RESPIRATORY SYNCYTIAL VIRUS-INFECTION IN HOSPITALIZED-PATIENTS AND HEALTHY-CHILDREN IN EL SALVADOR

Nasopharyngeal specimens from 42 children less than one-year old hospi talized with bronchiolitis or pneumonia in El Salvador were analyzed f or the presence of subgroup-specific respiratory syncytial virus (RSV) antigens by the indirect immunofluorescence technique. The antigen RS V-A was demonstrated in 28 children, RSV-B in three, and in one child subgroup, specificity could not be determined. The male:female ratio i n the RSV-infected children was 1.9:1. The most severe disease, requir ing intensive care, was observed in two infants with RSV-B infection. Determination of serum IgG, IgA, and IgM antibodies in acute and conva lescent sera showed that none of the tests alone had sufficient sensit ivity for routine diagnostic purposes, although, in combination, they provided a correct diagnosis in 86% of the RSV-infected children. A se roprevalence study of IgG, IgA, and IgM antibodies in 206 healthy chil dren showed that a primary RSV infection is usually acquired during th e first year of life in El Salvador. These results also indicated that reinfections with RSV frequently occur during the first 3-4 years of life and suggest that the occurrence of serum RSV IgA antibodies may b e a marker of reinfection.