The Risks

There are three potentially serious laboratory acquired infections in which the risk of infection and serious illness can be reduced by immunisation. These are Hepatitis B, Hepatitis A and Tetanus.

Hepatitis B

Hepatitis B is transmitted most commonly as a result of blood to blood contact including injury with contaminated instruments. Transmission has also rarely followed bites from infected persons. The severity of the disease ranges from infections which can only be detected by laboratory tests to fatal cases.

Hepatitis A

Hepatitis A is transmitted by the faecal-oral route. Spread is most common through contaminated food or drink. Hepatitis A in healthcare workers has occasionally been seen in residential institutions for the mentally handicapped. Workers involved in sewage treatment facilities are also potentially at risk. The disease is generally mild and unlike Hepatitis B there is no chronic carrier state and no likelihood of chronic liver damage. However, the acute disease can be debilitating in some adults and occasional cases of fulminating Hepatitis A have been recorded.


Tetanus is a serious life-threatening condition caused by the toxin produced by Clostridium tetani. The organism is principally found in soil, animal faeces and dust (it has been isolated from carpets) and must be considered a possible contaminant in any dirty wound. The spore forming ability of the organism means that it will survive indefinitely in samples unless they are specifically inactivated. Transmission is via skin wounds and is believed to have been imperceptible in some cases.