49 



. Sergent (Ed.) & Sergent (Et.). Etudes Epid6miologiques et Prophy- 

 lactiques du Paludisme. (17% 18® et 19® Campagnes en Alg6rie, 

 en 1918, 1919 et 1920.) — Ann. Inst. Pasteur, Paris, xxxv, no. 11, 

 November 1921, pp. 801-813. 



Except in 1920, the incidence of malaria was high during the period 

 under review, owing to the weather conditions being favourable to 

 mosquitos, and the prolonged summer of 1919 encouraged the disease, 

 as the temperature necessary for development of the Plasmodium in 

 the mosquito continued for a long period. 



The range of flight of Anophelines seems to depend largely upon 

 their situation ; those inhabiting streams near a town, where the food- 

 supply is close at hand, take only very short flights, while in the open 

 country their range on the wing extends to about a mile, occasionally 

 considerably more. In 1920, Anopheles hispaniola {Pyretophorus 

 myzomyifacies) was found at an altitude of over 600 feet above its 

 breeding-place. 



In many localities the re-infection of towns by Anophelines brought 

 on the railways is very evident. Anti-larval measures in such towns 

 practically eHminate mosquitos during the hot weather, but they can 

 be seen in November and December emerging in numbers from 

 incoming trains at railway stations, where they always remain more 

 or less localised. 



It is of the greatest importance to know the date of the earliest 

 Anopheline oviposition, in order to organise anti-malarial measures 

 accordingly. When an individual of Anopheles maculipennis, after a 

 blood meal, was kept at a temperature of 12° C. [54° F.], oviposition 

 and hatching occurred normally. Newly deposited eggs of A . maculi- 

 pennis were kept at a temperature of- 10° C. [14° F.] for five months. 

 At the end of this period the temperature was raised to 22° C. [72° F.], 

 but none of them hatched. The variety of A. hispaniola previously 

 recorded in South Constantine, South Oran and in the Tell, has also 

 been found near to Oued-Hamiz, and the characters distinguishing it 

 are discussed. 



An important source of the spread of malarial infection has arisen 

 o\ving to the gradual migration of natives into the towns and villages of 

 the interior. Especially during the war, when the French population was 

 greatly reduced in numbers, the settlement of natives in the smaller 

 centres has been followed by the introduction of a new strain of 

 infection. This native strain is far more dangerous than the Serbian 

 or Macedonian ones, owing to the natives not having received quinine 

 treatment as the troops from the East have done. When an outbreak 

 occurs in the mountain villages, it is similarly alwaj^s more intense 

 than one in the plains, where a relative immunity has been acquired. 

 It is a matter of repeated observation that in a newly infected locality 

 the spleen index is higher for adults than for children. A few cases 

 of quartan malaria were recorded. 



The conditions created by the war during the years under review 

 greatly increased the difficulties of anti-malarial work. The use of 

 quinine stopped almost completely ; labour and petrol were almost 

 unobtainable, and funds were not increased. The activities of the 

 anti-malarial service in various departments are reviewed. 



Following the theory of Roubaud regarding the role played by 

 domestic animals as a protection against mosquitos {R.A.E., B, viii, 

 141], it is always stables and shelters for animals that are first 

 examined for Anophehnes in Algeria, and it is there that they are 



(5864) \Vt. P.3;i84 1500 3/22 Harrow G.75. E 



