Hubungan praktek cuci tangan dengan kejadian hepatitis akut klinis di daerah kejadian luar biasa (KLB) hepatitis A desa Cogreg Kecamatan Parung Kabupaten Bogor tahun 2001 - 2002 = Relation between washing hand with acute hepatitis. Case in Cogreg County in Parung Sub District of District of Bogor, which is outbreak area of hepatitis A year of 2001 - 2002