GENOME TYPE ANALYSIS OF CHILEAN ADENOVIRUS STRAINS ISOLATED IN A CHILDRENS-HOSPITAL BETWEEN 1988 AND 1990

In a study designed to evaluate the genetic variability of adenovirus strains associated with infantile cases of respiratory disease requiri ng hospitalization, a collection of 136 adenovirus isolates obtained i n the Roberto del Rio Children's Hospital of Santiago, Chile between J une 1988 and November 1990 was studied by restriction enzyme analysis. Nasopharyngeal aspirates were obtained on admission from children und er 2 years. During the study period a total of 227 adenovirus respirat ory infections (ARI) were diagnosed at the ward for ARI by immunofluor escence, representing 23% of all admissions. Fifty percent of the 136 typed strains were found to belong to subgenus B, and the other 50% co rresponded to subgenus C. Digestion with a set of seven enzymes allowe d the identification of nine different genome types of subgenus C, thr ee of which had not been previously described, exhibiting novel restri ction patterns with either Bgl II or BstEII. Ad7h, identified in 66 is olates, was the predominant genome type and was associated with the ni ne cases requiring mechanical respiratory assistance and with the two fatalities recorded during the 29 months. No differences were found be tween the age and sex distribution of subgenus B and C genomic variant s, but the mean length of hospital stay (X+/-2 SE) recorded among pati ents infected with subgenus B types was significantly higher (17.72+4. 52 days (n=55) vs. 7.54+1.70 days (n=53); F=17.22; P<0.0001).