ANNUAL REPORT OF THE GORGAS MEMORIAL LABORATORY, 1943 PHYSICAL PLANT The activities of the Gorgas Memorial Institute have for a number of years been confined to the investigation of diseases affecting man and animals and to research and other cooperative activities which concern themselves with the Panama Canal Health Services, the armed forces of the United States in the Panama area, and the Public Health Services of the Republic of Panama. All activities, other than those of an administrative nature which are carried out by the office maintained in Washington, D. C., are centered in the Gorgas Memorial Laboratory located at No. 68 Avenida Justo Arosemena in the city of Panama, Republic of Panama. The central laboratory maintains three field stations in the Isthmian area for the conduct of special field investigations, namely, (1) a malaria-control station at Santa Rosa, R. de P., on the Chagres River near the eastern boundary of the Panama Canal Zone; (2) a field entomological station at Juan Mina on the Chagres River within the Canal Zone and near the malaria-control station at Santa Rosa; (3) a field veterinary station located at Corozal, C. Z. The physical plant in the city of Panama and the subsidiary field stations have been described in detail in previous annual reports to the Congress and are therefore omitted from this report. One of the functions of the veterinary station at Corozal is the breeding of small animals for laboratory use, both for the Gorgas Memorial Laboratory and for the Board of Health Laboratory of the Panama Canal. The vast increase in the population of the Isthmus due to the war emergency has made it impossible to meet all the needs of the latter organization for guinea pigs. It has been necessary in all local laboratories to reduce, so far as possible, the use of laboratory animals. Transportation difficulties and the great demand in the general market for such animals make it imperative to raise our stock locally, and this is not as easy to do as in other more favorable places. Consequently, the laboratory has discontinued carrying five of the seven strains of T. hippicum, the horse trypanosome, and all strains of the relapsing fever spirochete, S. neotropicalis. During the year our laboratory has used for all purposes only 362 guinea pigs, 68 white rats, and 10 rabbits. Some monkeys have been used for the special Office of Scientific Research and Development problems. The animal stock at the veterinary station at the end of the year comprised 740 guinea pigs (breeding stock), 696 young guinea pigs, 18 rabbits, 91 white rats, 2 calves, 1 goat, and 1 mule. The city laboratory had 2 sheep, 2 capybaras, 2 dogs, 15 monkeys, 11 rabbits, 34 white rats, 47 guinea pigs, and 15 vampire bats. During the year the pastures connected with the veterinary station have almost entirely been claimed for new buildings, and there is just enough grass area left to feed the few large animals under experimentation. It is necessary, daily, to cut and haul grass from Summit, C. Z., a distance of about 10 miles. Because of the shortage of food and its high cost during the present emergency, we keep under experimentation as few large animals as possible. FERSONNEL Regular employees of the laboratory during the year consisted of 29 persons as listed below. Scientific staff.-Dr. Herbert C. Clark, director; Carl M. Johnson, B. S., Sc. D., assistant director and protozoologist; Daniel M. Jobbins, B. S., M. Sc., senior entomologist; Graham B. Fairchild, B. S., M. S., junior entomologist. Mr. Jobbins resigned on March 20, 1943, to enter the United States Public Health Service as a Reserve officer and Mr. Fairchild terminated his service on April 7, 1943, to accept a commission as first lieutenant in the Sanitary Corps, Army of the United States. Technical staff.-One chief technician and four assistant technicians. Office and other employees. One clerk, one librarian-clerk, one janitress, one chauffeur, one night watchman, two animal handlers, and one auditor (part time). Santa Rosa station.-One river supervisor and motorboat operator and seven native practical nurses. Corozal veterinary station. One foreman, one assistant foreman, one helper, and one janitress. Juan Mina station.-No regular employees. A cook hired at intervals and other persons engaged from time to time to collect insects or to subject themselves to certain classes of experiments, sometimes for day duty and sometimes for night duty. In addition to its own regular personnel, the laboratory has had from time to time the services of scientists from other organizations. Mr. W. H. W. Komp, senior sanitary engineer, United States Public Health Service, has been on tour of duty at the Gorgas Memorial Laboratory since 1931. A group of four officers of the Sanitary Corps, Army of the United States, has recently been assigned to the laboratory by the Office of the Surgeon General in Washington, D. C., to conduct experimental studies and field trials of various protective and control measures for use against mosquitoes and other insects of medical importance. Lt. A. G. B. Fairchild, who had been a member of our staff up to the time he entered the Army, was detailed to the laboratory for this special work immediately after he received his commission. Maj. Marshall Hertig arrived on June 15, 1943. First Lt. W. C. McDuffie and First Lt. Roy Melvin will join this group, which, under Major Hertig's direction, will undertake the investigations mentioned above. MAINTENANCE AND REPAIRS The chief items of expense in connection with the upkeep of the central laboratory building in Panama were for repairing and painting of the indoor and outdoor animal cages, painting of doors and window frames in the main building, and repairing of the insectary house. There was considerable expense for repairs to some of the laboratory equipment, particularly the refrigerator and the Chevrolet carry-all. At Juan Mina station the boat dock was repaired and also the foundation of the building which houses the station. The boats were painted. At the veterinary station the quarantine stalls were repaired and a concrete drain was installed in front of the dairy barn to dispose of roof drainage. Statement of cash receipts and expenditures RECEIPTS Contribution by the U. S. Government_ Reimbursements under Office of Scientific Research and Development Contract No. OEMcmr-29_. Reimbursements under Office of Scientific Research and Develop ment Contract No. OEM cmr-58_ Refund of travel expense advance. Refund of pay-roll tax not deducted prior year.. Other expenses (water, gas, electricity, postage, etc.). Publication expense and reprints. Corozal veterinary station.. Excess of cash receipts over cash expenditures for operatingPurchase of U. S. Savings bonds (from equipment-replacement reserve) _____ Excess of total cash disbursements over cash receipts.. Cash on hand at the beginning of the year. - - Cash on hand at the end of the fiscal year.. Bank deposits, etc., as of June 30, 1943: Petty cash fund, Panama.. Total, operating accounts... Riggs National Bank, equipment-replacement account.. Total bank deposits, etc.. $50, 000. 00 4,057. 18 2, 511. 82 40. 00 181. 50 56, 790. 50 846. 97 734. 30 782. 30 29, 246. 69 256. 00 1, 226. 81 582. 45 929. 72 1, 914. 21 3, 062. 73 1, 494. 53 81. 71 2, 312. 70 1, 919. 47 1, 201. 43 2,042. 21 306.53 181.50 49, 122. 26 7,668. 24 10, 000. 00 2, 331. 76 16, 011. 72 13, 679. 96 7, 196. 03 3, 395. 82 135. 11 50.00 10, 776. 96 2, 903. 00 13, 679. 96 SCIENTIFIC ACTIVITIES OF THE YEAR Experimental work in control of malaria by use of drugs.-Observations on the control of malaria by the use of drugs started in September 1930 at the Santa Rosa station in the midbasin of the Chagres River. A consolidated report of the first 10 years of work can be found in Human Malaria, publication No. 15 of the American Association for the Advancement of Science, 1941. Because of the widely discussed cyclical variations in malaria incidence a number of malariologists desired further yearly reports on these same groups of people and our own organization needed a continuation of the work in order to measure entomological experiments in progress at the Juan Mina station. The experiment has therefore been continued beyond the 10-year period originally planned. The reports for the eleventh and twelfth years can be found in the annual reports of the Gorgas Memorial Laboratory for 1941 and 1942. The thirteenth year's report is given here. Four new features should be mentioned which might be expected to affect the malaria parasite index in the river-bank towns during the year under review. (1) The Panama Canal changed its method of killing the aquatic vegetation along river banks and lagoon areas. During the rainless months of the year, copper sulfate was applied extensively throughout the area where four of our villages are located (Santa Rosa, Guayabalito, Gatuncillo, and Las Guacas). This procedure becomes an antimosquito measure as well as a means of destroying aquatic vegetation. (2) The sanitary forces of the Panama Canal have also been using a high-powered paris green dusting apparatus over the same river area each week. (3) The impounded water of Madden Dam located above our villages has been used at certain intervals to flood the river and its lagoons so that much of the aquatic vegetation was washed down the stream to the Gamboa boom where it was collected and destroyed. All three of the procedures mentioned affected the river and lagoon mosquito-breeding areas. However, we have believed, for several years, that the chief anopheline breeding areas that affect the four river-bank towns are in small branches of the river that run behind the towns and which are not affected by any of the measures cited above. (4) Citizens returning to our villages after periods of employment in rural construction units in the Canal Zone or along the Trans-Isthmian Highway show a greater index of parasite infection than when they left the group of villages under drug control. Most of these people have been employed outside sanitated areas in unscreened quarters. Bimonthly thick blood film surveys were continued during the year. In all the alternate months Dr. Clark made an inspection visit of all villages and took blood films on all fever cases and instituted antimalarial treatment for all such cases. The detailed report given later will show the actual number of these cases that revealed the parasites of malaria. The villages that comprise Santa Rosa station lie between the Madden Dam (midbasin of the Chagres River) and the eastern boundary of the Panama Canal Zone. The inhabitants of the six villages included in the study are divided into two approximately equal groups. One group has been treated with atabrine (dihydrochloride) made by the Winthrop Chemical Co. of New York, and the other has been treated with tablets of quinine sulfate. No plasmochin was used in either group. The controls consisted of Rio Pescado, a village on the west shore of Gatun Lake near the center of the Isthmus, and Mendoza, a hill village about 3 miles behind Rio Pescado and at an elevation of about 3,000 feet above the lake shore. Mendoza is made up almost entirely of school children drawn from a radius of about 3 miles among the hills. A small unit known as Los Azules contributed a few people on some of the surveys. These live on a remote peninsula of the lake shore. At the request of local military, Canal Zone, and Republic of Panama authorities we placed the village of Camaron, R. de P., on monthly surveys and drug control. It is a fishing village just outside the western boundary of the Canal Zone on the Pacific coast. Its people have constant contact with Panama City and with several nearby Canal Zone centers and so its seedbed of malaria is important. Thus there are four groups to be reported on for the year 1943. A. The atabrine group included five small towns situated quite close together on the banks of the Chagres River (Santa Rosa, Guayabalito, Gatuncillo, Las Guacas, and Agua Clara). Persons found positive in the bimonthly surveys for the parasites of malaria were treated with atabrine 0.1 gram, three times a day for 5 days. All tablets of atabrine were broken in half or were crushed just before administration because our experience has been that the tablets are so hard that some persons when treated, particularly children, pass the tablets unchanged. The river supervisor assisted the trained practical nurses in each village in the administration of the drug. The river supervisor lives in Santa Rosa and has a motorboat and so the inhabitants of the villages have almost constant access to his services. Visits are made by him to all the villages about once a week. B. The group treated with tablets of quinine sulfate is composed of the citizens of New San Juan, a village containing about the same number of people as the combined five towns that are treated with atabrine. It is located on the banks of the Gatuncillo branch of the Chagres River and lies between two small branches of the Gatuncillo. It is about 2 miles on an air line from the channel of the Chagres River. Here persons found positive on the bimonthly surveys were given 18 grains of quinine sulfate, in tablet form, each day for 5 days. Two native practical nurses assisted the river supervisor in providing this treatment. Only one visit a month was made to this village by Dr. Clark. C. The new town of Camaron was given atabrine in the same manner as the A group. In addition, on one day each week between the monthly blood film surveys, the group found positive and treated following the monthly survey were each given 3 atabrine tablets of 0.1 gram. This meant that each treated person received 24 tablets during the month. The drug was supplied by the Canal Zone for free use, and the Gorgas Memorial Laboratory paid the salary of a native woman to act as a practical nurse and supervise the treatment. Through the courtesy of a local military unit, transportation was provided to the village for the surveys. The population of this fishing village is very unstable and being new in its efforts to cooperate, the results obtained from the survey and treatment during the year were not as good as our staff had hoped for. Several small streams empty into the Pacific Ocean in and near the town. 9370644- -2 |