Waitematā DHB Laboratory Services
Public Service, Laboratory Tests
Some microorganisms (germs), generally bacteria and yeasts, live in and on the body normally. These organisms can cause disease if they spread to parts of your body where they are not usually found or if your resistance to infection is reduced by stress, injury, use of antibiotics or a viral infection.
Other microorganisms, not normally found in or on your body, can also cause disease.
When microorganisms cause infectious disease, they are known as pathogens. When a pathogen is in or on your body, samples need to be taken so that the pathogen can be identified and the correct medicine can be used to treat it.
When your doctor, nurse or laboratory technician takes a swab, they gently rub a clean cotton bud over the part of your body they think has an infection. The cotton bud is then wiped onto a special jelly-like material that helps any bacteria present grow. Once bacteria have grown, they can be identified under a microscope. It may take several days for the bacteria to grow.
Respiratory (Breathing Tract) swabs may be taken from your throat and from the back of your pharynx (wind pipe) if you have symptoms such as a sore throat or painful sinuses.
Skin. If you have a skin infection or have a wound that may be infected, a swab will be taken from the infection/wound site.
Ears and Eyes swabs may be taken from your eye or outer ear if you have symptoms of a bacterial infection such as itchy, crusty eyes or a painful ear with discharge.
Urogenital swabs may be taken from your cervix, vagina or urethra (women) or urethra (men) if you have symptoms of a genital infection.
Infections occur in the bladder, kidney, ureter or urethra and can be identified by examining urine samples. You will be given a container to collect your urine sample in and instructed on how to collect a mid-stream urine (MSU) sample.
Faeces (Bowel Motions)
If you have symptoms of an intestinal infection, such as diarrhoea, you may be asked for a bowel motion sample so that the pathogen (germ) causing the infection can be identified. You will be given a container and instructions on how to collect the sample. Sometimes you may need to collect two or three samples, taken on different days, to make sure the pathogen is identified correctly and therefore the correct medicine is used to treat the infection.
Skin and Nails
Scrapings of skin tissue or nail clippings may be taken for examination if you have symptoms of a fungal infection such as ringworm or athlete’s foot.
A sputum sample may be collected for examination in order to diagnose pneumonia, bronchitis or tuberculosis.
If your blood is infected, it can lead to a serious condition known as septicaemia. A blood sample will be taken to identify the pathogen that is present in your blood.