Infections involving the central nervous system (CNS), such as meningitis/encephalitis (ME), are serious clinical conditions associated with high morbidity and mortality rates, as well as significant long-term consequences. ME can be caused by a wide variety of pathogenic agents. Clinical symptoms may vary and it has been shown that early identification of the pathogens causing ME allows for timely and appropriate treatment, thus reducing permanent neurological damage. The multiparameter panel "QIAstat-Dx®Meningitis/Encephalitis" can detect in one hour on a sample of 15 bacterial, viral and fungal pathogens. In the diagnostic routine, Real-time PCR takes an average of 3 hours and culture examination 2 days. In addition, compared to other comparable rapid molecular systems, the "QIAstat-Dx" platform has the ability to generate a cycle-related threshold value (Ct) for the targets detected. This value may have a correlation with the viral load and thus provide in a short time not only the result of positivity, but also an indication of the amount of virus present. Other commercially available multiparameter molecular tests provide only qualitative data.

The study is on biological samples of cerebrospinal fluid, positive for viruses or bacteria of interest, retrospective, monocentric, non-pharmacological.

For each sample included in the study (170 total samples), the molecular/culture test result, provided by the normal diagnostic process at the Microbiology Unit, is available for comparison with those obtained with the multiparameter panel QIAstat-Dx® Meningitis/Encephalitis (ME) and QIAstat-Dx 1.0 analyzer.

The aim of the study is:

1. To evaluate the analytical sensitivity of the test by identifying positive samples for bacteria (culture comparison) and positive samples for viruses (qPCR comparison).
2. Compare the value of Ct obtained with the number of viral copies per ml of cerebrospinal fluid obtained by qPCR.

Inclusion Criteria:

• 170 samples of CSF positive for virus and/or bacteria;
• Samples stored at -80°C, less than 5 years;
• Samples with a volume of at least 800μL.

Exclusion Criteria:

• Samples of a different matrix than CSF;
• Samples stored at room temperature;
• Samples for which diagnostic test results are not available;
• Samples with a volume of less than 800μL;
• Samples already thawed and refrozen.

Virus or bacterial positive samples from cerebrospinal fluid.