[Report 1956] / Medical Officer of Health, Newhaven Port Health Authority.

  • Newhaven (England). Port Health Authority.
Date:
1956
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: [Report 1956] / Medical Officer of Health, Newhaven Port Health Authority. Source: Wellcome Collection.

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    leratting exemption certificate may be issued. On the other hand, .f it is found that conditions are such that rat destruction by ;rapping, poisoning or fumigation is held to be justified, the Port ledical Officer can insist on such a course before a deratting cert- .ficate is issued. The numbers of rats on ships are much less nowa¬ days than they were formerly, and the number of exemption certificates .ssued at ports in the United Kingdom is now far less proportionately .han that of deratisation certificates. In some years the exemption :ertificates amount to over eighty per cent of the total deratisation Ind exemption certificates combined, Although United Kingdom ports iave been free of plague infected rats there have been instances I airing the last century where infected rats have been found in vessels rriving at British Ports. There still remains the danger of the importation of plague into this country by infected ships rats and :onstant watch is essential as regards the rat population of ships. The plague is caused by a germ called bacillus pestis. When hese germs are swallowed by a flea they multiply in the fleams gut. |hen the flea bites the rat to feed on it the germs are transmitted o the rat on the flea regurgitating them into the wound. The rat s then infected and other fleas become infected by feeding on it. f the germ-carrying flea, bites man the same process of regurgitating ^nto the bite occurs and man is infected. Rats which mostly inhabit .och areas belong to the species Mrattus rattus” the black rat, which ras the original rat belonging to this country until displaced to a reat extent by the brown rat, nrattus norvegicus. The latter is tow found mostly in towns and in country areas. Besides being the vector of plague infested fleas a rat may :arry other diseases such as Weil’s disease and infect foodstuffs hereby transmitting the diseases to human beings, 4s the period of ;estation in the rat is about only three weeks, and a litter usually lumbers six to eight young, it can be readily appreciated that a :ountry would be soon overrun unless the rat population was kept in heck. Besides trapping and poisoning as methods employed to get 'iu of ships rats, good results have been obtained through rat-proof-