An infection, also known as blood poisoning, in which bacteria multiply in the bloodstream

  • More common in children and elderly people
  • Intravenous drug use is a risk factor
  • Gender and genetics are not significant factors

Septicaemia, also known as blood poisoning, is a potentially fatal condition in which bacteria multiply rapidly in the bloodstream. It is common for bacteria to enter the bloodstream in small numbers through sites such as a breach in the skin or through the mouth when the teeth are brushed. The bacteria are usually destroyed by the immune system and cause no symptoms. However, if bacteria enter the bloodstream in large numbers from a major source of infection, such as a kidney infection (see Pyelonephritis), blood poisoning can result. Septicaemia can develop as a complication of almost all types of serious infectious diseases.

The infection is more likely to occur in people with reduced immunity due to disorders such as diabetes mellitus or HIV infection (see HIV infection and AIDS) or due to treatment with chemotherapy or immunosuppressant drugs. Young children and elderly people are also more susceptible. Others at increased risk are intravenous drug users, who may introduce bacteria into their blood from contaminated needles.

What are the symptoms?

The symptoms of septicaemia develop suddenly and include:

  • High fever.

  • Chills and violent shivering.

If septicaemia is left untreated, the bacteria may produce toxins that damage blood vessels, causing a drop in blood pressure and widespread tissue damage. In this dangerous condition, called septic shock, symptoms may include:

  • Faintness.

  • Cold, pale hands and feet.

  • Restlessness and irritability.

  • Rapid, shallow breathing.

  • In many cases, delirium and eventual loss of consciousness.

In some people, bacteria may lodge on the heart valves, especially if the heart has previously been damaged by disease. This serious condition is called infective endocarditis. In rare cases, septicaemia may result in a lack of the blood cells involved in blood clotting (see Thrombocytopenia), which increases the risk of excessive bleeding.

Bacteria in blood

This magnified blood sample from a person with septicaemia shows small, rod-shaped bacteria among the blood cells.

What might be done?

If your doctor suspects that you have septicaemia, you will be admitted to hospital for immediate treatment. Intravenous antibiotics are given first, and then blood tests are performed to identify the bacterium causing the infection. Once the bacterium has been identified, specific antibiotics are given. With prompt treatment, most people make a complete recovery.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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