Previous PageIndexNext Page

SURVEILLANCE AND TRANSPORT OF PATIENTS WITH SUSPECT VIRAL HEMORRHAGIC FEVERS THE UNITED STATES EXPERIENCE

JOHN A. BRYAN
Viral Diseases Division, Bureau of Epidemiology, Center for Disease Control, Atlanta, Georgia 30333, U.S.A.
RONALD M. ZWEIGHAFT
Enteric and Neurotropic Pathogens Branch, Viral Diseases Division, Bureau of Epidemiology, Center for Disease Control, Atlanta, Georgia 30333, U.S.A.

INTRODUCTION

Marburg virus caused illness and death in laboratory workers and animal handlers in Marburg (1) and Frankfurt (2), Germany and Belgrade (3), Yugoslavia in 1967 and was responsible for a small outbreak of disease in South Africa (4) in 1975. Lassa virus has been responsible for both epidemic and endemic disease in Sierra Leone, Liberia, and Nigeria (5), and retrospective serologic data have indicated Lassa activity in the Ivory Coast, Mali, and the Central African Republic-Zaire area (6). In the summer and fall of 1976, Ebola virus caused considerable morbidity and from 50-90% mortality in isolated outbreaks in southern Sudan (7) and northern Zaire (8,9). In addition, other viral hemorrhagic fevers have been identified in West (10) and South (11) Africa, South America (12-14), and Asia . Most of these viruses can be transmitted from person to person through either direct or indirect means.

In many countries where these diseases are found there are foreign nationals living and working in rural areas side by side with the indigenous population in settings such as hospitals, schools, and farms. The United States has citizens serving in areas where direct contact with persons harboring these agents is possible and periodically these persons return home for a variety of purposes such as furlough, change of assignment, or medical care. Moreover, since jet age travel has transformed our world into a global community, persons anywhere in the world can and do travel thousands of miles from one place to another within a mere 24 hours. Furthermore, this air travel takes place under conditions where large numbers of people are clustered for extended periods of time in confining environments and are subject to direct contact with an even much larger number of persons in airports. Therefore, the potential for spread of viral hemorrhagic fevers beyond their endemic foci into other areas of the world is very real.

IMPORTATIONS INTO THE UNITED STATES

Whether or not actual importations of hemorrhagic fever into non-affected countries can occur is no longer subject to question but definitely a fact because importations, both recognized and unrecognized, have already occurred in several countries of the world. At least two such importations have occurred in the United States.

The first known importation occurred on March 3-4, 1969 when an ill 52-yearold missionary nurse stationed in Jos, Nigeria was air evacuated from Lagos, Nigeria to New York City in the first class section of a commercial jet airliner accompanied by another missionary nurse and a physician. This patient had nursed a colleague who had died during the previous month with Lassa fever--a then undefined disease--and had assisted at her autopsy. At the time of air evacuation to the United States (the 16th day of her illness), the patient was quite ill with nausea and vomiting and was in shock. The entire first class cabin was utilized for transport aboard the airplane, and the seats in the left section were removed to accommodate the patient, her stretcher (specially designed to bolt to the floor of the aircraft) and equipment for intravenous fluid administration. A heavy curtain was hung across that section to permit the nurse and physician private access to the patient and to minimize exposure to the airline crew and passengers. After arrival in New York, the patient was transferred by ambulance without isolation precautions to a hospital and placed in isolation with full mask, glove, and gown precautions for all attendants. The account of her hospital course and followup have been published elsewhere (16). The physician and nurse who accompanied the patient on the flight did not develop serologic evidence of Lassa fever infection. No serologic survey or follow-up of the flight crew or passengers was undertaken, but it is presumed that no secondary cases occurred among this group (personal communication: J. Lyle Conrad, M.D.).

The second known importation occurred in February, 1976, when a 43-year-old white female American Peace Corps worker from Sierra Leone accompanied by her husband and a Peace Corps nurse returned to the U.S. with an undiagnosed illness which was later recognized as Lassa fever. This incident was studied because of the fear that secondary spread of infection to contacts of this patient might occur (17). Since the exact etiology of the patient's illness was not known prior to her hospitalization in the United States, precautions to minimize transmission of disease were not taken and therefore individuals who shared flights with her from Freetown, Sierra Leone, to London, and from London to Washington, D.C. as well as ground contacts at London's Heathrow Airport and in Washington, D.C. were considered to be at potential risk of infection.

A total of 552 contacts were identified as having had potential exposure to the patient either in Sierra Leone, on flights to and from London, or in Washington, D.C. Responsibility for the 115 contacts aboard the plane from Freetown to London as well as those at Heathrow Airport was assumed by the British government, since the airline company was British and most passengers were enroute to British destinations. No Americans other than the patient and her escorts were aboard that flight. British health officials sent press release notifications to airline passengers and requested that they report any fever or other symptoms of illness to the Quarantine Department by telephone. Of 65 persons (61 who deplaned in Great Britain, 4 who were contacts at London Heathrow Airport), 41 either called in or were subsequently contacted. Fifty-four passengers continued to destinations other than Britain or the United States. Appropriate embassies were notified by the British health officials in these instances. In Japan, contacts were hospitalized for observation during the surveillance period, but specific measures, if any, that were taken in the other countries are not known to us. Thirty contacts in Mobai and Freetown were identified and kept under surveillance by the Sierra Leone government. Responsibility for persons aboard the trans-atlantic flight was assumed by the United States. In the United States after the patient was in hospital isolation and appropriate specimens for diagnosis obtained, State Health Department epidemiologists were contacted by telephone and telegram to inform them of the imported Lassa fever case and to outline a plan for management. Next, in cooperation with the District of Columbia Department of Community Health and Hospital Administration, contacts in the District were identified by retracing the steps of the patient, her husband, and the nurse practitioner from the time of their arrival until admission to the hospital three days later. Each contact was given a printed bulletin briefly explaining the nature of the disease including the early symptoms and informing them of the potential risk of contracting the disease. A surveillance period of 21 days was established to include the longest known incubation period of Lassa fever. In the District, two types of contacts were defined: those at high risk because of face-to-face exposure to the patient and those at presumed low risk because of only casual exposure. The patient's husband and nurse were considered to be high-risk contacts. High-risk contacts were instructed to measure their oral temperature twice a day and report to the Health Department the actual reading plus any symptoms. Low-risk contacts were instructed to report each day any fever or other symptoms of illness. Activities of contacts were not restricted.

In addition to the District of Columbia, 21 states were involved in the surveillance of airline passenger contacts. State Epidemiologists or another designated person in each involved state were contacted to enlist cooperation and request that surveillance data be reported by telephone to CDC. Telephone reporting was conducted daily until all the passengers were located at which time reporting was reduced to twice weekly.

Interstate and international travel of contacts was monitored. As new states became involved in the surveillance system, appropriate state health authorities were alerted. Nineteen persons traveled internationally while under surveillance. High-risk individuals were requested not to leave the country. Low-risk contacts were permitted to leave but appropriate foreign health officials were notified in advance when such travel was agreed upon.

In the District of Columbia, 33 high-risk and 139 low-risk contacts were identified. No fever or clinical illness compatible with Lassa fever developed in any of these contacts within the 21-day surveillance period. Of the 233 passengers and crew aboard the transatlantic flight, one passenger did become ill with a compatible viral syndrome that included fever, cough, and myalgia. He was hospitalized in isolation and his initial leukocyte count was 3,700 WBC. Blood, urine, and throat swab specimens were negative for Lassa fever virus. Blood, urine, and throat swabs were also obtained from the patient's husband and nurse and were negative for virus isolation. Serum specimens from these persons did not contain Lassa antibody.

One month after surveillance ended, a serologic survey of high-risk contacts in Washington, D.C. was carried out, and specimens were analyzed for antibody to Lassa fever by the indirect fluorescent antibody technique. All were negative for antibody. So, in essence, no secondary cases of infection were detected among either high- or low-risk contacts of this patient both in the United States and abroad.

GENERAL CONCEPTS
Before moving on to a discussion of the specifics of managing a suspect case of surveillance of contacts, let us consider a few general principles of surveillance and prevention, some of which were contained in a report to the Director, Pan American Health Organization by a working group on international surveillance of air travelers (18).

Transmissibility. Thus far, experience with these diseases seems to indicate that transmission occurs mainly through direct personal contact with infected individuals, probably by way of inadvertent percutaneous, oral or mucous membrane inoculation of infected material. Transmission by way of respiratory droplets or aerosols probably also can occur but presumably is a less frequent means of transmission. Additional factors of importance to transmission may possibly relate to the length of time that an individual has been ill and whether virus can still be demonstrated in the pharynx or only in the blood or in urine. Isolation precautions should as completely as possible reflect the virologic and epidemiologic observations. It may be that not all patients with Lassa fever serve as "disseminators" of infection, and it seems useful to keep this in mind as we proceed. Clearly, it will be much easier to make decisions regarding management of contacts and the extent to which isolation precautions should be practised for both patients and contacts when more complete information is available on a larger number of observations documenting duration of virus presence in pharyngeal secretions, blood, and urine.

Local-National Cooperation. So long as people travel internationally to and from endemic areas, diseases such as Marburg, Lassa, and Ebola will continue to be imported occasionally in spite of whatever precautions are taken. When such importations occur, it is unlikely that they will be discovered on arrival at ports of entry and, therefore, recognition will most likely depend upon the existence of an adequate national surveillance network. This suggests that resources to strengthen and improve surveillance efforts should be directed toward state and local health departments and not toward bolstering surveillance at airports. The development of a plan for surveillance and trans port of patients with suspect viral hemorrhagic fevers requires the cooperation of public and private sectors and specifically depends upon a close working relationship between local, state and federal government resources.

International Responsibility. When considering a viral illness such as Marburg, Lassa, or Ebola in the differential diagnosis of an ill traveler, great emphasis must be placed upon whether there has been recent travel in a known endemic or epidemic area. In order for this to continue to be useful for identifying suspect cases, countries must report the existence of highly suspect or confirmed disease activity of an endemic or epidemic nature to the World Health Organization for dissemination to other countries. The performance of adequate surveillance includes not only collecting information but also in sharing that information with those who need to know. Disease control programs are adversely affected by late.or inaccurate international reporting of suspected or confirmed disease outbreaks.

Liaison with Air Transport Organizations. In developing a plan of management, it is best to formulate general national guidelines which can then be adapted to local situations. The plan should involve liaison with the air transport industry as well as organizations both governmental and non-governmental that deal with air travelers. This type of liaison is extremely useful to health authorities which can then make known their specific needs for information such as passenger lists and addresses, seating arrangements, etc. Moreover, periodic meetings with those involved at each level are important to keep all attuned to changing situations such as geographic variation in disease activity, methods for transport and isolation, immunization requirements, specimen handling, and management of ill passengers. Occasionally, the health authority in each country in conjunction with air carriers and others involved should undertake practice drills in managing the transport and quarantine of a suspect case and in locating flight or other contacts so that in the unlikely event of a traveler becoming ill with a hemorrhagic fever-like disease on or after arrival, the health authorities will have had experience in dealing with the problem.

Transport and Isolation. Finally, patients known or highly suspected to have viral hemorrhagic fever and considered to be potentially infectious should not be transported on commercial planes with other passengers. Patients with such diseases should receive the best possible medical care with the best available isolation techniques. If a decision is made to air evacuate such persons, appropriate isolation and/or barrier nursing techniques and facilities should be utilized.
MANAGEMENT OF SUSPECT IMPORTED CASES AND SURVEILLANCE OF CONTACTS

The plan used for management of the Lassa fever case imported to the U.S. in November 1975 was based on an adaptation of the smallpox emergency protocol developed by the Center for Disease Control (CDC) entitled "Comprehensive Action in a Smallpox Emergency". The key elements of this plan are management of suspect cases and surveillance of contacts. (Table 1).

TABLE 1
SURVEILLANCE AND TRANSPORT OF PATIENTS WITH SUSPECT VIRAL HEMORRHAGIC FEVERS MANAGEMENT AND SURVEILLANCE OF CONTACTS

A. Notify State Health Departments.

B. Identify and characterize contacts (high-risk, low-risk, etc.).

C. Notify and inform contacts.

D. Begin surveillance.

1. Check for symptoms and/or fever

2. Quarantine

E. End surveillance.

Management of Suspect Cases. Early recognition and detection of suspect cases is of crucial importance to reduce the opportunity for secondary transmission of infection. Physicians and public health workers need to be aware that history of recent travel in an endemic area is an important point to pursue with suspect cases since the early clinical manifestations of illness are generally nonspecific in nature. As soon as a suspect index case is identified, the patient is transported to and placed in a suitable isolation or quarantine facility, specimens are collected, appropriately packaged, and sent to CDC or another qualified laboratory for confirmation of the diagnosis, and state and federal public health authorities are notified. Transport to the isolation facility can either be accomplished using an ambulance and transport isolation equipment or, as an alternative, protective clothing for the patient and accompanying personnel could be used. Isolation of the patient may be accomplished in a conventional hospital setting using advanced barrier nursing techniques or, if available, the patient can be placed in a hospital bed isolator. The patient in Washington D.C. was quarantined in a private room suitable for respiratory isolation and all persons entering the room wore complete protective clothing and special biologic filter masks. Clothing, linens, urine, and feces were treated with sodium hypochlorite. Blood smears for differential WBC counts were fixed with glutaraldehyde and blood collected for cell counts and clinical chemistries was treated with 2% acetic acid or heated at 60ºC for one hour. After discharge, the patient's room was disinfected with 0.6% sodium hypochlorite, her mattress was incinerated and her jewelry and personal belongings sterilized with ethylene oxide (17). A suspect case should remain in isolation/quarantine until the diagnosis is confirmed or effectively ruled out. If confirmed, isolation/quarantine should be continued until throat swabs, blood, and urine are negative for viral isolation on at least 2 successive occasions at least 2 days apart.

Surveillance of Contacts. Immediately after identification of a suspect case, state and federal public health authorities must proceed to identify contacts and, depending upon the epidemiologic circumstances, (e.g., whether or not there has been actual face-to-face exposure, exposure to the patient's blood or specimens, etc.) separate them into various risk groups (high, low, etc.). Contacts are then notified and informed of the nature of the problem and the reasons for placing them under surveillance. In the Washington, D.C. situation, both highand low-risk contacts were checked daily for symptoms compatible with the disease (cough, pharyngitis, myalgia, vomiting, diarrhea, abdominal pain, chest pain, headache and abnormal bleeding) and in addition, high-risk contacts had their temperatures checked daily. Surveillance in this situation was continued to include the longest known incubation period for Lassa--21 days (17). This decision to monitor both high- and low-risk contacts daily required considerable time and effort. Therefore, alternatives to this plan need to be considered.

Since individuals at high risk are more likely to become ill than those at low risk, an alternative method could be to limit surveillance to the high-risk group until the diagnosis is confirmed (at which time surveillance of low-risk contacts would also begin) or to limit surveillance solely to high-risk contacts and not place contacts at presumed lesser risk under surveillance at all unless an individual in the high-risk group becomes ill. These alternatives offer the advantage of efficient utilization of the often limited resources that would be required for nationwide surveillance and concentrates them on those at greatest risk. Another option would be to consider restricting the activity of some or all of the highrisk individuals during the entire surveillance period. This would permit greater control and minimize the opportunity for exposure of others. This option would be particularly useful to apply to a subpopulation of the high-risk group such as medical personnel, spouses, or close associates of the index case since transmission of disease through second, third, and fourth generations is almost uniquely associated with exposures in a medical or nursing care setting or intimate contact among household members.

The next consideration is when to quarantine cortacts and whether there are occasions when quarantine of asymptomatic and healthy contacts should be undertaken. A reasonable position would seem to be to use quarantine only when a contact develops compatible symptoms. In the Washington, D.C. episode, contacts with fever and/or compatible symptoms would have been quarantined. Furthermore, these investigators planned to quarantine all other high-risk contacts if one of their number developed confirmed disease and all high- and low-risk contacts if a low-risk individual developed confirmed disease. Secondary contacts of any primary contact with confirmed disease would also have been placed under surveillance.

Several alternatives with regard to the method of quarantine for contacts who become ill can be considered. One approach would be to have the individual quarantined at home, but this poses a perhaps unwarranted risk to other members of the patient's household and makes regular observations difficult. Quarantine in a hospital facility would obviate the problems of observation and undue exposure for household contacts but presupposes that a hospital would agree to accept such a suspect case and raises quite valid questions about who would bear the cost involved. Other possibilities for quarantine might include hotel or motel rooms or specially-designed quarters such as the mobile quarantine facility which was used to quarantine U.S. astronauts after their return from the moon. Duration of the quarantine period for an ill contact should depend upon confirmation of diagnosis. If specimens collected subsequent to quarantine confirm the diagnosis, the patient and all contacts should be handled as outlined above (see Suspect Case). Ill contacts may be released from quarantine after specimens for viral isolation and serology are consistently negative.

Each of these quarantine alternatives solves some problems but raises others, and none offers the complete solution to a rather difficult and complex problem. An ideal situation would be to have facilities available at selected locations around the U.S. to which ill contacts could be transported so that quarantine, isolation and/or hospitalization, and treatment could be provided. Facilities which theoretically could presently serve or be renovated to serve this purpose exist throughout the country, but considerable work must be done to assure their availability and to equip and staff them. Success in this rather massive project requires planning, discussion, and close cooperation between local, state, and federal health agencies, the Department of Defense, and the health care delivery industry. Action is underway to initiate these activities. In addition, the CDC is moving forward with plans to develop facilities to quarantine/isolate and if necessary provide medical care for a patient with viral hemorrhagic fever. A quarantine facility is being developed on CDC grounds to accommodate individuals with suspect disease or accidental laboratory exposure. Small isolators for ambulance transport and large ones for hospital use and patient care have been purchased. Negotiations are underway with a local hospital to provide space and train personnel for delivering medical care and treatment to an individual in a hospital bed isolator. Specialists in infectious diseases and internal medicine will be identified to direct the medical care of such a patient. Finally, CDC is preparing visual and other training materials for future use in instructing others to develop, operate, and maintain such equipment.

CONCLUSION

Because of the nature and extent of international travel today, it is possible that importations of diseases like Marburg, Lassa and Ebola will take place. It is unreasonable to expect that such importations will be discovered at ports of entry; it is much more likely that state or local health department surveillance activities will bring them to light. Countries should develop comprehensive national programs for the diagnosis, management and surveillance of such patients and their personal contacts. Such a program, originally developed for use in a smallpox emergency situation, was first adapted for use following importation of an individual ill with Lassa fever and has subsequently been revised. No instance of secondary transmission of viral hemorrhagic fever following importation into the U.S. has thus far been documented. Efforts continue to refine and improve a comprehensive plan of action for management of suspect imported cases of viral hemorrhagic fever. Essential issues which remain to be solved include providing for a safe and efficient means of transport of individuals to specifically identified, equipped, and staffed locations around the country for the purpose of quarantine and possible treatment. The U.S. experience in surveillance and transport of patients with suspect viral hemorrhagic fevers has been quite limited. Actions taken and plans for management thus far devised have been tentative and based solely on the best available judgment as to the general application of principles of epidemiology and hospital isolation; this has had to be the approach because of a lack of adequate knowledge regarding the pathophysiology, epidemiology, and mechanisms of transmission of these diseases. Therefore, our approach to the future management of these problems must remain dynamic and adaptable to new developments in the epidemiology, control and prevention of these diseases.

REFERENCES
1. Martini, G.A. (1971) Marburg virus disease. Clinical syndrome, in Martini, G.A., Siegert, R. eds., Marburg-Virus Disease. Berlin and New York,Springer Verlag, pp. 1-9.
2. Stille, W., Bohle, E. (1971) Clinical course and prognosis of Marburg ("Green Monkey") disease, in Martini, G.A., Siegert, R. eds., Marburg Virus Disease. Berlin and New York, Springer-Verlag, pp. 10-18.
3. Todarovitch, K., Mocitch, M., Klasniat (1971) Clinical picture of 2 patients infected by the Marburg Vervet virus, in Martini, G.A., Siegert, R. eds., Marburg Virus Disease. Berlin and New York, Springer-Verlag, pp. 19-23.
4. Gear, J.S.S., Cassel, G.A., Gear, A.J., et al.(1975) Outbreak of Marburg virus disease in Johannesburg. Br. Med. J. 4:489-493.
5. Monath, T.P. (1975) Lassa fever: Review of epidemiology and epizootiology. Bull. WHO 52:577-592.
6. Frame, J.D. (1975) Surveillance of Lassa fever in missionaries stationed in West Africa. Bull. WHO 52:593-598.
7. Bowen, E.W., Platt, G.S., Lloyd, G., et al. (1977) Viral hemorrhagic fever in southern Sudan and northern Zaire. Lancet 1:571-573.
8. Johnson, K.M., Webb, P.A., Lange, J., et al. (1977) Isolation and partial characterization of a new virus causing acute hemorrhagic fever in Zaire. Lancet 1:569-571.
9. Pattyn, S., Jacob, W., Van der Groen, G., et al. (1977) Isolation of Marburg like virus from a case of hemorrhagic fever in Zaire. Lancet 1:573-574.
10. Kemp, G.E. (1975) Viruses other than arenaviruses from West African wild mammals. Factors affecting transmission to man and domestic animals. Bull. WHO 52:615-620.
11. Van Velden, D.J., Meyer, J.D., Olivier, J., et al. (1977) Rift Valley fever affecting humans in South Africa. A clinicopathological study. S.Afr. Med. J. 51:867-871.
12. Maitztegui, J.I. (1975) Clinical and epidemiological patterns of Argentine hemorrhagic fever. Bull. WHO 52:567575.
13. MacKenzie, R.B., Beye, H.K., Valverde, L., Garron, H. (1964) Epidemic hemorrhagic fever in Bolivia. I. A preliminary report of the epidemiologic and clinical findings in a new epidemic area in South America. Am. J.Trop. Med. Hyg. 13:620-625.
14. Johnson, K.M., Halstead, S.B., Cohen, S.N. (1967) Hemorrhagic fevers of Southeast Asia and South America: A comparative appraisal. Prog. Med. Vir. 9:105-158.
15. Casals, J., Hoogstraal, H., Johnson, K.M., Shelokov, A., Wiebenga, N.H., Work, T.H. (1966) A current appraisal of hemorrhagic fevers in the USSR. Am. J. Trop. Med. Hyg. 15:751-764.
16. Frame, J.D., Baldwin, J.M., Goche, D.J., et al. (1970) Lassa fever, a new virus disease of man from West Africa. I. Clinical description and pathological findings. Am. J. Trop. Med. Hyg. 19:670-676.
17. Zweighaft, R.M., Fraser, D.W., Hattwick, M.A., et al. (1977) Lassa fever: Response to an imported case. N. Engl. J. Med. 297:803-807.
18. Pan American Health Organization (1977) Report to the Director of the Working Group on International Surveillance of Air Travelers. 21-23 March, 1977. Washington, D.C., DCD-77-1.


DISCUSSION
G.A. Eddy : What laws exist in respect to restricting quarantining and in fact incarcerating patients ? It is quite conceivable that someone who is highly suspected of Lassa fever might not wish to reside in that plastic bag. What do you do with such a patient ?
J.A. Bryan : As far as the U.S. goes, there are no national regulations to handle such a situation and it is very likely that that kind of event is going to occur. Some States, do have legislation that would permit them to quarantine or isolate individuals although it is usually phrased in a very vague kind of language.
L.M. Roots : The same holds in the U.K. under the Public Health Acts, if a person is a danger to the public, action can be taken.
H. Bijkerk : in the Netherlands we decided to include Lassa and other haemorrhagic fevers in the so-called "Group of notifiable diseases" meaning that they should be notified already on suspicion. This gives the right to the Health Authority in agreement with other experts to put some body in isolation.
P. Brès : I would like to go back to the survey of the different febrile syndrome to be considered in the differential diagnosis. I think that we concentrated very much during these three days on viruses but there are numerous tropical diseases which have to be taken into consideration. I would like to mention malaria that can be confused with encephalitis, meningococcemia, hepatitis, borreliosis, leptospirosis, and more rare diseases such as infection by Streptobacillus moniliformis.
J. McCormick : Speaking about import of HF in the Western world, some groups of people are at high risk for such transport. They are some of the volunteers agency people and missionaries who, unlike the tourists, are going in the areas where these endemic diseases exist. The experience over the last five years in Sierra Leone shows that another Peace Corps volunteer was transferred to the United States with Lassa fever about two years before the one that Dr. Bryan mentioned. Only it was discovered serologically about a year later after she was transported into the country. We established in Sierra Leone a liaison with all of the volunteers and some of the missionary groups, to have blood from them and put their serum away. We instructed them to come to us if ill, so that we can evaluate them. Recently we treated such a person who thought he had Lassa fever for he had been working in an endemic area. It turns out he my not have it, although we have not finished all the virus isolation work. There are probably other areas in Africa where some of these groups work, which are endemic for some of these diseases and it would be worth the time to try to establish liaison and perhaps even bleed them when they go, so that one has the serum already in store and also to instruct them on what they should do in their particular area when someone gets sick enough that he thinks he might have one of these diseases.
D.P. Francis : We can use for these diseases the same logic used in the smallpox eradication programme. For smallpox, it was quickly seen one should spent the money where the disease was and not at one's borders and thus save a lot of money in the long run. If we look at the amount of work being done at this moment to understand the disease especially in the field, it's minimal and the only effort to my knowledge is T. McCormick's on Lassa. It seems to me that with the amount of money spent in some individual laboratories, this kind of effort could be supported for a long time. Thirdly, with all respect to our home countries, I would like, in the now of the teams in the field, to thank South Africa for being the only country that really would welcome us if we were sick.

Previous PageTop Of PageNext Page