Available online 3 June 2023, 105516

Cytomegalovirus (CMV) is a leading cause of congenital infections. Dried blood spots (DBS) collected in the first week of life (Guthrie cards) have been used in the diagnosis of CMV infection outside the three-week window period following birth. The present work summarizes the results of a 15-year observational study in which DBS from 1388 children were used for a late diagnosis of congenital CMV infection.

Three groups of children were studied: i) symptomatic (with symptoms at birth or late sequelae) (N=779); ii) born to mothers with serological profile of primary CMV infection (N=75); iii) without any information (N=534). A highly sensitive method of DNA extraction (heat-induced) from the DBS was used. CMV DNA was detected by a nested PCR.

In total CMV DNA was detected in 7.5% (104/1388) of children. Symptomatic children showed a low rate of CMV DNA detection (6.7%) than children born to mothers with serological profile of primary CMV infection (13.3%) (p=0.034). Sensorial hearing loss and encephalopathy were the two clinical manifestations with the highest CMV detection rate (18.3% and 11.1%, respectively). Children whose mothers had a confirmed primary infection showed a higher rate of CMV detection (35.3%) when compared with children whose mothers had a not confirmed primary infection (6.9%) (p=0.007).

The present work emphasises the importance of testing DBS in symptomatic children even a long time after symptoms onset and in children born to mothers with serologic diagnosis of maternal primary CMV infection when they miss the diagnosis during the three-week window following birth.

Cytomegalovirus (CMV) is a leading cause of congenital infection worldwide [1]. About 0,7% of all infants around the world are congenitally infected by CMV, with rates varying from 0.2% to 6.1% according to different socioeconomic and geographical factors [2,3].

One of the main diagnostic challenges of congenital cytomegalovirus infection is due to the fact that 87.3% of CMV congenital infected children are apparently asymptomatic at birth although 13,5% of those will develop late sequelae such

A total of 1388 archived DBS (Guthrie cards) of children born in Portugal, were tested for CMV DNA between 2000 and 2015. All DBS were collected in the first week of life and stored at Instituto de Genética Médica Jacinto de Magalhães (2000 - 2012) and at the Portuguese National Institute of Health (after 2012). CMV DNA detection was requested by the paediatricians based on a suspected CMV congenital infection outside the three-week window following birth. Clinical information was gathered from

A total of 1388 archived DBS from Portuguese children, of which 58% (798/1388) were boys and 42% (587/1388) were girls, were tested for the presence of CMV DNA (for three children no sex information was available). The age of the children at the time of DBS CMV testing ranged between 3 weeks and 13 years, having 74% (1025/1388) of the children ≤ 3 years of age (Table 1).

In total CMV DNA was detected in 7.5% (104/1388) of children. The detection rate of CMV DNA according to the age of the

The present work shows the results of our 15-year observational study of the use of archived DBS for the retrospective diagnosis of congenital CMV infection in three groups of children, namely children with symptoms of congenital CMV at birth or presented later sequelae, children born to mothers with serologic evidence of primary CMV infection and children without any information. Most of the children (74%) were ≤ 3 years of age at the time of the diagnosis.

From the total of 1388 children

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

The authors gratefully acknowledge all the pediatricians and neonatologists who sent the DBS included in the study and Sara Dias and Ana Papoila for their support in the statistical analysis of the results.

© 2023 Published by Elsevier B.V.