Age-specific Incidence Curves Research Articles

Epidemiology and histopathology of Hodgkin's disease in Finland.

All cases diagnosed as malignant lymphoma in Finland from 1961 to 1964 were histologically re-examined and re-classified. The original material consisted of 314 cases diagnosed as Hodgkin's disease, but after re-examination only 207 cases were regarded to be Hodgkin's disease. The age specific incidence curve of Hodgkin's disease both before and after re-examination was bimodal. The second peak was much lower in the re-examined series because of the exclusion of many non-Hodgkin's lymphomas. The bimodality was more clear in females. Hodgkin's disease was more common in urban than in rural areas. This difference was greatest in young adulthood. Nodular sclerosis, (NS) was the most common histologic type (53% in males, 83% in females). Its age specific incidence curve was bimodal with a high young adulthood peak. It was more common in urban areas and occurred there at younger age than in rural areas. Lymphocytic predominance, mixed cellularity and lymphocytic depletion groups had the highest incidence rates in old age. Hodgkin's disease seems to be a heterogeneous group composed of two or more entities, one of which is the young adult disease, probably the commonest entity in western countries especially in urban areas. The entities do not seem to correspond strictly to the present histologic types. However, most cases of NS probably represent young adult disease and most patients with young adult disease have NS.

Serological survey of rhinovirus infections in Japan.

Serological evidence for dissemination of rhinovirus serotypes 3, 5, 13, 14, 17, 26, 30 and 41, and a Japanese isolate 149N, which has not been typed as yet, was obtained by measuring neutralizing antibody in a total of 750 serum samples collected in Iwate Prefecture, a northern part of the main island Honshu of Japan, in 1965 to 1969. Judging from the age-specific antibody incidence curves obtained by testing sera from outpatients at Iwate Medical College Hospital, the circulation of types 13, 14, 30 and 41 seems more active than that of types 3, 5, 17 and 26. Comparison in the age-specific antibody incidence between two groups of sera collected from outpatients at the hospital over different periods, October 1968–June 1969 and February–August 1968, revealed very active circulation of types 13, 14 and 30 over the period between the collections as compared with type 41. Some differences in the age preference were shown among the serotypes. The results of tests in different cities showed marked differences in the antibody distribution by age depending upon the place and serotype. Seroconversion was shown in some individuals who were tested one year apart. These findings are interpreted to indicate that there is a constant flux in the serotypes infecting any given population, and that several serotypes are usually circulating almost simultaneously.