Technical Guidelines for Integrated Disease Surveillance ... - PHRplus

Suspected disease orconditionMeaslesREFERENCE:WHO Guidelines forEpidemic Preparedness andResponse to MeaslesOutbreaksWHO/CDS/CSR/ISR/99.1Diagnostic test Specimen When to collect How to prepare, storeand transportPresence of IgM antibodiesto measles virus in serum.Serum Collect blood samples on 5suspected measles caseswhen the number of casesexceeds the measlesoutbreak threshold (usuallymore than 5 cases in afacility in a district perweek).In countries with anelimination target: Collect specimen fromevery suspected caseof measles Collect serum forantibody testing at firstopportunity or first visitto the health facility. For children, collect 1to 5 ml of venous blooddepending on size ofchild. Collect into a testtube, capillary tube ormicrotainer. Separate blood cellsfrom serum:– Let clot retract for 30 to60 minutes at roomtemperature. Centrifugeat 2000 rpm for 10-20minutes and pour offserum into a cleanglass tube.– If no centrifuge, putsample in refrigeratorovernight (4-6 hours)until clot retracts. Pouroff serum the nextmorning. If no centrifuge and norefrigerator, let blood sitat an angle for at least60 minutes (withoutshaking or being drivenin a vehicle). To prevent bacterialovergrowth, ensure thatthe serum is pouredinto a clean glass testtube. The test tubedoes not need to besterile, just clean. Avoid shaking ofspecimen before serumhas been collected. Store serum at 4°C. Transport the serum inan EPI hand vaccinecarrier at 4°C to 8°C toprevent bacterialovergrowth (up to 7days). If not refrigerated,serum stored in aclean tube will be goodfor at least 3 days. Transport serumsamples using appropriatepackaging toprevent breaking orleaks during transport. The specimen shouldarrive at the laboratorywithin 3 days of beingcollected.ResultsResults are usuallyavailable after 7 days.If as few as two of fivesuspected measles casesare laboratory confirmed,the outbreak is confirmed.134Technical Guidelines for Integrated Disease Surveillance and Response in Ghana