الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
 |  | from | 184 |  |  |
| | | from | 184 | | |
Abstract
Giardiasis is an infection of the upper small intestine caused by the t1agellate protozoan Giardia lamblia. Its prevalence throughout the world ranged from 2.4 to 67.5. Reported waterborne outbreaks are those in which drinking water was implicated epidemiologically as the vehicle of illness transmission. Waterborne outbreaks of giardiasis not only affect developing countries, but also the developed ones. Outbreaks of giardiasis occur every year in the United States, and waterborne infections appear to be increasing. Drinking-water has also been implicated as the vehicle of transmission in outbreaks occUlTing in travellers to the USSR. In Egypt, private tap water samples taken in one of the Nile Delta villages, viz. EI-Mohagrin village from Khorshid area showed a contamination rate of 37.5 with Giardia lamblia. Recently, viable and infective Giardia cysts were isolated from raw, finished, and tap water samples in Alexandria with 100 animal infectivity rate. The present work aimed at studying the role of drinking water supply and roof tanks as sources of giardiasis and assessing the sanitary condition of water in its treatment plants in Alexandria, through detection of possible contamination with viable IO!. and infective Giardia lamblia (VIOL) cysts. In addition, the efficiency of sand filters with different heights for removal of VIOL cysts was evaluated. A household survey was carried out on 826 persons from 188 houses who were chosen randomly from the six districts of Alexandria using the equal allocation method. They were subjected to interview and stool examination.