SYMPTOM A TO LOG Y 



1247 



mosquito other than Culex fatigans and Stegomyia calopus can spread 

 the disease ; and how long the acquired immunity lasts in man. 

 In conclusion, it may be said that there is no evidence of infection 

 other than by the bite of mosquitoes, and there is no evidence that 

 a monlcey can be infected by inoculation. 



Pathology. — ^There is but little that can be written on this subject, 

 as the cause of the disease is unknown, and therefore, of course, its 

 action cannot be explained. 



Morbid Anatomy. — ^This appears restricted to the description of the 

 complication which killed the person — ^viz., peritonitis or pleuritis. 



Symptomatology. — ^The incubation period, judging from experi- 

 mental infection by mosquito-bites, varies from three to six days 

 in the case of culex, and five to nine and a half days in the case of 

 stegomyia. Prodromata are usually absent, but general malaise 

 may be felt during a period not exceeding three days before the onset. 



The attack is usually sudden, and introduced by severe pain in 

 some part of the body, or merely by the sensation of extreme 

 fatigue, or by chilliness and shivering, or by deep flushing of the 

 face. In children convulsions or delirium may usher in the illness. 

 In any case the temperature rapidly rises, the pulse quickens, and 

 the skin and mucosae become markedly congested, especially about 

 the face, mouth, and throat. The conjunctivae are injected, the 

 eyes watery, and sometimes vomiting and purging are also present. 

 The disease now progresses for one, two, or three days, after which 

 there is, as a rule, a remission or an intermission. 



Course. — ^During this period the temperature rises to 103° to 

 106° F., and the pulse increases proportionately with the tempera- 

 ture to 90 to 120 per minute. Severe pains in the head, and 

 especially in the eyeballs, are experienced, and, in addition, pains in 

 different parts of the body, especially in the lumbar region and the 

 legs. Often the j oints are painful, usually without any sign of redness 

 or swelling. This pain in the joints appears really to be due to the 

 muscles in the neighbourhood, as the joint can often be passively 

 moved without pain, while active movement induces almost agony. 

 There are, however, rare cases in which the joints are affected, as 

 is shown by redness and swelling. As regards the alimentary canal, 

 the tongue is moist, but becomes covered with a white-creamy fur. 

 There is no appetite, nausea and vomiting are not uncommon, and 

 constipation or diarrhoea may be present. Enlargement of the 

 cervical and axillary glands is present to the extent of 30 per cent, 

 to 70 per cent, of the cases of some epidemics. The glands remain 

 enlarged for some time, and may be tender on pressure. The juice 

 of these glands has reproduced the disease in two out of three cases. 

 The circulatory system is not affected, except that fainting occurs 

 at times, while a sensation of praecordial discomfort or of sufiocation 

 may be complained of. Insomnia and delirium are not infrequent, 

 but meningitis and neuritis must be uncommon if they occur at all, 

 though hyperaesthesia of the skin may be observed. The skin shows 

 the congestion already mentioned, which is not always present, 



