Serologically provenacuterubella infection inpatients with clinical diagnosis ofdengue

SUMMARY Patientswithaclinical diagnosis ofdengue butnegative byserological testingwere studied for rubella infection. Paired sera were obtained from 69 patientsduring an outbreakin Yucatafn, Mexico. Thepresenceofspecific anti-viral IgMinthe acute sera was considered as diagnostic for rubella infection. The im- munoglobulin was determined by measuring the difference in the inhibition ofhemagglutination between the non-reduced and the reduced fractionated sera.Immunoglobulinswereseparatedbysucrosedensitycentrifugation. Acuterubellainfectionwasfoundin 7 (1041 %)ofthepatients. Theseresults demonstrateactiverubella infection in patients clinically diagnosed as dengue. INTRODUCTION Rubella and rubella-like infections cannot be differentiated clinically: par-ticularly when cases occur simultaneously with a rubella-like infection outbreak[1]. Adifferential diagnosis is needed when pregnancies and implementation ofvaccination programmes are involved [2]. In Mexico, dengue and rubella infections