existence of plague, should be made as quickly as possible.
(_c_) If the destruction of rats is judged necessary, it shall be
accomplished under the conditions indicated above in the case of
ships with plague-stricken rats.
(_d_) Until all suspicion may be eliminated, the passengers and crew
may be submitted to observation, the duration of which should not
exceed five days, counting from the date of arrival, except in
special cases, when the sanitary authority may prolong the
observation to a maximum of ten days.
ART. XXV. The sanitary authorities of the port must deliver to the
captain, the owner, or his agent, whenever a demand for it is made,
a certificate setting forth that the measures for the destruction of
rats have been efficacious and indicating the reasons why these
measures have been applied.
To be in conformity with these agreements regarding the destruction of
rats, quarantine authorities may demand the fumigation of infected and
suspected ships; suspected ships within the meaning of the treaties
being those on board of which there have been a case or cases of
plague at the time of departure or during the voyage, but no new case
within seven days. In the case of indemne ships, on the other hand,
without demanding it as a general rule, the sanitary authorities may
subject them to fumigation to kill rats. When upon such ships rats
have been recognized as pest stricken, as a result of bacteriological
examination, or when a marked mortality has been established among
these rodents, fumigation is prescribed.
While the classification of ships and the limitations placed on
quarantine procedures in relation thereto, as contained in existing
international sanitary agreements, is more apparent than real, there
appears to be a lack of exactness with respect to the destruction of
rats necessary for the prevention of the importation of plague from
one country to another.
Since the adoption of the international sanitary agreement of Paris in
1903, some of the unproven convictions of that time regarding the rôle
of rats and fleas in the transmission of plague have been proven to be
positive facts. Many epidemiological observations and exact scientific
experiments have demonstrated particularly the importance of the rat
in the propagation of plague and the rôle of the flea as the carrier
of infection from rat to rat and from rats to man.
At the same time there has been a growing conviction that other
agencies, such as passengers, baggage, and merchandise play a very
minor rôle in the dissemination of plague. It is of interest,
therefore, to review the efforts being made at the more important
seaports to exterminate rats, as well as the methods being employed to
that end.
INQUIRY INTO THE CRUSADE AGAINST RATS THROUGHOUT THE WORLD.
The first law in modern times aiming at the destruction of rats
appears to have been enacted in Barbados in 1745.[CL] According to
Boelter this act was incorporated into a new act which was passed in
1748. The same author states that the next legislative body to enact a
law against rats was in Antigua in 1880. In the same article he refers
to the rat ordinance of Hongkong, adopted in 1902.
Footnote CL:
W. R. Boelter, “On Rat Laws,” Journal of Incorporated Society for
the Destruction of Vermin, October, 1908.
Private measures against rats have undoubtedly been practiced from
time immemorial. The action of Denmark, however, in passing a law for
the systematic destruction of rats and providing the organization for
that purpose is perhaps the most notable advance taken on this
subject. A copy of the Danish law appears elsewhere in this
publication.
That the citizens of other countries are equally alive to the
importance of rat extermination is shown by the fact that in England
there exists an incorporated society for the destruction of vermin,
which society in October, 1908, began the publication of a journal
which would supply trustworthy information upon the subject.
It is recognized that a detailed review of past efforts against
rodents would be unprofitable, but on account of the enormous trade
relations between important seaports it is thought that a review of
the measures taken therein against rodents would be of value.
RAT EXTERMINATION IN UNITED STATES PORTS.
Prior to the adoption of the International Sanitary Conventions of
Paris and Washington, the Federal Government had made provision in its
quarantine regulations for the prevention of the spread of plague on
ships through rodents.
The articles contained in the United States Quarantine Regulations,
issued April 1, 1903, and bearing on the subject, are as follows:
14. At ports or places where plague prevails every precaution must
be taken to prevent the vessel becoming infected through the agency
of rats, ants, flies, fleas, or other animals. At such ports or
places the vessel should not lie at a dock, or tie to the shore, or
anchor near any place where such animals may gain access to the
vessel. In case cables are led to the shore they should be freshly
tarred and provided with inverted cones or such other devices as may
prevent rats and other animals passing to the ship. The introduction
of vermin on board the vessel from lighters and all other sources
should be guarded against. In such ports sulphur fumigation should
be resorted to in the holds when empty and from time to time during
loading in order to destroy vermin.
45 (b) Free ventilation and rigorous cleanliness should be
maintained in all portions of the ship during the voyage and
measures taken to destroy rats, mice, fleas, flies, roaches,
mosquitoes, and other vermin.
45 (h) In the case of plague, special measures must be taken to
destroy rats, mice, fleas, flies, ants, and other vermin on board.
128. Vessels infected with plague, or suspected of such infection,
should be anchored at a sufficient distance from the shore or other
vessels to prevent the escape of rats by swimming.
133. Special precautions must be taken against rats, mice, ants,
flies, fleas, and other animals, on account of the danger of the
infection of the disease being spread through their agency.
134. As soon as practicable there shall be a preliminary
disinfection with sulphur dioxide for the purpose of killing rats
and vermin before further disinfecting processes are applied to the
vessel and her cargo. The killing of any escaping rats shall be
provided for by a water guard in small boats, and no person with
abrasions or open sores should be employed in the handling of the
vessel or her cargo.
135. The vessel shall be submitted to a simultaneous disinfection in
all parts with sulphur dioxide to insure the destruction of rats and
vermin. The rats shall be subsequently gathered and burned, due
precautions being taken not to touch them with the bare hands, and
the places where found disinfected with a germicidal solution; and
the quarantine officer shall assure himself that the vessel is free
of rats and vermin before granting free pratique.
Additional regulations prescribe the method of disinfection of vessels
for plague, and elsewhere in this publication is given a detailed
description of the measures taken aboard ships at Angel Island, one of
the national quarantine stations.
Elsewhere is also given an account of the measures taken to eradicate
plague from certain cities on the Pacific coast, among the measures
being the systematic destruction of rodents and practical rat
proofing.
In a letter dated November 21, 1908, requests were made to the
Department of State for reports from certain of the more important
foreign seaports as to systematic measures being practiced for the
destruction of rats. As a result much valuable information has been
received, and acknowledgments are due and here made to the consular
officers furnishing it. The data received was abstracted and
classified according to countries as follows:
RAT EXTERMINATION IN CHINESE CITIES.
Although the present pandemic of plague had its origin in Canton,
China, in 1894, and the disease has been endemic there practically
ever since, Consul-General Bergholz states that the provincial
government of Kwangtung has made no efforts to exterminate rats.
In Amoy the local authorities have never taken measures to encourage
the extermination of rats, and in the absence of assistance from the
local authorities but little can be done toward effective eradication.
An outbreak of plague in Shanghai in December, 1908, was attributed to
the introduction of rats by ships from plague-infected ports.[CM] A
plan of campaign for such an emergency had previously been formulated
and was put in operation. It included collection and laboratory
examinations of rats and organization of rat parties to destroy rats
and render houses rat proof.
Footnote CM:
The Municipal Gazette, Shanghai, January 7, 1909, Health Officer’s
report for December, 1908.
In Tientsin official efforts made to exterminate rats are on lines to
suit the convenience of the particular health official. The consulate
at that port states that generally on the appearance of plague, the
officials pay about one-half cent for each rat brought, and as the
epidemic becomes severe, as much as 2½ cents gold.
In Hongkong, the question of rats in relation to plague has been of
perennial interest. While on duty in the American consulate at that
port, my attention was forcibly called to the influence of rodents in
the transmission of plague. In 1900 it had been the practice to
encourage the destruction of rats in the city, and a reward of 2 cents
Mexican money was offered for each rat brought to the health
department. A certain number of these rats were examined from day to
day from different districts.
In August, 1901, arrangements were made by which the health department
collected and examined a specified number of rats each day to try to
determine in some degree the relative prevalence of plague among these
animals. This practice was continued for several months, with the
result that the mortality among rodents from the disease was shown to
have rapidly decreased until in November practically no
plague-infected rats were found.
In a discussion of the subject, furnished February 2, 1909, by Dr. W.
W. Pierce, medical officer of health, through Consul-General A. P.
Wilder, it is stated that in 1902 the fee for rats was raised to 5
cents, and a special staff of coolies was engaged to destroy rats. The
abuses on account of these bounties were so great, however, that it
was found necessary to discontinue it in 1903, but the method of
trapping rats was continued.
While the total number of rats taken in 1903 was 101,047, Doctor
Pierce stated in effect that on account of the prejudice against
disinfection, it was practically impossible to secure the addresses
where the infected rats were found. The services of the staff were
continued, however, until 1908, when they were abolished because it
was thought, as stated by Doctor Pierce, that results were not
commensurate with the cost, and many complaints were heard. The plan
of furnishing traps to all persons who applied was then introduced,
and in addition, structural methods which had gone on for years were
continued.
The traps were distributed through district committees consisting of
the more educated natives, who were informed that with their
assistance it would be possible to avoid abuses which had been
practiced by the official rat-catching staff.
Doctor Pierce stated that it had been impossible under other systems
to secure the addresses where infected rats were found, and in order
to overcome this prejudice, several hundred receptacles were placed in
different parts of the city whereby the rats could be collected. These
tins were visited from day to day, and by this means it was possible
to locate infected districts.
Doctor Pierce stated that the use of ordinary disinfectants in
plague-infected houses had been discontinued, and that a 2 per cent
mixture in water of a kerosene emulsion made by stirring warm tank
oil, 85 parts added gradually to 15 parts of hot, strong solution of
“sunlight” soap, was used. This solution was found to instantly kill
fleas and bugs, and it has been used systematically.
For ordinary cleansing a 1 per cent solution is used, but Doctor
Pierce stated that on the recurrence of plague special gangs would be
employed to apply a 2 per cent solution in infected localities.
Beginning with January 1, 1909, Doctor Pierce stated that a rat poison
known as “Punjaub rat exterminator” had been laid down, and that the
intensive destruction of rats by this means was under consideration.
In summarizing the measures taken against rats, the American
consul-general stated that four methods were in use, namely, rat
proofing, trapping, poisoning, and use of cats. The use of bacterial
viruses as poisons has thus far been unsatisfactory, and the use of
chemical poisons, such as phosphorus, prepared, and known as “Punjaub
rat exterminator,” has only given moderate results.
The keeping of cats is encouraged, and the consul states that some
hundreds of these animals have been imported from Macao and Canton by
the colony and distributed.
Finally, the consul states that the use of “rat funnels” has long been
compelled whenever large vessels lie at the wharves.
In Sinyang the work of exterminating rats is in charge of a physician
who has 12 assistants, which number, however, may be increased in case
of emergency. The means employed are trapping, offering rewards, and
catching by means of cats. In his report, the consul states that the
best results have been secured by trapping. For ridding houses of
rats, some use is made of fumigation. It is stated that there is not
much danger of rats invading cargo boats, but that in the country rats
are present in enormous numbers, and that the problem of their
destruction has thus far baffled all attempts at solution. Bounties at
the rate of 15 cents per hundred are paid, and in one year the
Government expended for this purpose $32,500.
RAT EXTERMINATION IN MADRAS, BOMBAY, AND CALCUTTA, INDIA.
In Madras, Consul N. B. Stewart states there is no legal enactment in
effect requiring the destruction of rats, but the Government has done
everything in its power to make the public understand the value of
such a measure as a preventive against plague. In 1907 a reward of
one-half anna, equal to 1 cent, was offered by the city for each large
rat killed, and one-fourth anna for each small one. Bounties of
one-fourth anna and one-twelfth anna each for the respective varieties
of rats were still being continued at the time report was made.
In Bombay, where plague has been endemic since 1896, destruction of
rats and examination of all dead rats and evacuation of rat-infected
areas are included among the measures taken by the health department
in connection with plague operations. In his report Consul E. H.
Dennison states that the present antirat campaign in Bombay includes
the distribution of poisons, the trapping of rats, and the reward of 1
cent for each live rat, and a half cent for each dead rat, delivered
to the health department. He also states that there are no by-laws or
acts under which the destruction of rats can be enforced in private
houses.
On account of religious opposition, and to teach the people,
educational posters signed by the health officer were displayed,
containing advice what to do to prevent plague, which in part reads as
follows:
1. Beware of rats in your dwelling houses.
2. To harbor rats is to court plague.
3. Rat infection and consequent rat mortality are the indications of
the impending plague visitation among human beings.
4. Allow the health department staff to place rat traps in and about
your houses to catch rats and take them back.
5. Freedom from plague is in the removal of rats.
6. Inform the health department when dead rats are found in or near
your houses.
7. Clear your houses of all materials likely to harbor rats.
The same placard also contains information regarding disinfection to
kill fleas, evacuation of infected areas, and inoculations to produce
immunity.
In a special report dated January 23 the consul described a new
experiment in rat destruction; that is, an intensive effort in the
Kamatipura district. The district was divided into divisions and
subdivisions in which simultaneously there were distributed for use on
a certain day 19,642 poison baits and 2,670 traps. It was stated that
as a result hundreds of rats were collected the following morning.
No reference is made to measures taken for the destruction of rats
aboard ships in the harbor.
In Calcutta, it is reported by Consul-General W. H. Michael that
various methods are resorted to for the extermination of plague, rats,
the use of poison being the most general. Rewards have been offered
for live and dead rats, and about 11,135 dead rats were produced, but
it was found that a considerable portion of these was picked up by
conservancy coolies, and the reward for dead rats was therefore
discontinued. Of live rats, only 9,447 were produced. After December
1, 1908, the reward was raised to 4 cents, with the result that 49,396
live rats were captured. It is stated, however, that this did not seem
to have any appreciable effect upon the rat population.
RAT EXTERMINATION IN YOKOHAMA AND NAGASAKI, JAPAN.
In the Kanagawa Ken, in which Yokohama is located, the following
ordinances relating to the extermination of rats have been enacted:
_Kanagawa Ken Ordinance No. 64 of 1902 (issued October 8)._
Finders of dead rats within the prefecture shall immediately report
and deliver same to the nearest police, village, or other
authorities in charge. Upon receipt thereof, the police or other
authorities shall without delay transmit the same to the police
headquarters (Yokohama).
_Kanagawa Ken Ordinance No. 45 of 1903 (issued June 26)._
Finders of a dead rat or capturers of a live rat shall report and
deliver the same within twelve hours to the police, mayor, medical
inspector or officer, antiplague committee, or officer in charge of
the Hygiene Guild.
Violation of the foregoing shall be punishable either by a fine or
detention in jail.
_Kanagawa Ken Ordinance No. 63 of 1907 (issued June 8)._
Persons who plan or are engaged in the importation of rats from
without into the city of Yokohama, or persons who plan to breed rats
in the said city, shall be punished by detention in jail or by a
fine.
_Extract from Kanagawa Ken Ordinance No. 14 of 1907, relating to
supervision over storage and warehouses (issued March 6)._
ARTICLE 1. The term “storage and warehouses,” hereinafter mentioned,
shall mean and include any godown, storage or storehouses, or
warehouses, used by storage or warehouse companies, individuals,
forwarding agents or express companies, wholesale dealers, works and
factories, wherein cotton, cereals, or grains, flour, peanuts,
beancake, and other pressed oil cakes, cocoons, feathers, leather,
old or waste cotton, old straw, bags, etc., are stored and kept.
ART. 8, sec. 1. Owners of a storage or warehouse shall exercise at
least four times a year a rigid and thorough method of house
cleaning and rat destruction in the storage or warehouse. The date
and time of cleaning shall be reported to the police, to whose
satisfaction and approval the cleaning must be carried out.
ART. 8, sec. 2. Owners of a storage or warehouse shall furnish and
always keep at each doorway a suitable rat trap, and shall always
endeavor to exterminate rats or pursue such method of extermination
as may be directed by the police.
In forwarding the above ordinances, Vice-Consul Babbit stated that
vessels engaged in foreign trade, when deemed advisable by the harbor
authorities, are required to endeavor to exterminate the rats on board
by sulphur fumigation or other effective methods, as are also
coastwise vessels.
To encourage the extermination of rats, the mayor of Yokohama was
authorized by the city council to pay bounties, the rate being 3 sen
(1½ cents) each. The vice-consul states that in addition to this
purchase price a ticket is given for a lottery, and for each 60,000
rats 156 prizes, amounting to a total of 1,000 yens are given by the
city.
In a table giving the number of rats purchased and sent to the hygiene
bureau for bacteriological examination, it is seen that for the year
ending December 31, 1908, 447,981 were received.
In Nagasaki the municipal council passed an ordinance January 6, 1906,
as follows:
1. Rats to be purchased are of two kinds—house and field rats—and
they must be either caught or found dead within this city.
2. A bounty of 3 sen (1½ cents) shall be paid for each rat with a
ticket, to be cashed on presentation.
3. Such tickets, to be cashed, must be presented at the city office
within thirty days from the date of issue.
4. Rats shall be purchased at the city office, police stations,
branch police stations, police boxes, or by city officials, who go
around for such purpose, by giving a ticket to be cashed upon
presentation, provided that distinction must be made between a rat
caught and one found dead.
In transmitting a copy of this ordinance Consul G. H. Scidmore stated
that it was issued in accordance with the infectious diseases law of
Japan, No. 36, of March, 1897, which provides that cities, towns, and
villages shall make all necessary arrangements relating to the
extermination of rats as may be ordered by the prefectural governors.
He also stated that when the above ordinance was decreed the mayor of
Nagasaki issued detailed instructions regarding its enforcement. The
ordinance was enforced from the time of its enactment until July 7,
1908, when the city ceased paying bounties; from January 13, 1908, to
July 7, 1908, 980.33 yen ($488.20) having been expended, and 30,767
rats having been destroyed.
RAT EXTERMINATION IN LOURENÇO MARQUEZ, EAST AFRICA, AND MADAGASCAR.
In Lourenço Marquez, Consul W. S. Hollis states that a disinfecting
barge is maintained, and requisitioned from time to time by vessels,
by which means considerable numbers of rats are destroyed.
He also states that the last efforts to destroy rats on shore were
made during the plague outbreak in November and December, 1907.
In a circular accompanying Provincial Decree No. 754 of the
governor-general, the following relates to the destruction of rats:
1. For the destruction of rats we advise the public to make use of
poison paste.
2. These may be obtained by requisition on the municipal chamber and
from police stations.
3. The paste furnished shall be divided into portions and
distributed in different parts of the dwellings.
In Provincial Decree No. 737, issued December 11, 1907, by the
governor-general, it is required that grain and forage warehouses and
stables be provided with cement floors, and that ventilators be
provided with wire screens sufficiently fine to prevent the access of
rats, and that interior doors and salient angles be provided with
metallic points to prevent the climbing and entrance of rats.[CN]
Footnote CN:
Cases of pest in Lourenço Marquez, official report.
In Provincial Decree No. 48, issued by the governor-general January
30, 1908, it is proposed among other things to establish a permanent
service for the capture and bacteriological examination of rodents in
the city and its suburbs.
In transmitting the publication containing copies of these decrees the
consul stated that by the end of February, 1908, the campaign against
rats was relaxed, and since then nothing had been done to continue the
work of extermination.
In Tamatave, Madagascar, and other ports of that island no efforts
were being made to exterminate rats, and the American consul reported
that there were no municipal or colonial laws or regulations directing
such action.
RAT EXTERMINATION IN CAPE TOWN, SOUTH AFRICA.