Handwashing and microbial contamination on the palms of preschool children in Kathmandu, Nepal / 国際保健医療

<b>Objectives</b><BR>  More than half of those living in developing countries do not have piped water in their homes. Although handwashing is effective for the elimination of microbes from the surface of the palms, thereby preventing the transmission of infectious diseases, the effect of using poor-quality water for handwashing is unclear. This study measured the water quality and the bacteria count on the hands of preschool children in Kathmandu, Nepal.<BR><b>Methods</b><BR>  Sixty-two children were asked to follow their normal handwashing technique, and the counts of 3 microbial bacteria—viable bacteria, <i>Escherichia coli</i>, and total coliforms—were measured in the water source and on the children’s palms. Microbial samples from the children’s palms were collected before and after handwashing. The Wilcoxon signed-rank test was used to compare the number of bacteria on the palms before and after handwashing.<BR><b>Results</b><BR>  The children washed their hands with a low volume of stored water without soap. Viable bacteria, <i>E. coli</i>, and total coliforms were detected in the water source. The number of viable bacteria and total coliforms on the palms increased after handwashing. In contrast, the numbers of <i>E. coli </i>colonies did not change after handwashing.<BR><b>Conclusion</b><BR>  Handwashing with poor quality of water did not have effect on removal of bacteria from hands. In areas with limited water sources, intervention for handwashing requires strategies for not only promoting hygiene behaviors also water storage management.

Long-Term Dynamics of Freshwater Red Tide in Shallow Lake in Central Japan

Objective: The aim of this study is to clarify the long-term dynamics of the red tide occurring in Lake Kawaguchi. Methods: The measurement of environmental factors and water sampling were carried out monthly at a fixed station in Lake Kawaguchi’s center basin from April 1993 to March 2004. On June 26, 1995, the horizontal distribution of Peridinium bipes was investigated using a plastic pipe, obtaining 0~1-m layers of water column samples at 68 locations across the entire lake. Results: P. bipes showed an explosive growth and formed a freshwater red tide in the early summer of 1995, when the nutrient level was higher than those in the other years, particularly the phosphate concentration in the surface layer. The dissolved total phosphorus (DTP) concentration was sufficient for P. bipes growth in that year. In the study of its horizontal distribution, P. bipes was found at all the locations. The numbers of cells per milliliter ranged from 67 to 5360, averaging 1094±987 cells/ml, with particularly high densities along the northern shore. Since then, P. bipes has annually averaged about 25 cells/ml in Lake Kawaguchi. Conclusion: We observed that the red tide caused by P. bipes correlates with a high DTP concentration in Lake Kawaguchi.

Long-term dynamics of freshwater red tide in shallow lake in central Japan

<p><b>OBJECTIVE</b>The aim of this study is to clarify the long-term dynamics of the red tide occurring in Lake Kawaguchi.</p><p><b>METHODS</b>The measurement of environmental factors and water sampling were carried out monthly at a fixed station in Lake Kawaguchi's center basin from April 1993 to March 2004. On June 26, 1995, the horizontal distribution ofPeridinium bipes was investigated using a plastic pipe, obtaining 0∼1-m layers of water column samples at 68 locations across the entire lake.</p><p><b>RESULTS</b>P. bipes showed an explosive growth and formed a freshwater red tide in the early summer of 1995, when the nutrient level was higher than those in the other years, particularly the phosphate concentration in the surface layer. The dissolved total phosphorus (DTP) concentration was sufficient forP. bipes growth in that year. In the study of its horizontal distribution,P. bipes was found at all the locations. The numbers of cells per milliliter ranged from 67 to 5360, averaging 1094±987 cells/ml, with particularly high densities along the northern shore. Since then,P. bipes has annually averaged about 25 cells/ml in Lake Kawaguchi.</p><p><b>CONCLUSION</b>We observed that the red tide caused byP. bipes correlates with a high DTP concentration in Lake Kawaguchi.</p>