One hundred and ninety-five newly arrived college students in Mexico City contributed control, acute and convalescent sera, and 28 contributed control and 35 acute stool specimens, in a study designed to determine whether a virus might be the cause of the diarrhea of travelers to Mexico. Sixty-six students (33.8%) became ill during the 3-week period of study.
Viruses were isolated from two stool specimens from sick subjects; one contained a Coxsackie A-1 virus, the other a Coxsackie B-3 virus. Both students showed accompanying antibody rises against the respective viruses. Ten randomly selected serum pairs, five from students who had a diarrheal episode and five from those who remained well, failed to show neutralizing or complement-fixing antibody rises to either of the two viruses isolated.
Five of the 35 stool specimens submitted by acutely ill subjects yielded organisms, other than viruses, with known enteropathogenicity for adults: Shigella sonnei, Salmonella london, Entamoeba histolytica, Giardia lamblia, and Trichomonas hominis.
Viruses isolatable by the techniques described appear to play only a minor role in the etiology of tourist diarrhea. The possibility remains that, with the development of more sensitive techniques, additional viruses will be found associated with this diarrheal illness.
Research Fellow in the Division of Virus Research.
Student of Medicine, fourth year.
Associate Clinical Professor of Medicine (Tropical Medicine).