April 2, 1903 J 



NA TURE 



5*3 



,1 RECENT STUDY OF MALARIA. 1 



\\f HEN Drs. Stephens and Christophers, the Royal 

 * * Society's Commission on Malaria, were in India, 

 Captain James had the advantage of being associated 

 with them, and the present volume contains the result 

 of his own observations, both at that time and since. 

 The writer first gives a detailed and eminently practical 

 description of the methods he has found most useful for 

 detecting the malarial parasite in the blood of patients, 

 and for tracing its further development in mosquitoes. 

 An important point to which he draws attention is that 

 the hospitals and jails of India are seriously discounted 

 as fields for the study of the malarial parasite by the 

 fact that the great majority of the patients are under the 

 influence of quinine, in which case the parasites are apt 

 to be banished from the peripheral circulation. In the 

 investigation of malaria among the general population 

 the same fact holds for India as Koch, Stephens, and 

 Christophers have independently, found for Africa, 

 namely, that in any place which is more or less 

 malarious, a certain number of young children will 

 have malaria parasites in their blood, and the per- 

 centage of young children so affected affords the most 

 accurate test of the amount of malaria and the liability 

 to infection existing there. The percentage of infected 

 children, or, as it is called, the "endemic index," is 

 therefore the first thing to determine when investigating 

 a village for malaria. The variety of parasites present 

 in the children's blood, and the number of cases of 

 " large infection," are further points to be observed, 

 for if there are a good number of large in- 

 fections, there will be more likelihood of finding 

 infected anopheles. A search is then made for 

 adult anopheles in the houses, outhouses, and 

 stables, the variety and relative abundance of 

 each species is noted, and it is determined by dissec- 

 tion (1) what species of anopheles are carrying malaria 

 at the time, and (2) the percentage of these infected with 

 sporozoites. Thirdly, a careful and detailed investiga- 

 tion is made in order to determine the exact position 

 and extent of the breeding grounds of each species of 

 anopheles present, special attention being paid to the 

 breeding grounds of the species found to be infected. 

 In the words of Captain James, " Every pool, stream, 

 and collection of water of any kind within a radius of 

 half a mile of the village should be thoroughly searched 

 for larva;. " The accurate knowledge of the conditions 

 determining the prevalence of malaria in the place under 

 examination thus obtained permits of a definite system 

 of prophylaxis being formulated for that place. An im- 

 portant point emphasised by Captain James is that no 

 general system of prophylaxis will apply to every place, 

 but that the malarial individuality of each must be 

 studied. 



As a model of what a malarial survey should be, he 

 quotes the survey of Ennur, made in February, 1902. 

 Ennur is a village on the coast near Madras, and was 

 formerly a health resort for Europeans, but is now de- 

 serted by them on account of the fact that it is scarcely 

 possible to pass even a single night there without get- 

 ting fever. The source of infection was found to be the 

 native children, 55 per cent, of whom had malarial para- 

 sites in their blood. With regard to the variety of 

 parasite present, 81 per cent, of the infected children 

 showed quartan parasites only, 5 per cent, tertian only, 

 and 14 per cent, mixed infection. No malignant tertian 

 parasites were found. Investigation of the mosquito?s 

 showed that only two species were present in the houses, 

 viz. .4. Rossii, which was in great abundance, and A. 



1 " Malaria in Ir^ia.' By Cartain S. P. James M P.. (Lond.), l.M.S. 

 Tssued under the authority of the Government of India by the Sanitary 

 Commissioner with the Government of India, Simla. Published by the 

 rfhee of the Superintendent of Government Pri itinjr, Calcutta, 1902. 

 Pp. 106. Price Rs. 1-8, or 2*. yi. 



NO. 1744, VOL. 67] 



Culefacies, which was moderately so. Dissection, how- 

 ever, showed that, while not one of 240 specimens of A. 

 Rossii examined was infected, no less than 8.7 per cent. 

 oi .1. Culefacies contained sporozoites. Captain James- 

 concludes that A. Culefacies is the chief carrier of 

 malaria at Ennur, and that the high infection rate of 

 this species indicates the great liability to infection of 

 anyone residing in the place. Extensive breeding 

 grounds for mosquitoes surrounded the village, the 

 nearest being within ten to twenty yards of the houses. 

 A. Culefacies was found to be breeding almost exclu- 

 sively in the " borrow pits " by the side of the railway, 

 and in the tanks in the compounds of the deserted Euro- 

 pean bungalows. 



The observations of Captain James on malarial in- 

 fection of native children have resulted in an important 

 addition to our knowledge of this subject, for by care- 

 ful investigation he has shown that the same febrile 

 disturbance takes place in children about the time of 

 segmentation of the parasites in their blood as in the 

 case of adults, and that there is, in short, no essential 

 difference between child infections and those occurring 

 in adults. 



The chapter on the causes which influence the spread' 

 of malaria in different parts of India, in which the 

 writer has been helped by Drs. Stephens and Chris- 

 tophers, is one of the most valuable in the book. The 

 data therein cited clearly show the great general in- 

 fluence on the prevalence of malaria due to the particu- 

 lar species of anopheles present, and to the nearness 

 and abundance of anopheles' breeding grounds. The 

 number of species of anopheles in India is large, and' 

 previous description of them inadequate. A consider- 

 able and well-illustrated part of the present monograph 

 therefore is devoted to the differentiation of the various- 

 species of Indian anopheles, and promises to be of high 

 practical value in future malaria investigations. The 

 remarks on the subject of the favourite breeding places 

 of the various species of anopheles are also of impor- 

 tance, and show how thorough inquiry in this direction 

 ought to be. Captain James's observations on the usual 

 distance of flight of anopheles in India go to show that 

 this rarely, if ever, exceeds half a mile, and therefore 

 that at this distance from a focus of infection " we are 

 practically safe from malaria." With regard to the 

 .influence of altitude, it has been found that under 4000 

 feet has no effect bv itself on the prevalence of malaria 

 in India. 



In reference to the prevention of malaria, the follow- 

 ing remarks of Captain James are significant : — " Com- 

 plete protection from malaria (and Blackwater fever) 

 may be ensured by any individual who is willing to- 

 take the trouble to pay scrupulous attention to the use 

 of a good mosquito curtain at night, and to adequately 

 protect himself from being bitten by mosquitoes during 

 the evening hours. If these simple precautions are 

 taken it is quite unnecessary to use quinine as a prophy- 

 lactic. No other precautions than these have been used 

 by any of us during our tours through some of the most 

 malarious parts of India, and none of us has ex- 

 perienced a day's fever during this time. Bv the use 

 of the same precautions also, and without taking any 

 quinine, Dr. Stephens previously passed two years in 

 the most malarious parts of Africa without a single 

 attack of malaria." When such success attends the 

 adoption of simple measures of defence against 

 malarial mosquitoes, there is good reason for hoping 

 that additional preventive measures, such as separation 

 of the residences of Europeans by a distance of at least 

 half a mile from the dwellings of natives, and, above 

 all, destruction of the breeding grounds of anopheles, 

 will do much to eliminate a disease the death-tribute 

 to which has been already far too costly. 



M. H. Gordon. 



