The significance of locating the source of outbreak efficiently: Epidemiological studies of Hepatitis A.

Hepatitis A causing by Hepatitis A virus, can transmit by feace can be outbreak in small numbers and large pandemics. In this paper how to choose the most efficient way by the situation of the cases, in this paper, the usage of a case-control study in a hepatitis A outbreak to locate the source of the outbreak and what should be done before, during, and after the outbreak will be mentioned. [ABSTRACT FROM AUTHOR]