YELLOW FEVER CONFERENCE (Washington, D. C., December 21-22, 1954)4 1"I: Scientific Publications No. 19 October, 1955 PAN AMERICAN SANITARY BUREAU Regional Office of the World Health Organization Washington, D. C. Reprinted from THE AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE (Vol. 4, No. 4, July 1955) YELLOW FEVER CONFERENCE (Washington, D. C., December 21-22, 1954) PAN AMERICAN SANITARY BUREAU Regional Office of the World Health Organization 1501 New Hampshire Avenue, N.W. Washington 6, D. C. YELLOW FEVER CONFERENCE' 21-22 December, 1954 PABTICIPANTS U. S. Public Health Service Dr. Justin Andrews, Assistant Surgeon General Dr. Fred J. Brady, Medical Director, International Health Representative Dr. Victor H. Haas, Medical Director, Microbiological Institute, National Institutes of Health Dr. Willard H. Wright, Veterinarian Director, Laboratory of Tropical Diseases, Micro- biological Institute, National Institutes of Health Dr. Roger Cole, Surgeon, Assistant to the Chief, Laboratory of Infectious Diseases, Microbiological Institute, National Institutes of Health Dr. George H. Bradley, Scientist Director, Assistant Chief, Communicable Disease Center Mr. Melvin Goodwin, Senior Scientist, Communicable Disease Center, Atlanta, Georgia Dr. John Scruggs, Communicable Disease Center, Atlanta, Georgia Dr. C. B. Spencer, Medical Director, Chief, Division Foreign Quarantine Dr. Knud Stowman, Division Foreign Quarantine Dr. John H. Hughes, Senior Scientist, Division Foreign Quarantine Mr. Roy F. Fritz, Senior Scientist, Chief, Surveillance Section, Epidemiological Branch, Communicable Disease Center, Atlanta, Georgia Dr. Donald R. Johnson, Entomologist, Health Services Branch, Division of International Health Dr. Henry Van Zile Hyde, Chief, Division of International Health U. S. Army Col. Norman W. Elton, Director, Medical Laboratories, Army Chemical Center, Edge- wood, Maryland Col. Tom F. Whayne, Chief, Preventive Medicine Division, Office of the Surgeon General Dr. S. Bayne-Jones, Technical Director of Research, Research Development Division, Office of the Surgeon General Dr. Joseph E. Smadel, Chief, Department of Virus and Rickettsial Diseases, Army Med- ical Service Graduate School, Walter Reed Army Medical Center Dr. Geoffrey Edsall, Director, Division of Immunology, Army Medical Service Graduate School, Walter Reed Army Medical Center Lt. Col. Ralph W. Bunn, Preventive Medicine Division, Office of the Surgeon General Capt. Thomas B. Dunne, Preventive Medicine Division, Office of the Surgeon General Dr. I. N. Dubin, Armed Forces Institute of Pathology Col. Richard P. Mason, Office of the Surgeon General U. S. Air Force Col. Theodore C. Bedwell, Office of the Surgeon General U. S. Navy Commander K. Knight, Preventive Medicine Division Commander John Seal, Preventive Medicine Division ' A Spanish translation of these proceedings will appear in the July issue of the Boletin de la Oficina Sanitaria Panamericana. 571 572 YELLOW FEVER CONFERENCE Rockefeller Foundation Dr. Max Theiler, Virologist, Laboratories of the Division of Medicine and Public Health, New York, New York Dr. Wilbur G. Downs, Director, Virus Laboratory, Caribbean Medical Center, Port of Spain, Trinidad Dr. John Bugher, Attached to Atomic Energy Commission as Director, Division of Bio- logical and Medical Sciences Gorgas Memorial Institute Col. (Ret.) Joseph E. Siler, President Dr. Carl Johnson, Director, Gorgas Memorial Laboratory, Panama Dr. Harold Trapido, Entomologist, Gorgas Memorial Laboratory, Panama U. S. Department of State Mr. H. B. Calderwood, Office of International Economic and Social Affairs Foreign Operations Administration (FOA) Dr. Charles L. Williams, Jr., Chief, Latin America Branch, Public Health Division Carlos Finlay Institute Dr. A. Gast Galvis, Director, Instituto Carlos Finlay, Bogotá, Colombia Pan American Sanitary Bureau (PASB), Regional Office of the World Health Organization (WHO) Dr. Fred L. Soper, Director Dr. C. L. González, Assistant Director Dr. J. Boshell, Chief, Central America Jungle Yellow Fever Studies Dr. G. Molina, Chief, Division of Public Health Dr. Myron E. Wegman, Chief, Division of Education and Training Dr. G. Samamé, Representative, Zone II, Mexico, D. F., Mexico Dr. S. Farnsworth, Representative, Zone III, Guatemala, Guatemala Dr. O. J. da Silva, Representative, Zone IV, Lima, Perú Dr. J. E. Glismann, Chief, Field Office for Caribbean, Kingston, Jamaica, B. W. I. Dr. A. Bica, Chief, Communicable Diseases Branch Dr. O. P. Severo, Aedes aegypti Eradication Adviser Dr. E. C. Chamberlayne, Consultant in Veterinary Public Health, Communicable Dis- eases Branch Dr. Louis L. Williams, Jr., Consultant Dr. P. F. de Caires, Chief, Health Promotion Branch Dr. Louis Verhoestraete, Health Promotion Branch Dr. I. C. Yuan, Medical Adviser to UNICEF, New York, New York Mr. Harold Ballou, Public Relations Officer ToPICS DISCUSSED Page Review of the yellow fever menace. DR. F. L. SOPER .................................. 573 The outbreak in Trinidad, 1953-1954. DR. W. O. DOWNS ............................... 582 Yellow fever in Panama and Costa Rica, 1948-1953. COL. N. W. ELTON ................ 591 The movement of yellow fever through Nicaragua and Honduras, 1952-1954. DR. J. BOSHELL............................ ........................................ 597 The question of the yellow fever threat to Asia. DR. F. L. SOPER ...................... 599 Yellow fever and quarantine regulations. DR. K. STOWMAN ........................... 603 YELLOW FEVER CONFERENCE 573 Page Control measures in international travel. DR. C. B. SPENCER .......................... 604 A&des aegypti eradication in the Americas. DR. F. L. SOPER ........................... 609 The vector situation in Central America and Mexico. DR. H. TRAPIDO ................. 616 The need for biological and ecological studies. DR. J. BUGHER ........................ 624 The epidemiological significance of the fundamental grouping of viruses. DR. M. THEILER 627 The vectors and reservoirs of jungle yellow fever in the Americas. DR. J. BOSHELL..... 630 Studies on Haemagogus spegazzinii in Panama. DR. H. TRAPIDO ....................... 634 The possibilities of controlling jungle yellow fever. DRS. F. L. SOPER, H. TRAPIDO AND W. G. DOWNS ................................................................... 637 Laboratory facilities and yellow fever diagnosis. DR. J. E. SMADEL .................... 639 Pattern of behavior of the yellow fever movement. COL. N. W. ELTON ................. 642 Monkey mortality in jungle yellow fever. DR. J. BOSHELL ............................ 647 Summary of discussions. DR. F. L. SOPER ............................................ 648 INTRODUCTION A conference was called by the Director of the Pan American Sanitary Bureau, for the purpose of discussing and reviewing the present status of yellow fever in the Americas. The conference highlighted certain gaps in the present knowledge concerning seedbeds of the disease and its survival in certain jungle areas, and the administration of control measures. Among those present were leading authorities in the U. S. Public Health Serv- ice, the Divisions of Preventive Medicine of the U. S. Army, Navy and Air Force, the Rockefeller Foundation, the Gorgas Memorial Institute, the U. S. Department of State, the Carlos Finlay Institute of Bogotá, Colombia, and members of the staff of the Pan American Sanitary Bureau. The Conference met in the International Conference suite of the U. S. Depart- ment of State, December 21 and 22, 1954, with Dr. Fred L. Soper presiding. PROCEEDINGS (Tuesday, December 21, A. M.) THE CHAIRMAN: Today's meeting is entirely unofficial and informal, and the objective is purely informational. There are no prepared papers to be read, the purpose being to have an opportunity for an informal discussion with some of the people who know the most about yellow fever in the Americas. Yellow fever is not a "dead duck". Yellow fever is not a disease which has been conquered. It is not a disease which has been eliminated from consideration as a permanent threat, and one of the important things that can be done here today is to attempt to take a long-term view of yellow fever and see what has been happening over the years. Too many health authorities get alarmed about yellow fever only when it be- comes an urban disease, overlooking entirely the fact that, for the jungle popula- tions and for rural workers who have to go into the forest, yellow fever carries the same threat that it previously had for the people in the cities. Yellow fever is one of the diseases which have varying epidemiological char- acteristics under different circumstances. It is a disease which, when studied under a given set of conditions, oftentimes leads to very definite beliefs and con- 574 YELLOW FEVER CONFERENCE victions related to these specific conditions. From personal experience I have some convictions of my own that are quite different from those of people who have observed the disease under other conditions. Yellow fever has been, in the past, one of the most important of the virus diseases to investigate. It has a number of characteristics which make it very useful for study. All of the strains of virus are apparentlyhomologous. It is possi- ble to make a diagnosis, a pathological diagnosis, in fatal cases. We do have sus- ceptible animals, so the isolation of virus is readily carried out, and the immunity reactions, particularly in primates, are very clearcut. The yellow fever virus has served as the basic virus on which a