Best tests July 2009
Hepatitis testing report
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Hepatitis A
Hepatitis A IgM antibody
| Hepatitis A IgM antibody |
You | PHO (per GP) | National (per GP) |
| Number of tests (1 April 08 - 31 March 09) | * | * | 7 |
The hepatitis A IgM antibody is useful for determining if a patient has acute viral hepatitis.
Hepatitis A does not cause chronic hepatitis, so hepatitis A IgM antibody is not indicated when investigating mild liver pathology in a non-febrile person e.g. mildly abnormal liver function tests.
Hepatitis A IgM antibody is indicated for a person presenting with symptoms suggestive of acute hepatitis, following overseas travel or exposure to an outbreak. Given the limited indications for testing hepatitis A IgM antibody, it appears to be overused.
Consider if your use of hepatitis A IgM antibody is consistent with these recommendations.
Hepatitis A IgG antibody
| Hepatitis A IgG antibody |
You | PHO (per GP) | National (per GP) |
| Number of tests (1 April 08 - 31 March 09) | * | * | 9 |
The hepatitis A IgG antibody is useful for determining if a person has been previously exposed to hepatitis A – either through vaccination or previous infection.
Pre-immunisation screening for hepatitis A antibodies is not routinely recommended.
Pre-immunisation screening is only recommended for those people who are at risk of having had a previous infection, for example:
- People who are likely to have been exposed as children (born in a country of high endemicity) or in the course of their employment
- People with a history of jaundice
- Men who have sex with men
- IV drug users
- People who have frequently visited areas of high endemicity (this includes many countries in South America, Asia and Africa)
Hepatitis B
Hepatitis B surface antigen
| Hepatitis B surfaceantibody |
You | PHO (per GP) | National (per GP) |
| Number of tests (1 April 08 - 31 March 09) | * | * | 21 |
When hepatitis B infection is suspected, hepatitis B surface antigen is the initial test.
If this test is positive, a hepatitis B core antibody test is usually required. Further testing will usually be recommended by the laboratory.
Hepatitis B surface antibody
| Hepatitis B surfaceantibody |
You | PHO (per GP) | National (per GP) |
| Number of tests (1 April 08 - 31 March 09) | * | * | 21 |
Hepatitis B surface antibody should be used for pre-immunisation screening in high risk occupational and exposure groups. Routine pre-immunisation screening is usually not indicated.
Simultaneous ordering of antigen and antibody
You requested hepatitis B surface antigen and hepatitis B surface antibody simultaneously in xx%* of the patients you tested for hepatitis B.
There are limited indications for simultaneous ordering of hepatitis B surface antigen and hepatitis B surface antibody. These indications include:
- Pre-immunisation screening for people at high risk of being a carrier for hepatitis B
- Checking response post hepatitis B immunisation in babies born to hepatitis B surface antigen positive mothers
- Checking the status of an exposed person following a blood or body fluid exposure e.g. needlestick injury
Consider if your simultaneous ordering of hepatitis B surface antigen and hepatitis B surface antibody are consistent with these recommendations.
Hepatitis B testing and ethnicity
In New Zealand, the prevalence of chronic hepatitis B infection for Maori, Pacific and Asian people is approximately 6%, while prevalence in European populations is generally less than 1%1.
Despite the differences in prevalence, per capita rates of testing are similar for all ethnicities.
Taking into account your practice demographic, it may be worth considering targeted testing for Maori, Pacific and Asian people.
Practice tips
- For a person presenting with an acute hepatitis illness, it is more likely to be caused by hepatitis A or B, whereas a chronic illness is more likely to be caused by hepatitis B or C.
- Pre-immunisation screening prior to hepatitis A or B vaccination is usually not required.
- Post immunisation testing is usually not required.
- Ensure clinical indications for testing are included on the laboratory form.
References
- Robinson T, Bullen C, Humphries W, et al. The New Zealand Hepatitis B Screening Programme: screening coverage and prevalence of chronic hepatitis B infection. NZ Med J 2005;118:1345.
Notes
- Data presented in this report is sourced from the NZHIS Laboratory claims database. There is a potential for data entry errors at the laboratory, HealthPAC or NZHIS. All tests associated with an NZMC number will be presented regardless of where they were generated e.g. an after-hours clinic or rest home. Data has been excluded where the NZMC number was not recorded.
- Simultaneous testing of Hepatitis B surface antibody and Hepatitis B surface antigen was defined as the same patient, on the same day and requested by the same NZMC number.
- * Some data has been removed
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