martes, 1 de septiembre de 2009

Program to Eradicate Malaria in Sardinia | CDC EID



Volume 15, Number 9–September 2009
Historical Review
Program to Eradicate Malaria in Sardinia, 1946–1950
Eugenia Tognotti
Author affiliation: University of Sassari, Sardinia, Italy


Suggested citation for this article

Abstract
During 1946–1950, the Rockefeller Foundation conducted a large-scale experiment in Sardinia to test the feasibility of indigenous vector species eradication. The interruption of malaria transmission did not require vector eradication, but with a goal of developing a new strategy to fight malaria, the choice was made to wage a rapid attack with a powerful new chemical. Costing millions of dollars, 267 metric tons of DDT were spread over the island. Although malaria was eliminated, the main objective, complete eradication of the vector, was not achieved. Despite its being considered almost eradicated in the mid-1940s, malaria 60 years later is still a major public health problem throughout the world, and its eradication is back on the global health agenda.

In 1944, Sardinia was used as a test site for eradicating native malaria-carrying mosquitoes (1). During that year, the insecticide DDT (dichloro-diphenyl-trichloroethane) was sprayed inside houses to annihilate mosquitoes in Castel Volturno (2). During that spring, another trial was conducted in the Tiber Delta and Pontine marshes, where breeding sites of Anopheles labranchiae, the most common, abundant, and widely distributed vector in the Mediterranean basin, had increased dramatically after German troops strategically flooded a large area to hinder the movement of the Allied Armed Forces (3). In the face of a potential malaria outbreak, the Allied Malaria Control Commission studied the effect of the DDT spray, in the absence of other control measures, on anopheline density.

The operations in central Italy were under the direction of Paul F. Russell and Fred Soper, officers of the Rockefeller Foundation. Russell was a veteran of malaria-control campaigns and a graduate of the Harvard School of Public Health Soper was a public health administrator and epidemiologist who during 1939 and 1941 (4) had directed successful eradication campaigns of an invading vector, A. gambiae, in Brazil and Egypt. Attempting to eradicate the indigenous well-adapted mosquito species A. labranchiae was more difficult than attempting to eradicate an invading vector. Both believed that the miraculous effectiveness of DDT (5) opened up a dazzling new era for the study of malaria: DDT was highly effective against the parasite-carrying mosquitoes and interrupted the transmission of the malaria parasite. In addition DDT was inexpensive, considered safe, and easy to use.

In this climate of optimism, the Italian malariologist Alberto Missiroli convinced civil authorities in Italy to conduct a massive malaria control program. The United Nations Relief and Rehabilitation Administration (UNRRA) provided funds (6). The idea of large-scale eradication work in Sardinia took shape in a series of meetings involving Missiroli, the director of UNRRA for Italy, and Soper, who was a staunch advocate of the vector-eradication approach to malaria control.

In a July 1945 letter from Italy (7), Soper informed George H. Strode, scientific director of the International Health Division (IHD), that Missiroli was "very insistent that the first work" begin in Sardinia. He also reported on meetings with Colonel Reekie of the UNRRA. They had undertaken a rapid reconnaissance flight over Sardinia, and in conclusion Soper stated:

…from available information and what little I had seen it appeared that anopheles eradication in Sardinia might be entirely feasible if the materials, transportation, money, and authority could be made available.

Last-minute decisions left little time for planning. In their haste, the Rockefeller Foundation staff underestimated the difficulties of the project. In addition, the rush to conclude the agreement with government representatives in Italy and with the High Commissioner for Sardinia led to a lack of clarity about the goal of the campaign (8). The aims of the IHD were entirely scientific, as was clearly explained in a letter from Strode to the UNRRA director in 1946: "The only reason that I was interested in the proposal was the fact that we were to attempt an eradication program among the indigenous species of anophelene" (9).

However, the public health authorities in Italy were interested in implementing a full-scale public health program and were willing to invest heavily in this endeavor and use their recovery funds. They were unlikely to have devoted so much interest to support a purely scientific experiment.

This ambiguity dragged on for 2 years. Ultimately, the project became a public health campaign against malaria. A change in the goal enabled the Regional Agency for the Anti-Anopheles Struggle in Sardinia (ERLAAS) team to convince the increasingly reluctant High Commissioners for Hygiene and Health to divert funds from the scant health budget toward the campaign. The story of the "Sardinian Project" (Technical Appendix, note 1 [ 91 KB, 3 pages]), the greatest antimalaria effort in Europe since the discovery of the cycle of transmission of the disease, needs to be reexamined in the light of the recent debate about the new global malaria eradication strategy (10). This article, based on firsthand sources such as letters, memoranda, and diaries (8), concentrates on the objectives, errors, results, and final implications of the campaign.

Sardinia, a Malaria-Endemic Island
Malaria is believed to have been introduced to Sardinia by infected workers imported from North Africa after the Carthaginian conquest of Sardinia in 502 bc. The disease became endemic to this region during the medieval period (11), but since the classical ages, Sardinia had been tarred with the reputation as an "unhealthy island" (12) (Technical Appendix, note 2 [ 91 KB, 3 pages]). In the last decade of the nineteenth century, the average number of deaths caused by malaria on this island oscillated between 2,000 and 2,200 per year (in 1901, the island had a population of 795,793) (13). Sardinia kept the unfortunate primacy of being the most malaria-ridden region in Italy (Table 1) because of the high prevalence of Plasmodium falciparum and its associated high mortality rates. Rates were particularly high for children <5 years of age in highly malaria-endemic areas.

Economic and demographic development (14) was dramatically inhibited. Malaria infested the plains, which constituted the most fertile and least populated areas. The productivity of those affected with chronic disease was low, and they were unable to work during fever attacks (15). A decline in the mortality rate began after advanced antimalarial legislation (1900–1907) provided free quinine, which attacks malaria parasites in the bloodstream. In the 1920s and 1930s, the fascist regime carried out an indirect battle for eradication through its great land reclamation project, which used modern technology on a large scale for drainage and sanitation (16). The centralized "Italian way" produced a decline in malaria mortality rates, but rates also declined as a result of greater access to medical services by the rural population, the main reservoir of malaria in the past. Over 40 years, mortality rates declined from an average of 2,000 during 1890–1900 to 138 in 1939 and 88 in 1940. The decline in illness and death from malaria was interrupted only by the 2 world wars: in 1946, 74,600 malaria cases and 169 deaths were reported (17).

At that time, malaria was still endemic to Sardinia. In 1947, an ERLAAS survey showed an overall spleen index (a measure of splenomegaly) of ≈21%; in many low-lying places, the index approached 100% (18). The effect of malaria on public health and economic growth was still severe; according to contemporary analyses, the vicious circle of poverty and disease could be broken only by eliminating malaria. Sardinia, therefore, appeared to be the ideal site. It was an island. In addition, the weakness of local power represented an additional advantage for a project that verged on being a military occupation of the territory.

However, there were enormous organizational and logistical problems. One was the sheer size of the island: 9,294 square miles, with mountainous massifs and ravines. Another was the fast-flowing streams that carried water into low-lying areas in the springtime, forming stagnant pools (19). The island was virtually devoid of internal communication systems, and the inhabitants lived almost exclusively in villages. Few local people had technical expertise, and it was not easy to recruit and train people as disinfectors, larva scouts, and sprayers or to find suitable staff to perform supply, transport, and administrative services. However, these obstacles did not hinder the IHD decision to implement the program. They feared that the ongoing crisis in UNRRA and the unstable political balance in Italy might ultimately impede their efforts.

On October 2, 1945, the Rockefeller Foundation formally agreed to collaborate in the project. A few weeks later, UNRRA allocated an initial sum of US $400,000 and approved the plan, in agreement with the Italian government and the Rockefeller Foundation. In April 1946, the IHD founded the special agency ERLAAS to implement the program. The first director was John Austin Kerr, and the medical entomologist was Thomas Aitken. The island was divided into divisions, sections, and sectors of 2.8 square miles, the basic geographic unit for antilarval spraying. The entomologic service headquarters were set up in Cagliari, and the chief executive officers operated from there. Workers on the ground were responsible for day-to-day operations in their specific localities and were crucial to the entire operation. The organization followed military principles of hierarchy and discipline. Scouts for larvae and pupae were given rewards for good work and penalized for sloppy performance.

Suggested Citation for this Article
Tognotti E. Program to eradicate malaria in Sardinia, 1946–1950. Emerg Infect Dis [serial on the Internet]. 2009 Sep [date cited]. Available from http://www.cdc.gov/EID/content/15/9/1460.htm

DOI: 10.3201/eid1509.081317

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