Regional Laboratory
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UPDATE: The Children’s Mercy Hospital was just notified that the commercial PCR for enterovirus will not be available. It is our intention to develop our own PCR and we hope to have it available in June. |
Nonpolio enteroviruses are the most common etiological agents of acute febrile illness and specifically of viral meningitis among young children and infants during the summer months. Children with symptoms of meningitis and young febrile infants are routinely hospitalized for 2 to 3 days. Bacterial cultures of CSF are used to rule out bacterial infection and enteroviral infection may be confirmed by identification in cell culture. It has been suggested that enteroviral culture alone can shorten hospitalization. However viral cultures can take up to 8 days and results would be rarely available before discharge. In addition, viral cultures have an estimated sensitivity of only approximately 65-75% in part due to the inability to culture all 67 serotypes. It has been hypothesized that the use of a rapid, highly sensitive polymerase chain reaction technique could shorten hospital stays, reduce empirical antibiotic therapy and decrease overall costs.
For the past two summers The Children’s Mercy Hospital has been studying a recently developed 5 hour PCR technique to detect enterovirus in CSF which detects 63 of the 67 serotypes. We examined the utility of this PCR assay in the diagnosis of enteroviral meningitis during two summers. The goal of the first summer, 1996, was to gain technical familiarity with the assay, to gauge its performance relative to culture and to gather baseline data for analysis. To achieve this, the PCR was performed on all CSF specimens submitted to the virology laboratory for culture. With rare exceptions, the clinician was unaware of the results. The data was used to implement the reportable assay the following summer. During the second summer, 1997, the PCR was an orderable test and was only performed when ordered. Enteroviral cultures were also done on these specimens. Charts were reviewed to determine the effect of results on patient care.
The results of testing are shown below. In summary, compared to culture, the PCR detected about twice as many cases of enteroviral meningitis. No negative controls were falsely positive. In 1996, 23% of PCR diagnosed cases remained in the hospital >2 days. In 1997, when the physicians were being notified of the results, only 10% of similar cases remained in the hospital >2 days.
We are now making this test available to the greater Kansas City area. It will be performed from June until October, “enteroviral season.” The assays will be done every day, 7 days a week, early in the morning with results available by 2 PM. The specimen requirement is 0.5cc of CSF. The specimen should be refrigerated and transported to The Children’s Mercy Hospital as soon as possible on ice. A specimen from a traumatic tap is acceptable. Concomitant culture will not be performed unless so ordered.
1997 CULTURE & PCR RESULTS
CULTURE
POSITIVE 36 39
NEGATIVE 5 196
SOUTH
EAST
WEST
CENTRAL