Created by Oswald Eden Dickinson
Feb 1924
Description:

'Sir,

You are doubtless aware that during the past year the Board has had under consideration the clinical trials which are being made in some mental hospitals in England and Scotland of the method of treating general paralysis by inducing attacks of inoculated malaria. The trials have the approval of the Board and their progress and results are being observed with great interest. Since July, 1923, the Ministry of Health has collaborated with the Board in enquiring into the subject, particularly with reference to its public health aspects. It is the purpose of the present circular letter to inform you of the chief results of this joint consideration and enquiry, and to state the rules based upon them which in the opinion of the Board should now be followed in mental hospitals where the treatment is or will be applied.

The results of the enquiry have shown in the first place that there are differences, some of them important, between the procedure adopted for carrying out the treatment in England and the procedure which it is understood to have been usually recommended by the initiators of this therapeutic measure in Austria, and that there are also differences of procedure among even the few hospitals where trials are being made in England. It is not proposed to detail these differences in the present letter, but in view of the Board’s desire to obtain as soon as possible a considered decision on the merits of the measure in England it is important to secure uniformity of procedure and practice in all the hospitals where the trials are being arranged. Next it has to be recorded that in some instances induced malaria in the inoculated cases in England has been of an unusually severe type accompanied by pronounced complications and with a tendency to fatality. When the trials were begun it was thought that inoculated malaria might differ in important respects from the naturally contracted disease and that in particular the cases would be of very mild type, that no relapses would follow their treatment and that the parasites in the blood of the patients would be too scanty to cause infection of mosquitoes before treatment was begun. It has been found, however, that no essential difference can be detected between the cases of induced malaria in England and somewhat severe cases of the naturally contracted disease as it occurs in the tropics. It is believed that as regards one strain of the parasite (“Benign tertian”) which has been particularly studied, its severity is a consequence in part of an increased activity and virulence resulting from its cultivation by direct passage through many human hosts. It is hoped that a strain of parasites which is free from objection on grounds of severity will be available shortly, but in any case the Board is advised that it is practicable to prevent the occurrence of untoward symptoms and complications by arranging that the blood of all inoculated patients shall be examined daily with a view to indicate when it may be necessary or advisable to cut short or to modify the course of the infection by treating the patient with quinine. It has been ascertained that in patients suffering from general paralysis clinical symptoms and signs are not a sufficient or satisfactory guide for arriving at this important decision. In a few cases which have been studied from the beginning of the malarial attacks the onset of severe complications was not apparent clinically but was observed to be preceded by a phenomenal increase of parasites and the appearance of other marked pathological changes in the peripheral blood which indicated clearly that to ensure timely treatment expert blood examination at least daily is a necessary procedure during the period of the malarial course. This procedure is also required in connection with the risk to which Professor Mühlens of Hamburg has recently drawn attention of unwittingly conveying a mixed infection of benign and malignant parasites from donors of blood who contract their malaria in the tropics. A translation of Professor Mühlens’ article is enclosed as an appendix to this letter.

The next most important result to be noted is that the investigation carried out by the Ministry of Health has shown that the common malaria-carrying mosquito of England (Anopheles maculipennis) after sucking blood from inoculated patients readily becomes infected and capable of spreading malaria to other patients and to the general public. You are aware that this mosquito is distributed practically everywhere in England. It is active and to be found in all stages of its life history during the months of May to October, but during the winter months only the adult female insects remain alive. They have been found during those months in a relatively inactive sluggish condition (so-called hibernating condition) in the stables and cowsheds of the farms attached to many mental hospitals situated in rural districts of the country. From November until the end of March, on account of the inactivity of the mosquito and the low atmospheric temperature, the risk of spreading malaria is negligable, but during the rest of the year adequate measures to prevent the risk are considered to be essential. They consist in providing that all inoculated patients shall be kept in a mosquito-proof ward or under satisfactory mosquito curtains from the onset of the malaria attacks until careful microscopical blood examination shall have proved that the blood is free from the sexual forms of the parasite which are infective to mosquitoes. This will usually be the case about three days after commencing a proper course of quinine treatment.

In connection with the same risk careful consideration has been given to the question whether or not patients who have undergone a course of treatment with inoculated malaria are liable to suffer subsequently from malarial relapses. In both Austria and England the opinion has been published that an entire absence of relapses is a particular feature of inoculated malaria. While this may be true as regards the cases hitherto observed in Austria, where the strain of parasite used for the original inoculations was of mild European indigenous type and where quinine dosage is in accordance with tropical practice, the present enquiry has shown that the opinion does not always hold good for cases in England, where the strains of parasite hitherto used were originally derived from the tropics and where in some instances treatment has been with only small doses of quinine. In these instances what are technically known as “parasitic relapses” have been detected by examination of the blood of patients some weeks after apparent clinical recovery. It is considered that if patients who are liable to these relapses were discharged to their homes in certain areas of the country they would provide a potential source of spread of malaria to their families and neighbours. For this reason it is strongly recommended that examination of the blood of inoculated patients should continue to be made at intervals until freedom from parasites has lasted at least three weeks. It is also considered necessary that when a patient who has undergone a course of malarial attacks is discharged from the hospital his name and home address should be notified to the Medical Officer of Health of the district to which he is discharged.

Lastly, it is desired particularly to emphasise the importance of effective quinine treatment and “after-treatment” in the interests equally of the patients and of the public. It is necessary that the patients should be thoroughly treated with quinine both to ensure their speedy recovery from teh induced malaria and to minimise as far as possible the risk that they will suffer subsequently from malarial relapses when discharged to their homes. This applies not only to cases in which the clinical course of the malaria is typical but also to certain cases which have been reported as instances of “spontaneous recovery”, for in some of the latter cases parasites have been found in the blod more than a month after observed attacks of fever has ceased. It is strongly recommended that the course of quinine treatment and “after-treatment” should be uniform in all hospitals and that it should be in accordance with usual tropical practice.

The rules which are recommended for adoption in connexion with the new line of treatment may now be summarized as follows:-

(1) The hospital should be adequately equipped with laboratory facilities for systematic blood examinations which as regards all inoculated patients should be made daily from the date of onset of the first febrile attack.

(2) The medical officer or laboratory assistant who makes the microscopic blood examinations should be well qualified in this branch of laboratory work.

(3) The patients undergoing the course of treatment should be in charge of a medical officer who is familiar with malaria in all its aspects. During the period of the course the patients should be nursed and nourished with special care and the progress of the infection should be modified or controlled from day to day in accordance with the laboratory findings and the clinical signs.

(4) From the 1st April until the 30th October patients undergoing the course of treatment should be kept in a mosquito-proof ward or under satisfactory mosquito curtains during the period when parasites are present in their blood.

(5) Treatment by induced malaria should be confined to hospitals in which all the above rules are complied with.

(6) Notification of cases of inoculated malaria to the local medical officer of health under the Public Health (Pneumonia, Malaria, Dysentery, etc) Regulations, 1919, will not be required until the patient is discharged from the hospital, when his name and home address with an intimation that he has undergone a course of inoculated malaria should be notified to the medical officer of health of the district in which he will reside.

[(7) [sic] As regards any trial of the measure which may be made outside mental hospitals, no modification of the Regulations of 1919 is contemplated in respect of any cases of induced malaria which are not dealt with in accordance with the procedure outlined in the above rules.] [sic]

I am to ask that you will let me know as soon as possible for the information of the Board whether trial of the new line of treatment can be carried out in your hospital in accordance with these rules and that if the reply is in the negative you will state what new or additional arrangements would be necessary. I am to add that to assist in providing facilities for compliance with rules (2) and (3) the Ministry of Health is prepared to arrange departmentally for a short practical course of instruction which a limited number of medical officers can attend. I shall be glad to know whether you desire that one of your medical officers should take part in this course. It is advisable that the officer selected should have had some experience of pathological laboratory work.

I am etc.

O.E. Dickinson’

[letter drafted by James]

[attached: translation of P. Mühlens, ‘The Dangers of the fever treatment of Paralysis,’ Klinische Wochenschrift, 24th Dec. 1923, p. 2340. [7890-7892]]