Utilization of alternative diagnostic sampling techniques during an imported measles outbreak - San Diego, California, 2008

Background: In January 2008, an unvaccinated child with a personal belief exemption (PBE) returned to the U.S. from Switzerland, where a measles outbreak was ongoing. While infectious, he attended a school with a high PBE rate and was seen in four different healthcare settings. The local health department received measles serology results one week after testing.

Methods: A public health investigation was initiated, including contact tracing and quarantine of exposed, susceptible persons, heightened surveillance and active case finding. Laboratory confirmation was attempted on all suspect cases.

Results: Eleven additional children were infected; all were unvaccinated. Clinicians did not suspect measles in a child with recent international travel and febrile rash illness and did not implement infection control precautions when measles was suspected. Obtaining venous blood draws on infant and child suspect cases was problematic. Use of reference laboratories that performed testing out of state delayed measles diagnoses.

Conclusions: Clinicians should suspect measles in patients with recent international travel and febrile rash illness and implement airborne infection control precautions. If measles is suspected, public health authorities should be immediately notified and serologic testing performed in the most expeditious manner. Capillary blood, collected via heel stick or finger prick, is an acceptable specimen for measles serology. Employment of alternative diagnostic sampling techniques may be warranted when suspect cases resist venipuncture or pediatric phlebotomists are not available to collect routine serologic specimens. Utilization of alternative diagnostic sampling techniques may expedite specimen collection, diagnoses, and determination of case status.