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 requiring hospitalization, a collection of 136 adenovirus isolates obtained in the Roberto del Rio Children's Hospital of Santiago, Chile between June 1988 and November 1990 was studied by restriction enzyme analysis. Nasopharyngeal aspirates were obtained on admission from children under 2 years. During the study period a total of 227 adenovirus respiratory infections (ARI) were diagnosed at the ward for ARI by immunofluorescence, representing 23% of all admissions. Fifty percent of the 136 typed strains were found to belong to subgenus B, and the other 50% corresponded to subgenus C. Digestion with a set of seven enzymes allowed the identification of nine different genome types of subgenus C, three of which had not been previously described, exhibiting novel restriction patterns with either Bgl II or BstEII. Ad7h, identified in 66 isolates, was the predominant genome type and was associated with the nine cases requiring mechanical respiratory assistance and with the two fatalities recorded during the 29 months. No differences were found between the age and sex distribution of subgenus B and C genomic variants, but the mean length of hospital stay (X+/-2 SE) recorded among patients 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).