same period was 22*5. The average percentage of malarial to
total deaths was 197, representing nearly one-fifth of the total
deaths.
378
MALARIA IN JAMAICA
[Sect.
A summary of the statistics is given in the following table :-
AVERAGE
DEATH-RATES,
ETC., FOR THE DECENNIUM
ENDING
30TH APRIL 1907.
Average death-
Average death-
Average death-
Average percent-
age of malarial
deaths to
total deaths.
Parish.
rate from
rate from
rate from
malaria.
other causes.
all causes.
St Thomas .
6-5
i8-5
25*0
26-1
St Catherine
6-2
19-4
25-6
24-4
Westmorland
5-9
15-8
217
277
St Mary
5-9
i8-o
23-9
24-6
Clarendon .
5*3
15-2
20'5
23-8
Portland
5-3
19-3
24-6
2 1 '9
St James
4-8
17-1
21*9
22-3
Hanover
4-8
19-5
24-3
19-9
St Andrew .
4-0
23-9
27-9
i4'6
St Ann .
3-4
14-5
17-9
19-4
Trelawny
3'4
20-8
24-2
14-4
St Elizabeth
2-9
15-6
i8-5
15-8
Kingston
2-4
26*3
287
8-6
Manchester .
1-6
14-8
i6"4
I0"0
Whole island .
4*4
i8-i
22-5
197
But the prevalence of malaria is really much greater than is
indicated by the death-rate, for of the admissions to the Govern-
ment hospitals of the colony, it is found that at least one-third
are due to malaria, and the malarial sick-rate shows a marked
increase of recent years.
Year.
Total admis-
sions from
all causes.
Total
deaths.
Death-
rate
per
cent.
Malarial
admissions.
Malar-
ial
deaths.
Malarial
death-
rate
per cent.
Percentage
of malarial
to total
admissions.
1904-05
1 905-06
1906-07
1907-08
16,103
17,856
21,555
21,837
669
563
661
830
37
31
3-06
3-8
4,827
6,285
7,113
7,510
89
88
99
121
1-8
1-4
1-3
1-6
29-9
35-1
32-9
34-3
Total .
77,351
2,723
...
25,735
397
Average
19,337
680
3-5
6,433
99
1-5
33-2
45] COST AND SPLEEN-RATES 379
It is calculated that the cost of the maintenance and treat-
ment of the malarial cases alone amounts to over j£6,^oo
per annum.
On banana and sugar estates the loss of time through illness,
mainly malarial and therefore preventable, amounted to sixteen
out of every hundred working days, per coolie labourer employed ;
while among the constabulary, a picked body of men, it is
estimated that there is a loss of nearly four thousand days'
service per annum from the same cause.
T/ie spleen rate. — That the endemic index of the island is
high is shown by the results of the examination of the spleens
of children. Among 2,036 children examined in all parts of the
island, 536 were found to have enlarged spleens, a spleen rate
of 263^. But if the mountainous centre of the island were
to be excluded, and places on the littoral only taken, the spleen
rate would be found to be much higher, and in certain localities
rises as high as 80%. The following table summarises the
results of the splenic survey : —
No of
Spleens.^
Total No.
Average
spleen.
Parish.
children
examined.
I
3
6
9
of enlarged , ^^^^
spleens.
1
Portland . .
St Mary . .
St Thomas
St Catherine .
St Elizabeth .
Kingston . .
Westmorland .
Trelawny . .
St Ann . . .
Manchester .
Chapelton . .
291
398
44
212
249
220
278
189
69
42
44
112
216
27
156
195
197
255
187
69
42
44
152
158
10
48
47
23
17
2
26
'72
'I
7
7
5
I
I
I
I
179
182
17
56
54
23
23
61-5
457
38-5
26-4
21.2
10-4
8-2
ro6
2-5
2-1
2-3
1-6
i'5
1-2
r2
1-03
ro
ro
ro
Total .
2,036
1,500
457
73
6
536
26-3
12
A complete splenic survey, in order to obtain an accurate
idea of the distribution of malaria, is one of the first steps to
be taken in any anti-malarial scheme.
1 See section 31 (4).
38o MALARIA IN JAMAICA [Sect.
Anti - malarial measures. — To diminish this extensive pre-
valence of malaria the following measures have been recom-
mended as being particularly applicable to the requirements
of Jamaica : —
1. To make the harbouring of mosquito larvae in com-
pounds a punishable offence.
2. To keep all margins of rivers and swamps in the neigh-
bourhood of towns free from grass and weeds.
3. The application of crude kerosene where possible.
4. The screening of wells, tanks, etc.
5. The cementing of gutters in towns.
6. The gradual reclamation of swamps.
7. Screening of public hospitals, police stations and coolie
barracks,
8. Prophylactic administration of quinine to police, coolies,
school children and the general public.
9. Education in sanitation and hygiene, all of which would
be under the supervision of a central anti-malarial
organisation.
As already stated, up to the beginning of 1909 little in
this direction has been done. Small quantities of quinine had
been distributed to estates for prophylactic purposes, but had
not been given systematically and continuously ; a few isolated
efforts at swamp reclamation had been made by private
individuals, and one police station had been made mosquito-
proof, but there was no concerted or systematic effort to stamp
out malaria.
As a result, however, of the attention which was drawn
to the subject by the expedition from the Liverpool School,
probably assisted by a severe outbreak of malaria which occurred
in the spring of 1909, public interest appears to have been
awakened, and in the autumn of that year the first steps were
taken to deal with the disease in an organised and systematic
manner. His Excellency the Governor appointed a Com-
mission, consisting of the Colonial Secretary, the Archbishop
45] MEASURES ADOPTED 381
of the West Indies, the Chief Medical Officer, and other medical
men, to enquire into the subject, and to take such steps as
appeared to be urgently necessary. A series of public lectures
have been given, which has done much to spread a knowledge
of the disease in different parts of the island ; a new Public
Health Ordinance has been passed ; steps have been taken to
train sanitary inspectors in the recognition of the breeding-
places of Anophelines, and in anti-mosquito measures ; and,
most important of all, in February 19 10 a sum of ^^"5,000 was
voted to carry out the various measures necessary. So that
now we may consider that the anti - malarial campaign in
Jamaica has been fully started, and the outlook for the gradual
extinction of malaria in the island is distinctly hopeful.
By H. WOLFERSTAN THOMAS, M.D, CM. (M'GiLL)
Of the Liverpool School of Tropical Medicine Research Laboratories,
Manaos, North Brazil
46. Malaria in the Amazon Regrion, and the Protection
of Ships. — (i). Malaria prevails throughout the Aiiiaao?i region.
The chief industry of this part of South America is rubber,
and the immense trade requires a large number of men to
collect the crop. The conditions under which they work cause
many privations and expose them to infection. The old say-
ing that every kilo, of rubber represents the loss of a life is an
exaggeration but there is an enormous mortality amongst the
" caucheros " who work in the interior.
In the vast territory watered by the Amazon River three
places of importance occur, which serve as the commercial
centres for the up-river traffic of the interior. Iquitos, 2,200
miles from the mouth of the Amazon, is the only large town in
Peru on the eastern side of the Andes. Manaos, on the Rio
Negro, some 900 miles distant from the mouth of the Amazon
River, and Para, which lies near the mouth, are in Brazil, and
possess the only hospitals for the accommodation of the
up-river patients. No attempts have been made by the states
of Amazonas and Para to create any hospitals along the rivers
in the interior of the rubber districts. They are very necessary,
but their establishment is hindered by reason of the enormous
expenses involved.
Iquitos has no pipe-borne water-supply, and the drainage is
of the most primitive character. Extensive swamps extend in
and about the town, but no attempt has been made to fill them.
382
Sect. 46] MANAOS 383
Cellia albimana ^ and Cellia argyrotarsis abound. The majority
of the cases appear to have contracted malaria up-river.
The cities of Manaos and Para receive many cases of malaria
from the interior, and consequently their death-rates are unduly
high. Both cities suffer from the return of the infected rubber-
collectors, who go and live in the suburbs along the swamps ;
they either neglect all treatment, or take an insufficient amount
of quinine, and, living in a state of poverty and misery, they lie
in their mud huts exposed to the bites of numerous mosquitos.
Their blood contains many gametes, and they therefore serve
as infecting agents for the Anophelines that feed on them.
Their presence is a menace to the community, as they may
cause most virulent epidemics of malignant types of the disease.
Manaos is intersected by many creeks and swamps. Those
in the centre of the city are completely filled ; but, on the
outskirts of the city proper, certain creeks and swampy areas
still form foci of malaria. In the suburbs extensive swamps
exist, and very severe forms of malaria prevail. A modern
system of drainage and water-supply exists, and has done much
to mitigate the evils.
COMPARISON OF MALARIA INDEX OF CHILDREN IN SUBURBS AND CITY ^
Swamps r Apparently healthy
in \ Ailing
Suburbs \_ Average both classes
City swamps ....
Children living along swamps \
in suburbs . . . . j
Children living along swamps \
on outskirts of city . . J
Spleen-rate.
0-5 years.
36-23
46-82
43 "o?
12-94
5-10 years.
4274
45-83
44'36
35-86
43-82
24-85
Blood-rate.
0-5 years.
48-93
51-80
50-61
29-23
5-10 years.
50-00
57-14
52-60
48-78
51-64
40-13
1 Newstead, R., and Thomas, H. Wolferstan : " The Mosquitos of the Amazon
Region," v^Mwa/j Trop. Med. and Parasitology, vol. iv. No. i.
" Thomas, H. Wolferstan: "The Sanitary Conditions and Diseases prevailing
in Manaos, North Brazil, 1905-1909," Annals Trop. Med. and Parasitology, vol.
iv. No. I.
384 MALARIA IN THE AMAZON REGION [Sect.
The state and municipal authorities are gradually destroying
the Anopheline breeding-places within the city. Free advice
and medicines are given to the poor, but no steps have been
taken to organise a campaign against the hordes of Cel. albiinana
and argyroiarsis, which, especially the former, are the carriers of
malaria throughout the whole of the Amazon region.
At Porto Velho on the Madeira River, a railway is being
constructed to connect Bolivia and Brazil. Several attempts
have been made to build this line, and each time malaria has
raged amongst the workmen. A most virulent form of fever
occurs which has at times incapacitated 50% to 80^ of the
total working force. The difficulties in combatting the disease
are great, and are increased by the possibilities of importing
yellow fever from Manaos, Serpa or Pard. The line is in the
interior, through virgin forests and large swamps ; an organised
attack on the lines of the anti-mosquito campaign of Panama
and Xerem in South Brazil would facilitate the progress of the
undertaking. A graphic account of some of the past unsuccess-
ful attempts is recorded by Craig.^
Belem or Para possesses a pipe-borne water-supply. The
swamps are numerous above the outskirts of the city. In 1909
the authorities were influenced to undertake the filling of much
swampy land, and to institute free distribution of quinine. A
most serious outbreak of malaria occurred amongst the poorer
inhabitants living in the outskirts of the city, along the swamps
of the Marco de Legua, Pedreira and Canudos, etc. A medical
commission ^ traced the outbreak to the arrival in Para of many
labourers who had returned in an infected condition from the
Madeira-Mamore railway and Alcoboca works. These people
went to the outskirts, and, living in a state of squalor, they
remained untreated, and quickly infected the numerous Ano-
phelines of the locality. Practically every one in the district
1 Craig, Neville B. : " Recollections of an Ill-fated Expedition to the Head- waters
of the Madeira River in Brazil." (Lippencott. )
- Relatorio apresentado pala commissao nomeada para debellar a epidemia de
pialmudismo, reinante no Marco de Legua, Pedreira e Canudos. Belem. Imprensa
official do Estado do Para, 1909.
46] PARA 385
suffered from malaria. Free clinics were opened, and in four
months nearly 13,000 people were treated with quinine; the
very severe cases were sent to the hospital. Endeavours were
made to have all patients with enlarged spleens confined in
the hospitals, or screened from mosquitos. Mosquito-nets were
lent and all gametocyte carriers were energetically treated with
quinine. A brigade was formed to fumigate the dwellings of
badly-infected individuals, and a general purgation of the sur-
rounding yards and houses was made. Measures were taken
to drain and fill the pools and swamps of the most heavily
infected districts, and as many breeding-places as possible were
destroyed. A great and general improvement was noted after
a few months. The number of infections and the number of
Anophelines diminished, and it is to be hoped that these satis-
factory results will encourage the authorities to continue their
efforts. The expenses were about ^9,500, which was expended
on clinics, hospital accommodation, drugs, draining and filling
of pools, swamps, etc.
The inhabitants of the Amazon region take very little care
to avoid contracting malaria. They frequently neglect to take
quinine, or discontinue it after a few days of treatment. The
labouring-class Brazilian hardly ever uses a mosquito-net, and,
unfortunately, Europeans are prone to follow their example. In
Iquitos, the Peruvian labourer generally protects his bed, not
because of malaria, but for relief from the swarms of Mansonia
titillans and Culex fatigans, which are veritable pests ; this helps
to account for the less pronounced infection of the Peruvian.
All through the Amazon region, where large engineering
works have been undertaken, the old familiar story has been
repeated. Not only has money been wasted, but many lives
have been sacrificed by the neglect of the promoters to realise
the dangers of malaria and Anophelines. The astute commercial
man has still to learn that it is cheaper as well as quicker to
organise a scientific force to combat malaria or yellow fever, and
to have such a force in operation before any attempt is made
2 B
386 MALARIA IN THE AMAZON REGION [Sect
to import labourers and commence the work. The Federal
authorities insert clauses regarding quinine prophylaxis, screen-
incr, etc., in the contracts with the concessionaires, but these
clauses are frequently neglected. Many important engineering
works are certain to be undertaken in the opening up of the
country in North Brazil, and an endeavour should be made to
prevent the serious loss of life which has hitherto occurred. The
sanitary authorities of both the Amazon and Pard states are
alive to the necessity of combatting the disease by extermina-
tion of the Anophelines.
(2). Protection of ships. — Very little attention has been devoted
to the protection of the crew and passengers of steamers navi-
gating regions where malaria prevails. On some steamers
mosquito-nets have been provided for the bunks, and a few
wire-screened doors for the outside cabins, wheel-house and
chart-room. These are inadequate, as they do not protect the
entire living quarters of the passengers and crew.
The screening of a steamer is a difficult undertaking. Four
facts must always be remembered.
(i) That the navigation and working of the ship should not
be interfered with.
(2) That the scheme of screening shall be as simple as
possible. Elaborate designs are certain to fail, as
they cause much trouble and inconvenience to those
on board. The members of a crew or even
passengers will neglect to carry out complicated
methods of closing doors and port-holes.
(3) That the maximum amount of air shall be available. In
the tropics the closeness of the atmosphere does
not encourage the average individual to reduce the
ventilation by the interposition of wire-gauze screens.
I have seen on a steamer plying to the Pacific large
screened wooden frames, designed to fit in the port-
holes, but so massively constructed that the cross
diameter was reduced nearly one-half It is hardly
46] PROTECTION OF SHIPS 387
to be expected, since so much air and light is cut
off, that the crew will make use of the screens.
(4) That an endeavour should be made to screen the vessel
in sections, so that if mosquitos succeed in obtaining
an entry, they can only circulate in that part of the
ship and can be hunted down and destroyed,
Mosquitos generally board a ship when it is moored near the
shore or is hugging the banks, and they quickly find their way
to the saloons and living quarters of the crew.
All parts of a ship which communicate with the danger zone,
i.e.y the open deck, should be protected. The doors should be
screened, and where there is much passing to and fro between
a protected area and the danger zone, a second door should be
placed some 3 or 4 feet away, thus forming a vestibule, and
allowing one door to be closed before the other is opened. All
doors should be provided with spring-locks which catch easily,
and a strong door-spring to ensure a rapid and tight closing of
the door. If the storm-doors are left on, care should be taken
that the knobs do not impinge upon the wire screens and so
tear or fray the gauze.
The ventilators leading to the cabin, alleyways, etc., should
be screened at the ceiling vent.
Through the courtesy of the Booth Steamship Company
the plans of a vessel specially screened against mosquitos are
shown. The ship is designed for use in ocean and river-trade, in
a district severely infected with malaria and Anophelines. The
port of call is far up-river, and is notorious for the severity of
the malarial infection. It is the outcome of the experience
gained by Dr Melville Davidson, Medical Superintendent of
the Company, to whom I acknowledge my indebtedness.
All the port-holes of the steamer are provided with removable
screened frames, which are so adapted that the port-hole can be
closed and screwed down without necessitating the withdrawal
of the screens. The frame of the screen consists of a metal
hoop, on which gauze is tightly stretched and soldered, The
388 MALARIA IN THE AMAZON REGION [Sect.
frame is provided with rigid bayonet catches, which are so
arranged that they sHp easily into the ordinary port, and a
half turn of the screen is sufficient to lock it.
All the ventilators, as is seen in the drawings (figs. 1-4), are
screened by a most simple and efficient arrangement. Ordinary
circular moulding is fastened on the ceiling around the vent
pipe ; the moulding has a deep groove, into which fits a round
metal frame covered with wire-gauze ; the screened frame is
retained in position by three small buttons, so that it can be
instantly applied or removed.
The screen doors have light wooden frames and panels of
wire-gauze. They are provided with spring-locks and strong
coiled wire door-springs.
By reference to the accompanying plan (figs. 5, 6) it will be
seen that the arrangement of the screening is quite simple and
yet adequate. The screened port-holes and doors are outlined
in black. The only entrances to the saloon, chart-room, captain's
cabin, pantry and bath-room, are through a screened door on the
port side, another on the starboard side, and a third at the foot
of the stairs leading from the wheel-house. The outside cabins
are all shown with screened doors and port-holes. Further aft,
and isolated by the steam-steering gear, are the cabins of the
doctor and hospital.
On the main deck the entrances on the port and starboard
sides through which the crew must pass to their work are
screened. On the starboard side there are two sets of screened
doors along the alleyway. These are provided because the ash-
discharger is open to mosquitos and therefore constitutes a
danger zone. On the port side this extra screening is un-
necessary, as in the river only one ash-shoot will be used.
A study of the plan will show that the only unscreened parts
of the ship communicating with the interior are the engine-room,
stoke-hole and galley. Theoretically, these sections should be
screened, but two factors must be taken into account, viz., the
intense heat of the places, which is always accentuated in the
8.S. "VINCENT."
ON OF SHIP SHEWING MOSQUITO
TION TO DOORS AND PORTS.
-f i:-H - u^4s-
Fi^.r
TbFojce' Page. 388.
SKETCH SHEWING MOSQUITO PROTECTION FOR
DOORS, VENTILATORS AND PORTS.
S.S. "VINCENT."
• «
DOORS AND PORTS
7V> Voc» Fbge 3/III.
SKETCH SHEWING MOSQUITO PROTECTION FOR
DOORS, VENTILATORS AND PORTS.
S.6. "VINCENT."
DOOR, PORT AND VENTILATOR
Fiq.3.
FiAj.2.
Method of »ttachin4 wire-gauil sciiken to frames.
DOORS AND PORTS.
1^.4.
ToFace'FkLge'388.
6.S. "VINCENT."
PART SECTION OF SHIP SHEWING MOSQUITO
PROTECTION TO DOORS AND PORTS.
Mg.1.
To Face Page 3S8.
BOAT DECK
•i I I ,^ r^
^ ^g^^ 1 ^ ^ I "757
" ' ^Ts. m f^ A . ^
-Fig 5.
POOP s, BRIDGE DECK
-f-i/G^ ^
Tc Face Page 3(t8.
46] PROTECTION OF SHIPS 389
tropics, and the coal-dust, that would cake and block the meshes
of the screen, and thus restrict the inlet of air. The wheel-
house is unprotected, as screening would be impossible when
navigating a river.
Provided the screening is not disturbed very few mosquitos
should be able to gain an entry, and adequate regulations can be
made to prevent such acts as the taking off of a port-hole screen
or tying back a door.
For port-holes an 18 mesh should suffice, and the gauge of
wire need not be thicker than 32 or 30. For doors which are
liable to be roughly used, a heavier gauge wire is necessary.
The mode of application of the wire-gauze is important. The
gauze should not be tacked on to the frame. A far better
method is to have a deep groove running around the panel
(fig. 3), and a rod either of wood or metal of a size slightly
smaller than the groove. The wire-gauze is laid over the entire
panel and the rods driven into the grooves. This makes the
wire taut and the tension is equally distributed. All strands of
the mesh are fastened securely, which is not the case with gauze
fastened down by tacks. Over the rod a neat strip of moulding
can be fixed, which finishes off the panel and can be easily
removed. The great advantage of this method is that it is a
comparatively simple matter to take off the strip of moulding,
remove the rods, and substitute another piece of gauze. This
method is extensively used all through the United States.
Excellent arrangements for large private yachts and even
passenger steamers can be devised. I have seen nearly the
whole of the bridge deck enclosed with ordinary mosquito-
netting. The top was made of tarpaulin stretched on robes,
and the sides were made of gauze. At sunset the sides were
let down, and from fifteen to thirty people were able to dine and
sleep in comfort. The expense is not so great, and is amply
compensated for by the relief from mosquitos.^
^ Messrs John Holt & Co. have recently screened an entire ship for West
Africa. — R. Ross.
46] PROTECTION OF SHIPS 389
tropics, and the coal-dust, that would cake and block the meshes
of the screen, and thus restrict the inlet of air. The wheel-
house is unprotected, as screening would be impossible when
navigating a river.
Provided the screening is not disturbed very few mosquitos
should be able to gain an entry, and adequate regulations can be
made to prevent such acts as the taking off of a port-hole screen
or tying back a door.
For port-holes an 18 mesh should suffice, and the gauge of
wire need not be thicker than 32 or 30. For doors which are
liable to be roughly used, a heavier gauge wire is necessary.
The mode of application of the wire-gauze is important. The
gauze should not be tacked on to the frame. A far better
method is to have a deep groove running around the panel
(fig. 3), and a rod either of wood or metal of a size slightly
smaller than the groove. The wire-gauze is laid over the entire