Chapter reviewed and updated in December 2017. A description of changes can be found at Updates to the Communicable Disease Control Manual.

Epidemiology

New Zealand epidemiology

New Zealand epidemiology

Campylobacteriosis is the most frequently notified disease in New Zealand. There is marked seasonality in notifications, with the peak in spring and summer.

Traditionally, campylobacteriosis has mainly been attributed to C. jejuni, and to a lesser degree, C. coli and C. fetus, but other species are increasingly recognised as human pathogens.

More detailed epidemiological information is available on the Institute of Environmental Science and Research (ESR) surveillance website.

Further information on foodborne illness is available on the Ministry for Primary Industries website.

Case definition

Clinical description

Clinical description

An illness of variable severity with symptoms of abdominal pain, fever and watery diarrhoea, sometimes including bloody stools. Less frequently, Campylobacter can present as an invasive disease.

Laboratory test for diagnosis

Laboratory test for diagnosis

Laboratory definitive evidence for a confirmed case requires identification of Campylobacter spp. from a clinical specimen by one of the following methods:

  • isolation (culture)
  • detection of Campylobacter nucleic acid
  • detection of antigen.

All species of Campylobacter should be notified. Where possible, culture should be attempted. Diagnostic laboratories may choose to identify further than genus level but should refer isolates for confirmatory speciation to the Enteric Reference Laboratory at ESR.

Case classification

Case classification
  • Under investigation: A case that has been notified, but information is not yet available to classify it.
  • Probable: A clinically compatible illness that either is a contact of a confirmed case of the same disease or has had contact with the same common source – that is, is part of a common-source outbreak.
  • Confirmed: A clinically compatible illness accompanied by laboratory definitive evidence.
  • Not a case: A case that has been investigated and subsequently found not to meet the case definition.

Spread of infection

Reservoir

Reservoir

Zoonotic infection. C. jejuni associated primarily with poultry; also cattle, sheep and domestic pets. C. coli associated with pigs and poultry and C. fetus with cattle. Asymptomatic carriage.

Incubation period

Incubation period

Usually 2–5 days, range 1–10 days.

Mode of transmission

Mode of transmission

Historically, most often by ingestion of contaminated food, typically poultry or unpasteurised milk. Cross-contamination from raw meat to other foodstuffs may occur via hands, utensils, chopping boards or incorrect storage. In New Zealand, consumption of faecally contaminated water and direct contact with farm or domestic animals are common routes of transmission. Person-to-person transmission is uncommon.

Period of communicability

Period of communicability

Campylobacter spp. may be shed in the stool for several weeks after infection.

Notification

Notification procedure

Notification procedure

Attending medical practitioners or laboratories must notify the local medical officer of health of cases of probable or confirmed campylobacteriosis.

All health care workers are encouraged to talk with a medical officer of health about any suspected outbreaks or cases in people who are in high-risk occupations.

Management of case

Investigation

Investigation

Investigate and obtain a detailed history if there is an outbreak or if the case is in a high-risk occupation or attends an early childhood service.

Obtain a food consumption history and details of water consumption and animal contact as well as details of occupation as appropriate per local protocol.

Ensure symptomatic cases submit stool samples for testing.

Restriction

Restriction

In a health care facility, only standard precautions are indicated in most cases. If the case is diapered or incontinent, apply contact precautions for the duration of illness. For further details, refer to the exclusion and clearance criteria in Appendix 2: Enteric disease.

Counselling

Counselling

Advise the case and their caregivers of the nature of the infection and its mode of transmission. Educate about hygiene and risks of infrequent significant complications such as GBS and reactive arthritis.

Management of contacts

Definition

Definition

As set out in the exclusion and clearance criteria (Appendix 2: Enteric disease), screening or restriction is not indicated for contacts of infectious cases or for people who have been exposed to the same food material suspected to be the source of infection.

If symptomatic, investigate and manage as a case until the stool test results are known.

Other control measures

Identification of source

Identification of source

Check for other cases in the community. Investigate potential food or water sources of infection only if there is a cluster of cases or an apparent epidemiological link.

If indicated, check water supply for microbiological contamination and compliance with the latest New Zealand drinking-water standards (Ministry of Health 2008). Liaise with the local territorial authority staff to investigate potential water sources of infection.

Disinfection

Disinfection

Clean and disinfect surfaces and articles soiled with stool. For more details, refer to Appendix 1: Disinfection.

Health education

Health education

Educate the public about safe food preparation (see Appendix 3: Patient information).

Hand-cleaning facilities should be available and used after contact with animals. Young children should be supervised during contact with animals and during hand cleaning. Food-related activities should be separated from areas that house animals. Domestic animals that have diarrhoea should be taken to a veterinarian for assessment and treatment.

If a water supply is involved, liaise with the local territorial authority to inform the public. Advise on the need to boil water.

In early childhood services or other institutional situations, ensure satisfactory facilities and practices regarding hand cleaning; nappy changing; toilet use and toilet training; preparation and handling of food; and cleaning of sleeping areas, toys and other surfaces.

Reporting

National reporting

National reporting

Ensure complete case information is entered into EpiSurv.

Where food/food businesses are thought to be involved inform the Ministry for Primary Industries.

If a cluster of cases occurs, contact 0800GETMOH - CD option, and outbreak liaison staff at ESR, and complete the Outbreak Report Form.

Further information

References

References
  • Ministry of Health. 2008. Drinking-water Standards for New Zealand 2005 (Revised 2008). Wellington: Ministry of Health.