Dried newbom blood spots examination allows congenita) CMV infection diagnosis

An accurate, easy and widely available method of diagnosing congenitally CMV infection as an alternative to the laborious virus isolation in celi culture is important for clinica) and epidemiological purposes. We report on a method for CMV DNA search in dried newbom spots (DBS) collected on Guthrie cards for the screening for metabolic and genetic disorders. The procedure was tested on 285 babies boro in our region between 1994 and 1996 who underwent virus isolation testing in the first two weeks of life to assess congenita] CMV infection. Blood was eluted from filter paper in MEM and heat extracted. The products of a nested PCR amplifying a region of 100 bp in the gp 58 gene were detected by agarose gel electrophoresis. Strict control measures were adopted to avoid carryovers and contaminations. The test was positive in ali congenitally infected babies, both symptomatic at birth (n=10) and asymptomatic (n=21), and in six out of 254 children CMV isolation negative. Positive DBS were collected between 3 days and 22 months before examination and have been stored in standard conditions. We propose this method as a valid procedure to diagnose congenita! CMV infection. Due to the ease of collection, storage and shipment of DBS few laboratories performing the test properly could allow the diagnosis congenita] CMV infection to be widely available.