Only two examples are described here: Minor (1996) reported on 28 cases of infections occuring between 1932 and 1987 in which individuals who had close contacts with macaque monkeys infected with a highly pathogenic virus (Herpes simiae or B virus) fell ill. This virus is latent in these monkeys, but causes fatal disease in man. Twenty cases were fatal and seven had severe sequelae. The second example concerns the contamination by the Marburg virus. Smith et al. (1967) reported that the contamination of monkeys with this filovirus led to an infection of 31 operators/monkey handlers of which 7 died. These monkeys had been imported into Germany for vaccine production by using their kidney cells. More details can be found in Peters et al. (1992) .