Vaccine preventable diseases and vaccination coverage in Aboriginal and Torres Strait Islander people, Australia 2006–2010

Appendix B: Case definitions in effect during data collection period

Page last updated: 19 December 2013

NNDSS case definitions are also available at www.health.gov.au/casedefinitions, and previous versions described in Vaccine preventable diseases in Australia, 2005 to 2007.24

Diphtheria

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence only. A probable case requires laboratory suggestive evidence and clinical evidence, or clinical evidence and an epidemiological link to a laboratory-confirmed case.

Laboratory definitive evidence:

  • Isolation of toxigenic Corynebacterium diphtheriae or toxigenic C. ulcerans.

Laboratory suggestive evidence:

  • Isolation of C. diphtheriae or C. ulcerans (toxin production unknown).

Clinical evidence:

  • At least one of the following:
  • pharyngitis and/or laryngitis (with or without) membrane), or toxic (cardiac or neurological) symptoms.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code A36 (diphtheria) was used to identify hospitalisations and deaths.

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Hib

Notifications

Invasive Hib infection

Only confirmed cases are notifiable. A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence:

  • Isolation of Haemophilus influenzae type b from a normally sterile site where typing has been confirmed at an approved reference laboratory, or
  • Detection of Hib antigen in cerebrospinal fluid when other laboratory parameters are consistent with meningitis.

Hospitalisations and deaths

There were no ICD-10-AM/ICD-10 codes which specified Hib as a causative organism. The ICD-10-AM/ICD-10 code used to identify presumed Hib cases was G00.0 (Haemophilus meningitis). The ICD-10-AM/ICD-10 codes for H. influenzae pneumonia, H. influenzae septicaemia, H. influenzae infection and acute epiglottitis were not included as these were considered insufficiently specific for invasive H. influenzae type b disease.

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Hepatitis A

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence only. A probable case requires clinical evidence and an epidemiological link to a laboratory-confirmed case.

Laboratory definitive evidence:

  • Detection of anti-hepatitis A virus IgM antibody (in the absence of recent vaccination), or
  • Detection of hepatitis A virus by nucleic acid testing.

Clinical evidence:

  • Clinical hepatitis (jaundice and/or bilirubin in urine) without a non-infectious cause.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B15 (hepatitis A) was used to identify hospitalisations and deaths.

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Acute hepatitis B (newly acquired)

Notifications

Only confirmed cases are notifiable. A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence:

  • Detection of hepatitis B surface antigen (HBsAg) in a patient shown to be negative within the last 24 months, or
  • Detection of HBsAg and IgM to hepatitis B core antigen, in the absence of prior evidence of hepatitis B virus infection, or
  • Detection of hepatitis B virus by nucleic acid testing, and IgM to hepatitis B core antigen, in the absence of prior evidence of hepatitis B virus infection.

Hospitalisations

The ICD-10-AM code B16 (acute hepatitis B) was used to identify hospitalisations. As in the previous reports, hospitalisations were included only where the relevant ICD code was the principal diagnosis.

Deaths

The ICD-10 code B16 (acute hepatitis B) was used to select deaths from acute hepatitis B.

* Queensland implemented a consistent but less comprehensive definition for laboratory notification in December 2005 for ‘Hepatitis B (acute)’: HBsAg positive and anti-HBc IgM positive. However, the public heath protocol for notification in Queensland accepts cases meeting the broader national case definitions for notification.

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Influenza

Notifications

Only confirmed cases are notifiable. A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence:

  • Isolation of influenza virus by culture from appropriate respiratory tract specimen, or
  • Detection of influenza virus by nucleic acid testing from appropriate respiratory tract specimens, or
  • Detection* of influenza virus antigen from appropriate respiratory tract specimen, or
  • IgG seroconversion or a significant increase in antibody level or a 4-fold or greater rise in titre to influenza virus, or
  • Single high titre* to influenza virus.

Laboratory-confirmed influenza only became notifiable in South Australia in May 2008.

Hospitalisations

The ICD-10-AM codes used to identify hospitalisations were J09 (influenza due to certain identified influenza viruses), J10 (influenza due to identified influenza virus) and J11 (influenza, virus not identified). In this report, we did not make the distinction between admissions where a virus was identified and those where it was not.

Deaths

The ICD-10 codes used to identify deaths were: J09 (influenza due to certain identified influenza viruses), J10 (influenza due to identified influenza virus) and J11 (influenza, virus not identified).

* The criteria of the national case definitions were revised and implemented in 2008. The revisions consisted of specifying that the influenza virus antigen detection has to be laboratory detection, and that the single high titre qualifying for notification has to be performed by complement fixation test (CFT) or by haemagglutination inhibition (HAI).

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Measles

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence, or clinical evidence and an epidemiological link to a laboratory-confirmed case. A probable case requires laboratory suggestive evidence and clinical evidence.

Laboratory definitive evidence:

  • Isolation of measles virus, or
  • Detection of measles virus by nucleic acid testing, or
  • Detection of measles virus antigen, or
  • Measles virus-specific IgG seroconversion or significant increase in IgG antibody level or a 4-fold or greater rise in antibody titre to measles virus, with paired sera tested in parallel and in the absence of receipt of measles-containing vaccine 8 days to 8 weeks prior to testing, or
  • Detection of measles virus-specific IgM antibody confirmed in an approved reference laboratory (in the absence of recent measles-containing vaccination).

Laboratory suggestive evidence:

  • Detection of measles-specific IgM antibody other than by an approved reference laboratory (in the absence of recent measles-containing vaccination).

Clinical evidence:

  • A clinical illness characterised by a generalised maculopapular rash lasting at least 3 days and fever of at least 38°C at the time of rash onset and cough, coryza, conjunctivitis or Koplik spots.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B05 (measles) was used to identify hospitalisations and deaths. Subacute sclerosing panencephalitis (SSPE) was not included in these analyses.

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Meningococcal disease

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence, or laboratory suggestive evidence and clinical evidence. A probable case requires specified clinical evidence only.

Laboratory definitive evidence:

  • Isolation of Neisseria meningitidis from a normally sterile site, or
  • Detection of specific meningococcal DNA sequences in a specimen from a normally sterile site by nucleic acid amplification testing.

Laboratory suggestive evidence:

  • Detection of Gram-negative diplococci in Gram stain of specimen from a normally sterile site or from a suspicious skin lesion, or
  • High titre IgM or significant rise in IgM or IgG titres to outer membrane protein antigens of N. meningitidis.

Clinical evidence for a confirmed case:

  • Disease which in the opinion of the treating clinician is compatible with invasive meningococcal disease.

Clinical evidence for a probable case:

  • The absence of evidence for other causes of clinical symptoms and either clinically compatible disease including haemorrhagic rash, or clinically compatible disease and close contact with a confirmed case within the previous 60 days.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code A39 (meningococcal infection) was used to identify hospitalisations and deaths. This includes meningococcal meningitis (A39.0), Waterhouse-Friderichsen syndrome (A39.1), acute meningococcaemia (A39.2), chronic meningococcaemia (A39.3), meningococcaemia unspecified (A39.4), meningococcal heart disease (A39.5), other meningococcal infections (A39.8), and meningococcal infection unspecified (A39.9).

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Mumps

Notifications

Only confirmed cases are notifiable. A confirmed case requires laboratory definitive evidence, or laboratory suggestive evidence and clinical evidence, or clinical evidence and an epidemiological link to a laboratory-confirmed case.

Laboratory definitive evidence:

  • Isolation of mumps virus, or
  • Detection of mumps virus by nucleic acid testing, or
  • IgG seroconversion or a significant increase in antibody level or a 4-fold or greater rise in titre to mumps virus (in the absence of recent mumps-containing vaccination).

Laboratory suggestive evidence:

  • Detection of mumps-specific IgM antibody (in the absence of recent mumps-containing vaccination).

Clinical evidence:

  • A clinically compatible illness characterised by swelling of the parotid or salivary glands lasting 2 days or more without other apparent cause.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B26 (mumps) was used to identify hospitalisations and deaths.

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Pneumococcal disease (invasive)

Notifications

Only confirmed cases are notifiable. A confirmed case requires laboratory definitive evidence only.

Laboratory definitive evidence:

  • Isolation of Streptococcus pneumoniae from a normally sterile site by culture, or
  • Detection of S. pneumoniae from a normally sterile site by nucleic acid testing.

Hospitalisations

The ICD-10-AM codes used to identify hospitalisations were: G00.1 (pneumococcal meningitis); A40.3 (pneumococcal septicaemia) (together considered to be a proxy for invasive pneumococcal disease); and J13 (pneumococcal pneumonia). To avoid double counting, cases were identified in a hierarchical fashion. First, all those with code G00.1 were classified as meningitis, then those without G00.1 but with A40.3 were classified as septicaemia without meningitis, and then those with neither of these codes but with code J13 were counted as pneumococcal pneumonia.

Deaths

ICD-10 codes G00.1, A40.3 and J13 were used to select deaths attributed to IPD.

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Pertussis

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence, or laboratory suggestive evidence and clinical evidence, or clinical evidence and an established epidemiological link to a confirmed case with laboratory evidence. A probable case requires specified clinical evidence only.

Laboratory definitive evidence:

  • Isolation of Bordetella pertussis from a clinical specimen, or
  • Detection of B. pertussis by nucleic acid testing.

Laboratory suggestive evidence:

  • Seroconversion or a significant increase in antibody level or a 4-fold or greater rise in titre to B. pertussis (in the absence of recent pertussis vaccination), or
  • Single high IgA titre to whole cells, or
  • Detection of B. pertussis antigen by immunofluorescence assay (IFA).

Clinical evidence for a confirmed case:

  • A coughing illness lasting 2 or more weeks, or
  • Paroxysms of coughing or inspiratory whoop or post-tussive vomiting.

Clinical evidence for a probable case:

  • A coughing illness lasting 2 or more weeks, and
  • Paroxysms of coughing or inspiratory whoop or post-tussive vomiting.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code A37 (whooping cough) was used to identify hospitalisations and deaths.

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Rubella

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence only. A probable case requires clinical evidence and either laboratory suggestive evidence or an epidemiological link to a laboratory-confirmed case.

Laboratory definitive evidence:

  • Isolation of rubella virus, or
  • Detection of rubella virus by nucleic acid testing, or
  • IgG seroconversion or a significant increase in antibody level or a 4-fold or greater rise in titre to rubella virus in the absence of recent rubella vaccination, in paired sera tested in parallel, or
  • Detection of rubella-specific IgM antibody in the absence of recent rubella vaccination (in pregnant women, must be confirmed in a reference laboratory).

Laboratory suggestive evidence:

  • In a pregnant patient, detection of rubella-specific IgM antibody that has not been confirmed in a reference laboratory (in the absence of recent rubella vaccination).

Clinical evidence:

  • A generalised maculopapular rash and fever and one or more of arthralgia/arthritis or lymphadenopathy or conjunctivitis.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B06 (rubella (German measles)) was used to identify hospitalisations and deaths.

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Poliomyelitis

Notifications

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence and clinical evidence. A probable case requires clinical evidence and that the case is not discarded as non-polio paralytic illness by the Polio Expert Committee.

Laboratory definitive evidence:

  • Isolation of wild poliovirus (or Sabin-like poliovirus for vaccine-associated paralytic poliomyelitis (VAPP) cases), confirmed in the WHO Western Pacific Regional Poliovirus Reference Laboratory, or
  • Detection of wild poliovirus (or Sabin-like poliovirus for VAPP cases) by nucleic acid testing, confirmed in the WHO Western Pacific Regional Poliovirus Reference Laboratory.

Clinical evidence:

  • Acute flaccid paralysis: acute onset of progressive weakness and flaccidity of one or more limbs with decreased or absent tendon reflexes in the affected limbs or bulbar palsy without other apparent cause, and without sensory or cognitive loss.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code A80 (acute poliomyelitis) was used to identify hospitalisations and deaths.

Note: This code includes VAPP and specific codes for Indigenous and imported wild-type poliovirus infection. Sequelae of poliomyelitis (ICD-10 code B91) were not included in these analyses.

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Rotavirus

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code A08.0 (rotaviral enteritis) was used to identify hospitalisations and deaths.

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Tetanus

Notifications

Only confirmed cases are notifiable. A confirmed case requires either laboratory definitive evidence or clinical evidence.

Laboratory definitive evidence:

  • Isolation of Clostridium tetani from a wound in a compatible clinical setting and prevention of positive tetanospasm in mouse test from such an isolate using specific tetanus antitoxin.

Clinical evidence:

  • A clinically compatible illness without apparent cause.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 codes A34 (obstetrical tetanus) and A35 (other tetanus) were used to identify hospitalisations and deaths.

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Varicella-zoster (chickenpox)

Notifications

National definition from 2006

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence and clinical evidence, or clinical evidence and an epidemiological link to a laboratory-confirmed case. A probable case requires clinical evidence only.

Laboratory definitive evidence:

  • Isolation of varicella-zoster virus (VZV) from a skin or lesion swab, or
  • Detection of VZV from a skin or lesion swab by nucleic acid testing, or
  • Detection of VZV antigen from a skin or lesion swab by direct fluorescent antibody, or
  • Detection VZV-specific IgM in an unvaccinated person.

If the case received varicella vaccine within 5 and 42 days prior to onset of rash, the virus must be confirmed to be a wild-type strain.

Clinical evidence:

  • Acute onset of a diffuse maculopapular rash developing into vesicles within 24–48 hours and crusting over within 5 days.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B01 (chickenpox) was used to identify varicella hospitalisations and deaths.

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Varicella-zoster (shingles)

Notifications

National definition from 2006

Both confirmed cases and probable cases are notifiable. A confirmed case requires laboratory definitive evidence and clinical evidence. A probable case requires clinical evidence only.

Laboratory definitive evidence:

  • Isolation of varicella-zoster virus (VZV) from a skin or lesion swab, or
  • Detection of VZV from a skin or lesion swab by nucleic acid testing, or
  • Detection of VZV antigen from a skin or lesion swab by direct fluorescent antibody.

Clinical evidence:

  • A vesicular skin rash with a dermatomal distribution that may be associated with pain in skin areas supplied by sensory nerves of the dorsal root ganglia.

Hospitalisations and deaths

The ICD-10-AM/ICD-10 code B02 (zoster (shingles)) was used to identify herpes zoster hospitalisations and deaths.

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