A prospective study was carried out in 49 families of newborns in Avellaneda District, Argentina, recruited when the mother was in the last trimester of pregnancy and followed until the newborn was aged two years, to study the epidemiology of rotavirus infection under natural conditions. Weekly surveillance of all family members for diarrhea and rotavirus-related diarrhea was carried out from May 1983 to July 1986. Serum samples were also collected every six months to study the incidence of rotavirus infection in all family members. The peak of diarrhea incidence was observed in children aged less than two years (2.1 cases per person-year). Rotavirus infection was a common rather than a sporadic phenomenon (0.63 cases per person-year, on average) in all age groups, and at least 61% of rotavirus infections were reinfections. In contrast, the peak of rotavirus infection in seronegative persons (0.58 cases per person-year) and the peak of rotavirus-related diarrhea incidence (0.25 cases per person-year) were found during the first year of life. These results showed that infants aged less than one year are the most appropriate candidates for a rotavirus vaccine in the Avellaneda population. However, improvements in sanitary conditions and personal hygiene and education of the high-risk population should be considered the primary means of reducing infectious diarrhea in Argentina.

Human papillomavirus type 6 subtype a (HPV-6a) was detected in a human invasive tonsiilar carcinoma. Southern blot hybridization analysis showed the presence of additional bands when using non-cutting and single-cut restriction enzymes. Molecular cloning yielded two recombinant clones of 8-0 and 1.4 kb in size. The first represents the complete HPV-6a genome. Sequence analysis of the second clone showed a 0.6 kb DNA sequence corresponding to the L2 region of HPV-6a, whereas the rest belongs to cellular sequences. These data show the presence of a usually low risk HPV type in an invasive carcinoma, at an unusual infection site, with viral DNA integrated into the host genome. These findings add evidence in support of the hypothesis of a relationship between HPV infection and at least some ororespiratory cancers.A strong association exists between human papillomavirus (HPV) and some human cancers. HPV types 16, 18, 31, 33 and 35 and a few others account for more than 90 of cervical carcinomas (zur Hausen, 1989) whereas the genome of HPV type 5 and more rarely also types 8, 17 and 20 are found in almost all malignant lesions of individuals suffering from epidermodysplasia verruciformis, a disease in which 30 to

Rotavirus gastroenteritis was studied by enzyme-linked immunosorbent assay (ELISA) and by PAGE from April 1983 to April 1985 at the Buenos Aires Ricardo Gutierrez Children’s Hospital and at the San Justo Children’s Hospital. Based on examination of 576 cases, rotavirus was identified in 109 (18.9%) cases by ELISA and in 99 (17.2%) cases by PAGE. As a diagnostic tool PAGE presented a sensitivity of 90.8% compared with ELISA. Compared with the control SA-11 genome, 84 samples (84.9%) presented a long electropherotype and 15 isolates (15.1%) presented a short electropherotype. We detected 35 different long electropherotypes and report a short electropherotype that did not show genome variation and was responsible for an outbreak in the San Justo Children’s Hospital population from September 1983 to July 1984.