PHLEBOrOMUS FEl'ER {THREE- DAY FEVER) 361 



It is not found on the heights. It confines itself chiefly to inhabited 

 places (Doerr). 



It is a disease of tlie summer. The fly dies out in winter, but 

 perhaps the infection is continued by the Qgg. 



iETIOLOGY. 



An unknown virus is infective during tlie first and up to the end 

 of the second day of the fever only. 



The Pasteur-Chamberland filter keeps back the virus. 



The carrier, P. papatasii, is not infective until one week after it 

 has itself become infected, hence some organism develops in the fly. 



The infection nia\' be transmissible to the young broods. 



An antibody is probably produced. Serum from convalescent 

 patients may neutralize infected serum. 



SYMPTOMS. 



Incubation one to seven davs. 



Sudden onset, as a rule, like most fevers with chilliness, severe 

 frontal headache, pain about the eyeballs, general body pains, injected 

 conjunctivce. 



Skin hot and dry, temperature rises rapidly to 104° F. in twenty- 

 four hours, pulse 100 to 116, often slow. Ocular movements painful. 

 Patient irritable, sleeplessness, appetite lost, taste impaired, epigastric 

 pain. Diarrhoea sometimes, congested mouth and throat. Pain in 

 joints, knee and elbow especially. Sensation of burning in the palms 

 and soles. Leucopenia 4,000 to 5,000. Sometimes a general ervthema. 

 Temperature falls in thirty-six to forty-eight hours, slowly with (often) 

 epistaxis, sweating, vomiting, diarrhoea and weakness. 



Convalescence is long. No death has been recorded. 



Relapses are common. Perhaps there are no reinfections. 



DIAGNOSIS. 



The short duration, three days, is about the only diagnostic feature. 



From Influenza by there being no catarrhal symptoms with Three- 

 day fever. 



From Dengue by the short duration only. 



From Malaria by there being no parasites. 



From Malta fever by the duration, sudden onset, absence of 

 organisms in the blood and negative agglutination test. 



TREATMENT. 



Rest in bed. Saline purges. Aspirin. Tonics later. 

 Prophylaxis as in Malaria. 



