Rotavirus. I. Hemagglutination and complement fixation inhibitor antibodies in individuals of Mexico city

Hemagglutination inhibiting antibodies were studied in 1,278 sera of individuals of different ages in Mexico City representative of four different socioeconomic levels. It was found that 1,261 (98.7 per cent) had antibodies against the Nebraska strain (calf rotavirus). An unusual finding was that more than 95 per cent of children from one to four years of age, had antibodies. For this reason five year old children were studied utilizing two viral strains as antigens in hemagglutination inhibition tests. It was found that in 918 sera, 821 (89.4 per cent) had antibodies against SA-11 samples (monkey rotavirus); percentage increased from 87.2 per cent in neonates to 97.5 percent in children from four to five years of age. A similar phenomenon was observed when Nebraska strain hemagglutinin was utilized. Also complement fixation antibodies against SA-11 strain in 583 sera were studied finding that 260 (44.6 per cent) had antibodies. Utilization of this technique showed that seropositivity percentage decreased from 47.6 per cent in the neonate group to 14.5 per cent in the one ot three month old children increasing progressively until reaching 65.1 per cent in children three to four years of age. These results show that rotavirus infection takes place at early ages, as has been confirmed by other authors that have used electron microscopy techniques, RNA electrophoresis, etc., regardless of the presence of transplacental antibodies.