Typically, sampling for legionella check is not legally required, except in very specific circumstances (such as cooling towers or evaporative condensers). However, regular testing is often recommended as a practical way to confirm that your water management programme is working. Sampling will also help you identify any areas where additional measures are needed, such as flushing your system or making changes to water temperature.
There are a number of different tests that can be used to check for the presence of Legionella bacteria in urine or sputum. These include a urine antigen test, a sputum culture or a quantitative real-time PCR (qPCR) assay for the detection of both Legionella species and Legionella pneumophila.
Urine Antigen Test
A urine antigen test is a simple blood-based test that can help identify people who are at risk of contracting Legionnaires’ disease. It is a quick and relatively cheap test to carry out, but it can be inaccurate and doesn’t identify the specific strain of Legionella that is present in the sample.
A sputum culture test is a more detailed lab-based method that can be used to detect the presence of Legionella in sputum. This can be a useful tool for those who have already been diagnosed with Legionnaires’ disease or for health and safety professionals investigating possible exposure to the bacteria in their workplace. A sputum culture should only be carried out by trained and experienced individuals, as the test requires a special collection procedure and the correct laboratory analysis.