Varying numbers of Xavante Indians from two villages in the state of Mato Grosso in Brazil were tested for immunologic status with respect to various diseases and organisms. Among the findings of note were:
1.Positive skin tests to the histoplasmin antigen were encountered in 42.7% of those tested, but there were no certain positives for tuberculin or coccidioimycin.
2.All persons investigated gave positive tests for antibodies to Toxoplasma, usually in high titer.
3.Of those tested, 62% had antibodies to malaria antigens, usually in intermediate titers.
4.There was no serologic evidence (in a small series) for treponemal infections.
5.Between 30 and 80% of those tested, depending on the Salmonella subtype, had antibodies to Salmonella representative of groups A, B, C, and D.
6.Of those tested, 58% were found to have antibodies to Bordetella pertussis.
7.The distribution of titers to three streptococcal antigens suggests moderate contact with this pathogen.
8.Between 71 and 95% of subjects, depending on the specific type, had antibodies to poliomyelitis types I, II, and III.
9.Antibodies to measles were found in 89% of a small series.
10.The results of tests for antibodies against 23 arboviruses isolated in Brazil suggest extensive exposure to the Mayaro and Ilhéus viruses, and lesser exposure to a number of others, including yellow fever.
Although these findings constitute only a beginning in defining the antibody profile among the Xavante, it is clear that this apparently healthy population has been exposed to a wide variety of what would ordinarily be termed pathogens.
Department of Human Genetics, School of Medicine, University of Michigan, Ann Arbor, Michigan. Supported in part by U.S.P.H.S. grant GM-09252 and AEC grant AT(11-1) 1552.
Belém Virus Laboratory, Belém, Brazil.
Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan. Supported in part by U.S.P.H.S. grant POI-05876.
Department of Medicine, University of Tennessee, Memphis, Tennessee. Supported in part by U.S.P.H.S. grant HE-09561.
Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.
Department of Dermatology, School of Medicine, University of Michigan Medical School, Ann Arbor, Michigan.