[Short communication: The sensitivity of measles diagnosis by physicians and families during an intraepidemic period in Edirne: implications for measles surveillance]

Measles is still a leading cause of death among young children, despite the availability of a safe and effective vaccine for the past 40 years. EURO Region of World Health Organisation including Turkey has targeted elimination of measles by the year 2010. It is concluded that there must be a sensitive surveillance system to investigate all suspicious measles cases, and diagnosis should be based on both standardized case definition and laboratory confirmation. Standardized case definition based notification has started in 2005 in Turkey. This study was carried out to determine the sensitivity and specificity of clinical measles diagnosis by physicians and families during a measles epidemic affecting 597 cases in Edirne province in 1997. Blood samples and data were collected by trained teams consisting of one physician and one nurse. Thirty clusters sampling method was used for sampling and 210 blood samples were taken from the children. The sera were then sent to Refik Saydam Hygiene Institute, Ankara, for the detection of measles specific IgG and IgM antibodies. Positive results for IgM were considered as acute measles during epidemics, and positive results for IgG were considered as acquired immunity due to vaccination or passed infection. Of 210 children, 19 were found to have recent infection (IgM+, IgG-), 101 were found immune (IgM-, IgG+), 67 were found in convalescence phase after infection (IgM+, IgG+), and 23 were found susceptible (IgM-, IgG-) to measles. The overall IgM seropositivity was detected as 40.9% in the study group. Only half of confirmed cases (43/86) were diagnosed as measles clinically by the physicians. The sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) of clinical diagnosis by physicians were estimated as 33%, 89%, 67% and 86%, respectively. Validity measures for measles diagnosis by the families were as follows; 8% sensitivity, 96% specificity, 6% PPV and 60% NPV. It is concluded that, all required measures should be taken for the availability of laboratory confirmation of all suspicious measles cases and field investigation via structured case investigation forms, is necessary for the success of measles surveillance system in our country.