Infections are from microorganisms, like fungi, parasites, viruses and bacteria. A doctor can identify the type of infection based on the physical examination, person’s symptoms and other risk factors.
The doctor would usually assume that the sickness is because the patient has an infection than think of other sicknesses. For instance, a patient is coughing and currently experiencing breathing difficulties, hence it can be a type of lung infection called pneumonia, but it can be heart problem or asthma too. Through X-ray doctor can assess the real condition of the patient.
After the doctor confirms that it is an infection, he or she should determine the specific microorganism that is triggering the infection. There are a lot of microorganisms around that may cause the infection. Like in pneumonia, it can be cause by bacteria, fungi or viruses. And the medication that should be administered is different depending on the microorganism.
There are many types of tests that can be used to determine the microorganism. Infection test may use sample of sputum, urine, blood or any other tissue or fluid in the patient’s body. The sample can be:
- Stained and will be examined very closely using a microscope
- Cultured, where the sample will be placed in a condition that will encourage microorganism’ growth
- Will be tested for antibodies, that is produced by a patient’s immune system in relation to the microorganism
- It can be tested for some genetic materials like RNA or DNA, from the microorganism
There is no one test that can identify all microorganisms, a test that may be working well with one microorganism is not an assurance that it will work for the rest. The doctor’s judgement will take in to account, identifying which amongst the microorganism is the cause of the patient’s disorder.
Most of the time, few tests will be ordered, that is most of the time established from the results of the tests previously taken. Each of the tests will narrow down possibilities up until the time the microorganism has been identified. If the test is not appropriate, there is no way a doctor can identify the microorganism that is causing the infection.
Samples sent through swabs on patient’s throat or nose, stool or sputum, most of the time have bacteria that is not the actual cause of the sickness. Doctor will then determine the bacteria present on the sample, which can be the culprit of the disease.
On the other hand, urine, cerebrospinal fluid and blood, typically should not contain microorganism or bacteria, hence when there is presence of them, abnormality is easily identified.
Once microorganism is known, doctors can start running different tests to identify which amongst the available drugs is best to treat the condition.