[Case 1]
65438+From February 2002 to May 2003, there were 147 students suffering from acute infectious hepatitis in a county middle school in the south. According to the investigation by experts from the provincial CDC, the outbreak of acute infectious hepatitis in this middle school is the spread of this infectious hepatitis, which is mainly caused by water transmission. The water quality test results of the school's self-prepared well show that the well is polluted by feces, and the Escherichia coli in the water seriously exceeds the standard, and most of the hepatitis A virus is hidden in the feces.
[Case 2]
In 2003, typhoid fever broke out in a middle school in a county in the south. A total of 1 16 students were infected with typhoid fever due to drinking polluted water (drinking raw water) and developed typhoid fever symptoms.
These two cases are typical water-borne cases.
[Case 3]
In September 2004, two chefs and two waiters in a middle school in the west were healthy carriers of typhoid Bacillus, which led to six students being infected with typhoid fever one after another, causing typhoid epidemic.
This example is a typical case of food transmission.