Theodor Maximilian Bilharz (23 March 1825 – 9 May 1862) was a German medical doctor who made pioneering discoveries in the field of parasitology. His contributions led to the foundation of tropical medicine. He is best remembered as the discoverer of the blood fluke Schistosoma haematobium, the causative parasite of bloody urine (haematuria) known since ancient times in Egypt. The parasite, as the cause of bladder cancer, is declared by the International Agency for Research on Cancer as Group 1 carcinogen. The infection is known by an eponymous term bilharzia or bilharziasis, as well as by schistosomiasis.
Bilharz was born and educated in Sigmaringen, Hohenzollern-Sigmaringen, Germany. After graduating in natural science and philosophy from the Albert-Ludwigs-Universität in 1845, he earned a medical degree from the University of Tübingen in 1849. In 1850, he followed his former teacher Wilhelm Griesinger to Egypt to work at the Qasr El Eyni Hospital in Cairo. He became the first autopsy performer there. From autopsies of children, he observed a variety of helminth parasites and discovered the tapeworm Hymenolepis nana and the flatworm Heterophyes heterophyes in 1851. Early in that year he found a male worm from a dead soldier. As a novel worm with two mouth-like suckers, he named it Distomum haematobium, the description of which was published by his mentor Karl Theodor Ernst von Siebold in 1852. He further discovered that it was the eggs and not the flukes that caused the disease. He also unknowingly discovered another related blood fluke, later identified as Schistosoma mansoni, the most prevalent human helminth.
While he was professor of anatomy at the Qasr El Eyni Medical School (later part of the University of Cairo), he contracted typhoid fever or typhus at Massawa during an expedition organised by Ernest II, Duke of Saxe-Coburg and Gotha. He died of it at age 37. The United Arab Republic established Theodor Bilharz Research Institute in his honour in 1962.
Early life and education Theodor Bilharz was born in Sigmaringen, Hohenzollern-Sigmaringen, Germany. His father Josef Antony Bilharz (1788–1877), a councilor of the exchequer, was an advisor to the Prince Karl Anton of Hohenzollern. His mother Elisa Fehr (1800–1889) was from a Swiss family of Zollikhofer. He was the eldest of nine children, four of who died at infancy. He studied at the local school in Sigmaringen and completed his secondary education (Fürstlich Sigmaringer Gymnasium) in 1843 with the highest score. He developed keen interest in geology, biology and poetry. His surviving poem Die Trane des Seraphs (The Travels of the Seraphs) was composed during his school days. He scored the highest in his class in Latin, Greek and Hebrew. At age 14, he wrote a drama and translated an ancient comic epic Battle of the Frogs and Mice (Batrachomyomachia). He soon developed a passion for natural science mainly from the library and specimens he inherited from his great uncle Kaspar Zollikofer von Altenklingen, a reputed Swiss biologist.
In the winter semester of 1843, Bilharz entered the Albert-Ludwigs-Universität (University of Freiburg) in Freiburg im Breisgau and took up natural science and philosophy. After completing his degree in 1845, he followed his anatomy teacher Friedrich Arnold to the University of Tübingen where he enrolled in medicine. In 1846, he won the medical faculty's prize competition for his dissertation on "The microscopic characters of the blood of invertebrate animals." With the prize money he bought a compound microscope (Oberhaus microscope) that he used throughout his career. He became closely associated with Wilhelm Griesinger, a neurologist and psychiatrist who was working as an internist at Tübingen.
Bilharz passed the state exam in 1849 to obtain a license as medical doctor. Some sources state that he graduated in 1848, and was awarded the medical degree without requiring an examination due to his superior performance. This information may not be reliable as better biographical sources say he passed the exam in 1849. After graduation, he was immediately appointed as an assistant to Karl Theodor Ernst von Siebold at the University of Freiburg. Von Siebold became his major influence in parasitology and later discoveries. Bilharz initially planned to do parasitology research in South America as he said: "The path to become a professor maybe shorter via America than via Tübingen." The next year, a recently appointed professor of anatomy at Freiburg, Georg Ludwig Kobelt recruited him as his prosector.
Career and achievements In 1850, Wilhelm Griesinger, then at the University of Kiel, was appointed by Abbas I of Egypt, Wāli (governor or viceroy) of Egypt and Sudan, to head medical services in Egypt. He responded to the Wāli that he would accept the appointment only if his former student Theodor Bilharz was appointed as his assistant. Bilharz was still waiting for his medical certificate, and recounted that he could not sleep the night he received the official appointment out of excitement. Griesinger was to hold three positions such as Director of both Qasr El Eyni Hospital and its medical school (later part of the University of Cairo), President of the Sanitary Council and personal physician to the Wāli. Von Siebold wrote of his recommendation to Bilharz's father saying, "I can't help it to speak out the wish that the stay of your good Theodor may be a credit to him and to science... I won't believe anything else than that a longer stay in wonderful Egypt would be excellently used by your son. God may save his health."
Griesinger and Bilharz left on 25 May and reached Alexandria on 18 June. Bilharz held the position of senior consultant for the department of internal medicine, and also enlisted in the military where he was given the rank of lieutenant colonel (Kaimakam). As an authorised autopsy performer, it was an ideal assignment for Bilharz because autopsy was generally opposed by religious and traditional establishments at the time. Bilharz thereby became the first person to legally perform autopsies in Egypt as the first chief of surgery. While in charge of autopsy between 1850 and 1852, he performed more than 400 operations.
In 1852, Griesinger left Egypt and Bilharz became professor of medicine in his place. The next year, Bilharz was appointed as chief surgeon of internal diseases. When Abbas I died in 1854, his successor Mohamed Sa'id Pasha, a Francophone and a Francophile, dismissed all Germans from official services. Bilharz was replaced by Antoine Clot (known in Egypt as Clot Bey) from Marseille. The German consul however managed to persuade the viceroy to reinstate Bilharz because of his scientific contributions. In 1856, Clot allowed Bilharz to become professor of anatomy. But he exchanged it with the position of professor of descriptive anatomy the same year. He also took charge as medico-legal adviser to the Egyptian government.
Helminthology
Bilharz in his first year in Egypt found and reported different human parasites including Ancylostoma duodenale, Ascaris lumbricoides, Trichuris trichiura, pinworm (Oxyuris), pork tapeworm (Taenia solium), dog tapeworm (Echinococcus granulosus), hookworms (Ancylostoma and Necator) and guinea-worm (Dracunculus medinensis). His first major discovery was that of the tapeworm Hymenolepis nana that he recovered from the small intestine of an Egyptian boy in Cairo in 1851. Von Siebold gave the original name as Taenia nana in 1852. In 1851, Bilharz also discovered a novel intestinal flatworm from an infected child in Cairo. Von Siebold named it Distoma heterophyes in 1852. English biologist Thomas Spencer Cobbold created a better generic name Heterophyes in 1866; thus, the parasite became Heterophyes heterophyes. Bilharz's specimen became the first known helminth in the family Heterophyidae.
Discovery of bilharzia and Schistosoma haematobium Ancient Egyptians had recorded urinary disease which can be attributed to S. haematobium infection. 16th-century BCE medical papyri mention the disease as aaa that indicates symptoms of urinary bilharzia. Mummies of 5,000 years old have been found to contain the parasite eggs. The French army physician Adrien-Jacques Renoult reported the disease as haematurea (bloody urine) in 1808. Napoleon's army in the late 18th century called Egypt as "the land of menstruating men." This is because of the high prevalence of the disease that severely affected the French army. The cause of the disease was never known.
In 1851, during an autopsy, Bilharz discovered an obvious worm from the portal vein connecting the urinary tract of a dead soldier. It was the first time anyone had seen a parasitic worm that lived inside a blood vessel. Not really knowing what kind of worm it was, he wrote to his former zoology professor von Siebold at Breslau on 1 May 1851:As helminths in general and those who attack humans in particular are concerned, I think Egypt is the best country to study them. Nematodes in particular populate the intestines of the indigenous population in unimaginable quantities. It is not unusual to encounter 100 individuals of Strongylus duodenalis [Ancylostoma duodenale], 20–40 Ascaris, 10–20 Trichocephalus [Trichuris trichiura] and close to 1000 Oxyuris. My attention soon turned to the liver and associated structures; in the blood from v. portae I found a number of long, white worms that with the naked eye appeared to be nematodes. A look in the microscope revealed an excellent Distomum with flat body and a twisted tail. These are a few leaves of a saga as wonderful as the best of Thousand and One Nights – if I succeeded in putting it all together.He also added an identification puzzle:[It] had a flat body and a spiral tail at least ten times as long as the body... The tail was a continuation of the flat body of the worm itself, rolled sideways towards the stomach surface in a half canal; the forked blind end of the intestinal canal extended into it very plainly. What then is this animal? In spite of its long tail, it probably cannot be called a cercaria [a fork-tailed larva of trematodes], which is completely different, histologically and morphologically.As unique among flukes, the schistosomes have two bodies – a female which is like a roundworm and a male which is curled-up fluke – that are combined permanently (a condition called in copula) to make up individual adult worms. Bilharz had discovered a male fluke. He knew it has similarities to other flukes, especially the two mouth-like suckers (now called oral sucker or acetabulum and ventral sucker), for which he immediately used the name Distomum, a Greek for two mouthed. But the rolled-up body made him think that it was a roundworm. At the end of May, he found a female specimen from another corpse that was all wrapped up by the same kind of worm he had discovered. It occurred to him that the worm was an extraordinary fluke, exclaiming, "Something more wonderful, a trematode with divided sex." All previously known parasitic flukes were hermaphrodites with both male and female reproductive organs in the same individual, a condition called gonochorism. Describing his observation in a letter to von Siebold on 18 August, he wrote:You can imagine my surprise when I saw a trematode [fluke] protruding from the frontal opening of the groove and moving back and forth; it was similar in shape as the first, only much finer and more delicate... [The female] was completely enclosed in the groove-shaped half canal of the male posterior, similar to a sword in a scabbard.
Bilharz was able to find the male fluke rolled itself up to form a canal in which the female resided, and he named the canal as gynaecophoric canal.