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THE PREVENTION OF MALARIA



PRESENTED TO HIS MAJESTY THE KING
BY

HER ROYAL HIGHNESS PRINCESS CHRISTIAN

Honorary President
Liverpool School of Tropical Medicine



THE PREVENTION
OF MALARIA



BY RONALD ROSS,

D.P.H., F.R.C.S., D.Sc, LL.D., F.R.S., C.B.
NOBEL LAUREATE



WITH CONTRIBUTIONS BY



Professor L. O. HOWARD,

United States
Colonel W. C. GORGAS, Panama
Mr J. A. LE PRINCE, Panama
Sir R. BOYCE, West Indies
Dr W. T. PROUT, Jamaica
Dr H. WOLFERSTAN THOMAS,

Amazon Region
Dr OSWALDO CRUZ, South

Brazil
Dr IAN MACDONALD, Spain
Professor A. CELLI, Italy
Professor C. SAVAS, Greece



Professor C. SCHILLING,

German Possessions
Dr ED. SERGENT, French

Possessions
Mr H. C. ROSS, Egypt
Dr a. BALFOUR, Khartum
Dr L. BOSTOCK, South Africa
Dr P. MURISON, Durban
Dr M. WATSON, Malay States
Professor T. TAKAKI, Formosa
Colonel C. H. MELVILLE,

Troops in War
Major C. E. P. FOWLER,

Troops in Peace



WITH MANY ILLUSTRATIONS



NEW YORK
E. P. BUTTON & COMPANY

1910



?UBLI :

HEALTH .
LIBRARY






PREFACE

Malarial fever is perhaps the most important of human
diseases. Though it is not often directly fatal, its wide
prevalence in almost all warm climates produces in the
aggregate an enormous amount of sickness and mortality.
In India alone it has been officially estimated to cause
a mean annual death-rate of five per thousand ; that
is, to kill every year on the average 1,130,000 persons
— a population equal to that of a great city. This is
more than the mortality of plague at its height or of
cholera and dysentery combined. The total amount
of sickness due to it is incalculable, but may be put
by a rough estimate at between a quarter and a half
the total sickness in many tropical countries. Often
all the children and most of the adults are infected by
it. Unlike many epidemic diseases it is not transient,
but remains for ever in the areas which it has once
invaded. It tends to abound most in the most fertile
countries, and at the season most suitable for agricul-
ture. Very malarious places cannot be prosperous : the
wealthy shun them ; those who remain are too sickly for
hard work; and such localities often end by being deserted
by all save a' few miserable inhabitants. Malaria is
the great enemy of the explorer, the missionary, the
planter, the merchant, the farmer, the soldier, the

vii



215031



viii PREFACE

administrator, the villager and the poor ; and has, I
believe, profoundly modified the world's history by
tending to render the whole of the tropics comparatively
unsuitable for the full development of civilisation. It is
essentially a political disease — one which affects the wel-
fare of whole countries ; and the prevention of it should
therefore be an important branch of public adminis-
tration. For the State as for the individual, health is
the first postulate of prosperity. And prosperity should
be the first object of scientific government.

Fortunately, as often remarked, malaria is of all
diseases the one regarding which we possess perhaps
the fullest knowledge. We know the cause of it and
the manner in which it is spread. We know a specific
cure for it, and several efficient methods of prevention.
It is our own fault then if we do not reduce it as much
as possible.

The literature of the subject dates back for more
than two thousand years. To write a complete book
on malaria, including references to all that has been
worthily said or done in connection with it, would be
a gigantic task. The history, the symptoms, the
pathology and the treatment would fill several volumes ;
a long essay could be written on the parasites ; an
entomological work on their carriers ; and a full account
of the laws of diffusion, of the local distribution, of the
preventive measures, and of the numerous preventive
campaigns which have been conducted since the time
of the ancients, would of itself occupy many hundreds
of pages. But the task would be largely an unnecessary
one, because we already possess many good books on



PREFACE ix

the medical, parasitological and entomological aspects
of the subject.

Regarding prevention, however, especially in the
light of the great developments which followed the
discoveries of twelve years ago, there is much need
for yet another work. Though certainly based upon
biological knowledge, this part of the subject presents
also its own problems for solution. The diffusion of
disease is a theme which requires exact, and indeed
mathematical analysis ; and the art of controlling it
belongs, not only to the medical man, the parasitologist
and the entomologist, but even more to the experienced
hygienist, the engineer, the administrative officer and
the statesman.

On considering how best to meet the demand, I
concluded that the only satisfactory way was to collect
in one volume the thoughts and observations of the
able men who have themselves worked in this laborious
field, or who are in the best position to furnish the
required information ; and my warmest thanks are due
to those who have given me so much of their valuable
time and labour. My own part consisted merely in
attempting to compile a preliminary analysis of the
general problems and difficulties before us.

Some readers will perhaps be surprised when they
fail to find in a book on the prevention of malaria any
description either of the parasites and their carriers, or
of the necessary technique. But in these days almost
every medical man in the tropics, at least any one likely
to be entrusted with the charge of anti-malaria work,
is sure to be already familiar with these details. More-



X PREFACE

over, the present volume should be written largely for
the use of readers who are neither medical men nor
zoologists, but who may be called upon to deal with
the administrative side of the subject ; and minute
technicalities would be as useless to them as they would
be superfluous to the trained biologist. I have there-
fore determined to limit myself to matters which will, I
hope, be useful to the advanced student without being
unintelligible to any educated reader — that is, to a
logical consideration of the broader (and often more
neglected) principles of the subject.

An historical introduction is always necessary to give
coherence to ideas ; and I have taken the opportunity
to write as complete and accurate a one as my space
and knowledge permit of. The summary of facts which
follows (taken from my report on Mauritius) may be
useful in propagandism ; the experimental inoculations
of men by means of blood drawn from patients or of
infected Anophelines have been collected with care
because of their fundamental importance in the modern
theory of malaria ; and I trust that these three first
chapters will suffice to convince the busy layman that
this theory has been based upon something more than
mere conjecture.

In the chapters on the parasitic invasion of the
individual and of the community, I have departed con-
siderably from medical custom by laying much stress
upon quantitative, or rather enumerative, ideas. We
should distinguish between subscience, the mere study
of objects, and science, the study of causes. Measure-
ment is the very basis of science ; and the neglect of



PREFACE xi

it and of logical deductions founded upon it are too
common in biology. It is scarcely true to say that
malarial fever is caused by a parasite and propagated
by a mosquito : it can be caused only by many parasites
and widely propagated only by many mosquitos. The
how much and the how many are at least as important
as the bare facts. I am convinced that if more exact
results are desired, pathology must in the future tend
more toward exact enumerative methods. As for
epidemiology, it is principally a mathematical subject
— the route of infection being given, the rate of in-
fection depends upon laws like those which govern the
diffusion of gases or heat ; and ignorance of this has
led to many wild statements regarding the spread and
prevention of malaria. But the subject has yet to be
developed, and Chapter V can approach it only in an
elementary manner. Chapter VI is abbreviated owing
to the details contained in the following one, to which
it is largely introductory.

The contributions in Chapter VII are arranged
geographically, as far as possible, and have been
printed in the authors' words without modification. A
useful index has been found impracticable ; but a detailed
table of contents is given at the end of the volume.

The omission of several important matters must be
explained and apologised for. Some good campaigns
have been left undescribed because I could not find
reporters for them and failed in obtaining otherwise
all the necessary particulars regarding them ; not in
any way because they should not have been included.
A chapter on the local distribution and cost of malaria



xii PREFACE

would have been useful, and was attempted. The older
books contain much on the former point ; but the
information given was based upon evidence which would
scarcely satisfy us to-day, and accurate details could
not be obtained without such long enquiry that I was
forced to abandon the project entirely. Lastly, refer-
ences to much good literature have been omitted or
curtailed — not because such literature is of secondary
importance, but because the object of the book is to
present a general discussion of particular points rather
than a complete record of all the known facts and
hypotheses. But there is another reason for these
omissions. Owing to grants recently given by the
Advisory Committee for the Tropical Diseases' Re-
search Fund (collected by the British Colonial Office),
we are now preparing in Liverpool, not only for new
researches, but for an exhaustive descriptive biblio-
graphy of malaria, in which, I trust, all the literature
both of general and of local interest will be collated
and compared. Indeed before long the whole of this
immense subject will perhaps be dealt with in the only
adequate manner possible — that is, by a special Bureau
appointed for the study of it ; and this book is intended
to be a necessary preliminary to that work.

I hope that most of the matter contained in it will
be of use to any one who proposes to undertake a genuine
campaign against malaria. For this purpose we require
a knowledge, not only of biological technics and of the
various possible preventive measures, but also of the
broad principles of sanitary statesmanship. The pre-
vention of malaria on a large scale is a great economical



PREFACE xiii

as well as a great humanitarian undertaking. A genuine
campaign does not consist merely in the formation of
inexpert committees, the passing of ordinances for the
screening of water-butts, and the issue of wise advice
to the public. To be permanently and economically
successful, it must always be a permanent concern of
the State, requiring careful measurements of the amount
of sickness present, a nice appreciation of the measures
most suitable for the locality, exact estimates of their
cost compared with the cost of the disease, a well-
considered organisation, and, above all, a fixed deter-
mination to succeed.

The world requires at least ten years to understand
a new idea, however important or simple it may be.
The mosquito theorem of malaria was at first ridiculed,
and its application to the saving of human life treated
with neglect, jealousy and opposition. But now, owing
to the labours of many of those who have contributed
to this volume, and of all of those who have so long
and so patiently studied the subject, we are assured
of final success. To them and to the memory of them
this book is dedicated ; but we must not rest content
until the principles so well established by them are
followed in every civilised country of the world. I
hope, too, that mosquito reduction will before long be
undertaken in most of the towns in the tropics, whether
they are malarious or not.

RONALD ROSS.



University of Liverpool
\st June igio.



CONTENTS



CHAP






I.


HISTORY






Section


I.

2.




)>


3-




))


4-



Ancient Times ....

Early Modern Times

Discovery of the Parasites

Speculations regarding the Mode of Infection

5. Researches regarding the Mode of Infection

6. Confirmations and Extensions .

7. Recent History of Prevention

8. Remarks .....



SUMMARY OF FACTS REGARDING MALARIA

{Suitable for Public Instruction)

Section 9. The Parasites and the Fever
„ 10. The Mode of Infection .
„ II. Facts about Mosquitos .
„ 12. Personal Prevention
,, 13. Public Prevention



III. THE FUNDAMENTAL OBSERVATIONS AND EXPERIMENTS

Section 14. The Parasites cause the Disease
„ 15. Experimental Blood Inoculations
„ 16. The Parasites develop in Certain Mosquitos
„ 17. Experimental Mosquito Inoculations

IV. THE PARASITIC INVASION IN MAN .

Section 18. The Onset of the Invasion

„ 19. The Further Progress of the Invasion .

„ 20. The Decline of the Invasion

„ 21. Average Duration of Untreated Infections

„ 22. Enlargement of the Spleen and Liver .

„ 23. The Effect of Quinine

,, 24. Summary .....

XV



PAGE
I

I

6

8
10
20
26
29
43

49

49

54 /
58/
60

62

62
66

76 .

77

86

86

98
104
122
127
134
143



CONTENTS



Section


25.


))


26


?i


27



of



CHAP.

V. MALARIA IN THE COMMUNITY . . . .

Is the Infection caused otherwise than by

Anophelines ? .
Some Definitions
Conditions required for the Production

New Infections in a Locality

28. Laws which Regulate the Amount of Malaria
in a Locality ....

29. Laws which Regulate the Number of Ano
phelines in a Locality

30. Explanation of Various Phenomena

31. The Measurement of Malaria

32. The Mortality and Cost of Malaria



PAGE

145



VI. PREVENTION ......

Section 33. List of the Possible Preventive Measures
V



for



34. Protection against the Bites of Mosquitos

35. Mosquito-reduction

36. Prevention by Treatment

37. Selection of Measures

Domestic Prophylaxis

38. General Sanitary Axioms

39. Selection of Measures for Public

40. Conduct of the Campaign



VII. SPECIAL CONTRIBUTIONS



Personal and



Prevention



No. of Section.


Contributor.


Country.




41


Professor Howard


United States


, 42


Colonel Gorgas


Panama




V 43


Mr Le Prince


Panama




44


Sir Rubert Boyce


West Indies .




45


Dr Prout


Jamaica




46


Dr Wolferstan Thomas


Amazon Region




47


Dr Oswaldo Cruz


South Brazil .




48


Dr MacDonald


Spain .




49


Professor Celli


Italy .




50


Prof. Dr Savas


Greece




51


Prof. Dr Schilling


German Possessions




52


Dr Sergent


French Possessions




53


Mr H. C. Ross


Egypt .




54


Dr Balfour


Khartoum







CONTENTS


xvii


No. of Section. Contributor


Country


PAGE


55


Dr Bostock


South Africa


543


56


Dr Murison


Durban .


549


57


Dr Watson


Malay States


554


58


Professor Takaki


Japan


563


59


Professor R. Ross


Other Countries .


568


60


Colonel Melville


Troops in War .


577


61


Major Fowler


Troops in Peace


600




ADDENDA ....




621


62


Suggested Terminology for the


Phenomena of Cytogenesis


621


63


Notes on the Malaria-bearing Anophelines .


622


64


Examples of Legislation




636


65


Notes ....




638




REFERENCES




645




CONTENTS IN DETAIL .




664



LIST OF ILLUSTRATIONS

NET FOR MEASURING THE OUTPUT OF MOSQUITOS
FROM A MARSH — CLAIRFOND, MAURITIUS.

BANKS OF A STREAM ROUGH-TRAINED FOR RS.O-37 A

RUNNING FOOT FOR BOTH BANKS (MAURITIUS). . To face page l66

PLAN OF VACOAS CAMP AND CLAIRFOND MARSHES . To face page l88

FIG. I. SS. VINCENT. PART SECTION OF SHIP SHOWING
MOSQUITO PROTECTION TO DOORS AND PORTS.

„ 2. SKETCH SHOWING MOSQUITO PROTECTION FOR
DOORS, VENTILATORS AND PORTS. SS.
VINCENT. DOOR, PORT AND VENTILATOR.

„ 3. METHOD OF ATTACHING WIRE-GAUZE SCREEN
TO FRAMES.

„ 4. DOORS AND PORTS.

„ 5. BOAT DECK — POOP AND BRIDGE DECK.

„ 6. MAIN DECK To face page 388

TABLE 3. RESULTADOS DA CAMPANHA ANTI-PALUDICA NO

XEREM To face page 398

BANKS OF THE ILISSOS, ATHENS, UNTRAINED. BY DR
CARDAMATIS.

BANKS OF THE ILISSOS, TRAINED. BY DR CARDAMATIS. To face page i^^O

FIG. I. F. C. MAILLOT.

„ 2. PETROLAGE D'UNE MARE, GITE A ANOPHELINES.

„ 3. RECHERCHE ET PETROLAGE DES GITES A
ANOPHELINES.

„ 4. GITE A ANOPHELINE DANS UNE OASIS
SAHARIENNE.

„ 5. MAISON PROTEGEE PAR DES GRILLAGES, CONTRE
LES MOUSTIQUES.

„ 6. DEFENSE M^CANIQUE (PORTES ET FENETRES
GRILLAGEES).

„ 7. EXAMINATION OF CHILDREN.

„ 8. SAMPLE CHART FOR PUBLIC INSTRUCTION . To face page 480

xix



XX LIST OF ILLUSTRATIONS

FIG. I. AN EXCELLENT TYPE OF MOSQUITO - PROOF
HOUSE AS BUILT BY THE TRANSVAAL
GOVERNMENT.

„ 2. AN EXAMPLE OF ROUGH BUT EFFICIENT
MOSQUITO PROOFING IN THE VELDT.

„ 3. AN INGENIOUS IDEA.

„ 4. A GOOD EXAMPLE OF MOSQUITO-PROOF HOUSE.

„ 5. JOINT OFFICES OF THE WITWATERSRAND
NATIVE LABOUR ASSOCIATION, AND THE
PORTUGUESE DEPARTMENT OF EMIGRATION
AT RESSANE GARCIA, PORTUGUESE EAST
AFRICA.

„ 6. ACTUAL BREEDING - PLACES OF ANOPHELINE
MOSQUITOS ON THE CROCODILE RIVER,
EASTERN TRANSVAAL.

„ 7. COMFORT WITH SAFETY.

„ 8. ACTUAL BREEDING - PLACES OF ANOPHELINE
MOSQUITOS IN THE EASTERN TRANSVAAL.



To face page 544



1. PORT LOUIS, MAURITIUS, BARRACKS AND HUTS.

2. THE CAUSE OF THE MALARIA AMONGST THE

TROOPS IN THE HUTS.

3. ANOPHELINE BREEDING-GROUND IN A COLONIAL

CANTONMENT (MAURITIUS).

4. PART OF AN OLD FRENCH FORTIFICATION AND .

MOAT NEAR PORT LOUIS, MAURITIUS.

5. COOLIES "ROUGH TRAINING" A STREAM. THE

SAME FINISHED.

6. INDIAN VILLAGE IN THE MIDDLE OF A MARSH

(CLAIRFOND, MAURITIUS).

7. A NATIVE HUT IN THE SAME VILLAGE.

8. CLAIRFOND MARSH IN MAURITIUS, WITH

VILLAGE NEAR BY To face page 6zo



THE PREVENTION OF MALARIA



CHAPTER I

HISTORY

1. Ancient Times. — Dr Richard Caton has kindly tried
to ascertain for me whether there are any distinct references
to malaria in the ancient Egyptian writings ; but informs me
that he knows of none in the medical papyri or temple
inscriptions, and that Dr J. H. Walker confirms this state-
ment. It should be noted that Strabo (first century B.C.)
observed that Alexandria, in spite of marshes in the neighbour-
hood, was free from malaria in his time ; and even at the
present day the disease does not abound in Egypt as much
as might be expected.

In Greece and Italy, however, malaria has been well known
for more than two thousand years ; and Greek and Italian
authors have collected many references to it in old writings.
Recently Mr W. H. S. Jones has given us a laborious and
exhaustive study of the subject made in the light of our
present knowledge [1907, 1909].

The first-named authors have always taught that the disease
was very prevalent in those countries from the first ; but Mr
Jones, following a tentative suggestion of mine, gives many
reasons in favour of the view that it may have entered them
from without during historical times, and may subsequently
have exerted considerable influence upon their civilisation.
Thus, there are few references to it in the earliest literature,

A



2 HISTORY [Sect.

but many in later writings. Homer (say iioo B.C.) mentions
what might be malaria, but only once {Iliad, xxi. 31); and
Hesiod (say 735 B.C.), though he lived at Orchomenos on the
shore of Lake Kopais, now intensely malarious,^ and dealt
with rural subjects, makes no clear reference to it. Theognis
(say 550 B.C.) probably mentions it, and Heroditus (494 B.C.)
possibly so. Jones infers from the medical writings attributed
to Hippocrates that paludism was known in the medical
schools before his birth (about 460 B.C.) ; and from the Wasps
of Aristophanes (425 B.C.) that it " was attracting particular
attention at Athens " at that time. About 429-400 B.C. the
Athenians erected on the Acropolis a statue to Athena Hygieia,
and introduced the worship of Asclepius, tending to show that
" ill health was distinctly on the increase " ; and after this
"references to fevers became much more numerous," and
malaria probably very common in Greece. He describes
accurately and fully the effect which this must have had on
its civilisation.

Apart from the literature, I am strongly of the opinion,
based upon many considerations, that malaria could scarcely
have been very rife in Greece before the height of its prosperity.
The people were too vigorous and warlike. The gymnastic
training of youths could scarcely have been possible if enlarge-
ment of the spleen had been very prevalent. The figures on
the tombstones, though evidently idealised, do not suggest to
my own medical apprehension anything resembling a malarious
race ; and the open-air life and ceremonies do not suggest
a malarious country. The ancient flourishing population round
Lake Kopais, for example, would have been simply impossible
if the disease had been as rife then as it is now. It is
now very rife there and in most of the Grecian villages ;
and there must have been a time when the change took place.
Quite possibly it was introduced about the fifth century before

1 In 1906 I found that twenty out of forty children at Orchomenos were suffering
from enlarged spleen in June, that is before the malaria season.



i] ANCIENT TIMES 3

Christ by soldiers or slaves from abroad, as it was certainly
introduced into Mauritius in 1866 (section 30(21)). Spreading
gradually up the valleys, it would have tended to destroy
rural prosperity, to drive the people into the healthier towns
(as in Mauritius), and, assisted by other causes, to sap the
vigour and physique of the race [Ross, 1906].

It is well known that the ancient Greeks recognised the
quartan, tertian, quotidian and semitertian (probably malignant
tertian) varieties of paludism, and many of its accidents ; and
were acquainted with its seasonal and local variability, and,
above all, with its frequent prevalence near marshes. This
last point is most germane to our present part of the subject.
Thus there is an old story that Empedocles of Agrigentum
(say 550 B.C.) "delivered Selinus (in Sicily) from a plague
by draining its marshes, or by turning two rivers into them "
— that he was able, as Matthew Arnold says, to

" Cleanse to sweet airs the breath of poisonous streams."

Doubt has of course been thrown on the story ; but whether
it is true or not matters little. The mere fact that such a
tale was told proves that the Greeks, even at an early date,
had become in some way aware that marshes tend to generate
sickness, and, still more important, that by drainage or other
treatment this may be prevented. There are many passages
connecting malaria with marshes. Thus as already stated
Strabo (first century B.C.) says that Alexandria, in spite of
its site, was free from marsh-fever even in his time. "It is
to be inferred from this," Mr Jones says, " that damp places
were generally known to be unhealthy, so that exceptions to
the rule were noticed by observers as remarkable phenomena."
Hippocrates (Airs, Waters, Places) noticed that those who live
in low, meadowy and hot districts tend to be neither tall or
well-built, but stout, fleshy, dark-haired, dark-coloured, bilious,
and wanting in courage and endurance.

For ancient Italy we have a similar theory, namely, that



4 HISTORY [Sect.

references to paludism are scanty in the earlier writers, but
very abundant in the later ones. Mr Jones notices, both for
Greece and Italy, that many of the most ancient settlements
appear to have been made on sites which are now pestilential
— suggesting that they were not so unhealthy when they were
first selected. Professor R. C. Bosanquet tells me that some
of the oldest settlements in Crete, made during the wonderful
ancient civilisation of that country thousands of years before
Christ, were situated at spots which are now intensely malarious.
Many areas round Rome, now scarcely habitable, were the
homes of great and prosperous peoples in the prehistoric period,
and were later full of the country villas of rich Romans.^

Those who consider that malaria was always very prevalent
in ancient Greece and Rome cite legends such as that of the
destruction of the Lernean Hydra by Hercules — the Hydra
being supposed to be symbolic of malaria. Lerna is a marshy
district in Greece, and the Hydra was fabled to inhabit the
marshes and to ravage the country round it. It is possible,



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