Masters Thesis

A survey for human intestinal parasites in Cantua Creek (California) School District.

The presence or absence of intestinal parasites in a human population is one indication of the quality of life the people lead. Particularly, human intestinal helminths and protozoans have been used to indicate the sanitary standards of a population. Arnett, Wenrich, and Stabler (1933) reported on a survey for intestinal protozoans in 401 college freshmen in the eastern United States. They found 33.1% had one or more species of protozoans after analyzing one stool sample from each subject. McQuay found 20.1% protozoan and 20.2% helminth infections in 4,000 individuals drawn from furloughed missionary families from tropical and subtropical countries (McQuay, 1967). Gleason et al. reported on a stool survey of about half the permanent residents of Aspen, Colorado, done after an outbreak of giardiasis during the 1965-66 ski season (Gleason et al., 1970). Of the 419 people sampled, 5%. were positive for Giardia lamblla. All other protozoans were found in less than 2% of the subjects. The only helminth found was one case of Enterobius vermicularis. The outbreak was attributed to the contamination of water supplies with sewage. In 1971 Allen and Ridley reported on a survey for parasitic infections in patients of a British hospital who had once resided in tropical or subtropical areas (Allen and Ridley, 1971). In this study of 1,000 people, 33.3% were found to have pathogenic or potentially pathogenic helminths or protozoans. An additional 15.1% of the subjects were infected with commensals living in the digestive tract or elsewhere in the body. The present study was a survey for human intestinal parasites in Cantua Creek, a farm labor community 60 miles southwest of Fresno, California (Figure 1). It had a population of approximately 1,800 people, primarily Mexican Americans, Punjabis, and Caucasians. The only unifying force bringing the widely distributed labor camps into a community was the Cantua Creek Elementary School. There were several purposes for surveying Cantua Creek. The first was to determine what parasites the people had. The second was to determine if parasite transmission was occurring. The final purpose was to correlate demographic information on each subject with the presence of parasites.