Inactivation of Cryptosporidium parvum oocysts in field soil.

Cryptosporidium parvum oocysts from dairy calves are believed to regularly contaminate watersheds. Identifying oocysts and measuring their viability in the natural environment are important elements in estimating the risk posed by this resistant organism. A 152 day field study was conducted to measure the viabilities of oocysts inoculated into 25 sampling points. Water potential, pH, and ammonium content were also measured at the same 25 sampling sites. A three-dimensional mapping program (Surfer) was used to create 3-D maps of the viabilities of C. parvum oocysts and other factors measured during the experiment. The results indicate that 3-D graphical presentation may be a useful means to identify potential sites of greatest risk of oocyst survival and could indicate areas where natural conditions are causing the most rapid oocyst inactivation, and this method can be a means for the future measurement of microorganism inactivation in the natural environment.

Intestinal helminthiasis, nutritional status, and their relationship; a cross-sectional study in urban slum school children in Indonesia.

In a study of urban slum school children (276 boys and 231 girls), in Ujung Pandang, Indonesia, parasitological and anthropometric exams were cross-sectionally performed to assess prevalence and intensity of helminth infections and nutritional status. Prevalence of Ascaris, Trichuris and hookworm was 92%, 98%, and 1.4%, respectively. 91% children had both Ascaris and Trichuris infections. About half of the Ascaris- and Trichuris-infected children (46% and 58%, respectively) had moderate infections. Stunting was seen in 55% of the children, while wasting was observed in 10%. Boys had lower nutritional status than girls (p < 0.001), based on weight-for-age (WA) and height-for-age (HA) Z-scores. Age had an inverse relationship with WA and HA Z-scores (p < 0.0004). A relationship between helminth infections and nutritional status was observed between log Trichuris egg count and WA and HA Z-scores after controlling for age, sex, and log Ascaris egg count (p = 0.048 for HA Z-score, and p = 0.058 for WA Z-score). The relationship was also found when Trichuris infection was categorized into mild, moderate, and severe infections (p = 0.017 and p = 0.001 for HA and WA Z-scores, respectively). Scheffe's test for multiple mean comparisons showed that Trichuris-infected children with above 1,000 eggs per gram feces had significantly lower nutritional status than lower epg or non-infected children (p < 0.001 and p < 0.05 for HA and WA Z-scores respectively).