1- At slaughterhouse: Keep working knives at slaughterhou; 2- At_Slaughterhouse: Keep working clothes at slaughterhouse; 3-Ndere: Ngaoundere; 4- No_cleaning_C: No cleaning of working clothes; 5- No_cleaning_K: No cleaning of working knives; 6-Pitoa_G: Pitoa-Garoua; 7-S: Slaughterhouse; 8- U_River/well water_c: Use of river or well water to wash working clothes; 9- U_River/well water_K: Use of river or well water to wash working knives; 10- W_tap_water (K): Wash the knives of work with tap water; 11- W_tap_water+D (K): Wash the knives of work with tap water and detergent; 12- W_tap_water+D (U): Wash the uniform of work with tap water and detergent; 13- Wash_2/3_days: Wash work clothes every two to three days; Modality of active variable;Modality of illustrative variable;Perception class of basic hygiene rule of assistant butchers.