UNDULANT FEVER 567 



are present in the epithelial cells, regarded by Halberstaeder and 

 Prowazek as Chlamydozoa * (p. 537). The disease is inoculable 

 on apes and the virus is stated to be a filter-passer. The causative 

 organism cannot yet be said to be known. 



UNDULANT FEVEK. 2 Synonyms : Rock, Mediterranean or Malta 

 fever. A disease met with especially on the Mediterranean littoral, 

 but also in South Africa, India, China, the Philippines, and the 

 subtropical countries of America, and clinically often simulating 

 typhoid fever. 



A minute micrococcus (M. melitensis}, first described by Bruce, 

 is the cause of the disease. 



Microscopically, the organism from cultures occurs as a coccus, 

 single, in pairs, or in short chains ; it is easily stained by the ordinary 

 anilin dyes, but is Gram-negative. In hanging-drop cultures it 

 shows decided movement, which may be only an active Brownian 

 movement, but is perhaps a true motility inasmuch as Gordon has 

 described the presence of flagella (other observers have failed to 

 find them). The organism may be isolated from the spleen of a 

 cadaver. 



On agar it grows as minute transparent colonies, which first 

 appear when inoculated from the spleen in 90 to 125 hours. In 

 thirty-six hours more the colonies become amber-coloured, and 

 later still in four to five days, they become opaque, of a slightly 

 orange colour, and round with granular margins. On gelatin a 

 whitish growth slowly forms without liquefaction, and in broth a 

 diffused cloudiness forms, with a white deposit and without film- 

 formation. Litmus milk becomes alkaline without curdling. Alkali 

 is also produced in glucose media, but galactose, maltose, and 

 saccharose are unchanged (see Table, p. 248). The distribution of 

 the M . melitensis in the body corresponds closely with that of the 

 B. typliosus ; thus it is abundant in the spleen, relatively scanty 

 in the blood, and is excreted in the urine. 



The M. melitensis maintains its vitality outside the body in 

 the dry state in dust or on clothing for two to three months, in tap- 

 or sea-water for a month. The thermal death-point is about 

 55 C. 



Inoculated into animals no result usually ensues ; in the monkey, 

 however, a febrile condition is produced, with enlarged spleen, 

 sometimes terminating in death, the course of the temperature 

 resembling that of the disease in man. By intra-cerebral inoculation 



1 Berl. Idin. Woch. No. 24, 1909. 



2 See Reports of the Mediterranean Fever Commission (Royal Society), 

 pts. i-vii, Harrison & Sons, 1904-1907. 



