• Kawalan Penyakit di Penjara Pudu (1895-1910)

Wabak malaria telah pun melanda beberapa daerah yang telah diterokai sejak beberapa tahun sebelum kurun ke-20, contohnya yang direkodkan di Klang seawal tahun 1901. State Surgeon Selangor ketika itu, (Sir) Dr. Malcom Watson (1873-1955), berjaya mengawal wabak ini dengan mengeringkan kawasan paya di situ. Pada tahun 1907, beliau bersara dan meneruskan kajiannya, dan menjadi penasihat kesihatan di ladang-ladang seluruh Selangor: “It all began at the turn of the 20th century, when the Selangor state surgeon Dr Malcolm Watson started work on malaria control following a serious epidemic that floored many Klang residents. With full government aid and a $30,000 Sanitary Board grant to drain waterlogged swamps, Watson initiated mitigating measures that were met with resounding success both in Klang and Port Swettenham. By 1907, Dr Watson resigned from government service and began devoting more time and study towards malaria. He collected invaluable data and gained new insights into the disease by serving as medical adviser to many rubber estates that were rapidly opening up all over Selangor.” (Alan Teh Leam Seng @ New Straits Times, June 16 2021: |"Malaya led the way in medical research").

1901-01: Dr. Watson memulakan tugas sebagai District Surgeon di Klang: “Assuming duty early in January, 1901, as Government Surgeon of the Districts of Klang, Kuala Selangor and Kuala Langat of the State of Selangor, one of the Federated Malay States, I found the hospital at Klang full of malaria.” (Dr. Malcolm Watson, 1911: |"The prevention of malaria in the Federated Malay States", m.s.14).

Satu-satunya usaha yang dianggap realistik ketika itu adalah mengambus kawasan paya dan kolam yang berdekatan, untuk mengurangkan kawasan pembiakan nyamuk: “At Klang the work of eradicating malaria seemed well nigh hopeless. No hot or cold season even temporarily stopped the mosquito pest, and every well, ditch and swamp teemed with larvae. The active co-operation of the native community could not be expected, and active resistance, especially from the Chinese, was certain if any attempt were made to enforce the use of quinine. An enforcement of mosquito nets was, of course, impossible since this would have meant constant house visitation at night. Compulsory screening of the whole of all the houses was impossible for financial reasons. The large acreage of swamp, the heavy rainfall and the amount of supervision required, apart altogether from its cost and temporary efficacy, prohibited the use of petroleum. … Considering all these elements of the problem, I rejected as impossible Koch's quinine method, and the Italian mechanical prophylaxis, and decided to recommend Ross's method of mosquito reduction. To suit the local conditions I determined that any expenditure should be on works of a permanent nature. By draining and filling there would be a large and permanent reduction of the breeding places of mosquitos, and presumably malaria would be correspondingly reduced.” (Dr. Malcolm Watson, 1911: |"The prevention of malaria in the Federated Malay States", m.s.14).

Peta Pekan Klang, tahun 1901.

Peta menunjukkan kawasan paya di tengah-tengah bandar Klang yang menjadi pusat pembiakan nyamuk: “The area of the town was in 1901 approximately 290 acres. Of this 22 acres was swamp, 25 acres virgin jungle, and 80 acres dense secondary growth in many places 30 to 40 feet high. The distribution of these undesirable portions will be seen from the map. The whole town was permeated with their influence, and it is hardly surprising that malaria was a scourge. … As will be seen from the map the town is situated within, upon and around a somewhat semi-circular group of small hills. At the foot of the hills, especially where they bend to form small valleys, the ground water was so high as to form permanent swamp. In the absence of a town water supply, wells innumerable were found mostly teeming with Anopheline larvae.” (Dr. Malcolm Watson, 1911: |"The prevention of malaria in the Federated Malay States", m.s.12-14, 17).

1901-05: Pada Mei 1901, Dr. Watson membentangkan cadangan pengambusan paya dan perparitan kepada Lembaga Kebersihan / Sanitary Board Klang, dan diluluskan atas sokongan pengarahnya, Mr. H.B. Ellerton. Ianya dibentangkan kepada State Surgeon Selangor Dr. E.A.O.Travers pada Julai 1901, dan menerima sokongan penuh beliau serta pihak kerajaan. Pada bulan-bulan selepasnya, wabak Malaria meningkat mendadak di kalangan penduduk Klang. Penguatkuasaan undang-undang tahun 1890, yang mewajibkan setiap pemilik tanah mengambus atau mengalirkan paya dan air bertakung, dipertingkatkan. (Dr. Malcolm Watson, 1911: |"The prevention of malaria in the Federated Malay States", m.s.20-23).

1903-1904: Pada Disember 1903 dan Januari 1904 (1-2 tahun setelah projek pengambusan paya), Dr. G.F.Leicester masih merekodkan kehadiran nyamuk spesis Anopheline (tiruk, pembawa malaria) di pelbagai tempat takungan air (semulajadi atau pun tidak) di Klang. Hal ini berlarutan sehingga Mr. E.V. Carey mencadangkan perparitan di lereng bukit, sebagaimana yang diamalkan di ladang-ladang: “In December, 1903, and January, 1904, Dr. G.F. Leicester investigated the Anophelines of Klang and reported as follows in his 'Culicidae of Malaya'… The work was not, however, finished all at once and even in 1904 some small swamps were still in existence. It was not until Mr. E.V. Carey pointed out that the only way of draining the swamps effectively was by contour drains at the foot of the hills, the method universally employed by planters, that these were really dry.” (Dr. Malcolm Watson, 1911: |"The prevention of malaria in the Federated Malay States", m.s.17, 23).