HEALTH NOTES

Evening Post, Volume CXIII, Issue 42, 19 February 1927, Page 15

HEALTH NOTES

GREATEST OF PESTS

RATS AND-RAT-BORNE

DISEASES

(Contributed by. the Department of '

Health.)

Tho rat throughout the ages haj remained one of the greatest of household pests. ' By their dissemination of disease, particularly bubonic plague, rats present a serious problem in preventive .medicine. They create also great economic disturbance by the destruction of food and property. In Great Britain alone the consumption and waste of foodstuffs in stacks, granaries, mills, warehouses, and shops, the damage to buildings, goods and merchandise, the tlestruction of pou-ltry, and loss in other ways due to rats has been estimated to run into many millions of pounds annually. .In New Zealand the financial loss from similar causes is undoubtedly very high. SPREAD OP DISEASE. During the decade of 1898-1907 plague caused the death of upwards of five million persons in India alone. It has from time to time swept Europe, and paralysed trade with appalling loss of life and money. This disease, especially the common or bubonic form, is spread by the rats. Rats also transmit infectious jaundice, rat-bite fever, dysentery, food poisoning, and several forms of parasitic worms, including trichinosis found in measly pork. Plague is essentionally a. disease of xats, which only occasionally attacks the human race, and is transmitted .to human beings from rats by the rat flea. In the early stages of an epidemic there is a heavy nior.tality among the rats, the rat fleas leave the dead rats, and infest those rats which remain, and so spread the disease. During an epidemic it is noticed there is a marked-increase in the number of fleas found on each rat. Should a rat die, and there is no other rat available, the rat flea will attack the human being. Pleas breed: in. dust, particularly on dry earthen floors. Barefooted persons are more susceptible to plague and the leg glands are those usually, affected. JThis is one reason why Europeans suffer more lightly from plague than their native brethren. In New Zealand during: the years 1900-3 bub.onic plague made its appearance, resulting in a few deaths. In reference to this outbreak, ,in 1900, a considerable mortality among rats was reported by.a Medical Officer of Health of the Department of Health in the district around Mokau, -whidh he suspected was of plague origin. It appears that the rats were'migrating in a large body from the North; they suddenly invaded the district in question, and almost as suddenly disappeared, but, many side and dead rodents were left in the tram of the main band. On examination the rats obtained showed naked-eye and microscopical changes characteristic, of plague. In Auckland, where the ±atal cases of. plague occurred, dead rats obtained from wharves on examination showed that they had suffered from this disease. • HABITS AND PREVALENCE. Bats are very cunning. They will move about in search of food. They will desert buildings where active measures are taken for their destruction and take up their abode with persons who leave them in peace. Here they will ancrease and multiply and use their refuge as a base ■ of operations for raiding other buildings. They breed very rapidly, and,the number of rats is only limited by the food supply and opportunities to nest. Few people have any conception of-the ■enormous number m cities and on farms. Although few are seen in the' daytime, at night they fairly, swarm along river fronts and walls, as well as in sewers, stables, warehouses, markets, and other places where food .may be found.- For instance, in 1901. an estate near Chiehester England was. badly infested with rats. 31,98J were killed by traps, poisons, and ferrets,, whilei it is estimated that tenants at the threshing destroyed fully ouuu more. RAT DESTRUCTION . Considerable skill and experience is required to carry out an ■ effective rat campaign. The rat is very wary, has a keen sense of smell, and unless precautions are taken he will become aware of the measures taken for his destruction and avoid them. It is therefore necessary.that such measures should be ■ sufficiently comprehensive to. prevent rats finding a harbour outside the area or. operation. The campaign should be in the hands of persons sufficiently skilled to make their work effective, such as an official rat-catcher. The most successful attacks on the rat population have been conducted by a combined effort under the control of the local authority. In order to successfully combat rats, it is necessary to make buildlngs . C1) The basement should be impervious, i.e., of asphalt cement, or concrete.. (2) Ventilating openings should be protected by wire, (d) Drainage openings should be protected and all drains carefully examined and tested. Bats use underground drains aa thoroughfares and will readily connect their runs to any broken or detective drainage, or to an unprotected vent. (4) Food should be protected ±rom rats. Eats' come to a buildiuoprimarily for the purpose of obtaining" tood. All stores should be kept in ratproof cupboards or bins. In large warehouses, bags and boxes should bo so stored that there is a. free space between the packages and the walls frequently passages should be made between the groups of packages, and the goods should be stored in frames sufficiently high above the floor to allow free movement for a eat. This space should bo kept absolutely clean. All crumbs and refuse should be collected and placed in ratproof bins. Eats will hide and breed in accumulations of old sacks, bins, tins, and cases. They are very fond of paper for -making their nests. ■ ' ■ POISONING. The use of poisons should be confined to granaries, stables, wharves, etc. Most rat poisons are dangerous to children and domestic animals, and greatest care must be exercised in their use. In laying poison baits, care must be taken first that the material is not touched by human hands as rats will not touch food that has been so handled. As far as possible, the grain or meal peculiar to the country or locality should be used to allay suspicion. Tallow, cheese, and fish are very popular with the rat family, and these can all be added to the baits. Most of tho local authorities and chemists stock rat poisons, which can be obtained at a reasonable cost. In the home, traps, dogs, and the valiant cat are usually effective; in dealing with this pest. Bear in Mind.—Eats not only cause great economic loss but spread disease, such as plague. The prevention and suppression of plague and other ratborne diseases resolve themselves into a war upon these rodents. The appointment of official rat-catchers is an important step in this direction, as the introduction of plague into a country may lead not only to loss of human life, but to a state of grave economic importance owing to strict quarantine restrictions being enforced. A scarcity of food helps all other supprcssive methods. Care therefore should be taken as to disposal of remnants of lunches in office buildings and of organic waste generally. A great deal can be done to keep rats in check by making buildings ratproof.