320 VETERINARY HYGIENE 



milk the excretion is often intermittent. In the goat and sheep 

 infection chiefly occurs by ingestion of milk or urine of affected 

 animals, chiefly the latter, and this may also be derived from in- 

 fected persons. There is a good deal of evidence to show that in 

 the case of goats the disease may be transmitted by copulation. In 

 other animals infection also usually takes place by ingestion of viru- 

 lent excretions, but in the horse and mule infection may occur by 

 inoculation of the virus through skin wounds due to the animal 

 having lain on contaminated bedding. Small rodents may become 

 infected by feeding on contaminated material. The disease in 

 goats is frequently spread from animal to animal through the agency 

 of the milker. The micrococcus can live for several months in 

 a cool, dark place, but rapidly dies at 15 to 25 C when exposed to 

 light. It is capable of remaining alive for 69 days in dry sterile 

 manure, and for 7 weeks in urine. It is easily destroyed by heat 

 and disinfectants, thus heating of milk to 68 C for 10 minutes 

 is sufficient to sterilize it. 



The mortality from the disease is low, and in man it is only 

 fatal in about 3 per cent, of the cases.* 



PREVENTIVE MEASURES. Several factors combine to render 

 the suppression of Malta fever rather a difficult undertaking. The 

 disease is very liable to be disseminated through the agency of 

 small rodents, and new centres may thus be created. 



In order to prevent the introduction of the disease into a clean 

 herd make sure that imported animals do not come from a herd 

 in which cases of abortion have occurred. If no knowledge can 

 be gained on this point, the animal should be quarantined until 

 parturition has occurred. Once the disease has become established 

 in a herd it is very difficult to eradicate it. All animals which 

 abort must be isolated and measures taken to destroy the foetus 

 and its membranes, and to disinfect the floor, walls, &c. Submit 

 all the animals to serum tests, and those which react positively 

 must be considered infective for long periods. Often the quickest 

 way of dealing with the disease would be to slaughter out and 

 restock if possible with healthy animals. 



The suppression of the disease in man is not so difficult, inas- 

 much as infection from man to man very rarely, if ever, occurs. 

 The milk from goats in infected localities should always be heated 

 before being taken. The success of measures such as these was 

 evident during outbreaks among British soldiers in Malta in 

 1906. 



* Hutyra and Marek, Spec. Path., Vol. I., p. 196. 



