QUARANTINE

New Zealand Journal of Agriculture, Volume 71, Issue 4, 15 October 1945, Page 395

QUARANTINE

Its Role In Prevention And Control Of Animal Diseases

QUARANTINE in its broadest sense covers all regulatory measures instituted by Governments to prevent the introduction of the more serious diseases of animals. It also includes internal regulatory measures for the control and prevention of spread of diseases already existent, or of recent . introduction. In its literal interpretation quarantine means detention and isolation of livestock newly landed from a ship for observation and testing, or in order to keep such livestock apart from other livestock for a prescribed period. The term today, however, usually includes all measures designed to prevent the introduction of infection through any channel whatsoever; it thus becomes very wide in its ramifications, covering aspects frequently remote from the living animal. Thus at times restrictions imposed on the introduction of certain things having no apparent relation to the live animal are not readily understood, yet may in themselves be far more dangerous as a means of introducing infection than the living animal.

Careful Watch in N.£. The administration of measures

to prevent the introduction of serious animal diseases from overseas is thus an important function of the Department of Agriculture, requiring ever-watchful attention to cope with present-day conditions of rapid transport, the dangers resulting from the interruption to normal trading, and the tendency to breakdown of established precautions as a result of the war. We in New Zealand must consider ourselves extremely lucky that so far we have escaped the introduction of one or other of the serious animal diseases existent in countries not so remote from our shores. No one is probably more appreciative of this element of good luck than the officers of the Department respon-

sible for the administration of precautionary measures.

The development of quarantine throughout the older countries of the world became a necessity following on the disastrous losses occasioned by the ravages of the more virulent animal plagues in those countries. The history of those early losses provides fascinating reading, and illustrates the slow but developing recognition of veterinary sanitary service in controlling such disasters. The following extracts from a very old authority, Fleming’s “Veterinary Sanitary Science and Police,” serve to illustrate the happenings of those early periods. In Great Britain up to the time of the invasion of the cattle plague (rinderpest) in 1865 it may justly be said that veterinary sanitary

science, except in the Army, had no existence so far as the prevention of contagious disease is concerned. In 1865 cattle plague was introduced into England, and in October of that year it was calculated 17,000 cattle had become affected. In November only four counties in England were exempt, and the disease was present in 19 out of the 33 Scotch counties.

Further, during 1865 and 1866 some 279,000 cattle were reported sick, and 233,000 died or were killed. Up to 1869, for 30 years since the introduction of the two contagious maladies foot-and-mouth disease and bovine pleuro-pneumonia, it was estimated that the loss from these alone amounted to five and a half million cattle, roughly valued at eighty millions sterling.

In or about the period mentioned in this quotation stock was being imported to New Zealand. The danger of introducing serious disease from Europe must, therefore, have been very great, and New Zealand must indeed be considered fortunate in that only two major diseases were introduce, bovine pleuro-pneumonia in 1864 and sheep scab earlier. Happily, pleuro-pneumonia did not persist, and was either stamped out or died out. It is recorded that a slaughter policy was put into operation in the district of the South Island into which the disease was introduced. A veterinary surgeon, the late Mr. Alexander Hamilton, M.R.C.V.S., who was located in the district, diagnosed the disease, and on his advice a slaughter policy was enforced, with the fortunate result of disappearance of pleuro-pneumonia. Australia was not altogether so lucky. History records that pleuro-pneumonia was seen in Victoria in 1858, and was recognised by the late Mr. Henry Wragge, M.R.C.V.S., who advised the Government of the day to slaughter all the cattle involved. This advice was not acted upon, but instead a Royal Commission was set up to inquire into the matter. Had the veterinarian’s advice been acted upon in Australia, as it was in New Zealand, Australia would most likely have been spared a costly legacy.

WHILE New Zealand has been fortunate in escapg ing the more virulent livestock S diseases of other countries, in g assessing the Dominion’s pres--3 ent favourable position great g credit must be given to those ■ responsible for the early J introduction of import regulag tions and the adoption of g vigorous and severe control 3 measures when outbreaks of H disease occurred.

S This survey of the history § of stock diseases and quarH antine regulations in New g Zealand by W. C. Barry, J Director of the Livestock g Division, should be of great fl interest to all concerned with U the welfare of our livestock g industry.

Early Legislation

Legislative authority to deal with cattle diseases at this period in New Zealand was contained in the Diseased

Cattle Act of 1861, and it is of interest to note the definition of “disease” in that Act, which reads as follows: —“Disease: The diseases called pleuro-pneumonia, rinderpest, foot-and-mouth disease, or any other infectious or contagious diseases which may hereafter be brought under this Act by proclamation in the New Zealand Gazette.” The inspectors appointed under the Diseased Cattle Act of 1861 were not qualified veterinarians. The measures which resulted in the complete eradication of sheep scab from New Zealand stand as a permanent memorial to the men responsible for what must be recorded as an outstanding achievement. Sheep scab was known to have been existent in New Zealand before 1850. Records exist of its introduction into the Nelson district in 1850 in sheep imported from Australia, and its distribution in the years following became extensive. The first public dip was erected in Canterbury in 1857. In November, 1878, the Sheep Act, defined as “an Act to provide for the eradication of scab in sheep,” became law. One is filled with admiration today for the people responsible for its production, the detail and thoroughness of the measures prescribed being exemplary. Inspectors appointed under the Act were known as Inspectors of Sheep, and their powers were obviously not limited. The fight went on for seven years. Dipping, and later wholesale slaughter, were vigorously enforced. . The last cases were seen in 1885, seven years after the passing of the Sheep Act. Thus, the intention of the Act “to provide for the eradication of scab in sheep” was fulfilled.

Two extracts from the Sheep Act are worth quoting. The first is the definition of the word “destroy,” which is “to kill and bury at a depth of not less than two feet under the ground, or consume by fire, or boil down.” The second is a warrant for herding or yarding sheep under Section 28, and reads: — THE SHEEP ACT, 1878—SECTION 28. Schedule C.—Warrant for Herding or Yarding Sheep. District of New Zealand, To ;...., To Wit. and all others whom it may concern. WHEREAS it appears to me....... Inspector of Sheep, upon my own view, that certain sheep are depastured upon land situated at , being in the occupation of of in the said district, and that such sheep are infected with the disease called and that there is a danger lest such sheep, being suffered to run at large, should cause damage to the owners of the sheep in the neighbourhood thereof: These are therefore, in the name of our Lady the Queen, and in pursuance of the provisions of “The Sheep Act, 1878,” to require you that you do cause the said sheep to be. constantly • herded by day and to be kept by night within a sheep-proof enclosure; and I do hereby require all persons having or being concerned in the charge, control, or management of such sheep, to aid and assist you in causing. the same to be constantly herded and enclosed, according to the provisions of the above-recited Act in that behalf made. Given under my hand at in the said district, this day of in the year of our Lord one thousand eight hundred and Inspector of Sheep. .

These quotations indicate the merit of a pioneer piece of legislation in control of animal disease.

The eradication of sheep scab in Australia was an equally meritorious performance. Not enough appreciation appears to be given to the fact that two such prominent sheep countries as Australia and New Zealand were able to eradicate and keep their flocks free over the years from a parasitic sheep disease which is productive of great economic losses in practically all other countries.

The “Gilruth Era”

The period in the history of animal disease control in New Zealand which began in 1894, at the time of the first appointment of official veterinary control, may be referred to as the “Gilruth era,” for undoubtedly the genius and foresight of the late Dr. Gilruth played the most important part in the control of animal disease in this country during the years of his stay here. The control regulations inaugurated by Gilruth saved New Zealand from stock

losses which it would be difficult to compute in pounds sterling. The control of anthrax affords interesting study and cannot help but evoke appreciation. From the time of

his arrival Gilruth had recognised the presence of anthrax, the first cases being seen in the Auckland Province. During 1899 four outbreaks occurred, one in the Bay of Plenty and three in Taranaki. Even earlier than this Gilruth had concluded that the infection was being introduced in imported bone manures, either green-bone manure or that which had not been sufficiently sterilised. An extract from his report of 1900 reads: “We have come to the conclusion that the introduction was due to the . importation by some means of infected bones, for the following reasons : 1. The outbreaks occurred on turnip pad docks; 2. These paddocks formed only a small area of the farm; 3. . The stock on other paddocks on the same farms were unaffected;, unless indirectly from the turnip paddocks; 4. All these paddocks had been recently dressed with manure containing a proportion of bones; 5. It was only when the turnips were eaten fairly well down that the disease appeared, that is, when it was possible that the soil had gained entrance to the system with the feed; and 6. The manures were all supplied by the same firm, which is one that

imports large quantities of Australian bones. “Raw bones imported from Australia are landed in sacks, taken to certain premises, where they are sterilised under pressure at a temperature of 250° F. for two hours. The introduction of anthrax, however, proves that these precautions have been insufficient. 1 From 1900 to 1907 outbreaks of anthrax were reported from widelyseparated parts of the North Island, and an outbreak was confirmed in Southland in 1903. Meanwhile regulations prescribing specific sterilisation (281° F. for three hours) . of all bone manures from India and Australia had been introduced, a New Zealand officer being stationed in India to supervise this procedure. Later on import of bone manure from India ceased. Concurrently with this, cases of anthrax in New Zealand decreased, its occurrence eventually disappearing altogether. For practically 20 years following 1907 no anthrax was recorded, which can definitely be attributed to the action taken regarding importation of bone manure. Of'later years two outbreaks in the Auckland Province could be regarded as recrudescence of infection on farms where the disease had occurred previously. The last occurrence of anthrax took place in 1944, on a dairy farm in the

Manawatu district, resulting in the death of 13 cows. In this instance the actual origin of the infection has not been satisfactorily determined. a Swine Fever The virus diseases present the most formidable difficulties in quarantine control. The presence of swine fever was recorded by Gilruth between the years 1895 to 1902. For 30 years following New Zealand enjoyed complete' immunity from this serious disease of pigs. In 1933, however, an outbreak occurred among garbage-fed pigs in the environs of Wellington. The following extract from the writer’s annual report of 1933 summarises the features of the outbreak;’ Swine Fever: An outbreak of this disease during the year on some farms in the Johnsonville and Lower Hutt districts, near Wellington, has to be recorded. A brief history of the outbreak is as follows: During May investi- , gation of some reported mortalities in pigs in the Johnsonville district led to the discovery of the existence of swine fever, confirmation of the disease being established by blood-transmission tests carried out at the Wallaceville Laboratory. 1 As a result of intensive inspection of all farms in the district, further unreported centres of the disease

were located. Quarantine restrictions were immediately imposed controlling the movement of pigs, and the risk of spread was thus minimised.

The pig farms on which the disease occurred were all of the same type—viz., pig farms on which pork was produced for sale to Wellington butchers. In every instance the pigs were garbage fed, the garbage being collected from hotels, etc., in Wellington. It thus became evident from the start that garbage feeding was the means by which the infection was spread, as interchange of garbage tins from,farm to farm was common. The closest inquiry failed to decide the manner in which the infection reached Wellington. The inference is very strong, however, that the virus was introduced in garbage from an overseas ship. Although it was not possible to prove the point, a strong suspicion exists that garbage from an overseas ship had in some way reached a piggery, thus conveying the virus infection in meat scraps. This remains the only feasible explanation, in spite of the fact that the removal of garbage from overseas vessels has been prohibited by regulation for some years.

The existence of the disease at Johnsonville was confirmed on May 12, and from then to July 7, when the final slaughterings took place on a farm in the Lower Hutt area, 13 pig farms were discovered to be infected. All affected and in-contact pigs, totalling 1,920, were slaughtered, and buried in deep trenches. All piggeries were demolished and destroyed by burning, compensation being paid on stock and buildings according to valuation.

The cases met with in Lower Hutt in July proved to be the last, as, although careful inspection was still maintained in the quarantined areas (Hutt and Makara Counties), no further evidence of swine fever was discovered. The first restocking with pigs took place in January of this year, and by the end of March five of the previously-affected pig farms had resumed operations. Regular inspections of those premises have been maintained, and it is satisfactory to record that all pigs introduced have remained healthy. The outbreak was successfully stamped out in a short period, thus removing the existence of a disease which, had it persisted, would prove a menace to the pigbreeding industry. The longevity of swine fever virus in the animal tissues has long since emphasised the danger of garbage feeding to pigs, and it is now realised

in countries in which the disease is endemic that garbage feeding is undoubtedly the means of perpetuation. Realising this danger, Canada some years ago introduced very stringent measures relating to garbage feeding. An experiment carried out in the United States of America in 1917 showed that in places where meat inspection was maintained it was impossible, even with the severest interpretation of temperatures, symptoms, and lesions, to remove from market all carcasses of hogs that contain hog-cholera virus. In an examination of 21 cured hams from infected no-lesion hogs virus was found in 12. The vitality of the virus persists for three months in pork and bacon and possibly much longer under certain conditions. The danger of meat scraps being brought ashore as garbage from overseas ships is very obvious. In 1930 regulations were brought down under the Stock Act prohibiting the landing of garbage from ships, and these have been enforced with as much thoroughness as possible. In 1934 entry of all meats (except cooked meats) into the Dominion was prohibited, a measure which resulted from the discovery that cured bacon and ham from England were actually on sale in Wellington. Needless to say the war years brought serious difficulties, and the dread that American pork or bacon would be brought in was ever present. In this respect we were more fortunate than Australia, which country experienced a costly outbreak of swine fever in 1942, originating in Western Australia and extending to New South Wales.

The internal control of garbage feeding in the Dominion was strengthened in 1943 by the introduction of regulations which make it compulsory on all -feeders to possess a licence from the Department of Agriculture to feed garbage to pigs, the main conditions of the licence involving the cooking of garbage prior to feeding. Rinderpest One of the most ancient cattle plagues, rinderpest, another virus infection and fortunately now confined to certain localities in Europe and Asia, was introduced into Western Australia at the end of 1923. A ship in port at Perth, from India, was believed to have had live animals on board as ship’s stores, from which the infection was in some way carried ashore. Prompt recognition of the disease, with adoption of drastic measures by the veterinary authorities, resulted in eradication, and is. another instance of a debt due to the value of veterinary control. During a visit to the Dutch East Indies in 1937 the writer observed the activities of the veterinary authorities there in coping with the introduction of rinderpest from Malay, in which country it is endemic. The disease had occurred in Java, but owing to adoption of vigorous methods had been eliminated,, and the Dutch Islands kept free of it. for some 10 years. Rabies Another anxiety of the war years has been rabies, which has never been seen in Australasia, which must be

regarded as the greatest of good luck. Nevertheless, every precaution must be taken, although this is rendered doubly difficult by the long incubative period in rabies. An instance is on record of a dog developing the condition in England after release from a six months’ quarantine. The surreptitious bringing in of dogs by servicemen, either by ship or plane, has been a worry during the war, and several dogs introduced in this way have been followed up and destroyed. Fortunately the landing of dogs from the United States for training for war purposes was obviated. As an added precaution the introduction of dogs from England was prohibited in 1944, a prohibition which will continue until some time after the war. This action followed a similar prohibition enforced by Australia. Horse Diseases New Zealand has remained immune from serious horse diseases. Glanders has never occurred here, yet it was introduced to Sydney years ago in a troupe of circus horses which had been brought over from America. On inspection at the port the existence of glanders was recognised by the late Edward Stanley, F.R.C.V.S. The affected horses were destroyed, and the remainder quarantined on an island.. This happened before the Mallein test had been introduced, and it was fortunate that the disease was clinically —another instance of the debt due to veterinary control. In dealing with horse diseases mention must be made of precautions taken against the introduction of enzootic encephalomyelitis, a disease which has resulted in enormous losses

in the United States of America within recent years. In 1938 no less than 184,662 cases were reported, while in 1941 reports were received of 32,872 cases and 8,210 deaths. The importation of horses into New Zealand from the United. States and ■ Canada was prohibited in 1939; the relaxation of this measure will depend on the demonstrated efficacy of immunisation, which is now largely practised in America. Foot-and-mouth Disease . The possible introduction to this country of foot-and-mouth disease is of outstanding significance' because the very great distribution of the disease and the numerous avenues through which the introduction of the virus is possible complicate the administration of quarantine safeguards. This responsibility has been greatly increased in recent years, when war conditions and various implications and dislocations have seriously endangered control measures. Recent research has thrown much light on the characteristics of the virus of foot-and-mouth disease. Knowledge regarding its vitality and longevity outside the animal body has been disseminated, all undoubtedly assisting in the formulation of preventive measures, yet at the same time causing a degree of wonder at the immunity experienced by New Zealand and Australia over the years. The work of the Foot-and-mouth Research Committee in England previous to the war, published in a series of reports, included invaluable information regarding longevity of the virus on inanimate things outside the

animal body, the duration of infectivity on hay, straw, fodder, and other commodities, occurrence in the rat and hedgehog, and its vitality in the carcasses of animals slaughtered and passed for human food in the early infective state, the last-named throwing considerable light on its repeated occurrence in England, and again em-

phasising the danger of imported meat gaining access to garbage fed to pigs. Before commenting on the precautions instituted in New Zealand, more particularly regarding introduction of livestock from Great Britain, it is of interest to refer to happenings in other countries. America, like Great Britain, has adopted the slaughter policy when outbreaks occur. Ten outbreaks have been reported in the United States, viz., in 1870, 1880, 1884, 1902, 1908, 1914, 1924 (2), 1929, and 1932. Explanations given regarding the origin of some of these outbreaks are of interest. In 1908 it was traced to contaminated smallpox vaccine. The extensive outbreak in 1924 was traced to pigs that received garbage from a navy yard, presumably infected from supplies of meat purchased in the Orient. The last outbreak, in California in 1932, was believed to originate in garbage from ships which had provisioned in the Argentine. Our anxiety, therefore, over the war years, in case Argentine meat should be introduced to New Zealand, or garbage from overseas ships possibly carrying Argentine provisions, can be appreciated. An outbreak in England of a few years ago was officially pronounced to have originated through the use of pituitrin by a veterinary surgeon in a herd of cows. The pituitrin was of French origin, and its manufacture

was proved to include glands from cows killed at a Paris abattoir, it being known that infected cattle were slaughtered at the time. It is of interest to note that an Import Prohibition Order introduced in New Zealand in 1939 includes in the definition of “veterinary biologies” preparations made from animal glands or tissues.

During his visit to New Zealand in 1935 the late Sir Arnold Theiler stressed the danger of introduction of infection by means other than through the live animal, holding that importation of stock under properly-con-trolled conditions constituted the much lesser risk. Sir Arnold Theiler also commented on the possibility of cases occurring in human beings being responsible for spread. He himself had had knowledge of its occurrence in humans, which recalled an experience in Java in 1937 when the writer was visiting a dairy farm on which foot-and-mouth disease was running its course, and where, one of the milkers had experienced typical vesicular eruptions on the lips and mouth. The Dutch farmer said that in his experience this was also known to happen in Holland. Such information makes one feel that there are ways and means not usually dreamt of in our philosophy. : Great Britain was free from foot-and-mouth disease between 1895 and 1899. From 1900 to 1903 outbreaks occurred, which were localised by slaughter of affected herds. Between 1903 and 1908 the United Kingdom again remained free. Since 1910 . occurrence of the disease has been recorded almost annually. However, the disease cannot be classed as endemic in a country which adopts the slaughter policy in dealing with each outbreak. The year 1924 was a disastrous one in England. The number of outbreaks in this year totalled 1,440, the number of animals slaughtered was 88,726, and the compensation paid £1,389,697. N.Z. “Embargo” Since 1924 the direct importation of cattle, sheep, pigs, and goats from Great Britain to New

Zealand has been prohibited. Stock was, however, admitted if . domiciled for six months in an intermediate country from which importation to New Zealand is allowed. This period of six months was reduced in 1933 to a stay of three months in the intermediate country. New Zealand’s so-called “embargo” on the direct import of stock from Great Britain has been the subject of much controversy. New Zealand still remains the only British possession which refuses to allow direct import of stock from Great Britain. This position has resulted no doubt from the extreme dread held by a section of the farming community of the danger of introducing foot-and-mouth disease, and the insistent demands made to Governments not to alter the position. This policy is no doubt actuated by an honest fear, but it is a policy which has placed enormous additional cost and difficulties in the way of importers of pedigree stock for the past 20 years. It has also naturally created much criticism in Great Britain. , The Royal Agricultural Society of England established in 1928 the London Quarantine Station, situated at the East India Dock, London. The station, taken over by the Ministry of Agriculture, England, in 1934, was designed for the purpose of quarantining stock intended for export prior to shipment. Certain specific conditions designed to ensure absolute

safety were laid-' down governing " location from which stock were derived, transport conditions, etc. The conditions were accepted by all importing countries, with the exception of New Zealand. That no occurrence of foot-and-mouth disease has eventuated in any of the importing countries over 20 years should by now convince x everybody ; of the absence of any risk. During the war the London Quarantine Station was closed, but a subsidiary station was established at Glasgow. No doubt the London station will again be opened. With the end of the war New Zealand'stud breeders will desire to import pedigree stock in increasing numbers if the standard of flocks and herds is, in their opinion, to -be maintained. The increasing difficulties which can be foreseen in prevention of introduction of animal diseases in future years should be emphasised. Modern means and speed of trans- • port will make possible the introduction of animals and prohibited things by channels hitherto unknown, while our former security in distance will be imperilled by the speed of modern transport. We can, however, but express the hope that control measures, construed and administered in accordance with knowledge derived from scientific investigation of disease causation and control, will help to protect the livestock industry of New Zealand.

New Wage Rates

NEW minimum rates of wages to be paid to agricultural workers employed on dairy farms are fixed under the Agricultural Workers’ Wagefixation Order 1945, which came into force on August 1, 1945. The weekly wages are as follows: workers under the age of 17 years, £l/15/-; for workers of the age of 17 years but under the age of 18 years, £2/5/-; for workers of the age of 18 years but under the age of 19 years, £2/15/-; for workers of the age of 19 years but under the age of 20 years, £3/5/-; for workers of the age of 20 years but under the age of 21 years, £3/15/-; for workers of the age of 21 years and upwards, £4/5/-. If board and lodging are not provided, however, the rates must be increased by £1 a week. . I i

CARELESS HANDLING OF PIGS.

Pigs which arrive for slaughter showing marks, bruises, and weals are degraded with economic loss to the farmer. Much of this bruising and marking is caused when the pigs are being loaded for the works. Bulletin No. 175, “Careless Handling of Pigs,” shows how to construct a simple loading race which will enable pigs to be loaded easily and without the use of whips and sticks. This bulletin is available free from the offices of the Department of Agriculture.