Massive development of amebas in the large intestine. Fedor Aleksandrovich Lesh (Lösch).

Fedor Aleksandrovich Lesh (Lösch) 1840-1903. Although Lösch was a distinguished Russian physician, little has been written about him in English. A graduate of the Medico-chirurgical Academy in St. Petersburg (1863), he defended a doctoral thesis on pulmonary embolism and infarction in 1866, and became an assistant professor of medicine in 1871. From 1872 to 1885 he was a lecturer on diagnosis at the Women's Medical College and a consultant to the Nikolayev Military Hospital. In 1885 he became Professor of Diagnostic Medicine at Kiev University where he remained until his retirement in 1897. In 1870, Lösch found Balantidium coli in the stools of two patients and made a detailed study of the clinical aspects of balantidiasis. In the same year he described in detail Giardia lamblia and Blastocystis hominis. Altogether, he published some 20 papers on the diagnostic and clinical aspects of various diseases, with special emphasis on the microscopic aspects of coprology. It was in 1875 (exactly 100 years ago) that Lösch, in this monumental paper, reported the clinical aspects of recurrent intestinal amebiasis, identified and described its cause, Entamoeba histolytica, and produced the disease in an experimental animal. This work on amebiasis was completed while he was assistant professor at St. Petersburg, on the wards of Prof. E. Eichwald. Clinicians will cherish the description of the patient's symptoms; protozoologists must be delighted by the description of the parasite and its motility; experimentalists will be nervous about his luck in infecting one of three dogs; and iconoclasts must derive satisfaction from Lösch's caution in not automatically assigning a direct causal relationship between the presence of the parasite and the disease.