Created by Sydney Price James
1924
Description:

'[Chart: 'Case W.']

Colonel S.P. JAMES.-- Further Specimens and Charts illustrating Naturally Infected Malarla in Cases of General Paralysis in England.

My exhibition to-night relates to the treatment of general paralysis with malaria, and is in continuation of the demonstration on the same subject which I gave at the Society's last labora$ory meeting. The material shown comprises:-- 

1. Copies of an official memorandum recording the chief results of the enquiry into the technique of the treatment as it has been carried out hitherto in England, and of the rules which it is desired should be followed in future.

2. Selected temperature charts from a series of sixteen cases, in which the malaria has been induced not by direct inoculation of blood but by the bites of infected mosquitoes.

3. Microscopic specimens of the parasite in the blood of the patients and in the stomach and salivary glands of the mosquito.

It is recorded in the memorandum that, in some instances, the malaria induced by direct inoculation of blood has been of an unusually severe type, accompanied by pronounced complications and with a tendency to fatality. We believe that this severity is a consequence in part of an increased activity and virulence resulting from the cultivation of the parasite by direct passage through many human hosts. Having in view what happens as regards acquired characters in some other protozoa, I thought it possible that passage of the strain through its insect host would cause it to lose this added virulence. I may say at once that this conjecture has not been confirmed. The temperature charts show that the malaria in the mosquito-infected cases is of quite a severe type, and that in the majority of instances we have been obliged to resort to quinine after the patient has passed through seven or eight [2-3]

[chart: [patient 'A']]

paroxysms. The copurse of the temperature of the patient A----, who was infected by inoculating 2c.c. of blood from the mosquito-infected patient M----, is particularly instructive. It is quite clear from the chart that if the strain of parasites by passage through the mosquito has undergone any change of virulence, the change is an increase rather than a diminution. From the point of view of the treatment of general paralysis, it is, of course, a great advantage to have available a strain of parasites which cause high temperatures, but it means that great care must be taken in the nursing and treatment of the cases. If the fever influence is that of a "spirochaeticide," it would seem, from the experiments of WEICHBRODT and JAHMEL, that a temperature of 105° or 106° must be reached to be effective. On this ground our present strain is probably the most effective yet obtained.

The charts show the course of the temperature during the incubation period and early days of the febrile attacks, and demonstrate that, though the patients were bitten on only one occasion, their fever in most cases was of quotidian type.

Note.-- The case of W----, which has developed since the laboratory meeting was held, is of particular interest in this connection, and I have, therefore, asked to be permitted to publish the temperature chart of the case in these TRANSACTIONS. The patient, a boy aged 13, was a case of infantile general paralysis under the care of Dr. FIRTH, at King's College Hospital. On 15th March, in the forenoon, two mosquitoes (maculipennis) were applied to the patient's thigh and closely watched. Only one of them was seen to bite, and when they were removed from the leg it was found that neither of them had sucked blood. But as the mark of one bite was plainly visible, and later became a definite wheal, I did not consider it necessary, that the patient [3-4] should be bitten again. The attack of malaria which the chart illustrates began on the tenth day following the single bite, which (as no blood had been extracted by the mosquito) could not have lasted more than a few seconds. We know from numerous examinations of the strain in other patients, both before and after its passage through the mosquito, that it is a pure benign tertian strain, but I find it difficult to explain why it causes so frequently a quotidian type of fever. In the case illustrated the fever was quotidian from the first, but, unfortunately, I had no opportunity of making the frequent blood examinations which would be necessary for endeavouring to correlate the growth and sporulation of the parasites with the particular times at which the rigors occurred. It would be very surprising if it could be shown that a strain of Plasmodium vivax, which has been passed through many human hosts and through a mosquito, goes through its asexual cycle in the blood of man in a period of approximately twenty-four hours instead of forty-eight.'