Beginning in 1974, the Japanese Ministry of Health Welfare directed the screening of schoolchildren for proteinuria. We studied their procedure and methods in 6197 school children and also evaluated a new urine dipstick that measures albumin concentrations down to about 10 mg/l and creatinine down to about 300 mg/l. We used specimens from adult in- and outpatients to test the accuracy of the dipsticks. Based on the quantitative results, we set as cutoffs < 150 mg/l for protein and < 30 mg/l for albumin as the concentrations representing "low risk." The quantitative values were assumed to be correct, and the dipstick results were judged accordingly, i.e., a dipstick protein of > or = "150" mg/l or an albumin of I "30" mg/l indicated increased risk of developing or having a genitourinary disorder. The sensitivity/specificity of the protein dipstick was 95.1%/95.5%, and the same for the albumin dipstick was 83.8%/93.8%. The cut-off for the albumin dipsticks probably should be set somewhat lower to reduce the number of false negatives and increase the sensitivity of the dipstick. When we compared the quantitative albumin to the protein dipsticks with the above cut-offs, we found the sensitivity/specificity to be 79.3%/94.4%, i.e., much like the albumin dipstick results. The many reports on the association of albuminuria and risk of renal disease recommend that screening should be done for albumin rather than protein. Based on the data from the school children, we estimate that a dipstick albumin of "30" mg/l is borderline increased risk, and that a protein dipstick of "150" mg/l is the same. If we call the dipstick "10" mg/l albumin, "30" mg/l albumin and the "150" mg/l protein results "low risk," then we estimate the prevalence of albuminuria in the school children to be about 2.1% and proteinuria to be about 4.3%. Children with these values should have a quantitative test for albumin and protein. We also tested a dipstick for creatinine and found increasing values with increasing age in both genders; the older boys had significantly higher creatinine values than the older girls and younger boys. For the albumin/creatinine ratio, we found 6028 children with a ratio of < 30 mg/g indicating low risk and 159 children with a ratio of > or = 30 mg/g indicating increased risk. The ratio may be more useful owing to the likely reduction of the number of false negatives and false positives.

ABSTRACT. The effect of heat treatment was examined against oocysts of Cryptosporidium parvum, Cryptosporidium muris and chicken Cryptosporidium sp. isolated in Japan. The oocysts of these species were exposed at 50, 55, 60 and 70°C for 5, 15, 30 and 60 sec in water bath, respectively. To determine the infectivity of heated oocysts, the mice and chickens were inoculated with the treated oocysts and the oocyst output in the feces after inoculation was examined. In C. parvum and chicken Cryptosporidium sp., the oocysts were not detected from mice or chickens which were received oocysts heated at 55°C for 30 sec, 60°C for 15 sec and 70°C for 5 sec. In C. muris, the oocysts were not detected from mice which were received oocysts heated at 55°C for 15 sec, 60°C for 15 sec and 70°C for 5 sec. Consequently, it was clarified that the infectivity of Cryptosporidium oocysts to mice and chickens was lost by heating at 55°C for 30 sec, 60°C for 15 sec and 70°C for 5 sec.KEY WORDS: chicken Cryptosporidium, Cryptosporidium muris, Cryptosporidium parvum, infectivity of heated oocyst.

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ABSTRACT. We isolated Cryptosporidium parvum-type oocysts from naturally infected siberian chipmunks which originated in the People's Republic of China and examined the infectivity to rodents as experimental animals. The naturally infected chipmunks did not show any clinical symptoms. The oocysts were 4.8 × 4.2 µm on average in size. They were ovoid and morphologically similar to the C. parvum oocysts isolated from human and cattle. Experimental rodents were inoculated with 1.6 × 10 6 original oocysts each. SCID mice began to shed oocysts on day 7 and the OPG value was 10 5 from 50 days. The oocysts were found from ICR mice on days 13 and 16 by only sugar flotation method, however, any oocysts were not detected from the rats, guinea pigs and rabbits until 30 days. Two infected SCID mice were necropsied on days 100 and 102 and examined for coccidian organisms. Merozoites and oocysts were found in the low part of jejunum and ileum, however, no parasites were detected in the stomach. Consequently, it was considered that the present species was C. parvum and was probably genotype 2 from result of infectivity to rodents.-KEY WORDS: Cryptosporidium parvum, infectivity to rodent, isolation of Cryptosporidium, siberian chipmunk.

ABSTRACT. To determine the infectivity of Cryptosporidium to hosts in slight infections, we examined the infectivity and oocyst output patterns of Cryptosporidium muris in mice inoculated with small numbers of oocysts. One of the 25 ICR mice inoculated with 2.4 × 10 1 oocysts and 19 of the 25 mice inoculated with 2.4 × 10 2 oocysts shed oocysts in the feces after inoculation. Four of the 50 mice inoculated with 2.4 × 10 1 oocysts for 10 consecutive days also shed oocysts and their OPG values were similar to that of the mice which received 2.4 × 10 2 oocysts. Consequently, it is clear that less than 10% of the mice which received 2.4 × 10 1 C. muris oocysts for 10 consecutive days.

ABSTRACT. The removal effects of the faucet mounted type water purifier for home use were examined against Cryptosporidium parvum oocysts. The water purifier is composed of a layer of granular activated carbon and the hollow fiber membrane filter. The cartridges were unused, 25%, 50% and 75% flow down by Arizona-dust of U. S. A. Two respective cartridges were used of the examination. Th e faucet and the water purifier were connected by anti-pressure tube, and 3.0 × 10 7 oocysts of Cryptosporidium parvum were injected into anti-pressure tube while water was running. Twenty liter of collected purified water was examined under the fluorescent microscope. Any oocysts in the purified water collected from all cartridges were not found. Therefore, we considered this purifier as an effective one in removing Cryptosporidium oocysts from drinking water. KEY WORDS: Cryptosporidium oocyst, removal effect, water purifier.

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