Smallpox laboratory tests

This chart describes the laboratory testing protocol for a patient that presents with generalized vesicular or pustular rash illness. It is also based upon the risk level the patient has of developing acquiring smallpox.



Laboratory criteria for confirmation

 * Polymerase       chain reaction (PCR) identification of variola DNA in a clinical specimen, OR


 * Isolation       of smallpox (variola) virus from a clinical specimen (WHO Smallpox Reference        laboratory or laboratory with appropriate reference capabilities) with  variola        PCR confirmation.

Laboratory diagnostic testing for variola virus should be conducted in a       CDC Laboratory Response Network (LRN) laboratory utilizing LRN-approved PCR        tests and protocols for variola virus. Initial confirmation of a smallpox outbreak     requires additional testing at CDC.

Note: Generic orthopox PCR and negative stain electron microscopy (EM) identification of a pox virus in a clinical specimen are suggestive of an 'orthopox ' virus infection but not diagnostic for smallpox.

The importance   of case confirmation using laboratory diagnostic tests differs depending    on the epidemiological situation. Because of the low predictive value of   a positive lab test result in the absence of a known smallpox outbreak, in    the pre-outbreak (pre-event) setting, laboratory testing should be reserved        for cases that meet the clinical case definition and are thus classified    as being a potential high risk for smallpox.

Vaccine
The chart below describes a patient that appears to show an adverse reaction to the smallpox vaccine and the protocol involved with it.