I hold no brief for the mosquito. She has always treated me as a mere
restaurant, and I have provided her with so many meals that I feel all
obligations to be already on her side. Also, her extreme talkativeness
is almost as objectionable as her voracious appetite. Any one who has
been kept awake by her buzz-z-z, buzz-z-z, buzz-z-z, on a tropical
night must have come to the conclusion that “good will to all men” can
never be strained to include good will to all insects. Moreover, the
fact that the lady of the species alone feasts upon blood seems a
reflection on the female sex. Yet, so it is: her husband is a harmless
vegetarian.
All the same, when a sense of justice is strong, one does resent the
misdemeanors of man being laid at the door of even the most
exasperating insect. Certainly the sturdiest viewpoint of disease is
to regard it as the outcome of inattention, personal or general, to
one or other of nature’s observances. Instead, nowadays, parasitic
organisms are blamed for most of the aches and pains of humanity,
while their distributors are searched for in the realm of insects and
animals. The mosquito has, perhaps, fallen a prey to her own weakness.
Had she talked less, it is possible that she might have evaded her
doubtful celebrity. As it is, she stands accused of being concerned
with a no less formidable array of maladies than elephantiasis, yellow
fever, dengue, and malaria.
Let us here concern ourselves with the last-mentioned, and the hungry
suspect, whose name has been coupled with the disease, her Ladyship
Anopheles.
She may at once be singled out from her fellows by her habit of
discreet silence and her odd proclivity for standing on her head when
resting and feeding. Other mosquitoes remain on all fours, or rather,
all sixes, when dining. This acrobatic insect is, as everyone knows,
accused of inoculating her human prey with a protozoon, or microscopic
animal organism, which in its turn is held responsible for the heats
and chills, the aches, the pains, the languor, all the miseries of
malaria. The idea is a simple one, requiring little intelligence to
be understood. Is it rude to ask, what wonder that it has become
popular? Less marvel, too, when one reflects that the theory is
safeguarded by dividing Anophelines into a variety of groups, and
claiming that the guilty must be the right sort, and yet further, the
right sort duly infected.
Now, the means of infection must come about through the insect having
feasted on a malarial subject. That its subsequent bite might poison
the healthy sounds a contingent by no means unlikely. The drawback to
this probability is that the mosquito possesses the feminine
characteristic of fastidiousness. Malarial subjects are the very ones
avoided by her hungry Ladyship. Here I may interject that I am not
writing of insects under control. What a famished mosquito may or may
not eat during the course of an experiment, I am not concerned with. I
refer to mosquitoes in a natural state, and personal experience has
made me observe that the one benefit of malaria consists in the
freedom it confers from mosquito bites. Though these insects are in
the habit of treating me as a very Ritz or a Carlton among
restaurants, periods of malaria always freed me from their ravages.
They like their food to be of the best, and the blood freest from
fever is the provender for their delectation. During nineteen years of
tropical life, my mother never experienced a single attack of malaria;
yet she was always the chief _pièce de résistance_ for every mosquito
within her vicinity. It may be noticed that the individuals least
susceptible to malaria are those most feasted upon by mosquitoes,
including the suspects, though whether these be _Anopheles Umbrosus_,
_Anopheles Maculatus_, _Anopheles Christophersi_, _Anopheles
Albimanus_, _Anopheles Argyritarsis_, or any others of high-sounding
title, I should certainly not presume to discriminate.
Why should this general evidence count for less than the few
experimental cases upon which the mosquito theory is built up? These
latter are mostly conspicuous by their weakness. Take, for example,
the mosquito-proof hut placed at Ostia, and inhabited for three months
by Dr. Sambon, Dr. Low, Mr. Terzi, and their servants. What analogy
does this well-ventilated erection, raised above the soil, bear to
many of the insanitary homesteads of the Campagna? What analogy is
there between its healthy inhabitants, further fortified by zest for a
theory in dire need of proof, and the permanent dwellers in those
unpropitious surroundings? If we admit strength in the case of the
infected mosquitoes sent to the London Tropical School, whose stings
are said to have produced attacks of fever in the late Dr. Thurburn
Manson and Mr. George Warren, we must also remember that Abele Sola in
the Santo Spirito Hospital in Rome, according to the account quoted by
Herms in his _Malaria: Cause and Control_, is claimed to have fallen a
victim to this disease from the bites of mosquitoes that had developed
from larvæ in his own room, and therefore could not be reckoned as
infected. Moreover, they numbered hardly any Anophelines, and of the
very few present, it was not known whether any stung the patient. Yet,
according to the modern theory, Anophelines alone could have been
responsible for the mischief. The proverbial grain of salt seems a
necessary condiment for the cases of experimenters.
In the short space at our disposal, we are not concerning ourselves
with the micro-organism, first discovered in Algiers by Dr. Laveran,
and considered to be the parasite of malaria. Without in the least
committing oneself to a general belief in the germ-theory of disease,
there may, here and there, be maladies produced by parasites. Yet,
apparently, fever, bearing all the clinical symptoms of malaria, may
occur without the presence in the blood of such organisms, no matter
whether parasitic or inbred. On page 8 of the Medical Report of the
Federated Malay States’ Government reference is made to an unusual
swarm of sandflies, and the following commentary is given. “Whether
sandfly fever exists we are not prepared to say, but many cases
_with all the clinical symptoms_ were noted and _no malarial parasite
was detected_ on blood examination.” Hence the sandflies come under
suspicion! Might not another moral be drawn, and that is that fever
may be due to causes less crude than the inoculation of parasites by
objectionable insects?
The conditions that produce mosquitoes seem to be the same as the
conditions that produce malaria, and, in any case, it is these that
must be attacked, no matter whether Lady Anopheles be proved innocent
or in any measure guilty. The mysteries that surround the subject, the
occasional outbursts of disease when areas have been drained, the
usual method of improvement, the occasional betterment of health when
the reverse process of flooding has taken place, may possibly be
explained by the law of subsoil water. Dr. Charles Creighton writes in
his _History of Epidemics in Britain_ (p. 278): “According to that
law, the dangerous products of fermentation arise from the soil when
the pores of the ground are either getting filled with water after
having been long filled with air, or are getting filled with air after
having been long filled with water. It is the range of the fluctuation
in the ground-water, either downwards or upwards, that determines the
risk to health.”
However, far be it from me to descant upon the mysterious causes of
malaria. My object is only to try to prove the unwisdom of rivetting
attention upon the anopheline mosquito. Deductions as to her innocence
may be drawn from the accusations endeavoring to prove her guilty. We
are told how noticeable among troops the difference in fever rate has
been between those that slept on shore and those that remained on
board ship in malarious districts. But as the mosquito is free to come
aboard too, how does that statement tell against her? I remember a
host of such insect invaders on the _Sydney_, the French mail boat,
when anchored at feverish Saigon. We carried a shipload away with us,
and when out at sea they feasted on me to such an extent that I
arrived at Singapore looking as though stricken with a rash, but
otherwise none the worse for their greediness.
Again I was scarred for a long period after the venomous attacks of
mosquitoes and sandflies combined at Kuala Klang, on the Malay coast,
in its old days of fever, before it started a new sanitary career
under the name of Port Swettenham. Yet these myriad bites produced
fever of no sort, although I was at that time pronounced a malarial
subject. I did not remain in Kuala Klang long enough to be affected by
its unhealthiness; but, had Lady Anopheles been justly blamed, the
terrible biting I underwent should have taken effect, irrespective of
my removal. On the contrary, my own experience of fever was connected
entirely with locality and never with mosquitoes. Intermittent fever,
the genuine article, with its burnings, its icings, its whole
programme of miseries, had me constantly in its grip during residence
at a particular house in Kuala Lumpur, the Capital of the Federated
Malay States. My one compensation was freedom from mosquito bites.
When I left that abode, fever left me, and soon after mosquitoes began
to feed on me again with infinite relish. What matter? It was a proof
of sound blood, freedom from that worse scourge, malaria!
To turn from the personal to what is far more important, the general,
let us consider the Medical Reports from that haunt of malaria, the
Malay Peninsula.
The year 1911 in the Federated Malay States held the unpleasant
distinction of being particularly malarious. The mosquito theorists
explained as cause a great influx of, often, unhealthy coolies from
India, and much clearing of land, which distributed the mosquitoes,
and drove them into the houses and among the inhabitants. But, if
mosquitoes be culpable, why should this same year have also been
particularly unhealthy in regard to most diseases, phthisis excepted?
Yet the Medical Report for 1912 shows that, concomitantly with a fall
in malaria, 1,010 fewer cases of dysentery were this year treated in
hospital. There were 77 notified cases of smallpox, as against 286 in
1911; 29 cases of cholera, as against 620; and 5,676 cases of
beri-beri, as against 6,402. The greater prevalence of disease in
general in 1911 surely shows that the causes for its specific forms
must be deeper seated than mere insect bites. Yet so dominating is the
fashion to rivet attention on such factors as these that fundamental
troubles, even when known, appear often to be unheeded.
The F. M. S. Medical Report for 1912 provides a good instance, taken
from the portion dealing with the Institute for Medical Research,
Kuala Lumpur.
On page 25 it states that the occurrence of several cases of bubonic
plague in and near Kuala Lumpur rendered it advisable to consider the
possibility of the disease appearing as an epidemic and measures to
avert such a calamity. A short paragraph refers to reported cases of
plague, and then follow nearly four pages devoted to rats. Toward the
bottom of the fourth page come the pregnant words: “Nearly 50 per
cent. of the plague-infected rats came from the small stretch of
Ampang Street, about 150 yards long.” The short description of this
small area surely reveals a source of danger. “At the back of most of
the houses there is a kitchen or bathing-place from which an open
brick drain, covered with planks, runs through the house to the front
of the shop and under the pavement of the five-foot way into one open
drain at the side of the street. The plank covering of the house-drain
is usually buried beneath sacks of grain or other heavy articles, so
that the drain is not often cleaned. The open cement street-drain
forms a convenient highway for rats, which can readily gain access to
the house by the unprotected house-drains leading into it. Some eighty
yards away the main drain empties into the Klang River, here a shallow
and muddy stream with irregular, foul banks covered with reeds, rank
grass and collections of garbage.” Now, who could expect rats to keep
well in the vicinity of such a drain “not often cleaned,” and such a
river, “shallow and muddy,” with “foul banks covered with collections
of garbage”? Surely gratitude is due to the rodents, who, being nearer
the level of the bad conditions, get ill first, and thus give human
beings a fair warning of the sickness likely also to be their due,
unless surroundings are made healthy for all animals, four-legged and
two-legged. Yet, actually the Report has not a commentary upon these
palpable ills, and, though it has by no means exhausted itself on the
subject of rats, proceeds to vary the topic with fleas, the
meteorological conditions that affect these high-jumpers, and the uses
of guinea-pigs as flea-traps. The results of searching questions to
medical men on the subject of flea bites are even given. “Of eighteen
who replied one stated that he had never been bitten by a flea in his
life” (p. 31). Most people must wish they were equally lucky. But not
a single mention again of the uncleaned drains and the river choked
with garbage during the course of pages all the more diverting because
intended so seriously.
When such open evils can be so ignored, what wonder that the more
occult sources of malaria should not be arrived at? And when will they
be understood while accusations against particular insects require to
be held in reverence as dogmas? In the F. M. S. Report for 1911 Dr.
Sansom allows (p. 3) “there exists in the minds of a great many people
a doubt whether the mosquito carries malaria or any other disease”;
and proceeds to add “until this heresy has been corrected.” Heresy
indeed! Is not free thought the first fundamental of science? Having
thus labelled disbelief in his theory, Dr. Sansom in his next Report
for 1912 has to admit (p. 5), “I have visited many (rubber) estates
where anti-malarial work has not been completed _or even begun_,
so that infection remains as bad or nearly as bad as ever, yet, from
the time the laborers have been fed, down has come the death-rate.” If
food has so much to do with the trouble, why lay all the blame on Lady
Anopheles?
And just as too little food helped to make the coolies ill, is it not
likely, if it be not rude to ask, that too much food was part cause
for the malaria that troubled the prosperous members of the community
of Kuala Lumpur, the Federal Capital, so long as a need of drainage
left much to be desired in their surroundings? Who acquainted with the
Far East does not recall the many courses of the Chinese cook, and the
constant refilling of the champagne glass at dinner parties? There
seems small wonder that the carnivorous feeder and spirituous drinker
from a chilly latitude should fall a victim in the East to malarial
and other fevers: and this without any assistance from Lady Anopheles
or her sister mosquitoes. To her a meed of praise would seem due, for
where the mosquito exists there is proof of a need of drainage,
clearance, and general sanitary attention. But man, who has stoned the
prophets throughout the ages, equally execrates the insects that come
as warnings.
That non-proven is the verdict upon Lady Anopheles’ guilt seems well
shown by Dr. Fraser’s Report, incorporated with the general Medical
Report for the Federated Malay States for the year 1911.
After rather shakily chanting the orthodox creed of the mosquito
theory, Dr. Fraser negatives faith by fact in the most heretical
manner. “It appears to have been assumed on inadequate grounds,” he
writes, “that a small number of malaria-carrying species in an area is
necessarily associated with a low incidence of the disease. Certain
observations made in the course of the present inquiry would appear to
controvert this view. On some estates where the maximum spleen and
parasite rates prevailed few anophelines of any sort were to be found,
while in other areas, where malaria-carrying anophelines were
numerous, these rates were low. Also it was noted that where different
classes of laborers were under identical conditions so far as the
mosquito factor is concerned, such as free and indentured laborers on
the same estate, the parasite rates varied widely in the two groups.
It is clear that factors affecting the general well-being of laborers,
such as the quality of the food supply, housing, etc., are by no means
negligible in the prevention of malaria, as they are equally not
negligible in the prevention of other diseases. To these factors
attention must be directed as well as to measures which aim at the
reduction of mosquitoes, if the disease is to be combated successfully
in the conditions which obtain in this country.”
Precisely! We must attend to general sanitation and personal hygiene,
and then, having removed the beam from our own eye, we may be able to
see clearly to cast out the mote in the eye of the Lady Anopheles.