[Levels of humoral antibodies to Epstein-Barr virus in the population of Cuba].

Indirect immunofluorescence was used to study the levels of humoral antibodies to capsid (VCA) and early (EA) antigens of Epstein-Barr virus (EBV) in sera of 322 normal subjects living in the province of Habana and varying in ages from several months to 93 years. The results suggest that the population of Cuba, like in other countries, is widely infected with EBV, although the pattern of spread of this infection has some specific features. In particular, the infection rate of the pediatric population (3--4 and 5--9 years) is moderately high, 73% and 65%, respectively, whereas in adult population it is rather low (62--86%) despite the tropical location of the country. In all the age groups examined, geometric mean titers (GMT) of antibody to VCA were also lower than in comparable groups of population from other countries. The observed high GMT of VCA antibody in persons over 55 years and a considerable increase in the number of positively reacting sera and sera with high antibody titers (greater than or equal to 1 : 160) agree with the data by other workers and appear to be due to reduced immunological defence of the cellular type in elderly people. Antibody to EBV EA were found in all the age groups examined, although in a small per cent. The subjects with high antibody titers to this antigen (greater than or equal to 1 : 40) were found more frequently in the two youngest age groups (0--2 and 3--4 years) which appears to be due to large amounts of virus usually occuring in the period of primary infection. The analysis of infectious mononucleosis incidence for 5 years (1972--1976) in various age groups of Habana province population indicates a general low level of incidence. Two small peaks in 3--4 and 15--19-year groups corresponded to increased GMT values of antibody to EBV EA in these particular age groups.