Shiba Kumar Rai

Contamination of River Water by Cryptosporidium parvum Oocysts in Western Japan

ABSTRACT In Japan, only a few rivers have been inspected forCryptosporidium parvum contamination, and the methods used had low sensitivity. In 1998 and 1999, we used a method with higher sensitivity to examine all large rivers used as sources of water supply in one prefecture (which we divided into four areas) in western Japan for Cryptosporidium oocysts. One sample was collected at each of 156 sites along 18 rivers, and samples were tested for Cryptosporidium oocysts by immunomagnetic separation. Samples were classified as being obtained on an island with livestock and fishing industries, a densely populated urban area, a western region including farming villages, or a still more rural northern area with agriculture and fishing. Restriction fragment length polymorphism analysis was used for identification of the C. parvum found as the bovine or human type. C. parvum was detected in at least one sample from 13 of the 18 rivers and in 47% (74 of 156) of the samples. One-third to all of the samples from each area contained C. parvum oocysts. The number of C. parvum oocysts per 20 liters of river water varied in the same pattern as the number of cattle kept in the four kinds of areas (as determined by the Mantel extension test). Oocysts isolated were of the bovine type; the C. parvum detected in rivers probably came from cattle kept in that valley. As we had expected, when tested with a more sensitive method, river water in western Japan was found to be greatly contaminated with C. parvum oocysts, as reported in other countries.

The health system in Nepal—An introduction

We present here a study on the health system in Nepal. Approximately two-thirds of the health problems in Nepal are infectious diseases. Epidemics occur frequently with a high rate of morbidity and mortality and there are occasional outbreaks of infectious diseases of unknown etiology. In addition, the rapid rate of HIV infection in the Indian sub-continent is likely to add a new dimension of opportunistic infections. Until now, the Health System introduced as the General Health Plan in 1956 has been expanded by focusing on primary health care, and a comprehensive network-like Health System has been developed; the most basic unit is a Sub-Health Post or Health Post in each Village Development Committee area. However, the expansion of the Health System has not been matched by an expansion in the domestive resources, workers and supplies, and the available resources are not efficiently distributed. In addition, insufficient resources available for preventive and promotive medicine and the occurrence of non-infectious diseases such as cancer and cardiovascular diseases has been increasing. The Government recently introduced a Health Policy encouraging the private sector to invest in the production of health workers and in providing quality health services. As a result, several private health institutions have been founded and are expected to contribute to the development of the human resources required by Nepal.

A new filter-eluting solution that facilitates improved recovery of Cryptosporidium oocysts from water

Cryptosporidium is a zoonotic coccidian parasite associated with diarrhea, and the disinfectant-resistant oocysts are threats to public health even in industrialized countries. In order to make an accurate assessment of the risk to public health, a detection method that has a high recovery rate of oocysts in water is required. In this study, we developed a new filter-eluting solution that facilitates more efficient recovery of Cryptosporidium oocysts from different kinds of water samples. The filter-eluting solution, referred to as PET, consists of sodium pyrophosphate (0.02%), Tween 80 (0.01%) and trisodium EDTA (0.03%). By using PET instead of conventional filter-eluting solutions, the average recovery rate significantly increased from 25.5+/-15.1% to 43.1+/-13.9% (p<0.05). The improved oocyst recovery was likely due to the increased separation of the oocysts from debris trapped on the filter membrane as well as increased capture of the oocysts by immunomagnetic beads. We recommend that PET be used as the filter-eluting solution for detection of Cryptosporidium oocysts in environmental water.

Cryptosporidium and cyclospora -associated Diarrhea in Kathmandu, Nepal

Publisher Summary The purpose of this chapter is to discuss Cryptosporidium and cyclospora-associated diarrhea in Kathmandu, Nepal. This chapter describes a study that determines the bacteriological indicator of drinking water contamination, taken together with the isolation or the detection of enteropathogens in diarrheal fecal samples collected in all four seasons in Kathmandu Valley, Nepal. A total of 737 diarrheal fecal samples collected from children attending Out Patient Hospital in Kathmandu were included in this study. The various methods employed to carry out the study were bacterial culture, electron microscopy, cell culture methods, direct saline and iodine wet mounts, sucrose floatation technique, and fluorescent antibody technique. The results showed the presence of eight species of bacteria, three genera of viruses, and five species of protozoan parasites. The study presented in this chapter highlights the magnitude and pattern of enteropathogens in all four seasons, together with the status of fecal contamination of drinking water in Nepal. Therefore, an inclusive program needs to be launched to battle diarrhea-related morbidity, mortality, and its socio-economic impact in Nepal, and the results of such a program should be monitored by periodical survey.