[Reprinted from MOSQUITO NEWS, Vol. 26, No. 4, December, x966] PARIS GREEN IN THE ERADICATION OF ANOPHELES GAMBZAE: BRAZIL, IHO; EGYPT, 1945' FRED L. SOPER, M.D., DR.P.H. INTRODUCTION. In March 1930, Anoph- `YS gambirze, probably the world's most J ient vector of malaria, was found at tal, Brazil, (Shannon, 1930). Its ar- rival was associated with the development of rapid communications with Europe by way of Dakar. Although the breeding of gambiae when discovered was less than I sq. km. in extent, a serious outbreak of malaria occurred in the following month. The severity of this outbreak was such that the Health Department had to dis- tribute "food as well as quinine." Twelve years later, in March 1942, severe outbreaks of malaria in Upper Egypt signaled the invasion of Egypt by gambiae coming from the Sudan. This invasion was associated with greatly in- 1 Presented at Seminar on Mosquito-Borne Dis- eases-past, Present, and Future, Communicable Disease Center, Atlanta, Georgia, March IO, 1966. creased traffic into Egypt from the south, due to wartime difficulties of shipping in the Mediterranean. In the fall of 1942 gambiae-transmitted malaria struck as far north as Asyut, some 320 kms. from Cairo. Gambiae was eradicated in Brazil in rg4o (Soper and Wilson, rg43), after a sojourn of IO~/~ years in the country; in Egypt eradication came in 1945, (Shousha, rg47/48), three years after the invasion occurred. The basic method used in each country was a straightforward chemical attack with paris green. Victory in each country came only after unnecessary and costly delays. These delays can be at- tributed to lack of vision, lack of courage, lack of salesmanship, and lack of adminis- trative experience. Through a series of coincidences I par- ticipated in the delays in eradicating, and in the eradication of, gambiue in both Brazii and Egypt. i DECEMBER, 1966 MOSQUITO NEWS 477 LOCAL ERADICATION AT NATAL, 1931- 32. I returned to Brazil on March 20, 1930 to become the Director of the Coop- erative Yellow Fever Service maintained by the Government and the Rockefeller Foundation; gambiae was found at Natal three days later. On April 28 I visited 40 houses at Natal, seeing one or more persons ill in prac- tically every home; some entire families were sick, with none able to procure and prepare food. This was malaria in a new dimension, a dimension which required "food as well as quinine." Gambiae is not just another vector of malaria, but one which transforms malaria into a great epidemic scourge, ranking as a killer with cholera, plague, smallpox, typhus, and yellow fever. The severity of the initial gambiae-malaria outbreak in Natal and the small size of the breeding area of the new invader inevitably stimulated discus- sion of and hope for species eradication. With a sense of responsibility engen- dered by knowledge of the situation, I discussed the eradication of gambiae with the State Director of Health, with the Governor of Rio Grande do Norte, with the Director of the National Department of Health, and with my chief, the Director of the International Health Division of the Rockefeller Foundation. Action by the State Director of Health depended on the decision of the Governor, who was unwill- ing to authorize flooding the tidal flat where gambiae were breeding by opening the dike to let in salt water. The Director of the National Department of Health recognized the eventual threat of gambiae to other states, but the Federal Govern- ment declined to put pressure on the state government in a presidential election year. My chief in New York suggested I was fully occupied with the reorganization of the Yellow Fever Service and had better leave the gambiae problem to the Bra- zilians. Malaria in Natal died down during the dry season of 1930, but with the onset of the rains in January 1931 an even more severe outbreak occurred. This was ex- pected since a December survey showed gambiae had spread to the limits of ' initial breeding area, a total of some sq. kms. The presidential election was followed by successful revolution with interruption of the normal relationship existing be- tween the states and the Federal Govern- ment. The appeal for aid from Rio Grande do Norte to meet the epidemic of 1931 found the new Federal Government unprepared; the National Director of Health requested the Yellow Fever Service to assume responsibility for the gambiae problem in Brazil. Considering the needs of the Yellow Fever Service and the nega- tive attitude of the Foundation, I refused to consider this proposal. On further insistence of the Director, however, I agreed to an emergency malaria preven- tion program in Natal for a six-month period; this would enable the Government to prepare its own anti-gambiue program. The Yellow Fever Service actually began the application of paris green to the in- fested area early in March 1931, just a year after it had been found. In accord with current practice, paris green was mixed I to 2 percent with a suitable diluent before delivery to the field for application. Malaria receded and the number of gambiae to be found in tl- houses declined rapidly; only II WI found in 8,393 houses searched in ~ weeks between July and the middle of October. The Government met its obligation by appointing a malariologist as Director of the State Health Service with a special Federal budget to be devoted to malaria in Rio Grande do Norte. The State Ser- vice assumed the responsibility for the paris green program on October 14, 1931; the application of paris green was only until mid-April 1932 when the special budget was spent. The 1931-32 attack on gambiae with paris green resulted in its complete dis- appearance from Natal; it has not since been found breeding there. Gambiae ESCAPES TO THE INTERIOR, 1931. In the meantime, in June 1931, a sharp outbreak of malaria at SPo Bento, 180 MOSQUITO NEWS VOL. `3, No. 4 -ms. from Natal, had shown that gambiae was no longer limited to its original point of entry. In the following months a dozen places between Natal and SCo'Bento were found infested. Although the in- vaded area was not highly favorable for gambiae, my July diary shows that the extension of gambiae so far to the interior had convinced me that eradication was no longer possible. In retrospect this negative attitude was most important; it may well have been responsible for the failure to realize that the scarcity of gambiae in Natal after July was a prelude to its eradication there. It may well have been responsible for the failure, once gambiae had been eradicated at Natal, to organize a drive to clear it from the in- terior of the State. The elimination of gambiae at Natal and the effects of the severe drought of 19p-33 on gambiae in the interior quieted the public demand for relief from malaria; everyone relaxed, if fearfully, since gam- biae continued to appear among mosquito collections made in the interior by the Yellow Fever Service. Thus five years passed before gambiae moved into more -k avorable areas. ,NVASION OF CEARA, 1937. In `937 nbiae moved to better-watered areas in 20 Grande do Norte and passed over the frontier into the State of Ceari; the re- sultant outbreaks of malaria were not immediately sufficient to cause a reaction on the national scene. The picture changed rapidly during the rainy season of 1938, when newspaper accounts appeared of large State expenditures on relief meas- ures because of malaria in the Jaguaribe River Valley. (Again the theme of epi- demic malaria requiring "food and qui- nine.") The 1938 epidemic in Cear6 was es- pecially devastating; infection rates were IOO percent in some areas with high mor- tality and complete economic paralysis. In August the Federal Government created a special Malaria Service with an emer- gency budget. When the chief of this Service reached the field, it was obvious that the funds allotted were grossly in- adequate; that"the epi&nic situation and the continuing expansion of the gambia- infested area COL$ ,,b;. my\.L only by an experienced adml_nlstrative service. The suggestion w&.mad& again in 1938, as it had been in 1931, that the Yellow Fkver Service shouk! take ,the responsibility for the gambiae protilem. THE GOVERNMENT OF BRAZIL AND THE ROCKEFELLER FOUNDATION JOIN FORCES AGAINST gambiae, 1939. The situation in 1938 was quite `different from that of 1931. Although gambiae now occupied a triangular area almost 500 kms. on the side instead of a few square kilometers, the forces which could be brought against it were far superior both administratively and psychologically. In 1931 the Yellow Fever Service was preoccupied with Aedes aegypti-trans- mitted yellow fever still to be found in towns and villages in the north and in the south of Brazil; the memory was still fresh of the failure to eradicate yellow fever as planned and of the reinfection of Rio in 1928-29; still fresh in mind was the rg27-zg failure to eradicate Aedes aegypti in a single town after an intensive attempt to do so. Ill 1931 the Y&OW Fever Service, which had been limited to a number of the larger cities of the north, had just assumed the responsibility for yellow fever throughout Brazil, except in Rio. The Yellow Fever Service was still operating under varied state regulations. In 1931 many still believed that there was no reason to be perturbed over the intro- duction of another vector of malaria since Brazil already had its fair quota; it was also widely held that gambiae would not be able to establish itself in Brazil since there was no known instance of an Anoph- eles of one fauna1 region invading an- other. By 1938 Aedes aegypti-transmitted yel- low fever had disappeared; the Yellow Fever Service was operating throughout Brazil with the full confidence of the Brazilian Government, under a special national yellow fever regulation establish- ing adequate authority for anti-mosquito measures. Even more important was the DECEMBER, 1966 MOSQUITO NEWS 473 psychological change which had come with the progressive eradication of aegypti beginning in 1932-33. First proven in a number of large port cities, the eradica- tion of aegypti had been extended in the following years to the suburbs of these cities and to infested towns, villages, and even rural areas. The experience in de- veloping the administrative program for the eradication of aegypti had given the Yellow Fever Service a knowledge of me- ticulous administration and a confidence in its own capacity to apply this knowl- edge to other programs. Important psy- chologically also in 1938 was the knowl- edge that gambiae had definitely become established in Brazil, had reached favor- able areas where progressive expansion of its range was imminent, and constituted a serious threat to the health and economic development of the tropics and subtropics of South, Middle, and North America. In 1938 the Yellow Fever Service was far better equipped to meet the gambiue emergency than it was in 1931; further- more, it was the only administrative agency able to undertake the eradication of gam- biae. So, under the pressure of circum- stances, without knowing exactly how the job could be done, the Rockefeller Foun- dation and the Ministry of Health of Brazil joined hands to combat Anopheles gambiae; the Malaria Service of the North East (MSNE) was created as a twin ser- vice through which the knowledge, skill, and discipline of the Yellow Fever Ser- vice, already experienced in the eradica- tion of Aedes aegypti, could be applied to the gambiae problem. ERADICATION OF gambiae, 1939-42. The administrative framework of the MSNE was created by the transfer of key per- sonnel and equipment directly from the Yel!ow Fever Service. During the early weeks, the classical methods of malaria prevention then in vogue were tested and proven ineffective. The efficacy of paris green larviciding had been demonstrated for a limited area at Natal, but there was no precedent for its use in area-wide species eradication. In planning for the anti-gumbiue work, thou- sands of large gunny sacks had been pu. chased for the transportation of paris` green-dust mixture, without determining the source of a proper dust or the means of transporting the diluted insecticide to the rural areas where needed. The successful use of paris green in the eradication of gambiae began only after Barber demonstrated mixing it with dust, soil, sand, or even pebbles at the site of application and broadcasting by hand. The most serious logistical problem was solved; abandoning the dust-gun with its need for a uniform powdered diluent, the MSNE made its inspector fully mobile and independent of supply lines. Armed with an empty pail, a small supply of paris green, a measuring spoon, and his ham- mock, he could move freely, even on foot, for days at a time, unhampered by weighty equipment and insecticide. From June 1939, the basic attack on gambiae was a straightforward chemical attack with paris green. In retrospect, Barber's visit should have been unnecessary. Barber and Hayne had written in 1921: "We have tried certain mechanical means for distributing the dust such as the dust guns used in dusting arsenic on cotton plants but thus far v have succeeded best by simply throwi the dust into the air by hand." The detailed administrative techniques developed by the Yellow Fever Service, which had led to the eradication of Aedes aegypti (SOper et al. 1943), were readily adapted to the gambiae eradication pro- gram. By the end of 1939 considerable progress had been made in reducing the area of infestation; the threat of expansion had been almost eliminated. As the infested area became smaller, more workers were moved in from the cleared periphery; the year 1940 witnessed a continuing reduc- tion of the gambiue-infested area, even during the rainy season. November 1940 was the last month in which gambiae was found in Brazil. The MSNE continued a wideflung search for gambiae, both within the previ- ously infested area and far beyond it dur- L774 MOSQUITO NEWS VOL. 26, No. 4 ,`another 18 months. The MSNE was disbanded at the end of June 1942. ANOPHELES gambiae in Egypt, 1942-43. Six months later, on January 7, 1943, as a member of the United States of America Typhus Commission, I arrived in Cairo to learn that Egypt had been invaded by .-lnopheles gambiae the previous year. The fall months of 1942 had been marked by a disastrous epidemic of malaria, paralleling in severity the gambiae-malaria outbreaks seen in Brazil but on a much larger scale. On invitation of the Under Secretary of Health, I visited the infested epidemic area; my report emphasized the threat of continuing epidemic malaria if gambiae were not eradicated. I explained that the "same factors which make Anopheles gambiae such a dangerous vector of ma- laria, namely, its tendency to breed in shallow sunlit pools without vegetation and its habit of resting and feeding in human habitations, make it highly vulner- able to simple frontal chemical attack." I stated that complete species eradication, although not easy, was "entirely possible with the careful meticulous application throughout the entire infested area of measures already &own and demon- -ted." *recommended that an emergency Anti- lmbiae Service be organized; that this Service be of temporary character, directly under the Minister of Health, and respon- sible only for "the prevention of the spread of A. gambiae to those parts of Egypt not already infested, and the complete eradica- tion of A. gambiae from Upper Egypt; . . . that this Service should have adequate funds and necessary liberty of action to carry out the administrative measures necessary for the rapid discharge of these responsibilities." The Service should not be responsible in any way for the study and treatment of malaria. I insisted the Director be given full au- tonomy in the choice, appointment, and discharge of all personnel; have full free- dom to determine how and where work should be carried out; and be able to requisition needed items, including techni- cal personnel, from other branches of the Health Department. My report was also submitted to the diplomatic and military authorities of the United Kingdom and the United States since Egypt was at that time occupied as an active theater of war. I appeared be- fore the Middle East Medical Supply Com- mission recommending the allocation of shipping tonnage for the importation of paris green. This was approved. I failed to convince interested British workers that eradication of gambiae was possible; I likewise failed to convince the Egyptian authorities that they should re- quest the Rockefeller Foundation to par- ticipate in the attack on gambiae with ex- perienced administrators from Brazil. Failing this, I left with the Egyptian work- ers the manuscript of the then unpub- lished report on "Anopheles gambiae in Brazil, 1930 to 1940" and a copy of the detailed manual of instructions of the Brazilian operation. (This manual had been carefully prepared after Anopheles gambiae had already disappeared from Brazil, as an historical record of the pro- cedures used and in the hope that it might be useful later in gambiae eradication pro- grams in Africa south of the Sahara.) ANOPHELES gambiae in Egypt, 1944-45. I left Egypt in June 1943 and not until February 24, 1944 did I learn of Egypt's catastrophic epidemic of the fall of the previous year. Then I saw at Naples, in the United States Army news sheet The Stars and Stripes, a British denial of the Egyptian charge that the occupation forces had so depleted the country's food supply that thousands. had died of starvation in Upper Egypt. The British claimed that food stocks were adequate, that starvation had occurred because of paralysis of food distribution by an overwhelming epidemic of malaria. (Again emphasis on "food as well as quinine.") On invitation of the Government of Egypt, I returned to Cairo early in May 1944 to make recommendations on malaria in the Nile Valley. The enormity of the 1943 catastrophe had made malaria a top political issue in which King Farouk him- DECEMBER, 1966 MOSQUITO NEWS 47= self became involved. The true measure of the 1943 epidemic will never be known; His Majesty told me a Royal Commission, after visting the blighted areas, had esti- mated malaria deaths in two years at 130,000. Interest, finances, and authority would not .be lacking for the attack on the invader. After a week-long visit to the infested area, I rewrote for the Minister of Health the essential recommendations I had made 16 months before; I again offered the ad- ministrative assistance of the Rockefeller Foundation. These recommendations and offer were accepted, and in June 1944 a special Gambiae Eradication Service was created, independent of the Malaria Ser- vice, directly under the Minister of Health, and responsible only for the eradication of gambiae from Egypt. Foundation participation began on July `5. Fortunately, the Egyptian Malaria Service had used the manual of instruc- tions of the MSNE of Brazil in zoning the gambia-infested area and had adequate personnel already in the field. It had, however, failed to substitute paris green for oil in the attack on gam- biae; the logistics problem for using oil had not been solved. Beginning in July, the shift from oil to paris green was made as rapidly as pos- sible, but the flood season was imminent and a great deal of malaria occurred in the fall of 1944. In Egypt, as in Brazil, gambiae proved to be highly susceptible to paris green lar- viciding. The last gambiae in Egypt was found on February 19, 1945, just seven months after routine application of paris green began. COMMENT. Thus the invasions of Brazil and of Egypt by gambiae, together cover- ing a decade and a half, terminated with the invader rejected. Although the two campaigns were administratively and tech- nically very similar, the geographical and psychological problems were quite differ- ent. In Brazil gambiae was actively spread- ing at the periphery with an entire con- tinent in jeopardy. The technique of blocking this spread and of eradicat L gambiae in the infested area was un- known. Not the certainty of winning but the cost of failure was the stimulus to action. In Egypt gambiae had been successfully blocked at Asyut; the infested area was the narrow irrigated zone along the Nile sur- rounded by hostile desert; the limits of the problem were known as was its solution; no research was needed nor attempted; from the start the result could be foretold. In Brazil work began with an inade- quate budget; at a critical time during the first year there was considerable difficult! in financing operations. In Egypt instruc- tions from the Minister of Health were' from the beginning that Anopheles gam- bia must be driven out. He said, "Go on spending!" It is now 36 years since gambiae invaded Brazil and 24 years since it came down the Nile into Egypt. Brazil and Egypt are just as vulnerable to invasion by gam- biae today as they were decades ago: many other regions of the world are equally vulnerable. Also it seems certain that some areas now suffering from gam- biae-malaria could be more easily freed of this curse by eradication of gambiae tl? by other means. Malariologists should I fail to study the records of Brazil ano- Egypt as they face up to the challenge of African malaria. In Brazil, towards the end of the campaign, a small test area was cleared completely of gambiae in three weeks' time; in Egypt, gambiae was wide- spread in November but had disappeared before the end of February. I have retold this story of long ago be- cause it has lessons for each generation of conscientious public health administrators. I have told it in the first person because I have referred to killing costly delays due to lack of vision, lack of courage, lack of salesmanship, and lack of administrative experience; even the casual reader may identify examples of each. BARBER, M. A. and HAYNE, I. B. 1921. Ar- senic as a larvicide for anopheline larvae. Public Hm'tli Reports 36:3027-3034. 476 MOSQUITO NEWS VOL. 26, No. 4 -CANNON. R. C. IOZO. 0 aonarecimento de ,< , I espCcie africana de Anopheles no Brasil. .fil-MPdico 44~515-516. SHOUPHA, SIR ALY TEWFIK, 1947/48. The eradication of Anophelei ganzbiae from Upper kgypt, 1942-1945. Bulktin of the World Health O~~ganization I ~309-352. SOPER, F. L. and WILSON, D. BRUCE. 1943. .fnophrks gambiae in Brazil, 1930 to 1940. The Rockefeller Foundation, New York.1 1 This is the story of dmphclrs gmnbiae m Brazil from its arrival in 1930 to ita eradication in SOPER, F. L., WILSON, D. B., LIMA, SERWLO, and AKIVNES, WALDEMAR 56. 1943. The Or- ganization of Permanent Nation-Wide Anti-A&-s aegypti Measures in Brazil. The Rockefeller Foundation. New York. 1940 and of after-eradication measures continued to June 1942. The companion Portuguese vol- ume, Campanha Contra o "`z4nopheles gambiae" no Brasil, 1939-1942 (F. L. Soper and D. B. Wil- son, Ministry of Education and Health, Rio de Janeiro, 1945), covers particularly the final eradi- cation campaign; it contains less text and more ztau\tical tables.