Zoonotic Disease Program
Vector-borne Disease Diagnosis

Many of the vector-borne diseases cannot be distinguished clinically. The only way to reach a confirmatory diagnosis is to perform laboratory tests on blood, cerebrospinal fluid, or on other tissues. The most commonly used procedure is to test blood serum samples.

A confirming laboratory diagnosis using blood serum can only be made by concurrently testing two samples, taken two weeks or more apart (acute and convalescent phase sera). Testing the two samples is important, because the acute serum sample is often negative or provides an inconclusive test result. A cerebrospinal fluid sample should accompany the acute phase blood sample in a case of encephalitis, meningitis, or meningoencephalitis. Brain or other tissues submitted from fatal cases will be forwarded to the Centers for Disease Control and Prevention (CDC) for testing.

The Ohio Department of Health Laboratory (ODHL) no longer offers testing of human samples for La Crosse encephalitis, St. Louis encephalitis, West Nile virus or Lyme Disease. Arrangements should be made by the physician or hospital with a private laboratory for testing blood serum for the diagnosis of these diseases.

Blood serum samples for the diagnosis of human ehrlichiosis or Hantavirus diseaseshould be sent for testing through the ODHL to the Centers for Disease Control.

For more details on specimens and laboratory testing of vector-borne diseases, see:

West Nile Virus: Plan for human surveillance, in Combating West Nile Virus, the West Nile Virus Response Plan for Ohio, or the specific disease section in the ODH Infectious Disease Control Manual (IDCM), or section 4 of the IDCM pertaining to the Ohio Department of Health Laboratory.

Last Updated: 04/20/2009

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