Centers for disease control and prevention.

Fifty Years of History

Editor's note: Throughout the last 50 years, the Centers for Disease Control and Prevention has made invaluable contributions to the field of environmental health. In bringing you a portion of its 50th Anniversary story, as published in the June 28, 1996 issue of Morbidity and Mortality Weekly Report, we hope you share our appreciation for the history of this organization and the impact it has made upon our dedicated profession.

CDC, an institution synonymous around the world with public health, [turned] 50 years old on July 1. The Communicable Disease Center was organized in Atlanta, Georgia, on July 1, 1946; its founder, Dr. Joseph W. Mountin, was a visionary public health leader who had high hopes for this small and comparatively insignificant branch of the Public Health Service (PHS). It occupied only one floor of the Volunteer Building on Peachtree Street and had fewer than 400 employees, most of whom were engineers and entomologists. Until the previous day, they had worked for Malaria Control in War Areas, the predecessor of CDC...which had successfully kept the southeastern states malaria-free during World War II and, for approximately one year, from murine typhus fever. The new institution would expand its interests to include all communicable diseases and would be the servant of the states, providing practical help whenever called.

Distinguished scientists soon filled CDC's laboratories, and many states and foreign countries sent their public health staffs to Atlanta for training. Any tropical disease with an insect vector and all those of zoological origin came within its purview. Dr. Mountin was not satisfied with this progress, and he impatiently pushed the staff to do more. He reminded them that except for tuberculosis and venereal disease, which had separate units in Washington, D.C., CDC was responsible for any communicable disease. To survive, it had to become a center for epidemiology.

Medical epidemiologists were scarce, and it was not until 1949 that Dr. Alexander Langmuir arrived to head the epidemiology branch. He saw CDC as "the promised land," full of possibilities. Within months, he launched the first-ever disease surveillance program, which confirmed his suspicion that malaria, on which CDC spent the largest portion of its budget, had long since disappeared. Subsequently, disease surveillance became the cornerstone on which CDC's mission of service to the states was built and, in time, changed the practice of public health.

The outbreak of the Korean War in 1950 was the impetus for creating CDC's Epidemic Intelligence Service (ELS). The threat of biological warfare loomed, and Dr. Langmuir, the most knowledgeable person in PHS about this arcane subject, saw an opportunity to train epidemiologists who would guard against ordinary threats to public health while watching out for alien germs. The first class of ElS officers arrived in Atlanta for training in 1951 and pledged to go wherever they were called for the next two years. These "disease detectives" quickly gained fame for "shoe-leather epidemiology" through which they ferreted out the cause of disease outbreaks.

The survival of CDC as an institution was not at all certain in the 1950s. In 1947, Emory University gave land on Clifton Road for a headquarters, but construction did not begin for more than a decade. PHS was so intent on research and the rapid growth of the National Institutes of Health that it showed little interest in what happened in Atlanta. Congress, despite the long delay in appropriating money for new buildings, was much more receptive to CDC's pleas for support than either PHS or the Bureau of the Budget.

Two major health crises in the mid-1950s established CDC's credibility and ensured its survival. In 1955, when poliomyelitis appeared in children who had received the recently approved Salk vaccine, the national inoculation program was stopped. The cases were traced to contaminated vaccine from a laboratory in California; the problem was corrected, and the inoculation program, at least for first and second graders, was resumed. The resistance of these 6- and 7-year-olds to polio, compared with that of older children, proved the effectiveness of the vaccine. Two years later, surveillance was used again to trace the course of a massive influenza epidemic. From the data gathered in 1957 and subsequent years, the national guidelines for influenza vaccine were developed.

CDC grew by acquisition. The venereal disease program came to Atlanta in 1957 and with it the first Public Health Advisors, nonscience college graduates destined to play an important role in making CDC's disease-control programs work. The tuberculosis program moved in 1960, immunization practices and the MMWR in 1961. The Foreign Quarantine Service, one of the oldest and most prestigious units of PHS, came in 1967; many of its positions were soon switched to other uses as better ways of doing the work of quarantine, primarily through overseas surveillance, were developed. The long-established nutrition program also moved to CDC, as well as the National Institute for Occupational Safety and Health, and work of already established units increased. Immunization tackled measles and rubella control; epidemiology added family planning and surveillance of chronic diseases. When CDC joined the international malaria-eradication program and accepted responsibility for protecting the earth from moon germs and vice versa, CDC's mission stretched overseas and into space.

CDC played a key role in one of the greatest triumphs of public health: the eradication of smallpox. In 1962 it established a smallpox surveillance unit, and a year later tested a newly developed jet gun and vaccine in the Pacific island nation of Tonga. After refining vaccination techniques in Brazil, CDC began work in Central and West Africa in 1966. When millions of people there had been vaccinated, CDC used surveillance to speed the work along. The World Health Organization used this "eradication escalation" technique elsewhere with such success that global eradication of small-pox was achieved by 1977. The United States spent only $32 million on the project, about the cost of keeping smallpox at bay for 2 1/2 months.

CDC also achieved notable success at home tracking new and mysterious disease outbreaks. In the mid-1970s and early 1980s, it found the cause of Legionnaires disease and toxic-shock syndrome. A fatal disease, subsequently named acquired immunodeficiency syndrome (AIDS), was first mentioned in the June 5, 1981, issue of MMWR. Since then, MMWR has published numerous follow-up articles about AIDS, and one of the largest portions of CDC's budget and staff is assigned to address this disease.

Although CDC succeeded more often than it failed, it did not escape criticism. For example, television and press reports about the Tuskegee study on long-term effects of untreated syphilis in black men created a storm of protest in 1972. This study had been initiated by PHS and other organizations in 1932 and was transferred to CDC in 1957. Although the effectiveness of penicillin as a therapy for syphilis had been established during the late 1940s, participants in this study remained untreated until the study was brought to public attention. CDC also was criticized because of the 1976 effort to vaccinate the U.S. population against swine flu, the infamous killer of 1918-19. When some vaccinees developed Guillain-Barre syndrome, the campaign was stopped immediately; the epidemic never occurred.

As the scope of CDC's activities expanded far beyond communicable diseases, its name had to be changed. In 1970 it became the Center for Disease Control, and in 1981, after extensive reorganization, Center became Centers. The words "and Prevention" were added in 1992, but, by law, the well-known three-letter acronym was retained. In health emergencies CDC means an answer to SOS calls from anywhere in the world, such as the recent one from Zaire where Ebola fever raged.

Fifty years ago CDC's agenda was noncontroversial (hardly anyone objected to the pursuit of germs), and Atlanta was a backwater. In 1996, CDC's programs are often tied to economic, political, and social issues, and Atlanta is as near Washington as the tap of a keyboard.

(Adapted for MMWR by Elizabeth W. Etheridge, Ph.D., from her book, Sentinel for Health: A History of the Centers for Disease Control. Berkeley, California: University of California Press, 1992.)

Notifiable Disease Surveillance and Statistics - United States, June 1946 and June 1996

National surveillance for infectious diseases is used to document the morbidity and impact associated with these conditions in the United States. This report includes morbidity data for the weeks ending June 8, 1946, and June 22, 1996, and describes changes since 1946 both in the procedures for conducting surveillance and in the incidence of selected diseases.

Surveillance Notes

The history of the reporting and tracking of diseases that could pose a risk to public health in the United States dates back more than a century. In 1878, Congress authorized the U.S. Marine Hospital Service (the forerunner of today's Public Health Service [PHS]) to collect morbidity reports on cholera, smallpox, plague, and yellow fever from U.S. consuls overseas; this information was used to institute quarantine measures to prevent the introduction and spread of these diseases into the United States. In 1879, a specific Congressional appropriation was made for collecting and publishing reports of these notifiable diseases. The authority for weekly reporting and publication was expanded by Congress in 1893 to include data from states and municipal authorities. By 1928, all states, the District of Columbia, Hawaii, and Puerto Rico were reporting 29 infectious diseases to the Surgeon General.

Fifty years ago, morbidity statistics published each week were accompanied by the statement "No health department, State or local, can effectively prevent or control disease without knowledge of when, where, and under what conditions cases are occurring." These statistics appeared under the heading "Prevalence of Disease - United States" in each issue of Public Health Reports printed by PHS, Office of the Surgeon General. In 1949, the collection, compilation, and publication of these morbidity statistics was transferred to the National Office of Vital Statistics, which produced the Weekly Morbidity Report. In 1952 the publication was renamed Morbidity and Mortality Weekly Report, and responsibility for the publication was transferred to CDC in 1961.

In 1946, reports of notifiable diseases consisted of summary statistics, transmitted by telegram each week by all state and some city health officers. The numbers were tabulated and sent immediately by letter to each site for verification. Data published in the June 28, 1946, issue of Public Health Reports were for the week ending June 8,1946. Today, for most diseases, each state health department enters individual case reports (rather than summary numbers) into a computer for transmission to CDC through the National Electronic Telecommunications System for Surveillance.... Except for New York City and Washington, D.C., morbidity data from individual cities are no longer published weekly.

Because the reporting frequency varied for different conditions (i.e., weekly, monthly, or annually), the precise number of conditions considered nationally reportable in 1946 is unclear. The first list of 41 infectious diseases that all states agreed should be nationally notifiable to PHS was developed at the first conference of state and territorial epidemiologists in 1951 (1). This group was the forerunner of the Council of State and Territorial Epidemiologists (CSTE), now CDC's primary collaborator for determining what is nationally reportable. In 1951, as now, because reporting can be mandated only at the state level, reporting to CDC by the states was voluntary. Today, 52 infectious diseases are notifiable nationally (2); in addition, at the 1995 CSTE meeting, the first noninfectious condition - elevated blood lead levels - was added to the list of conditions designated as reportable at a national level (3). On June 6, 1996, CSTE added silicosis and acute pesticide poisoning/ injuries to the list of nationally reportable conditions. Also on June 6, CSTE unanimously agreed to include prevalence of cigarette smoking in the list of conditions designated as reportable by states to CDC; this is the first time tobacco has been included and the first time a risk behavior, rather than a disease or illness, has been included.

Disease Notes

Comparing reports of notifiable conditions during June 1946 and June 1996 highlights some of the differences in the prevalent or common diseases. For example, 50 years ago, in the fundamentally prevaccine era, for the week ending June 8, 1946, health departments reported 161 cases of poliomyelitis, 229 cases of diphtheria, 1886 cases of pertussis, and 25,041 cases of measles. Through the week ending June 22, 1996, a cumulative total of no confirmed cases of polio, one case of diphtheria, 1419 cases of pertussis, and 263 cases of measles have been reported for 1996. Since 1946, vaccines have been licensed for all four of these conditions: diphtheria and tetanus toxoids and pertussis vaccine in 1949, inactivated polio vaccine in 1955 and live attenuated vaccine in 1961, and measles vaccine in 1963. Because of the advent of these and other disease-control strategies, during the past decade public health authorities have established as targets for the year 2000 eradication of polio globally and measles elimination in the Americas. Four cases of another vaccine-preventable disease, smallpox, were reported for the week ending June 8,1946, and a total of 337 cases for the entire year of 1946; the last documented cases of smallpox in the United States occurred 3 years later, in 1949. In 1958, the World Health Organization targeted smallpox for global eradication, a campaign that was declared successful in 1980 (4).

Among the 10 nationally notifiable infectious diseases that are most commonly reportable today, several were unknown in June 1946. The 10 most frequent nationally reportable infectious conditions in 1994 (the most recent year for which final data are available) were, in descending order, gonorrhea, acquired immunodeficiency syndrome (AIDS), salmonellosis, shigellosis, hepatitis A, tuberculosis, primary and secondary syphilis, Lyme disease, hepatitis B, and pertussis (5). Fifty years ago, AIDS and Lyme disease were unknown. "Infectious hepatitis" (subsequently identified as hepatitis A) had just been identified, and morbidity reports for this condition first appeared in 1947. In 1953, serum hepatitis (subsequently named hepatitis B) was recognized as a separate entity, although it was included in the general category of hepatitis until 1966, when infectious and serum hepatitis began to be reported separately. Other diseases reported on a weekly basis during 1946 included amebiasis, murine typhus fever, and tularemia; during the past 10 years, these three conditions were deleted from the nationally notifiable disease list and are no longer routinely reported to CDC.

Because of the acknowledged under-reporting of most diseases (particularly those typically characterized by clinically mild illness) to this passive surveillance system, the National Notifiable Disease Surveillance System (NNDSS) does not capture all cases of disease nationwide. However, these data are essential for monitoring disease trends and for determining relative disease burdens. In addition, this same NNDSS - with origins dating more than a century ago - continues to be used for monitoring the decline in incidence of vaccine-preventable and other diseases and to detect and document the appearance of new public health problems.

Reported by: Systems Operations and Information Branch, Div. of Surveillance and Epidemiology, Epidemiology Program Office, CDC.

REFERENCES

1. CDC (1952), "National Morbidity Reporting - 1952," CDC Bulletin 1951, 12:50-3.

2. CDC (1996), "Changes in National Notifiable Diseases Data Presentation," MMWR 1996, 45:41-2.

3. CDC (1995), "Blood Lead Levels Among Children - Rhode Island, 1993-1995," MMWR 1995, 44:788-91.

4. World Health Organization (1980), "The Global Eradication of Smallpox," Final Report of the Global Commission for the Certification of Smallpox Eradication, Geneva:World Health Organization.

5. CDC (1994), "Summary of Notifiable Diseases, United States, 1994," MMWR 1994, 43(53).