The coagulability of the blood is decreased and this may be a factor in the fatal results which at times follow spleen puncture.
Parasites are found in the peripheral circulation in about 80% of cases, after prolonged search, and may be phagocytized by either large mononuclears or polymorphonuclears.
Patton found parasites in the peripheral blood in the examination of a single slide in 42 out of 84 cases and with three slides in 25 of those not showing parasites with the first slide. By repeated examinations up to the seventeenth slide, he got positive results in all 84 cases.
The Sudan commission found that the alkalinity of the serum of their patients was diminished.
Rogers has noted an acidosis in unfavorable cases of kala-azar while those showing improvement only showed slight or no acidosis.
Respiratory and Circulatory Systems.—There is very little that is constant, the lungs being quite normal in 90% of Rogers’ cases. The pulse rate is rather variable, although usually accelerated.
Diagnosis
Clinical Diagnosis.—Cases of kala-azar are usually diagnosed as malaria and it is in the lack of response to quinine that we have our best point of differentiation.
In children showing splenomegaly the probability of the case being kala-azar rather than malaria is indicated if the case has shown progressive deterioration of health.
Malta fever shows a rather similar succession of febrile and afebrile periods but the spleen of the former rarely shows marked enlargement and the bronchial catarrh, sweatings, transient joint swellings and neuralgic manifestations are characteristic of Malta fever. Kala-azar may show muscular pains and slight sweatings and the differentiation has at times only been made by the laboratory diagnosis.