Very little light has been thrown on the conditions which
favour the prevalence of plague. We do not know why it has
developed a diffusive activity of late years, nor why it has
attacked some places and consistently passed by others, such
as Singapore. The words “dirt” and “insanitary conditions”
are much used, but such general terms explain nothing. Singapore,
where plague has several times been introduced, but
never taken hold, is probably quite as dirty and insanitary as
Hong-Kong, and it is pertinently remarked by the Bombay
Research Committee that filth per se has but little influence,
inasmuch as “there occurred in the House of Correction at
Byculla, where cleanliness is brought as near to perfection as is
attainable, an outbreak which exceeded in severity that in any of
the filthy chawls and tenements around.” Again, in Oporto
there is an area which combines every possible sanitary
defect—dense overcrowding, great poverty, no light, no air,
no drainage, no scavenging, water brought in buckets. Plague
got into this quarter, but did not spread there; on the other
hand, it appeared in other and vastly superior parts of the
town Yet in at least one case neither the patient nor the “contacts”
were removed, but were all shut up in one room with
a sentry at the door and another in the street. The seasonal
variations have been well marked and extremely regular in
Bombay. The disease begins to be active in late autumn or
the beginning of winter, and reaches its height in February or
March, dying down in the summer. Baldwin Latham made an
elaborate examination of the meteorological conditions, and
more particularly of the vapour tension, from which he draws
the conclusion that the seasonal variations are due to exhalation
from the ground. His observations are original and worth
attention A simpler explanation is that the people live more
indoors, and are so more exposed to infection during the
plague season. The curve shows two rises, one at the beginning
of winter, and the other at the commencement of the
monsoon, and at both these times the people are driven indoors.
A broad survey of the epidemiological facts suggests some
general conclusions. The outbreaks fall into two well-defined
groups. (1) those in which the disease is destructive and persistent,
(2) those in which its effects are slight and transient.
In the former the poison clearly fastens on the locality, and
gradually increases its hold. The place is infected, not merely
the people in it; for if they evacuate it, the disease soon ceases
among them, and if they return in a short time, they are again
attacked. Now the poison is contained, as we have already
seen, in the discharges from patients, and in such infected
localities the standing conditions and the habits of the people
combine to retain the discharges on the premises. The floors,
mostly of mud covered with dung, are fouled with spittle,
vomit, and urine, and, being seldom or never cleaned out, foster
a gradual accumulation of poison, to which infected rats and
the concealment of illness contribute. These are just the conditions
which prevailed in Europe in the old plague days. They
do not prevail now in those “white countries” which have been
invaded but have repelled the attack with comparative ease
and little loss. It may be concluded, with some confidence,
from experience and theory alike, that localities where they do
not prevail may fail to keep plague out, but have very little to
fear from it, except the disturbance of trade caused by the
traditional terrors that still cling to the name.
Prevention.—The principles are the same as those which govern the prevention of other infectious diseases. “Sanitary cordons” and the like are obsolete. International procedure is supposed to be regulated by the Venice convention of 1897 (see Quarantine), but that instrument contains an optional clause, which allows countries to do as they please with their own frontiers Except Great Britain and Germany, they all retain quarantine in a more or less stringent form at seaports. It is generally used as a system of local extortion imposed upon travellers and shipping According to the Venice convention, ships are divided into (1) healthy, (2) suspected, (3) infected. (1) Healthy are those free from plague throughout the voyage; (2) suspected, those in which plague has occurred, but no fresh case within twelve days; (3) infected, those in which plague has occurred within twelve days. Great Britain relies on medical inspection, removal of sick or suspected cases, and supervision of the healthy arriving on an infected ship, infected clothing is burnt and infected ships are disinfected. The procedure is the same as for cholera, but it has been equally successful. Ships passing through the Suez Canal are subject to similar inspection, sick persons are landed at Moses Wells, and suspected ones detained. The risk of importing plague from India has been materially lessened by medical inspection of outward-bound ships at the principal ports. This has been very thoroughly carried out at Bombay with good results. In 1897 pilgrimages from India to the Hedjaz were prohibited. By the Venice convention a number of articles of merchandise are classed as susceptible and liable to be refused admission, but the only ones which there is any reason to consider dangerous are used clothing and rags. A watch should be kept on rats at ports of arrival and on board ships from infected countries.
When plague is present in a place, the measures to be taken are the usual ones for dealing with infectious disease, with some additions. The sick and suspected should be removed in special ambulances to an isolation hospital, their soiled linen, &c., should be burnt, and the premises disinfected. Corrosive sublimate in an acid solution is the best disinfectant, but sulphuric acid, 1 in 250, is efficient and cheaper. Suspected cases should be bestowed in a special isolated building until the diagnosis is fully determined. “Contacts” should be kept under observation. Rats should be exterminated as far as possible, especially by means of the Danysz virus, which spreads a disease amongst rats which cannot be communicated to man. The greatest care should be taken in dealing with the hospital linen and discharges from patients. Hospital staffs should be kept apart. Inoculation with Haffkine’s prophylactic fluid should be offered to all persons willing to avail themselves of it. It is especially desirable for hospital and ambulance staffs to be inoculated with a vaccine prepared from sterilized cultures of plague bacillus. Inoculation is harmless, and the results obtained in India justify a favourable opinion of its protective efficacy.[1] At Hubli, where nearly the whole population was inoculated between the 11th of May and the 27th of September
- ↑ The system of inoculation against plague with a fluid prepared
from sterilized virus of the disease was introduced in India by Professor
Haffkine earl in 1897. The composition of this fluid was
subjected to a searching inquiry by the Indian Plague Commission,
who pronounced its employment to be free from danger, and it
was used on a large scale in various parts of India without producing
injurious effects. In September 1902 the standard method of
manufacturing this fluid was changed) b the director of the Plague
Institute on his own authority, with the object of expediting the
process, and thus meeting the heavy demand then being made
by the Punjab government in connexion with a large scheme of
inoculation. The change involved the omission of a small proportion
of carbolic acid which had up till then been added to the
original fluid as a further precaution against contamination. The
new fluid, or water agar process, contained no carbolic acid, other
methods being relied upon to ensure its purity. On the 6th of
November 1902, nineteen persons who had been inoculated on
the 30th of October in the villa e of Malkowal from a single bottle
(labelled 53-n) of the new fluid were found to be suffering from
tetanus, and all of them subsequently died. A commission, consisting
of Sir Lawrence Tenkins, Lieut.-Colonel Bomford, M.D.,
principal of the Medical College, Calcutta, and Major Semple,
R.A.M.C., director of the Pasteur Institute, Kasauli, was appointed
by the government of India to inquire into the disaster. They
found that the germ of tetanus had been introduced into the fluid
before the bottle was opened at Malkowal, and they thought it probable
that this might have occurred owing either to insufficient
sterilization or to the process of filling the bottle from a larger
flask having been performed with defective precautions. They
also expressed the opinion that carbolic acid was a valuable agent
in restraining tetanus growth when added to plague prophylactic,
and they, therefore, thought that its omission was a grave mistake.
Experiments undertaken in India by two independent inquiries
appeared to confirm the view, and their conclusions, together with
the data on which they were based, were submitted with the report
of the commission for examination and further experiment to the
Lister Institute in London. With reference to the findings of the
Malkowal commission the Institute were asked to report: (1) On
the comparative efficacy of the standard and new fluids as a
protection against plague; (2) on the comparative liability of each
fluid to contamination, and (3) on the probable origin of tetanus
virus in the Malkowal cases. Their report on these points (Dec.
1904) contained the following conclusions: (1) “The Institute
sees no reason to differ from the conclusions of the commission
that the new prophylactic is not less efficacious than the old.
(2) The Institute is of opinion that in the hands of more or less
unskilled workers it is easier to ensure freedom from contamination
by Haffkine’s ‘standard method’ of manufacturing plague vaccine
than with the ‘water agar process’ as employed by him. (3) The
Institute is in entire agreement with the commission as to the value
of 5% carbolic acid in restraining tetanus growth when added to
plague prophylactic, and its experiments emphasize still further
the importance of this addition in preventing growth and toxin
formation in a vaccine which might be liable to the possibility of
contamination with spores of tetanus. (4) The conclusions of the
Institute coincide with those of the commission that in all probability
tetanus was at the time of inoculation in the fluid contained in
the bottle, but that it is impossible to determine at what stage in
its history or in what way the bottle (53-n) became contaminated.”
The government decided, on the advice of the director, that only the standard fluid should be manufactured at the lague institute. This fluid was sterilized by methods approved by tile Indian Plague Commission and contained the requisite proportion of carbonic acid It was bottled by a new method patented by Dr E. Maynard.
The result of the inquiries by the commission and the Lister Institute led to a protracted controversy with regard to the responsibility of Mr Haffkine’s laboratory, and to his subsequent treatment by the government of India; and the leading bacteriologists in England warmly took up his cause. A parliamentary “Return of Papers” was issued in June 1907, and in The Times of the 29th of July there appeared a letter signed by the distinguished pathologists, Ronald Ross, R. T. Hewlett, A. S. Grunbaum, W. J. Simpson, R. F. C. Leith, W. R. Smith, G. Sims Woodhead, E Klein, S. Flexner and C. Hunter Stewart, pointing out that the evidence, so far from showing that Mr Haffkine’s laboratory was to blame, made it clear to those acquainted with bacteriological work that It could have had nothing to do with the occurrence They agreed that there was strong evidence to show that “the contamination took place when the bottle was opened at Malkowal, owing to the abolition by the plague authorities of the technique prescribed by the Bombay laboratory, and to the consequent failure to sterilize the forceps which were used in opening the bottle, and which during the process were dropped on the ground”; and they complained of the inadequacy of the inquiries made by the Indian government, and called for Mr Haffkine’s exoneration The evidence showed that It had been much too readily believed that the tetanus germs llad entered the fluid before the bottle was opened, and that a grave injustice had been done to Mr Haffkine. Acting on this view, in November 1907, the Indian government invited Mr Haffkine again to take up work in India.
