Clinical characteristics of measles and rubella and sensitivity and specificity of surveillance case definition

Objective To understand the clinical characteristics of measles and rubella and evaluate the accuracy of measles surveillance case definition. Methods An investigation of rash fever illness was conducted in Changping in 2010 to collect the information about the clinical manifestation and history of measles vaccination of the cases. Results Measles cases and rubella cases differed in degree of fever, duration of rash, interval between rash and fever, respiratory symptoms, incidences of conjunctivitis, lymph node enlargement and joint pain. The sensitivity and specificity of local and national suspected case diagnostic criteria were 94%, 50% and 45%, 94% respectively. The sensitivity and specificity of the diagnostic criteria: fever≥38℃, rash 3 days after fever, respiratory symptom and conjunctivitis, were 81% and 92% respectively. Conclusion The incidence of measles was low in Beijing, and the local suspected measles cases diagnosis criteria’s sensitivity was high. It is important to select appropriate surveillance case definition to effectively improve the measles surveillance.