174 Arthropods as Direct Inoculators of Disease Germs 



precautions to prevent the ingress of rats. Cargo must be inspected 

 just before being brought on board, in order to insure its freedom from 

 rats. Even lines and hawsers must be protected by large metal discs 

 or funnels, for rats readily run along a rope to reach the ship. Once 

 infested, the ship must be thoroughly fumigated, not only to avoid 

 carrying the disease to other ports but to obviate an outbreak on 

 board. 



When an epidemic begins, rats must be destroyed by trapping 

 and poisoning. Various so-called biological poisons have not proved 

 practicable. Sources of food supply should be cut off by thorough 

 cleaning up, by use of rat-proof garbage cans and similar measures. 

 Hand in hand with these, must go the destruction of breeding places, 

 and the rat-proofing of dwellings, stables, markets, warehouses, docks 

 and sewers. All these measures are expensive, and a few years ago 

 would have been thought wholly impossible to put into practice 

 but now they are being enforced on a large scale in every fight against 

 the disease. 



Rats and other rodents are regularly caught in the danger zone 

 and examined for evidence of infection, for the sequence of the epi- 

 zootic and of the human disease is now understood. In London, rats 

 are regularly trapped and poisoned in the vicinity of the principal 

 docks, to guard against the introduction of infected animals in ship- 

 ping. During the past six years infected rats have been found 

 yearly, thirteen having been found in 1912. In Seattle, Washington, 

 seven infected rats were found along the water front in October, 1913, 

 and infected ground squirrels are still being found in connection with 

 the anti-plague measures in California, 



The procedure during an outbreak of the human plague was well 

 illustrated by the fight in San Francisco. The city was districted, 

 and captured rats, after being dipped in some fluid to destroy the fleas, 

 were carefully tagged to indicate their source, and were sent to the 

 laboratory for examination. If an infected rat was found, the officers 

 in charge of the work in the district involved were immediately 

 notified by telephone, and the infected building was subjected to a 

 thorough fumigation. In addition, special attention was given to 

 all the territory in the four contiguous blocks. 



By measures such as these, this dread scourge of the human race 

 is being brought under control. Incidentally, the enormous losses 

 due to the direct ravages of rats are being obviated and this alone 

 would justify the expenditure many times over of the money and 

 labor involved in the anti-rat measures. 



