superintendence, carried on a struggle against malaria in the
years 1901 - 1902. At the beginning of the campaign in
December 1900 there were 63 = 48% of the inhabitants infected
with malaria. In the first nine months of the struggle, 22 cases
in all occurred amongst labourers, drawn from regions free from
fever ; from that time, in the next fourteen months, there were
no fresh cases of infection at all, and only nine relapses ! ^
The fight against malaria is therefore twofold, consisting,
(i) in the treatment of the sick, and (2) in the destruction of
the parasites that have already made their way into the human
organism — the "prophylaxis" proper. If the solution of these
problems can be brought about, malaria must disappear.
Individual prophylaxis can be practised according to an
empirical scheme which has proved useful ; thus I have found
that in the worst fever regions, on marches and expeditions,
the dose of one gramme of quinine every fifth and sixth day is
sufficient to guard against fever. Other authors recommend
other methods ; as to the value of the separate schemes, the
last word has not been said. But it is certain that individual
quinine prophylaxis is able to prevent the outbreak of malaria
infection, and, on the other hand, that the use of the drug may
be left to the patient himself, under the control of the doctor.
It is a different thing with the general part of the fight, with
^ This work does not belong to my present subject. I mention it here because it
prepared for and completed the experiment of Stephansort.
5i] STEPHANSORT 457
the treatment of the persons infected : the latter can only be
detected by the doctor or by a staff specially trained for the
purpose, and their treatment must be individualised. The fight
against malaria by this method can therefore only be begun
and carried out under medical supervision.
In the year 1900 Koch found about 734 persons in
Stephansort, New Guinea, 157 of whom harboured malaria
parasites ; 240 Chinese with 63 infected, 209 Malayans with
53 infected, and 264 Milanesians with 157 infected were
examined. In the beginning the infected persons were treated
with one gramme of quinine, until the parasites had disappeared
from the blood ; from that date, for two months, every eighth
and ninth day one gramme of quinine each was given. The
result was a striking one, as appears from the number of
patients admitted to the hospital.
January .
February
March .
April
May
June
24 admitted on account of malaria.
13
2
3
I
Koch emphasises that the months of January to May are
notorious as being specially dangerous, and that also in the
year 1900 the rainy season lasted right on into June. Never-
theless they succeeded in reducing malaria morbidity to a very
slight amount, more especially as the cases of illness from it
which had occurred from April to June were only relapses and
not fresh cases of infection. And this success was obtained
through the rational usage of quinine. It does not make any
difference to the importance of this proof, even if one admits
that the conditions were rather favourable in Stephansort —
being here the case of plantation labourers living far from their
own homes and under complete control — and that the success
was lost with the time as the control slackened. The proof
I mentioned was given, and nothing more has been intended.
458 PREVENTION IN GERMAN POSSESSIONS [Sect.
It was only natural that Koch's experiments in Stephansort
were copied in the other German colonies and adapted to local
conditions.
In German South-west Africa, the northern tropical districts
of which suffer badly from malaria, Vagedes has undertaken
to make practical use of Koch's ideas ; because for those districts,
where numerous small collections of water such as those which
occur in footprints of cattle, horses and wild animals, serve as
breeding-places for Anophelines, and where mosquito preven-
tion by means of wire-gauze, screening the native huts, cannot
be spoken of, quinine treatment and prophylaxis are the only
possible methods. In Franzfontein and the surrounding settle-
ments, Vagedes found 30% to 75^ of the inhabitants infected
with malaria. Every eighth and ninth day, ninth and tenth
day, and every ninth, tenth and eleventh day respectively
the infected adults were given one gramme at a time ; the
children correspondingly less. Certainly, it was not un-
important that quinine was given whenever possible in the
form of hydrochloride in solution, and only in rare cases
in wafers. In children, who easily rejected the solution, sub-
cutaneous administration was adopted. This treatment was
continued from two to three months. The results were very
satisfactory. In Franzfontein, with its fixed and therefore
regularly-treated population, the percentage of infected persons
decreased from 79^ to 9^ ; out of 165 persons only 7 new
infections and 4 recidives occurred. In Tumamas ^7% ^^id
in Canas 30^ of infected persons were found at the beginning
of the campaign. In the course of the following rainy season
the settlements were free from malaria.
Koch's ideas of anti - malarial measures have been also
applied to Dar-es-Salaam.
Dar-es-Salaam, at the time when Ollwig began his activities
as director of the anti-malarial brigade, was a town of 12,000
to 15,000 inhabitants. The population consisted of Europeans
(officials and officers stationed there for periods of one and
5l] DAR-ES-SALAAM 459
a half years, and merchants with engagements of longer
periods), Indians, Goanese, Arabs and Negroes. The Europeans
live partly on the peninsula facing north - east, and partly
in the districts near the harbour. The Indians live in the
adjacent blocks of houses situated more inland, and the native
town is grouped around these. The larger portion of the
town is surrounded by a depression where water remains for
long periods through the dry season, and which renders the
cultivation of rice possible. Along the shore wells spring up
and form ditches and ponds. The town is therefore surrounded
by a ring of water - collections which offer most favourable
breeding-places to Anophelines.
The abolition of these water-collections, the land-level being
but little higher than the sea-level at high tide, would have
involved very great technical difficulty, and consequently would
have been most expensive. Other measures, such as oiling
of single water-collections with petrol, did not — as was to be
expected — affect the number of Anophelines infecting the
houses.
Ollwig first tried to establish the malaria index based on
microscopic examination of the blood. Palpation of the spleen
does not appear to have been practised. Ollwig accepts as a
sign of malarial infections also the basophile granulation of
the red blood corpuscles, if he could find no other cause
(anaemia due to ankylostomiasis) for its appearance.^
For this purpose the town was divided into twenty blocks,
and the inhabitants of these quarters were regularly examined
without exceptions. Owing to the fixedness of the Indian and
Goanese population, this examination could be fairly well
carried out; in the Negro quarters, however, this was an
extremely difficult task, as they continually change their
domiciles from village to town and vice versa. Therefore in
the following table the Negroes mentioned have undergone a
single examination.
1 Due to other causes. — R. Ross.
46o
PREVENTION IN GERMAN POSSESSIONS
[Sect.
From the table, in the column devoted to " first examina-
tions," the malaria index is given fairly accurately, and shows
that spontaneous immunisation in adults does not occur to
any appreciable extent, and that therefore the treatment with
quinine was justified also in the case of adults.
TABLE III
Children
Children
Children
A^..U,
First
up to I year
from I to 5 years
over 5 years
examined infected
examined
infected
examined
infected
examined
infected
Indians
examinations
27
8=29%
62
20 = 32%
l8l
53 = 29%
650
105 = 16%
and 1
Goanese
Later
examinations
75
2=27%
211
28 = 13%
415
23=5-5%
1,702
82=4'8%
First
examinations
26
9 = 34%
94
45 = 47%
288
74=26%
3.338
238=7-6%
Negroes <
Later
exammations
42
8 = 19%
169
55=33%
627
99 = 15%
"
1
The " first examinations " were made in August, September
and November 1901, and January to March 1902 ; the "later
examinations" from March 1902 to March 1903 — therefore
after i"5 year's campaign at most.
On the contrary, compared to Dar-es-Salaam the malaria
index of some villages further inland appeared rather high : of
children up to one year of age, 77*5% were infected ; of children
up to five years of age, 57'3% ; of children above five years of
age, 3 1 '9%; of adults, 217%.
The anti-malarial measures were limited to quinine treat-
ment of all persons who were found infected, as well as those,
naturally, who put themselves at the disposal of the doctor.
OUwig gave adults, at first on three consecutive days and
later on every fifth and sixth day, one gramme quinine muriate ;
after nine days' interval again three quinine days, and so on
for two and a half to three months. Children were given a
corresponding quantity of the drug in solution and a lump of
5i] DAR-ES-SALAAM 461
sugar afterwards ; adults, mostly in form of tablets. One can
see it was a question of a purely therapeutic anti-measure,
and not one of prophylaxis.
Many of the details in Ollwig's interesting report (one and
three-quarter years after the anti-work) cannot be referred to
here, and only the "facit" is drawn as resulting from Table III.
In one school (not referred to in the table) they were
successful in reducing the number of infected persons from
21*0% (August 1901) to 3-5% (March 1903). Amongst the
Indian population from July 1901 to June 1902, 410 cases,
from July 1902 to May 1903, 210 cases of malaria, came to
the knowledge of the medical officer. It may be noted here
that the Indians gradually gained confidence with the medical
officer ; and so in the first half of the period more infections
remained unobserved than in the second half. In the Negro
children, on the contrary, the results, though noticeable, were
not so favourable (decrease from 34% to 19%). This can
easily be understood because the Negro population is subject
to constant fluctuations, and it is only seldom possible to
continue the after-treatment long enough.
Statistics of adult Negroes have been omitted from Ollwig's
report ; the 7'^% of infected adults are of little importance in
proportion to the 26-40% of the children.
Ollwig proves in his report that the reduction in the malarial
morbidity can have been caused neither through climatic factors
nor through other possibly adopted measures. The periods of
rain and the numbers of Anophelines were not less during the
time of the observation than previously, and the work of
assainment and petrolisation of the water-collections have been
practised so irregularly and to such a slight degree that these
measures cannot have had great influence upon the large differ-
ences in the numerical value.
Ollwig rightly emphasises that only a very small staff —
one medical officer, one nurse, one European and five coloured
assistants — has been necessary for this successful struggle.
462 PREVENTION IN GERMAN POSSESSIONS [Sect.
It is to be regretted that Oil wig did not calculate the total
cost, as this calculation would have shown how cheap this
method of anti- malarial measures is in comparison to other
methods. Up to 1908 the number of native assistants never
exceeded half a dozen, besides three to four Europeans, by
whom 15,627 natives were examined microscopically and treated
with quinine.
Subsequently anti-malarial work was continued in Dar-es-
Salaam. For this work only one medical officer was available,
whose time was greatly occupied with quarantine and other
administrative work ; the staff of assistants was not much aug-
mented either. Ross-Ruge's method of blood examination (the
so-called thick film method) was adopted, and this method
made it possible to discover even quite isolated parasites. The
consequence was a remarkable increase in the positive cases
since October 1907, and for this reason the numerical values
given in Table V, before and after that date, are not to be
compared with each other " without further consideration."
Other methods of anti - malarial measures could not be
practised except to a very slight degree, as the money provided
by the Government was just enough for quininisation. In
some houses mosquito-proof rooms — such as verandas — have
been arranged ; the petrolisation of water - collections could
naturally yield but little success.
In Tanga, the most important seaport next to Dar-es-Salaam,
the anti-malarial work, according to the example of the capital,
was not taken up until 1905 (Table IV). Besides one medical
officer only three to four nurses understanding microscopical
examination of the preparations were available. In addition
to microscopical findings, tumours of the spleen decided the
need of treatment. This treatment was commenced with one
gramme doses in adults, and correspondingly lower doses in
children, on two consecutive days per week, and was continued
for three months. In all cases an enormous decrease of splenic
tumours (from 1,040 to 1,042) and distinct improvement in
51]
TANGA
463
the general condition have been stated. Only in very rare
cases this cure did not sufifice to cause the parasites to disappear.
TABLE IV
1905-06 i
All persons with
tumour of the
spleen or mal.
parasites in
blood, were
treated with
quinine for 3
months.
Negroes
Indians
Children
Adults.
Children
Adults.
June-Aug.
(before quinine treatment)
49 "6%
12 "4%
54'o%
13-8%
Jan.-March
(after quinine treatment)
24-6%
5-3%
29-5%
3 "9%
1906-07 A
In June, July, and
Aug. all nations
became quinine
prophylactically
May-July
84-0%
14-9%
87-1%
i8-3%
Dec. -March
30-0%
6-1%
3i'3%
4-6%
1907-08
1907
April-June
i8-3%
12-6%
July-Sept.
i6-i%
9-5%
Oct. -Dec.
i4"o%
7-5%
1908
Jan.-March
I2'0%
6-8%
1908-09
As the year before
April-June
668
170=24%
2,025
295 = 14%
July-Sept.
755
181 = 24%
1,879
272=18%
Oct.-Dec.
601
121=20%
2,100
258=14%
1909
Jan.-March
846
208=24%
2,23s
532=23%
1
The population in Tanga being smaller and much more fixed
than in Dar-es-Salaam, the result during the first year was
more satisfactory. From March to June 1906, however, the
number of infections increased threefold, which is explained
by the extraordinary amount of rain during that time. In the
course of the following dry season the index sunk to the level
464 PREVENTION IN GERMAN POSSESSIONS [Sect.
of the previous year. In 1907 to 1909, apparently another
rise in the cases of malarial infection occurred in Europeans
at Tanga ; but this is due to numerous immigrations from further
inland, the people in case of infection having the opportunity
to get to the hospital in Tanga by means of the recent rail-
way extension. Among the settled white inhabitants of the
city of Tanga the malaria morbidity has gone back from 37%
to 35y/ of the total strength.
Drainage of the town, petrolisation — though not quite
general — of water-collections, and deforestation of numerous
uncultivated pieces of land, were undertaken simultaneously ;
also many Europeans' houses were provided with wire - gauze
protection.
The increase of malaria during 1908 to 1909 {vide Table V)
may be due to the hospital being more generally used by the
patients from the district, which is more and more frequented
by Europeans, and by people employed in the construction
of the railway. In Dar-es-Salaam itself malaria has diminished
to such a degree among the whites settled there in the European
quarter, that individual quinine-prophylaxis is no longer regarded
absolutely necessary ; rather, numerous officials have passed
the whole of their one and a half years' time of service without
taking quinine, and without once contracting malaria. Many,
however, continue the quinine prophylaxis.
In the other settlements in East Africa, where medical
officers and officials are stationed, no proper anti-malaria work
is practised to any appreciable degree.
From a general report on infected Europeans who have
been treated by the medical officers, it can be concluded that,
both together, the anti - malarial measures and the individual
prophylaxis in Dar-es-Salaam as well as in Tanga have been
a success,
51]
RESULTS
TABLE V
46s
Europeans in Dar-es-Salaam.
Strength, Dar - es - Salaam
(town), (Iststarke)
Morbidity, malaria and
blackwater fever in the
district of Dar-es-Salaam
Mortality, malaria and black-
water .....
1902-03.
1903-04.
1904-05,
1905-06.
1906-07.
1907-08.
3"
377
380
657
851
897
^ 166
168
141
355
287
268
I S3 -3%
44 "5%
37'i%
54-0%
337%
29-8%
7
3
4
6
6
1908-09.
743
342
46 '0% •
Europeans in Tanga.
Strength, Tanga
(Iststarke) .
(town),
Morbidity, malaria and black-
water fever, in the district of
Tanga .....
Mortality, malaria and black-
water .....
95
148
192
205
211
222
c no
61
178
156
128
206
^"5-8%
41-2%
87-5%
76-1%
6o-6%
92-8%
2
2
5
6
3
2
258
203
787%
1 Vide page 464.
The reports on the garrison (Table V«) were the most accurate
ones, as the majority of recorded infections were observed by a
medical officer. The statements about " civil persons " (Table Nb)
are far less precise, only a small number of the malaria infections
among them coming to the knowledge of the doctor. The
figures showing the morbidity here have therefore been stated
far too low, but, as these conditions do not change from year
to year, it is quite permissible to compare the different years
with each other.
With the coloured population matters are entirely different
(Table VI). The percentage value in itself is here not
standardised, as it was impossible at the repeated examina-
tions to find always the same persons who had been treated
with quinine. In addition to those there were persons who
had come into town meanwhile, and who had been treated
with quinine only insufficiently or not at all. Some other
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Sect. 51 J
RESULTS
467
comparative instances must be sought, and they are given in
the blood examination of the inhabitants of the suburbs of
TABLE V^
View
ON THE MALARIA MORBIDITY IN THE TERRITORY
Africa, among the European population.
IN East
White
persons.
Civil
persons.
Cases of ma
White.
aria among
Civil.
Total.
1903-04
151
1,200
164
292
51-3%
1904-05
151
1,340
171
461
66-1%
1905-06
198
1,688
188
701
47-1%
1906-07
233
2,142
206
500
297%
1907-08
192 2,734
156
614
1 -*
25-3%
1908-09
3,283
S92
27-1%
Dar-es-Salaam, who had been examined since October 1907
in sufficient numbers without being given quinine.
The results, concerning children, show clearly how much
more favourable the morbidity is among the town children
who are partly under quinine treatment. This favourable
consequence is not only due to a lesser danger of infection to
which the children living in towns are exposed. And this can
be seen from the single figures of morbidity which are higher
alternatively in the centre and at the periphery of the town.
If the danger of infection were less in the centre, its figures of
morbidity also should be lower.
Clearly enough, this difference is not as pronounced in the
case of adults, in whom acquired immunity plays a considerable
part. On consulting Table IV on Tanga, it is quite clear
that, under the circumstances prevailing in the seaports of
German East Africa, the malaria among the natives can be
kept on a certain level simply by methodical treatment of all
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