clearance letter (high risk contacts).
Appendix 5:   Typhoid / Paratyphoid / Cholera / Shigella dysenteriae letter (low risk contacts).


Professor Bryant Stokes
A/DIRECTOR GENERAL
DEPARTMENT OF HEALTH WA

Date of effect: 14 January 2014 to 14 January 2019

Policy Framework

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Supporting information