What are the indications for requesting multiplex polymerase chain reaction (PCR) in pediatric patients with suspected central nervous system (CNS) infections, pulmonary infections, or bloodstream infections?

From the Guidelines

Multiplex PCR is indicated in pediatric patients with suspected CNS infections, particularly for the diagnosis of viral encephalitis, such as herpes simplex virus (HSV), enterovirus, and parechovirus.

Indications for Multiplex PCR

• CNS infections: Multiplex PCR is useful in diagnosing CNS infections, including meningitis, encephalitis, and focal infections of brain parenchyma 1.
• Viral encephalitis: Multiplex PCR is particularly useful in diagnosing viral encephalitis, such as HSV, enterovirus, and parechovirus 1.
• Immunocompromised patients: In immunocompromised patients, multiplex PCR can help diagnose CNS infections caused by opportunistic pathogens, such as cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6) 1.
• Pulmonary infections: Multiplex PCR can also be used to diagnose pulmonary infections, such as those caused by Mycoplasma pneumoniae and respiratory viruses 1.
• Bloodstream infections: In cases of suspected bloodstream infections, multiplex PCR can help identify the causative pathogen 1.

Specific Tests and Specimens

• CSF PCR: CSF PCR is a sensitive and specific test for diagnosing CNS infections, including viral encephalitis 1.
• Serum antibody testing: Serum antibody testing can be used to diagnose infections, such as Mycoplasma pneumoniae and EBV 1.
• Throat swab PCR: Throat swab PCR can be used to diagnose enterovirus and other respiratory viruses 1.

Clinical Considerations

• Clinical presentation: The clinical presentation of the patient, including symptoms and signs, should guide the selection of tests and specimens 1.
• Epidemiological factors: Epidemiological factors, such as travel history and exposure to animals, should be considered when selecting tests and specimens 1.
• Immunocompromised status: Immunocompromised status should be considered when selecting tests and specimens, as these patients may be at risk for opportunistic infections 1.

From the Research

Indications for Requesting Multiplex PCR in Pediatric Patients

The following are indications for requesting multiplex PCR in pediatric patients with suspected central nervous system (CNS) infections, pulmonary infections, or bloodstream infections:

• CNS infections:
  • Meningitis or encephalitis with unknown etiology 2, 3, 4
  • Patients with suspected CNS infections who require rapid identification of causative pathogens to guide targeted therapy 2, 3, 4
• Pulmonary infections:
  • Respiratory infections in pediatric intensive care unit (PICU) patients where rapid pathogen identification can inform antibiotic use 5
  • Patients with suspected viral or bacterial respiratory infections who require definitive diagnosis to guide treatment 5
• Bloodstream infections:
  • Patients with suspected bloodstream infections who require rapid identification of causative pathogens to guide targeted antibiotic therapy 6

Benefits of Multiplex PCR

The use of multiplex PCR in pediatric patients with suspected CNS, pulmonary, or bloodstream infections has several benefits, including:

• Rapid identification of causative pathogens 6, 2, 3, 4, 5
• Improved diagnostic accuracy compared to conventional testing methods 6, 3, 5
• Targeted therapy and reduced use of broad-spectrum antibiotics 2, 3, 5
• Reduced morbidity and mortality due to timely and appropriate treatment 2, 3, 4