[1] 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.

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 also unknowingly discovered another related blood fluke, later identified as Schistosoma mansoni, the most prevalent human helminth.

[2] While he was professor of anatomy at the Qasr El Eyni Medical School (now 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.

[4] He studied at the local school in Sigmaringen and completed his secondary education (Fürstlich Sigmaringer Gymnasium) in 1843 with the highest score.

He soon developed a passion in natural science mainly from the library and specimens he inherited from his great uncle Kaspar Zollikofer von Altenklingen, a reputed Swiss biologist.

In 1846, he won the medical faculty's prize competition for his dissertation on topic "The microscopic characters of the blood of invertebrate animals.

[3] 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.

[11] 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...

[3] 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).

[4] 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).

In 1851, during an autopsy, Bilharz discovered an obvious worm from the portal vein connecting the urinary tract of a dead soldier.

Not really knowing what kind of worm it was, he wrote to his former zoology professor von Siebold at Breslau on 1 May 1851:[23]As helminths in general and those who attack humans in particular are concerned, I think Egypt is the best country to study them.

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.

"[27] All previously known parasitic flukes were hermaphrodites with both male and female reproductive organs in the same individual, a condition called gonochorism.

[28] 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.

Griesinger had thought that the fluke caused dysentery, but Bilharz found that it was responsible for urinary tract diseases including haematuria as well.

[31][32] He referred to the disease as "endemic haematuria of warm climates" and the "dysenterische Veränderung des Dickdarms" (dysenteric pathology of the colon).

A closely related name Distoma had been introduced by French zoologist Marie Jules César Savigny in 1816 for other animals, the tunicates.

[40] In 1856, Heinrich Meckel von Hemsbach critically argued that the usage of such names was inappropriate as it was a misnomer for the flukes since these animals do not have two mouths.

Writing in his book Mikrogeologie: Ueber die Concremente im thierischen Organismus (Microgeology: About the Accumulations in the Animal Organism), he remarked: "The genus name Distoma should not be used, but be replaced with Billharzia [double l is the original printing mistake].

Not knowing von Hemsbach's publication which had limited circulation at the time, David Friedrich Weinland proposed the name Schistosoma (a Greek term for "split body" reflecting the separation of male and female in an individual) in 1858.

[40] After a century of debate and confusion on the name, in 1954, the International Commission on Zoological Nomenclature (ICZN) officially declared Schistosoma haematobium as valid on the ground of priority rule.

[56][57] For this historical importance, Bilharz considered his research on electric organs more valuable than bilharzia,[3] and published them as preliminary note in 1853 and as a full monograph in 1858.

Ernest II, Duke of Saxe-Coburg and Gotha, requested him to work as personal physician to the Duchess[6] on an expedition around the Red Sea.

While staying at Massawa he contracted typhoid fever or typhus (reports are contradictory) and became seriously ill.[3] When he returned to Egypt, he was in terminal condition and died on 6 May 1862, at the age of 37.

[61] British parasitologist and biographer, Harry Arnold Baylis wrote of Bilharz's death: "No one, probably, had ever been more universally or more sincerely mourned in the European colony in Cairo.

"[62] Bilharz's works and grave remained largely forgotten until the first International Congress of Tropical Medicine and Hygiene held in Cairo in 1928.

[3] His is in Old Cairo next to that of Hans Eisele (1912–1967), a Nazi concentration camp doctor, who was convicted by the US military court for crime against humanity.