PREVALENCE OF LYMPHOCYTIC CHORIOMENINGITIS VIRUS-INFECTION IN A HUMAN-POPULATION OF ARGENTINA

The activity of lymphocytic choriomeningitis virus (LCMV) in the endem ic area of Argentine hemorrhagic fever has been previously reported an d represents the first evidence of the coexistence of two arenaviruses pathogenic for humans, Junin and LCMV, in the same geographic area. D ata are presented on the prevalence of LCMV human infection in a 10,00 0-km(2) area located in Santa Fe Province, Argentina. Study subjects w ere males, 15-65 years old, living and/or working in the rural area of 41 localities. One serum sample was obtained from each of 7,227 volun teers from a total population of 21,340 individuals with the described features. Antibodies to LCMV were assessed by means of an indirect im munofluorescence assay. These antibodies were found in 172 serum sampl es, with titers ranging from 1:8 to 1:128 (geometric mean titer = 15.0 3), and a mean percentage of infection of 2.38%. A significantly diffe rent distribution of positive individuals was found between the easter n (1.54%) and western (3.07%) borders of the region studied (P < 0.000 3). The higher percentage of infection on the western side was due to the existence of two clusters of counties with a mean percentage of 6. 06% that was significantly different from the 1.67% obtained in the re st of the study area (P < 0.0003). These results provide new informati on on the LCMV activity in Argentina, and update the evidence on the c oexistence of two arenaviruses in the same region of Argentina. This c ircumstance increases the probability of generation of viral reassorta nts with changes that could determine the need for new therapeutic and /or preventive strategies for arenaviral diseases.