From the Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD.
Received for publication October 8, 2003; accepted for publication October 8, 2003.
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INTRODUCTION |
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The corollary of this decision was that the first two issues of each volume were likely to contain little of interest to epidemiologists. There were two exceptions in 1933. Volume 17 contained a review of the immunologic effects of vitamin A and D deficiencies, accompanied by a report on the authors experimental work with rabbits (1). Vitamin A-deficient rabbits showed a markedly diminished response to immunization with sheep or ox red cells, while controls and vitamin D-deficient animals responded normally. Both A deficiency and D deficiency were associated with increased susceptibility to infections with Bacterium lepisepticum and type I pneumococci.
Also published in a nonepidemiologic issue was a report from a study supported by the John J. Abel Fund for Research on the Common Cold (2). This study dealt with the incidence and distribution of minor respiratory illnesses among adults and children in 114 selected families. Weekly reports of all illnesses were provided by the families for a period of 2 years. Upon report of a case, a staff physician visited the family to obtain and record historical and clinical findings. The attack rate was highest among children aged 14 years. It declined to a low point among persons aged 1519 years, rose slightly among persons aged 2534 years, and gradually declined thereafter. The mean annual attack rate was 312 per 100 persons, with the highest rates being observed in the fall and winter.
Three additional reports from studies supported by the Abel Fund appeared in the epidemiologic issues of 1933. In the first of these (3), most of the participants were medical or public health students at the Johns Hopkins Medical Institutions. During the first 3 years, the numbers under observation in a given week varied from a low of 191 to a high of 364. During the fourth year, the study was limited to 5961 persons. The findings were essentially the same as those in the first study, with a mean annual attack rate of 313 per 100 persons. The most striking finding was that there was a relatively small effect of influenza outbreaks on the attack rate.
The second Abel Fund study to appear in an epidemiologic issue was a bacteriologic study with epidemiologic interest (4). It was based on 2,812 throat cultures obtained from 1,460 persons, mostly medical students and outpatients. Cultures were taken during the months of November through July in the years 19281931. Streptococcus haemolyticus (beta) was isolated in 8.3 percent of the cultures during the months of November through February and in 11.9 percent during the months of March through July. (Both percentages are weighted mean monthly percentages, as calculated by G. W. C.) Positive cultures were slightly more common among females than among males, and the frequency decreased from nearly 20 percent among children under the age of 10 years to 8.6 percent among persons over the age of 20 years. Positive cultures were more common if the fever was higher than 99°F or if the white blood cell count was greater than 10,000 per mm3. Positive cultures were slightly more common (11.9 percent vs. 9.0 percent) when there was a complaint of sore throat, as long as acute follicular tonsillitis was not present. This finding calls into question the wisdom of the almost routine practice at present of prescribing antibiotics if a throat culture shows beta-hemolytic streptococci.
What appears to have been the final report from an Abel Fund study appeared in the epidemiologic issue of volume 18 (5). It dealt with the stability of apparent immunity to attacks of the common cold. It had long been noted that some persons seemed completely immune during a given cold season and that others seemed to be immune for an average of 7 weeks after their first attack. By studying the same people over a period of several years, the Abel Fund researchers were able to show that individuals had much the same degree of immunity in the second year that they had in the first. The correlation between degrees of immunity in the first and third years was poor; the correlation between the first and fourth years was no better than that expected to occur by chance. The bibliography of the paper lists 37 publications based on studies supported by the John J. Abel Fund (5).
A group whose research was devoted to minor respiratory illnesses in isolated communities furnished a report on the situation in Spitsbergen, an island archipelago lying midway between northern Norway and the North Pole (6). Almost the entire population lived in Longyear City and were employed by the coal industry. Outside contacts occurred only during the short summer shipping season. The mean annual incidence of colds was approximately 100 per 100 persons. Peak incidence occurred shortly after the arrival of the first ship. Colds occurred at a lower rate for the rest of the summer, with only rare and scattered cases being seen for the rest of the year. The average incubation period was 48 hours. Sudden changes in temperature were not associated with colds.
Students of poliomyelitis had suspected that the decreasing attack rate of the disease with age after infancy must be due to immunity following nonparalytic illnesses with nonspecific symptoms, often referred to as abortive cases. In the first paper of a series, John R. Paul and colleagues described their method of identifying and defining these abortive cases (7). They studied 225 families with 215 children in which a diagnosed case of poliomyelitis had occurred. A detailed history of all illnesses among family members was obtained for the 3 weeks preceding and the 3 weeks following the diagnosis of the first family case. An abortive poliomyelitis illness was defined as one with fever, usually accompanied by vomiting, headache, and sore throat, that lasted for only a day or two. Malaise was often present for some time thereafter. Sixty-one similar families without a diagnosed case were also studied for a 6-week period during the poliomyelitis season.
In a second paper, the same authors reported their findings (8). When abortive cases were added to diagnosed cases, the attack rate for poliomyelitis was similar in magnitude and age distribution to the rates of other childhood communicable diseases. From age 5 years to age 16 years, the ratio of paralytic cases to abortive cases decreased, while after the age of 16 years, abortive cases became relatively uncommon.
Hedrich, in a paper derived from his doctoral thesis, developed a formula for calculating the proportion of children under the age of 15 years who would be considered susceptible to measles (9). From 1900 through 1931, this proportion in Baltimore ranged from 32 percent to 53 percent, producing an irregular saw-toothed curve. Peaks occurred at the start of years in which a measles outbreak occurred; troughs were seen in the following years. This historical article should interest persons who deal with epidemic modeling.
Two papers investigated the high proportion of Canadian and Greenland Eskimos (now more properly referred to as Inuit) whose Schick tests showed that they were immune to diphtheria (10, 11). This was a surprising finding, because there was no history or record of diphtheria ever having been present in these isolated communities. The first of the two papers reported on throat flora (10). The mixture of organisms obtained from the throats of normal Eskimos was similar to that obtained from persons living in the United States or Europe. Typical Corynebacteriae diphtheriae were relatively common. The authors suggested that these organisms must be relatively avirulent, capable of causing only apparent infections and consequent immunity.
A second paper added to Schick testing the results of testing of serum samples for antitoxin (11). Approximately half of the Eskimos who were tested had positive Schick tests, a proportion slightly higher than that found in a crudely age-matched group of children in Vienna, Austria, where diphtheria was endemic. The proportion of adults with demonstrable concentrations of antitoxin was approximately the same among Eskimos and a group in St. Louis, Missouri. These findings confirmed the authors belief that immunity among Eskimos was the result of relatively widespread infection with avirulent organisms.
While the paper entitled "Urbanization, Prosperity and Mortality in United States Counties" is ecologic (12), its findings fit with the current interest in using the characteristics of place of residence as risk factors in epidemiologic studies. This report by Wu and Winslow, once again a distillation of the first authors doctoral thesis, was based on 1,926 of the 3,054 counties in the United States in 1920 for which death rates were available in six categories: all causes, cancer, pneumonia, tuberculosis, typhoid fever, and diseases of infancy. Independent variables included demographic, sociologic, and economic indicators for each county, along with a measure of availability of medical carethe ratio of number of physicians to the total county population. Unexpectedly, initial analyses showed that indices of prosperity had a positive association with mortality from all causes, cancer, pneumonia, tuberculosis, and diseases of infancy. However, after other factors had been taken into account, prosperity was a favorable factor, while urbanization was not. Typhoid fever had a negative association with indices of prosperity and urbanization, except for the availability of medical services. (If there are no physicians in a given area, who will diagnose and report typhoid fever?) The authors concluded that "urbanization and industrialism involve very real health hazards" (12, p. 538).
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ACKNOWLEDGMENTS |
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NOTES |
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REFERENCES |
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