Sleeping Sickness

From England was reported a sharp increase in the number of cases of the new sleeping sickness (Encephalitis lethargica). Every week of 1924 has revealed, for that matter, a relentless increase. For the week ending Jan. 12 the number was ten; for the week ending April 19, 253. Only 541 cases were recorded for the whole of 1919. The current year thus far has recorded 1,409 cases.

Lethargic encephalitis has not the slightest connection with African sleeping sickness (Trypanosomiasis). The name is more appropriate to the former disease than to the latter. Sleep symptoms are not invariably characteristic of the African sickness, but they occur whenever the parasite localizes in the fluid of the spinal cord or in the brain. Since they are conspicuous when present, the disease got its popular name from them. Sleep is a marked and invariable symptom of encephalitis, ranging from a light slumber to a profound coma.

The cause and cure of encephalitis are still unknown. There are no known preventive measures to be taken. It first attracted wide attention when it appeared in Europe and North America in the wake of the epidemic of influenza in 1917-18, and it has been noticeable in England only for the last five years. Its history, however, is longer, for a few isolated cases were recorded in Central Europe in 1712, and it followed, also, the influenza outbreak of 1890.

It is probably not communicable. In the U. S. the case fatality rate has been about 29%, with the greater number of fatalities in cases where the onset of the disease was sudden. The onset is usually gradual. Symptoms: Headache, vertigo, eye troubles, changes in speech, a low fever, a peculiar masklike expression of the face, a lethargy which gradually develops into coma, or, rarely, into wakeful delirium.

In 1918 investigators of the U. S. Health Department decided that encephalitis is "a specific disease and must be caused by a specific living virus which has a specific affinity for the central nervous system." It is sui generis. The virus eludes discovery.

In Africa. The cause of African sleeping sickness, on the other hand, is well known to be a blood parasite (trypanosome) transmitted by the tsetse fly. It never occurs outside of Africa. It has been almost conquered by driving the fly away from human habitations, and the prescribed method of treatment (usually with arsenic in certain forms) is generally effective. Unlike encephalitis, trypanosomiasis is always characterized by a severe progressive fever--a daily rise of temperature.

Better remedies for trypanosomiasis will be needed as long as there are tsetse flies in Africa. During 1920 Germany is known to lave developed a valuable trypanocide, "Bayer 205." This medicine was so effective that it attracted the attention of all interested in tropical diseases, but its makers refused to tell the secret of its composition. The Germans virtually offered it as the price for the restoration of their African colonies (TIME, Feb. 4).

At last a French chemist, Fourneau, and his associates have produced a substance which they think is identical with "205."