Volume 1

Some enumerative studies on malarial fever / by Ronald Ross and David Thomson.

  • Ronald Ross
Date:
[1910?]
Catalogue details

Licence: Public Domain Mark

Credit: Some enumerative studies on malarial fever / by Ronald Ross and David Thomson. Source: Wellcome Collection.

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    One kilogramme of blood of average density (10575) contains 945,626 cu. mm., and the blood in a man’s body is estimated to weigh about 4°9 per cent. of the total body weight—from which data it 1s easy to compute the total number of parasites in a patient. A man of 64°74 kilogrammes, or about 10 stone, will contain about 3,000,000 cu. mm. of blood. 4, The Cases studied by us numbered 33. All had been infected in West Africa or America, so that none was of less than some weeks’ duration when admitted into hospital in Liverpool. All were males of from 18 to 60 years of age. They were mostly shipmen or traders, and two were negroes. The parasites of all were counted almost every day and sometimes several times a day ; and the temperature was taken every four hours, or more often. One case showed Plasmodium malaria, together with crescents (sexual forms of P. falciparum). Eight showed P. vivax only, and 24 P. falewparum only, two of the latter containing only sexual forms. Quinine was often withheld for some days while other methods of treatment were used. The cases were studied for over 600 days altogether. There were no deaths. All the cases will be recorded in the ‘Annals of Tropical Medicine,’ vol. 4, No. 3, but charts of Cases 17 and 20 are given on pp. 164 and 165. At this preliminary stage of the enquiry we have undertaken to study only the gross daily correlations between the numbers of parasites and othe1 phenomena—leaving more minute hourly or four-hourly analysis to future work. Hence, if a number of counts or other observations have been made on one day, we have recorded only the averages in the tables. For tempera- tures, however, it has been thought best to record maxima instead of averages, and, as the tables should be as economical as possible, we have used the hemnatothermic scale suggested by one of us (R. R.), in which the 10° between 95° and 105° F., or between 35° and 45° C., are divided into 100 parts. Except in Case 6, specially studied by Dr. Fantham, we have not distin- guished in the tables the various forms, sets, or stages of P. vivax—this being reserved for future study. Similarly, the treatment, leucocytes, heemoglobin, and urobilin are not differentiated too minutely. Case 25 was counted by Dr. Korke. 9. Lhe Correlation between the Parasites and the Fever—It is well known that fever is caused only by the asexual forms of the parasites, but though these are generally thought to be more abundant during pyrexial periods, no extensive numerical studies on the point appear to have been made, with the result that some sceptics still profess doubts on the subject. Our cases, except four without fever (Cases 1, 15, 16, 27), would seem to indicate a very strong (almost convincing) correlation. Twenty-one of them suffered each from one pyrexial period, lasting from one to seven days, and preceded
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