220 REVIEW — TROPICAL MEDICINE, ETC. 



Veterinary where it is constantly being re-introduced from Abyssinia and Erythrea. The attempts 

 Diseases— to isolate the organism causing this pest have so far been unsuccessful, although it is 

 coniinufil certain that the infecting agent is contained in the excretions of the nasal passages, 

 conjunctiva, intestines, and in the blood of infected animals, for with any one of these the 

 disease can be reproduced in other individuals. The virus of rinderpest from the blood or 

 any of the secretions possesses but little viability. Left at a fairly warm room temperature 

 it becomes inactive ; but it retains its activity longer when it is placed on ice. The length 

 of time during which it may be kept in a viable condition varies according to reports 

 between three and thirty-two days, but WooUey's' observations indicate a limit of from 

 three to sis days. At a temperature of 36° to 40° C. it becomes inactive after two days, 

 according to Theiler. According to Koch, dried blood may remain virulent for four days. 

 In the presence of other organisms it is killed, and sunlight destroys it in five minutes, 

 according to Braddon, but ordinary daylight has little effect. Yersin observes that the 

 filtrate obtained by passing rinderpest blood through Chamberland candles can cause 

 the disease. 



There is a difference of opinion regarding the characteristic lesions of this disease, no 

 doubt due to the fact that the European, South African and Philippine types of rinderpest 

 differ in many points. The most constant morbid changes in the body are emaciation, 

 sero-purulent conjunctivitis, congestion and general inllammation or ulceration of the gastro- 

 intestinal tract. PetechisB present themselves in the heart, kidneys, liver and lymphatic 

 glands. The classical cutaneous eruptions and ulcerations of the nasal and oral mucous 

 membranes present in the European disease are rarely seen in the Philippine variety. 

 As regards blood changes, Baldrey- found leucocytosis immediately after infection in 

 uncomplicated cases of rinderpest. 



There are but two methods of preventing the entrance and spread of rinderpest in a 

 country. These methods are immunisation and quarantine. 



The methods of producing immunity to rinderpest are three in number, namely, the 

 active, passive, and a combination of the active and passive. The active immunity is larger 

 than the passive, and in animals which have recovered from the natural disease it is 

 apparently permanent. Of the methods of producing active immunity mention may be made 

 of Koch's bile method. Ten cubic centimetres of bile taken from an animal on the sixth to 

 the eighth day of the disease will, upon injection into a non-immune animal, produce an 

 immunity which persists for several months. All investigations have not had as 

 favourable results as those of Koch; those of Lingard and Rogers, for instance, were negative. 



The advantages of this method are that no reactionary fever, suppression of lactation, or 

 abortions occur, and the operations can be carried out in the field. The disadvantages 

 are that immunity is not established till the tenth day after inoculation, nor is the immunity 

 permanent, and it has no curative properties. Holstock and Edington modified Koch's 

 method, but without any particular advantage. The method of producing passive immunity 

 originated in the observation that the serum obtained from naturally salted cattle possessed 

 a slight immunising power. Kolle and Turner found that by injecting increasing amounts 

 of virulent blood into salted animals they were able to produce an efficient serum which 

 could be used successfully in doses of 10 c.c. to 20 c.c. The advantages of this method are 

 that it has no detrimental effect on pregnant or dairy cattle, that it will favourably modify 

 a disease of one to three days' duration, and, further, the serum will keep well for a long 

 time. Of the combined methods of immunisation, mention may be made of the serum- 

 simultaneous method and the deferred virulent blood method. 



In the serum-simultaneous method the animal is inoculated with 1 c.c. of virulent 

 rinderpest blood under the skin on the one side and a minimal efficient dose of immune 

 serum on the other. A mild attack of the disease follows and the animal recovers. About 

 90 per cent, of cases treated in this way display an immediate permanent immunity, while 

 in the remaining 10 per cent, the immunity produced is only a transient one. 



The chief disadvantage of this method is the danger of introducing latent blood 

 diseases such as Texas fever, trypanosomiasis, etc., and, further, lactation and pregnancy 

 are frequently interfered with, while there may be a difficulty in obtaining virulent blood. 



In the deferred virulent blood method the serum is given a day or several days before 

 the introduction of the virulent blood, the temperature being observed. If no reaction 



' WooUey, P. G. (June, 1906), "Rinderpest." Journal of Tropical Velcrinarij Science. 



' Baldrey, P. S. (June, 1906), "Some Observations on Normal Rinderpest Blood." Journal of Tropical 

 VeUrinary Science, p. 47. 



