On the border of the hill land

The lines on this division were situated on flat land at the end of a spur of the hill. A. umbrosus was abundant, and came from the unopened swampy jungle marked 125 acres, part belonging to the estate, and part to a reserve of the Public Works Department of Government.

In 1911 permission was obtained from Government to open its portion (37 acres) of the land; at the same time the estate, on my recommendation, opened the 125 acres which it owned. The result was an immediate improvement in health, as the spleen rates in Table 16.1 show. The large increase in the child population and decrease in the spleen rate makes comment unnecessary.

Here the malaria came from swampy jungle about twenty chains away. The problem was complicated; for that jungle belonged to another estate, and there was no intention of opening it.

The problem was solved in a curious way. In connection with the water-supply of the adjoining estate, I had suggested a large catchment drain at the foot of the hill marked Bukit Rajah on the plan; this was made, and other drains in the jungle were also dry. The result was to dry the jungle so that it no longer provided a breeding place for A. umbrosus. At the same time some breeding places of A. maculatus in the hill near to the lines were drained by subsoil drains. The spleen rate at once fell.

In both 1917 and 1918 two of the children with enlarged spleens arrived ill, the result of malaria contracted in India. In 1920 two of the three children with enlarged spleen had recently suffered from malaria. They had been several years on the estate, where presumably they had contracted it. The third was a recent arrival from a malarious estate.

This division is of special interest. The lines were situated on a portion of the spur of hill land that terminates at the lines of Division A. The hills are intersected by a number of quite short ravines, each only about a couple of hundred yards long. They debouch onto the flat land where the soil was somewhat peaty. The ravines, except one, swarmed with A. maculatus, which were controlled by subsoil drainage of the ravine streams.

As A. maculatus is never found in peaty water, it was unnecessary to pipe-drain a complete circle here, so the pipes ended as soon as they reached the peaty water. This knowledge of the habits of A. maculatus thus saved the estate much unnecessary expense; and the very small lengths of ravines to be drained made the cost of the control of malaria only a nominal sum—some $1500.

The malaria had been so intense that even Banjarese, a race of Malayans, who are usually immune to malaria, could not live on the division, and the Tamils were decimated. The spleen rates listed in Table 16.1 shows the improvement.

In 1920 three of the six children with enlarged spleen gave history of fever previous to coming to the estate, and another new arrival had a greatly enlarged spleen. Here, as on other healthy estates, there are children who have imported their spleens and malaria. The true spleen rate, therefore, is under 4. For the whole estate the death rate of 1919 was 9‰.

These were close to the corner of a block of jungle marked “196 acres”, through which runs the large drain “AA.” In 1911 this jungle was opened and planted on my recommendation; the spleen rates show the improvement (see Table 16.2).

The fever in these lines came from the jungle of the 196 acres, and from what are now small native holdings on the south boundary. Again, the spleen rates show the improvement (see Table 16.2). Of the four children with enlarged spleen in 1914, three came from a malarious estate. In 1917 the children were examined along with those in the triangle lines.

At one time a number of these people lived along the edge of the jungle that is now Shelford Estate. They suffered greatly from malaria. They subsequently removed to native holdings on the road.

In 1904 the nearest jungle according to the estate plan was 40 chains away; nevertheless the parasite and spleen rates were high. Later, they dropped to normal. In 1917 the rise is owing to the recruiting of labour from an estate known to be intensely malarious. It is, however, easy to make the necessary correction; and I give it as an example of the ease with which the correction can be made, and of how little one is liable to be misled by using spleen rates even on rubber estates where the population moves so freely. Of the seven Tamils with enlarged spleen in 1917 (cf. Table 16.2), all had come from a malarious estate; and the same is true of the Malayalans.

A case of this occurred in a bungalow in field 139 acres, before the jungle on the opposite side of the road belonging to North Hummock Estate was opened.

In the previous places the problem was simply that of removing and draining jungle on flat land. The Division of which I now write was a pestilential spot, full of difficulties for the sanitarian. The coolie lines were scattered, and mostly close to jungle. Part of the land was hilly, and A. maculatus, the dangerous hill-stream mosquito, existed on it. Another difficulty was that 57 acres belonged to Government—part being a quarry reserve which was of value for road upkeep, and which Government was strongly opposed to selling. The Government land was, however, intensely malarious. About 1902 I chose the top of the hill as a site for coolie lines for the Public Works Department, going on the teaching that in a malarious country a hill was the best site, and that elevation, however slight, was preferable to the heavy clay of flat land: “As high ground as possible is the golden rule for a camp. Against the vertical uprising of malaria, elevation, however small, affords some protection.”

The lines were built on the site I selected, but the coolies promptly died of malaria; and until the land was handed over to the estate they remained uninhabited and uninhabitable. On one occasion a man attempted to occupy the overseer’s bungalow; but he, too, had to leave.

To show how intensely malarious the whole area was in 1909, I will give the spleen rates of the various lines. At B, 14 out of 17 or 82% had enlarged spleen. At F, which is farther from the jungle, there were 9 out of 22 or 40% with spleen. At C, the lines were within 20 yards of the jungle, and the spleen rate was 10 out of 11 or 90%; while at C2, which is 200 yards from the jungle, it was 8/15 or 53%. In 1912 coolies were put into the lines D, E, and G, but the health was so bad they had to be moved. I have no figures of the spleen rates.

In order to give the estate a healthy labour force, I decided it would be best to “scrap” almost all the existing lines and sites, and to create a new healthy site somewhere in the area. Accordingly, I made the following recommendations, which were adopted, with the happiest results:

1. Site A was selected as the future headquarters of the Division—but not because it was healthy; for it was only a few yards from the Government reserve and site B where the spleen rate was 82%. It was chosen because it was possible to abolish all breeding places within half a mile. Site F would be protected by the same measures.
2. Sites C, C2, D, E, and G were abandoned, because they were close to jungle. To make them healthy, it would have been necessary to open up extensive areas of jungle, and probably lay down considerable subsoil drainage; this was undesirable, since the jungle and hills formed the catchment area of the water supply.
3. Part of the jungle marked 67 acres was drained and planted with rubber. The Government reserve was exchanged for a piece of land suitable for a rifle range. The reserve was cleared of jungle, and planted up; while the ravines were drained by subsoil pipes.

After these measures were carried out, the health improved, as the spleen rates in Table 16.2 show. In 1917, there were four children with enlarged spleen; three of these belonged to one family which had recently come from a malarious estate; the fourth child, with a spleen just palpable, came from an estate on which malaria had recently existed. There is now a large healthy labour force on a site which formerly was uninhabitable.

This division has always been healthy, for the lines have never been less than 30 chains from jungle, and I had advised the manager not to put new lines among the ravines; they are situated at the end of a spur of the hills. In 1917, one of the two children with enlarged spleen had been on the estate only a week, showing it had brought the enlarged spleen to the estate.

The various measures taken to improve health, chiefly the anti-malarial work, have resulted in a lowering of the death rate (Table 16.3). The labour forces and death rates are taken from the official report of the Labour Department, except for 1919, which are based on the average monthly population. Further comment is hardly necessary.

Close to the Boon Hean Division of Bukit Rajah Estate are many kampongs or native holdings. Until 1916, the drainage of the kampongs around Batu Blah Hill was defective. A. umbrosus was to be found in many drains and in wells around the hill. Consequently, malaria was prevalent. Two European houses and several of the better classes of native houses, built here from the spread of the town, were abandoned on account of their unhealthiness.

In 1914, I represented this to Government; in 1916, about $3000 were spent on an open drainage system. The spleen rate of Batu Blah Malay School has steadily fallen since (see Table 16.2). In 1919, two of the three children with enlarged spleens were old residents; the third lived 11/2 miles away.

The abandoned houses have been reoccupied. There is now no complaint from the natives; at first they said they could not get sufficient water; their wells were dried up or closed, and they had to go some distance to the pipe supply. Now they are reconciled, as the improved drainage has given them larger crops—mainly of rubber.

The removal of the lines was commenced in July 1913 and was completed by February 1914. The effect of this and the other measures is shown in the fall of the spleen rate (Table 16.4).

In 1920 there were three children with enlarged spleens; two of those were a brother and sister locally recruited three months before; the other was a child many years on the estate, whose spleen was just palpable. The true spleen rate is, therefore, under 1% and is in keeping with the low death rate (see Table 16.5).

In December 1914 in a report I made this remark:

But marked as this improvement is, an analysis of the figures gives curious and interesting independent evidence of the improvement which is taking place. In 1909-10, in the lines situated on the Government Road, and subsequently abandoned, 21 out of the 22 children had enlarged spleen; the spleen rate of the children who had been over six months on the estate was 81%; and out of the total 153 children on this division there were only 4 infants.

Now I find that among the 57 children who have been longest on the new site (since July 1913) only 8 or 14% have enlarged spleen, not a single one (except 1 in hospital) is ill, and there are 9 fat, healthy infants. On the other hand, of 21 children removed to the new site in February 1914 still 9 or 42% have enlarged spleen; but even here only 1 is ill, and there are 3 healthy infants.

This note is interesting, as giving a glimpse of spleen rates during a transition stage from high to low.

Figure 16.3: Plan of Midlands Estate. Abandoned sites are outlined and marked with “A”.

Figure 16.4: Chart of percentage of admissions for malaria, Midlands Estate. Shown are the monthly rates of admission to hospital for malaria, as fraction of the workforce, for 1913, 1916, and 1919.

The same policy was advised for the North Division of the estate. On 3^rd August 1910 I wrote to the manager:

Sites in proximity to the hills which pretty much follow the cart road, as shown on the plan, are to be regarded as unhealthy. It is, therefore, desirable to put the lines and bungalow as far as possible from them. I, therefore, advise that the new buildings be put close to the pipe line. This will put them close to jungle, which is also unhealthy, but it might be possible to make the clearings in the near future along the pipe line, thereby improving the health of the new buildings.

The buildings were put on the road close to the hills, and proved unhealthy. Between January and October 1914 some ravines were pipe-drained and others oiled, which improved the health. In 1915, 1917, and 1918 various blocks of the flat land beyond the pipe line were opened up, pushing the jungle some 40 chains from the pipe line, and making it possible to remove the labour force to the site suggested in 1910; and the whole labour force was removed early in 1918, with satisfactory results, as the figures will show. Not until 1919 was the jungle taken a full half-mile from the lines.

The plan (Figure 16.3), showing the abandoned sites, gives a better idea of the policy adopted than anything I can write; so I refer the reader to the study of it.

The drainage and oiling were not in force until towards the end of 1914, and so at that date the spleen rate was still high. The labour force was not removed from the hills until March and April of 1918. Hence the spleen rate of this division fell at a later period than on the South Division (see Table 16.4).

In 1920 there were two children with enlarged spleen; one, born on the estate, had a spleen barely palpable; the other, a local recruit, had been about three months on the estate.

With the falling spleen rates the death rates came down, as Table 16.5 shows. In the years 1909 and 1910 large numbers of Telegu coolies were recruited. It was not until the end of 1911, when Mr. Harrison became manager, that special measures against A. maculatus were commenced. In the first four months of 1920 only one death has occurred; it was from epilepsy.

The approximate cost of oiling each area of a half-mile radius is $400 per month.34

This estate is a brilliant example of how intense malaria can be overcome by removal of buildings to the best sites, coupled with subsoil drainage and oiling to breeding places within the new sanitary area. Quinine is not given to any except the sick.

This work has been carried out entirely by the manager, Mr. C. R. Harrison, and reflects the highest credit on him.

This division is situated on the river. To improve the health, quinine was given with the greatest care by Mr. H. F. Browell from 1904. In 1910 about six acres of secondary jungle and undergrowth was removed. In 1912 and 1913, 150 acres of land belonging to another estate on the opposite side of the river was opened. Some jungle still remains within 40 chains. The figures in Table 16.6 show the result.

On my recommendation, in 1910, jungle to the extent of 108 acres of flat land was opened. Later on, still more flat jungle belonging to an adjoining estate was opened, and hill-land ravines extensively oiled.

The lines were situated on a low spur of the hills, with streams breeding A. maculatus on each side. In 1910, I recommended that the lines be removed to a site on the flat, then under swampy jungle. Part of this jungle belonged to another owner, but it was acquired by the estate, and the whole block comprising 87 acres was drained and planted. Division “C” was removed to it, and on it was built the estate hospital.

In 1920, one of the two children with enlarged spleen was a local recruit from an unhealthy locality. The true spleen rate was 3-5%.

Formerly an intensely malarious spot. Two streams breeding A. maculatus were on the sides; in front was a mass of swampy, flat-land jungle. This is the estate to which I refer in Chapter 11 on the effects of malaria in children:

Among the children malaria is no less severe. On one occasion I was asked by a manager to advise him what should be done for the children, as fifteen had died in the previous two months out of a total of thirty-three. He told me a native clerk was giving them quinine daily. I examined the blood of the remaining eighteen, and easily found parasites in seventeen.

The manager then gave personal attention to the quinine administration of the children, and there were only two deaths in the next three months, these being children who were seriously ill before he took it in hand. The effect of this terrible death rate on the coolies was such, that even although they were living in good lines built less than three months before, and on land opened for ten years, they declared the lines were haunted. The lines had to be pulled down and rebuilt elsewhere.

The new site was on the river about 300 yards from the old one. The health improved when the flat land across the river was planted, and a ravine, part of which is probably not so suitable as it was for A. maculatus, on account of shade, was oiled for a time. (See Section 25.6 on the mosquitoes of ravines.)

The lines are situated on the end of a spur of the hills, on one side of which is a ravine, while in front is flat land. The most important ravine has been oiled intermittently since 1914, and regularly since 1918. The ravines farther off are under the shade of heavy rubber and small undergrowth, and so are less suitable for A. maculatus than they were previously.

In 1905, when quinine was being given with great care, the parasite rate of seventeen children was 23.5%. In 1906, parasites were found in twenty-five out of twenty-six children; the single child without parasites had suffered from “fever” four days before, and was on quinine; its spleen was enlarged.

In 1920, of the two children with enlarged spleen, one was a local recruit only six weeks on the estate; the other child was born on the estate. All the children looked well.

Figure 16.5: Chart of death rates of Damansara Estate

With spleen rates so high, one would expect to find high death rates, if many new coolies were employed; and this was so. The estate originally was not uniformly malarious, as will have been noticed from the spleen rates; but the two divisions last mentioned had at one time an appalling mortality not only among the children but among the adults. For example, in 1906, on Division “E” there were 116 coolies on the 1^st January; 170 were recruited from India. Of the 286, 26 deserted, and 60 died; the death rate, worked out on the quarterly labour force, was 300‰.

In 1907 the death rate of the 275 coolies on “E” Division was 178‰; of 275 coolies on “D” Division it was 200‰; and of 700 on Divisions “A” and “B” it was 138‰. These are examples of what malaria can do; and they occurred despite the most careful administration of quinine. On Division “E” the names of the occupants of each room were put on a special check roll, and each person was accounted for and given quinine daily, with extra doses of quinine solution when ill. Euquinine was given to the children.

The European staff suffered no less than the Asiatic, and the manager had to be invalided in 1907. Yet this intense malaria has been slowly overcome, and health has steadily improved since 1910, when radical methods were adopted on Divisions “A” and “B,” namely, the opening of swampy jungle and removal of coolie lines. Later, oiling, more or less efficiently carried out on the other Divisions, the opening of some jungle, and probably the heavy and close shade of rubber trees and ferns now growing in some of the ravines, have contributed to reduce the number of stream-breeding mosquitoes.

The death rates (Table 16.7; Figure 16.5) show the nature of the change. Still further improvement may be anticipated with confidence.

There being practically no native child population, no spleen rate could be obtained. The death rate was also valueless. When ill, many of the Chinese left for Singapore, where indeed a number died in the hospitals; eight are reported to have died in Singapore hospital in January 1912; but many Chinese refuse European treatment, go to friends, and die unknown to the manager of the place they come from. The hospital statistics showed that in 1911 there had been 811 admissions, of which 72% were for malaria; from 1^st January to 20^th July 1912, there had been 389 admissions, malaria being 61% of them.

The Europeans were suffering no less than the Asiatics, and a number had resigned. Of a total of thirteen former residents, I was informed that eleven had suffered from malaria. At the time of my visit, fourteen of the twenty-two had had malaria; some of the others had been only a short time on the island. There had been five cases of blackwater fever, three of which had been fatal.

The cause of the malaria was A. maculatus, which I found breeding in large numbers in every stream and spring on the hillside except two. The more the hillside was cleared of vegetation to stop the malaria, the more extensive became the mosquitoes’ breeding area; and the measures taken to reduce malaria were really causing its increase. Accordingly, among my recommendations, I said: “With regard to the clearing of the jungle, I do not recommend this area be extended. Rather I would advise that all mosquito breeding places in the already cleared area be abolished.”

I also advised that the best way “to eradicate these mosquitoes is to put all the water on the hillside underground.” The hillside was a mass of granite boulders, some of large size, and others small; and most of it was very steep. In the steepest portions of the streams, I noticed the water was already finding its way underground among the boulders (cf. Figure 16.8), and that the water only appeared where the grade was less steep. Therefore I advised that this natural subsoil drainage be assisted; subsoil pipes being laid down where the water could not be drained in the natural channels. As a warning: “In work of this kind, where everything tiny, spring or trickle of water oozing from the hillside is a danger, the first essential is thoroughness. It is also important to remember that new springs may appear in wet weather, if the whole be done in a dry period.”

Figure 16.9: Subsoil drainages used at Malarco, Karimon Island. A: A subsoil drain. The storm course is divided wherever possible. B: A subsoil channel.

The same energy and thoroughness with which Mr. Galbraith had developed the factory, and created a model village, was brought to the anti-mosquito work. Writing on 19^th December 1912, Mr. Galbraith said:

I had hoped to advise you before Christmas that we had sunk all the streams, but the weather has been so wet that we have been forced to suspend work until January. There are nineteen streams altogether to sink, besides a lot of little streamlets coming out of the foot of the hills along the seashore, and a dozen small outlets in the cutting behind the factory. We have cleared and exposed all the streams from end to end where they run on the surface, and have, so far, buried twelve, leaving seven large streams to finish. We have also done most of the work in the cuttings and cleared the seashore springs, and towards the end of January I hope to advise you we have finished.

The buried streams are holding fairly well notwithstanding the heavy rains (twice as much has fallen as in Singapore), and so far I don’t think we have had to repair 500 feet out of about 11,000 buried.

On 31^st December he added:

I may say that at first some of our pipes were displaced, but this was partly due to insufficient depth and the incidence of heavy rain immediately after placing them, and they were almost perpendicular. We have since used a light mixture of sand and cement to cap all streams whether in pipes or only under rocks (as per sketch on next page), and any recent trouble we have had is due to silt blocking the stream and the water then bursting out; but this in turn was due to the storm water finding an entry higher up, and in time we expect to get over such accidents entirely.

I cannot say the improving health is yet due to the burying of streams—indeed, I do not think it is to any great extent—the number still open in our more or less restricted area is too large to stop breeding yet awhile. By March, however, I hope to show you the hills as dry as bones two days after the heaviest rain.

On 15^th March 1913 I visited the island, and found the hills as dry as had been predicted, and the health greatly improved. Doubtless the heavy rains had helped to scour out the Anopheles, for they breed most freely in dry weather.

The work had been done splendidly; the photos (Figure 16.8) show how steep the hillside is, and the difficulties that must have been overcome to make the drainage an engineering and anti-mosquito success. The experiment was promising. While there had been difficulties, owing to the steepness of the hillside, and the complete unfamiliarity with anti-malaria work of those who were responsible for its execution, all the difficulties had been successfully overcome by the splendid energies and intelligent appreciation of the essentials brought to the work by Mr. Galbraith, Mr. Grant, Mr. Day, and others of the staff; and all A. maculatus breeding places had been destroyed. There was in its favour that no danger came from the seaside of the settlement; the jungle-clad hinterland beyond the clearing was steep hill land and probably harmless—for no A. umbrosus was taken at my visits. In other words, no dangerous Anopheles now existed; or, if present, were so only in small numbers.

So I was hopeful of a great improvement in health by the end of 1913. But on my return to the East I found that the heavy fall in the price of rubber had practically closed down this jelutong factory, and only some 200 coolies were left. Soon afterwards I heard the factory had been sold, and the place abandoned. Caution must therefore be exercised in accepting an incomplete record; it never was to be completed. Yet for what they are worth, I give the total admissions and total out patients (Table 16.8); they eliminate errors of diagnosis, and any anti-malaria success should lead to a reduction of sickness from all causes. They are the last figures I received.

On the day of my visit in 1913 there was only one case of malaria in the hospital out of the whole labour force.

I think the story worth telling, both for the sake of the splendid fight against malaria, and for the guidance it may be to others in similar circumstances. On my last visit one member of the staff, in commenting on the difference in health between the time of speaking and a year before, said: “If ever again I have to do a job in a place like this, I will begin by killing the mosquitoes. The rest of the work will then be quite simple.”