Taiwan Today

Taiwan is the first Asian area to be pronounced completely free of malaria, for centuries one of mankind's worst killers. This means a longer and healthier life for the 12½ million people of the island and a stronger free Chinese bastion for mainland recovery and national reconstruction.

The triumph did not come easily. It is the culmination of efforts begun shortly after World War II ended 20 years ago. The erad­ication campaign cost the Chinese government nearly US$4 million and involved about 20,000 workers. It included these stages:

1. Preparatory phase, from November of 1946 to April, 1952;

2. Attack phase of May, 1952, to June, 1958; and

3. Consolidation phase that lasted from July of 1958 to the end of 1964.

Ahead lies the mighty task of keeping Taiwan perpetually free from malaria. With the highly developed transportation systems of the world today, malaria-carrying people and mosquitoes may reach Taiwan at any time. Thus the maintenance phase of the eradication program is essential.

The announcement that Taiwan had wiped out malaria was made December 2 by Chang Chih-kang, director of health of the Chinese Ministry of Interior. On Decem­ber 4 the United Nations World Health Or­ganization presented the Chinese government with a certificate to that effect. It was signed by Director-General M.G. Candau on the recommendation of a WHO evaluation team that had visited Taiwan earlier in 1964 and found:

— No new malaria infection since No­vember of 1922, and

— Annihilation of malaria-carrying anopheles mosquitoes by June, 1964.

In Taipei to present the certificate were Dr. I. C. Fang, WHO's Western Pacific re­gional director, and Milton P. Siegel, assis­tant general director of the WHO headquarters in Geneva. Dr. T.L. Fazzi, WHO's area representative, also was present.

Chinese officials and health personnel cited for their contributions included 12 from the National and 64 from the Provincial Government.

The ceremony at Nankang in suburban Taipei also marked the completion there of a US$700,000 health building housing the Bureau of Medicine of the Provincial Health Administration. Specialists in the suppression of malaria and other diseases will work in the four-story building for a healthier Taiwan.

Ancient Killer

Malaria, characterized by periodic re­currence of chills and fever, is caused by blood parasites of the genus Plasmodium transmitted by anopheline mosquitoes. A malaria parasite in a human red blood cell grows and divides into 6 to 20 daughter parasites that eventually destroy the cell and in­vade as many new cells to repeat the cycle. Continuous rupture of red blood cells leads to a severe anemia. Residue of ruptured red cells and excretions of parasites are carried by the blood stream to the spleen and cause its enlargement. Death may follow extreme emaciation.

Malaria continues to be prevalent in tropical and subtropical areas where hot and humid climates are favorable to the breeding of anopheline mosquitoes and the develop­ment of malaria parasites in their bodies. In 1950, for instance, malaria afflicted 500 mil­lion people throughout the world—more than a fifth of the 2.4 billion population at the time. The 1950 deaths from malaria to­taled 5 million, one out of every 100 infected persons.

Malaria has been a dehabilitating disease in Taiwan for centuries. It ranked first as the island's most lethal disease from 1906 to 1916. Annual death rates fluctuated be­tween 20 and 39 per 10,000 people. From 1917 to 1929, death rates from malaria drop­ped from 28 to 10 per 10,000. Malaria was almost stable from 1930 to 1941, with death rates at 6 to 8 per 10,000 persons. The pop­ulation in the meantime increased from 4.3 to 5.7 million.

The Japanese made their first Taiwan attempt at malaria control in 1910. It was an experimental project at Peitou near Taipei. The program was expanded year after year with establishment of anti-malaria stations in other highly endemic areas. Each station had from one to eight technicians plus sup­plies and materials for blood examinations and for treatment. Drugs used were quinine, totaquine, and plasmoquine. Under control in 1942 were 185 localities, each with about 1,500 people in one or more villages.

During the 30 years of drug treatment by the Japanese, annual malaria deaths drop­ped from 13,000 among slightly more than 3 million people in 1915 to about 4,000 among 5.5 million in 1940. The infection rate was kept between 2 and 4 per cent but never dropped below 2 per cent.

Privation, dislocation, and destruction resulting from World War II broke down the system. Severe malaria epidemics spread unchecked from 1942 to 1945.

The war's end saw all 12 provincial hospitals virtually out of business. Many people who had been dispersed to mountain areas brought malaria back to cities and towns. In­cidence of the disease increased to 1.2 mil­lion cases in a population of 6.5 million in 1946. A survey at that time showed infection rates of 20 to 40 per cent among primary school children. Malaria then was in third place as a killing disease. (It dropped to ninth in 1949 and to tenth in 1952.)

Malaria was widespread in the rural areas. It was considered hyper-endemic (spleen rate over 50 per cent) in the foothills and low mountains, and hypo-endemic (spleen rate below 10 per cent) to meso-endemic (spleen rate 10-50 per cent) in the densely populated western plains.

Field Laboratory

Losses due to malaria are not easily as­sessed. A conservative estimate in a southern Taiwan epidemic area in 1953 put the per capita loss per annum for the total population concerned at well over US$10.

The Chinese government, taking over the island from the Japanese in 1945, feared any further spread of malaria might hamper social stability and economic growth. Offi­cials set about finding effective counter-meas­ures. The Rockefeller Foundation of the United States provided technical and financial assistance. Experts from the foundation and from the Chinese mainland came for on-the­-spot surveys.

In November of 1949, the Malaria Section of the National Institute of Health in Nanking established a field laboratory at Chao-chow near the southern tip of Taiwan. The Malaria Section, aided by the Rockefel­ler Foundation, then was headed by S.C. Hsu, now chief of the Rural Health Division of the Sino-American Joint Commission on Rural Reconstruction in Taipei. The Rockefeller Foundation earlier had set up a malaria research laboratory in Mang City in Yunan along the Burma Road.

The Taiwan laboratory was to conduct field experiments on malaria control and serve as a technical research institute. In 1949, the American foundation withdrew its support, but the authorities in Taiwan already had acquired the necessary incentive and en­couragement to continue the fight. The la­boratory in Chao-chow was reorganized as the Taiwan Provincial Malaria Research In­stitute (TAMRI), with the responsibility of planning and executing malaria control opera­tions throughout the island.

Assistance From WHO

In the following year (1950), JCRR as­sisted TAMRI to rehabilitate 144 of the malaria control stations the Japanese had established before the war. Refresher courses were given technicians who later played important roles in the island-wide control and eradication programs.

In October of the same year, WHO sign­ed an agreement with the Chinese govern­ment to give assistance. The original four­-year DDT spraying program, started in May of 1952, was supposed to remove malaria from the list of major public health problems. However, the initial control operations yielded such dramatic results that elimination of malaria appeared possible. Late in 1955 the authorities decided to shift the objective from control to eradication. Island-wide DDT spraying was extended for two more years and a surveillance program was begun.

While TAMRI was training health workers and specialists, the Provincial Health Administration increased the number of health bureaus and stations to 350. Spray personnel were chosen and trained in their home areas so as to save transportation and other expenses. For restricted military areas, servicemen were trained and assigned to the work. About 18,000 persons were engaged in the campaign at one time or another. TAMRI itself had 79 full-time employees when the campaign was at its height in June of 1957.

Sharp Decrease

A housing survey was carried out throughout Taiwan at the end of 1951. Included were assessment of house designs and construction, and measurement of inside surfaces. This helped determine the number of spray squads, allocation of squads, duration of field operations, types of sprayers, and their most efficient use under differing conditions.

In May of 1952, the Chishan district of Kaohsiung hsien in southern Taiwan with a population of 37,000 was made a study area for spraying. Residual house spraying of DDT once a year at a dosage of 2 grams per square meter completely changed the malaria picture there in as little as four years. Two rounds of DDT spraying virtually stopped transmis­sion. No new malaria infection in infants has been detected since November, 1953. Spleen rates of primary school children fell from 52.28 per cent in 1952 to 6.88 per cent in 1956. Parasite rates dropped from 23.04 per cent to 0.13 per cent. House-to-house surveys indicated a rapid reduction in fever incidence.

Island-wide DDT spraying was begun. Chishan and two other areas—Nantou in central Taiwan and Peitou near Taipei in the north—were used as indicator areas.

Great care was taken to insure maximum effect of the chemicals. Spray men were trained to spray at the fixed rate of 20 square meters per minute, keeping the nozzle tip 18 inches from surfaces. Spraying an area 2.3 meters long in five seconds with the nozzle at a distance of 18 inches from the surface provided such coverage.

A typical spray team of one foreman, four operators, and two helpers treated an area with a population of 7,000 within 60 working days. All aspects of their work were recorded for evaluation and improvement. The foreman checked the results. Government notices urged the people not wipe off DDT. The chemical remains effective on a sprayed surface for from 6 to 11 months.

The numbers of people affected by the spray program were:

— 156,217 in 1952

— 1,526,306 in 1953

— 5,467,664 in 1954

— 5,640,325 in 1955

— 6,728,465 in 1956

— 1,470,156 in 1957

— 206,922 in 1958

During the 1953-1957 general attack phase, more than 2,500 metric tons of DDT and BHC were used. All the DDT used in the initial stage was imported from the United States. In 1953, however, a local plant started producing WHO-standard DDT. The plant supplied one-third of the insecticide used in 1953, one-half in 1954, four-fifths in 1955, and the whole of the requirement in 1956 and since.

Repeated Sprayings

The attack phase cost about US$5,357,­000, of which 49 per cent was contributed by the United States, 44.5 per cent by the Chi­nese government, 3.5 per cent by WHO, and 3 per cent by JCRR.

By the end of 1951, the formerly hyper-endemic area (1.5 million population) had been sprayed five times, the meso-endemic areas (4 million population) three times, and the hypo-endemic region (1.2 million population) once. Pending the introduction of a sufficiently comprehensive surveillance sys­tem, DDT spraying was continued in some areas to prevent resurgence of transmission. Some places had been sprayed as many as 12 times up to 1960.

Attitudes Change

In 1953, when the first island-wide application of DDT was undertaken, the public welcomed the spray squads, but it was the dramatic disappearance of bugs, houseflies, fleas, and other domestic pests, rather than the reduction in malaria, that mainly secured enthusiastic support. When the efficiency of DDT against these pests began to wane, so did the popularity of the spraying campaign. Nearly 4 per cent of the population to be covered in 1955 refused to permit spraying. Their reasons included: DDT was ineffective against insect pests, the chemical killed cats, and stains on walls and furniture were ugly. Complaints about the inefficacy of spraying became less frequent as a result of the use of DDT-BHC mixtures in the following years. It was also fortunate that most of the refusals were in towns where malaria was no longer a serious problem.

Health personnel regularly visited rural families, schools, and public and private clinics to administer preventive and curative programs whenever isolated malaria cases were reported.

In early 1959, microscopic examinations totaled 808,037, but only 461 or 0.057 per cent were positive. By the end of 1964, posi­tive cases had dropped to 36 persons—only 0.003 per cent of the 1,036,871 blood smears examined. Most of the cases were imported ones or recurrences, not local infections.

Before the campaign entered its main­tenance phase in January of 1965, the Chi­nese government had spent NT$152,440,000 (US$3,811,000). Sizable sums also had come from WHO and other sources. The operation has been economical because of the following Taiwan conditions:

— Malaria-carrying mosquitoes were of domestic types, not of wild species, thus limiting DDT spraying to populated areas.

— The Taiwan mosquitoes did not de­velop anti-insecticide resistance.

— High humidity prevented DDT from evaporating too fast, thus retaining its effect for months.

— Isolation of Taiwan from other malarious areas made control and eradication work relatively easy.

Ceylon wiped out malaria a few years ago but it crept back. Taiwan seeks to avoid a repetition of this. Anyone who spots a malaria case and reports it to the authorities is eligible for a cash award.

Malaria eradication has never been con­sidered an end in itself. It is merely a step toward better general public health. Even as the government was concentrating on malaria eradication, it was planning for a full utilization of campaign facilities and manpower once the first battle was won. TAMRI has top staffing, equipment, and practical know­ledge. It will continue its good work for a healthier Taiwan at the new health building.

The Chinese say: "Ninety miles are half way for a traveler on a 100-mile journey." Public health workers who have gone all the way to conquer malaria are not neglecting the admonition.