LOOK SHARP: Incubation times vary for blood-borne viruses, which means they may not be detected in tests too soon after infection.

Photo: PTE John Wellfare

Runs in the blood
Being diagnosed with a blood-borne virus doesn’t necessarily end in discharge, as LTCOL Carmel van der Rijt, from the Directorate of Clinical Policy at the Defence Health Service, explains.

WHEN a Service member returns a positive test for Hepatitis B, Hepatitis C or HIV, a period of uncertainty follows, as further blood tests are taken and counselling occurs.

Understandably, most people loose a lot of sleep at this time. Normally, the patient’s doctor will explain that initial tests for blood-borne diseases can return a false positive result because they aim to identify the antibody in a person’s blood – the body’s reaction to a virus rather than the virus itself.

There are a number of people, including some in the ADF, who consistently return a positive test for the antibody, without having ever contracted a bloodborne virus. Follow-up tests focus on looking for the virus itself and these usually provide a more definite result.

The best strategy between tests is for the doctor to provide a patient with as much accurate information as possible. Counselling prepares and supports people through the diagnostic process, which may take several days to weeks and is extremely stressful.

Prevention is better than cure

HEPATITIS B, Hepatitis C and HIV can be contracted in different ways, but there are some simple precautions that will limit the risk of infection. Do not share needles. Do not share personal toiletries. Practice good general hygiene. Avoid unprotected sex. Use plastic, latex or rubber gloves when handling blood-contaminated objects or surfaces. Thoroughly wash hands and surfaces if they become contaminated with blood.

It is not normally possible to diagnose a blood-borne illness on the basis of a single test. During the period of uncertainty between blood tests, the patient is advised of the precautions that are necessary to avoid spreading a possible infection. Most of the precautions are similar to those for avoiding infection in the first place and are specific to the characteristics of each virus.

HIV, for example, is most often transmitted through unsafe sex, involving, in particular, male homosexual contact.

It can also be transmitted through drug injecting equipment and blood-to-blood contact, such as a blood transfusion or from mother to child. Hepatitis B can be transmitted through mucus membrane contact (including unprotected sexual contact), blood-to-blood contact, from mother to child or within a family.

Hepatitis C is predominantly transmitted through blood-to-blood contact. In Australia this is mainly as a result of injecting drug users sharing equipment, but it can also result from other activities, such as a needlestick or sharps injury and blood transfusion. The Australian Red Cross Blood Service screens all blood donations for blood-borne viruses, so the risk of contracting one from a blood transfusion in Australia is extremely low.

Hepatitis C viral infection is the most common of the three in Australia, both within the general population and in the ADF. Although any infection is a cause for concern, the reported statistics in the ADF are extremely low.

In 2001, Defence had one reported case of HIV, two cases of Hepatitis C and four cases of Hepatitis B. In 2002 there were three cases of Hepatitis C and one case of Hepatitis B reported. This compares to Australian statistics in 2003 of 1.5 per 100,000 population HIV cases, 74.5 per 100,000 population Hepatitis C cases and 1.8 per 100,000 population Hepatitis B new cases.

The other important fact is that ADF members are vaccinated for Hepatitis B. Currently there is no vaccination available for Hepatitis C, but all three viruses – HIV, Hepatitis C and Hepatitis B have treatments available, although the treatments are not all curative.

Defence members who contract blood-borne virus have their Medical Employment Classification (MEC) considered on a case-by-case basis, as there are many variables that need to be taken into consideration. Members who are generally well and have the Hepatitis B or Hepatitis C virus detected in their blood may be considered for MEC3 for up to12 months.

Members who remain well and eradicate the virus either as a result of treatment or the body’s immune response may be considered for MEC2. Between 20 and 30 per cent of people acutely infected with Hepatitis C will not develop a chronic infection and even more can defeat the virus with treatment.

Members who have eradicated the virus and who have been categorised as MEC2 would most likely have a medical restriction applied, making them ineligible to donate blood. Although treatment is available for HIV, at this stage there is no cure. Most people who contract the HIV virus will eventually develop AIDS, but the time between becoming HIV positive and AIDS developing varies from patient to patient.

In the ADF, the policy on HIV is flexible enough to allow the specific circumstances of the individual to be taken into account when determining the best course of action.

Members who are HIV positive who have not developed AIDS may be considered for retention on a case-by-case basis.

One of the most important things when a member is diagnosed as being HIV positive is for that person to have professional counselling to help in understanding the nature of the illness and what to do to maintain health.

Defence members are entitled to treatment for this illness over the period that they continue to serve as Defence members.

So when does the ADF test for bloodborne diseases?

Everyone applying to join the ADF is tested and then tested again three months after returning from an operational deployment.

Members who believe they may have been exposed to a blood-borne virus infection should seek medical advice as soon as possible. The viruses can have significant incubation times, during which time a false negative test may be initially returned.

This means it’s not a good idea to simply rely on a post-deployment test to exclude having contracted a blood borne disease as a result of a specific at risk exposure. These are very serious illnesses, so people need to be concerned if they think they may have been exposed to or contracted one of them.

The best person to talk to for people who think they have been exposed to a blood-borne virus is the unit medical officer.

The medical officer is able to provide professional advice and support while managing the diagnostic process.

The Defence policy on blood-borne diseases is outlined in Health Directive No. 210 and DI(G) Pers 16-6.