Is the disease a recent introduction into the Sudan ?

Incidence by months 130 REMARKS ON KALA-AZAR most definite in their assertions that she had been ill only twenty days before admission to hospital where she died six days later.

Another case, a boy at Abdin, declared most definitely he had only been ill 15 days, and had not previously had fever. He was evidently very ill indeed, but probably the history was faulty as his spleen nearly reached the umbilicus; his peripheral] blood showed Leishman parasites.

Chronic cases were seldom seen; three, however, gave histories of five years (Lueisa), three years (Abdin), and two years (Abu Galud) respectively.

The following points make one inclined to the view that the disease may be a new arrival amongst a previously uninfected people: (1) The virulent character; (2) the comparatively few chronic cases observed (this, in my opinion, is a very suggestive fact) ; (3) the epidemic character the disease has assumed at Mafaza and Sennar; (4) the absence of history of a past epidemic, though this is naturally extremely difficult to determine owing to the ever-present malaria after the rainy season both near and away from the rivers; (5) the failure of medical recognition, though it must be kept in mind that the disease has been but comparatively recently separated from malaria and many medical men are still ignorant about this malady.

No information was obtained as to the incubation period of the disease, though much attention was paid to this point.

The only case that in any way threw light on this point suggested 16-18 days as the incubation period.

The incidence of the disease appears to favour the months of July, December, and January, which correspond to the commencement of the cool and rainy season and the few months following the end of that season. It is often quite impossible to obtain definite information from a native about the date of onset, but the following table gives the approximate months of onset of all the cases, proved or suspected, that I have been able to follow :— KALA-AZAR CASES Month Proved | Suspected Total January... es ne bat 5 3 8 February ... as ca oar 2 3 5 March aad oe a: Sa it 2 3 April that Axi Bad 1 2 3 May va aie Re 3. — — — June 2. ay oo Aa — 1 1 July “er a ae. are 6 — 6 August ne ob ds a — 5 5 September ... si a eae 2 —_ 2 October... Bs mae sis 1 —_ 1 November ... Bi od ae — if 7 December ... sia aes ae 5 — 5 A point to be carefully remembered in the Sudan is that it is quite common for @ kala-azar patient to have had malaria and to give a history of fever every alternate