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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    may be the true cause of a disease though its pathogenicity is inconstant. | Recognition that a bacterium may produce disease in more ways than one makes it. difficult for the bacteriologist to plan suitable “‘ control’? experiments. It certainly seems very doubtful whether cultures of viridans from endocarditis lenta can be: re- garded as appropriate “ controls.’”’ As Clawson and many others have urged, rheumatic fever and bacterial endocarditis may be different stages of the same infection ; or they may be different types of infection due to the same bacterium. And _ the experimental behaviour of a strain of viridans which has not been associated with either of these diseases is not particularly helpful as a ‘‘control’’; whether it resembles or differs from the rheumatic strains, its behaviour will not settle the question as to the aetiology of the latter. Main and Subsidiary Issues. First a few words may be said about the alternative theory that streptococci are only secondary invaders, the true causal agent being a filter-passer. The two obvious difficulties about this view are that there has been no satisfactory demonstration of an ultra-microscopic virus and that diseases thought to be due to viruses of this nature are generally of high infectivity, a property which is certainly not associated with rheumatic fever. It may, however, be argued that knowledge of filter-passers is still in a rudimentary condition and the door is open for fresh discoveries. That is true enough. So anyone who wishes to pursue the search is entitled to say that this question remains a main issue in the aetiology of acute rheumatism. To return to viridans. Further work on blood cultures is of primary importance. The results are never likely to be so consistently positive as, for example, the detection of meningo- cocci in the spinal fluid from cases of cerebro-spinal fever. But positive findings are already substantial enough to justify a thorough antigenic analysis by modern methods, involving chemical work such as Lancefield’s as well as resort to absorption of agglutinins and other refinements of immunological tests. As regards other tests, most recent workers have failed to correlate serological reactions with capacity to ferment particular carbo- hydrates. ‘These “ sugar tests,” if they are not to be abandoned altogether, cannot be regarded as more than subsidiary. Occasionally cultures of viridans have been obtained from rheumatic joints and, more rarely, from subcutaneous nodules. These reports are interesting, but, owing to the preponderance of negative results, | think the majority of observers agree that such data have not assumed major importance. Throat cultures do not seem to me to be helpful. Streptococci are of such common occurrence in this situation, in other diseases | and in health, that a positive result is of little or no significance. And, if the bacteriologist finds that the throat of a rheumatic fever