Acute rheumatism in children in its relation to heart disease.

Date:
1927
Catalogue details

Licence: Public Domain Mark

Credit: Acute rheumatism in children in its relation to heart disease. Source: Wellcome Collection.

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    that no rival has made out as good a case as his own will not necessarily enable him to escape a verdict of ‘‘ not proven.”’ Examination of the present position practically amounts to an analysis of the evidence for and against Streptococcus viridans. The Nature of Current Laboratory Work. It is best to begin with a concrete example which will enable one to form a mental picture of what is actually going on. Assisted by this, I propose to raise a series of questions which will then serve for detailed discussion. With this preliminary object in view, I have selected for quo- tation a recently published article which covers the ground fairly well. It must, of course, be remembered that there are many investigators in this field who are working on more or less similar lines and borrow freely from each other’s ideas and results ; no one of them claims to be pre-eminently superior to the rest. B. J. Clawson 2 (1925) isolated streptococci from 20 cases of ‘“‘ well defined, acute rheumatic fever, rheumatic endocarditis or chorea.” Fifteen strains were obtained during life, 13 from the blood and 2 from rheumatic joints. The five post-mortem cultures were made from pericardial exudate, spleen, or blood. The patients were in the second or third decades of life, except one who was only a few days old. The mother had developed acute rheumatic fever a short time before delivery; similar organisms were isolated from the baby’s joints and the mother’s blood. The joints were involved in all of the 20 cases and the hearts in all but 4. Chorea occurred once. | As the organisms were usually scanty, Clawson took 50 c.c. of blood and incubated the clot in 250 c.c. of dextrose (0°2 per cent.) beef infusion broth with a reaction of pH 7-6. The initial growth was slow. “‘ Rarely was the organism found in the cultures by smear in less than 5 days. The usual time was about 10 days after the beginning of incubation. In one case, the organism was recovered after incubating for nearly a month. It is evident that a higher percentage of positive cultures would be found if examinations were made over longer periods of time.’ When the smear was positive, the culture was plated on blood agar and colonies were picked for further propagation of the strain. All the strains except one were classed as Streptococcus viridans. The exception was a typical haemolytic streptococcus ; it was found in pure culture in relatively large numbers in the pericardial exudate of a child dying during an attack of acute rheumatic fever with pericarditis. He prepared sera with 10 rheumatic strains and, as controls, with 3 strains isolated from cases of subacute endocarditis. Of the rheumatic strains and sera, 7 were found by agglutination tests to form a homogeneous group. (There is no record of absorp- tion tests.) The remaining three were “ heterogeneous,” 2.e., each serum reacted only with its own strain. Two of the endo- carditis strains and sera fell into the same homogeneous group as