Denguevirus type 2 unresponsive to the current PCRprimer; constructionof a new PCR primerto detect all strains of Denguevirus type 2

We found that one strain of denguevirus (Trinidad1751;TR) did not respond to the PCRprimer for Jamaica/83.We investigatedsuch propertywith other 10 strains of denguevirus type2 and found2 moreunresponsivestrains.All 3 strains wereisolatedfrom the central America.To detect the envelopegene of those 3 strains by PCR, we synthesiz- ed primersbased on TR strain as the reference sequence.Using these primers,we could detect the 3 strains by PCR at the usual annealingtemperature.We recommedthe new primer for diagnosisof DEN2.