Measles surveillance and control in Tunisia: 1979-2000

BACKGROUND: The aim of this study was to analyze measles epidemiology in Tunisia after the introduction of specific vaccine in 1979 and the results of the serological investigation of suspected cases, introduced as part of the National Program for Measles Elimination recently implemented. METHODS: Available data were used to examine trends in measles epidemiology from 1979 to 2000: number of reported cases, patient's age, reporting date, epidemiological link with similar cases and laboratory confirmation. Serological investigation included the detection, by ELISA, of measles and rubella IgMs in 542 suspected measles cases sampled from 1997 to 2000. RESULTS: Measles coverage level increased gradually and was maintained to over 90% since 1992. In parallel, the annual incidence of reported cases declined and outbreaks became less frequent, the latest occurred in 1992. Measles-specific IgMs were detected in only nine patients who received measles vaccine few days before blood collection, anti-rubella IgMs were detected in 52% of cases. CONCLUSION: Vaccination strategies including routine and supplemental immunizations, implemented in Tunisia, achieved a substantial decrease in measles incidence. Virological results highlight frequent confusion, at the clinical level, with the other etiologies of rash and fever and the importance of systematic serological confirmation of cases.