SEVEN DAYS' FEVER 



1251 



Climatology. — So far, in India and Ceylon it has been found in towns in 

 low-l5dng districts near the sea, and is believed not to spread inland. In 

 Calcutta it occurs from May to September, and is very common in Colombo 

 during the same months. 



/Etiology. — Rogers found a motile bacillus related to the coli bacillus in the 

 blood, which he thinks may possibly be the cause of the disease. It resembles 

 the Bacillus coli communis in size and shape, and possesses flagella; is de- 

 colourized by Gram; produces a diffuse haziness in broth; slowly liquefies 

 gelatine; grows on agar like B. coli ; does not produce gas in glucose agar; nor 

 gas, nor acid, in dextrose, laevulose, and maltose broths; nor does it ferment 

 arabinose, galactose, saccharose, lactose, inulin, salicin, erythrite, mannite, 

 or dulcite. It is agglutinated in i in 20 and i in 40 dilutions of the serum 

 of seven days' fever patients. These observations have not been confirmed. 

 Clayton suggests that the 

 disease is carried by mosqui- 

 toes. The fever is commonly 

 found among Europeans, and 

 especially among people having 

 to do with shipping, and also 

 in new-comers. 



Pathology. — The morbid 

 anatomy is unknown, as the 

 mortality is nil. 



Symptomatology. — The in- 

 cubation period is unknown, 

 and no prodromal symptoms 

 have been recorded. The in- 

 vasion is sudden, with a rapid 

 rise of temperature to 102° or 

 105° F., but the pulse is not as 

 quick as it should be, compared 

 with the temperature. 



The face is flushed and the 

 palpebral conjunctivae injected, 

 and some rose-coloured spots 

 may appear on the skin. Pain 

 is felt in the back and, less 

 commonly, in the limbs. After 

 the initial rise there is usually 

 a gradual marked remission 

 of the temperature for two to 

 three days, when the fever 

 again rises, producing the 

 typical saddle-back remission. 

 After the second rise the tem- 

 perature gradually or quickly falls to normal, and the disease ends about 

 the seventh to eighth day. There is generally frontal headache, and the 

 tongue is furred on the dorsum, while the edges are red. Nausea and vomiting 

 are not common ; the bowels are usually normal, though constipation or 

 diarrhoea may occur. The abdomen is often distended, and may be painful. 

 The liver is usually normal, but may in a few cases be slightly enlarged, and 

 the spleen is at times enlarged. The respiratory and circulatory organs are 

 normal, except that the pulse is often slow as compared with the temperature. 



The blood shows a slight reduction of the erythrocytes and a marked leuco- 

 penia — 2,000 to 4,000 per c.c. The polymorphonuclear leucocytes are re- 

 duced, and the lymphocytes and mononuclears are increased. Nothing 

 abnormal is found in the urine, except the usual appearance of febrile 

 urine. 



Rashes are frequent. The most common is a mottling or a diffuse erythema 

 of the extensor surfaces of the forearms on the fourth to sixth day, which 

 may fade before the temperature falls. 



