infections
Meningococcal Infections
Diagnosis of Meningococcal Infections
Examination and culture of samples of blood or other infected tissues, including cerebrospinal fluid obtained by spinal tap Sometimes polymerase chain reaction technique Doctors suspect meningococcal infection in people who have typical symptoms, particularly if symptoms occur during an outbreak. To confirm the diagnosis, doctors take samples of blood or other infected tissues or do a Spinal Tap (lumbar puncture) to obtain a sample of the fluid that surrounds the brain and spinal cord (cerebrospinal fluid). The samples are examined under a microscope to check for and identify bacteria. The samples are also sent to a laboratory, where the bacteria can be identified after it is grown (cultured) or other laboratory tests are done. If the bacteria is difficult to culture or other test results are inconclusive, doctors can do tests to identify pieces of the bacteria’s genetic material. Tests that detect genetic material in microorganisms are called nucleic acid–based tests. Polymerase chain reaction (PCR) is an example of this type of test. The PCR technique is done on samples of cerebrospinal fluid, blood, or other infected tissues. It is used to produce many copies of a gene from the bacteria, making the bacteria much easier to identify. Sometimes doctors do blood tests that detect antibodies to the bacteria or the capsule that encloses the bacteria. However, the results have to be confirmed by culture. The bacteria may also be tested to determine which antibiotics are effective (a process called Testing a Microorganism's Susceptibility and Sensitivity to Antimicrobial Drugs ). 