Griffith Evans (bacteriologist)

Griffith Evans (7 August 1835 – 7 December 1935) was a Welsh physician and veterinary pathologist who was the first to determine that a trypanosome parasite was responsible for surra disease in horses while serving in British India. Described as "the man who first saw a pathogenic trypanosome", he identified the causal organism as a haematozoon (blood parasite) in 1880 which was given the species name '' Trypanosoma evansi'' after him.

Biography

Evans was born in Ty-mawr, Towyn, Wales, as the only son to Evan Evans (1801–1882) and Mary Jones (1809–1877). Coming from a wealthy family with an illustrious history he went to school at Bryn-crug and later studied privately under a local medical doctor John Pughe at Aberdovey and Towyn. Due to family circumstances, Pughe suggested that Evans could become a veterinarian in shorter time than as a doctor. He joined the course, bought himself a microscope for private study, and qualified at the top of his MRCVS batch in 1855 from the Royal Veterinary College and joined the army in the Royal Artillery much against the wishes of his mother who believed that army life was "... a life of debauchery, low living and drunkeness."

Griffith first served in Canada during the American Civil War and was stationed at Montreal from 1861. He enrolled for medicine and received an MD from McGill University in 1860 with a thesis on tuberculosis. He met Abraham Lincoln, who directed him to work as a medic at the battle zones. He returned to England in 1870. In 1871, he exchanged his service in the Royal Artillery with the Royal Army Service Corps. Initially posted in Woolwich, he worked variously at King's College London and the Royal Ophthalmic Hospital at Moorfields. In 1877, he was deployed to India to study a disease outbreak at Sialkot in Punjab. In 1880 he was posted to study surra disease at Dera Ismail Khan (now in Pakistan). He returned to Britain in 1885 and retired five years later.

He married Catherine Mary née Jones (1843–1923) in 1870 and they had a son and four daughters. He retired from army service in 1890.

Scientific contributions

Anthrax

When Griffith investigated in 1877 a fatal disease of horses that severely struck those of the British Army, he was quick to identify bacteria in all diseases animals. He identified the disease, which was then called "Loodiana disease" (after the city Ludhiana) or "malignant fever," as anthrax. He reported his findings in ''The Veterinary Journal'' in 1878.

While identifying the anthrax bacteria from the horse blood under microscope, Griffith observed two other important pathological conditions. The first was that when he looked at the bacteria from fresh blood samples, the bacteria appeared to be surrounded more and more by certain white blood cells that were not present in the fresh samples. He described:

I officially reported, what surprised me most, that the first change in the blood seen by the microscope was a great increase in the number of the large white corpuscles before I could see a bacillus. I examined the blood regularly every hour from the first symptom of illness, and noted invariably the increasing number of these corpuscles for some time before I could find a bacillus. The bacilli, when they came, appeared to be closer to the white than to the red corpuscles; subsequently the number of the bacilli in each droplet multiplied rapidly, so they could be seen isolated, free from corpuscles. I expressed my conviction that the large granular corpuscles had a very important relation to the bacilli, but I could not think what it was I repeatedly emphasised my belief that it deserved special investigation.

He had no means to further study this phenomenon, which is now known as phagocytosis, a cellular process by which white blood cells protect by devouring pathogens. The phenomenon was discovered in its full form by Russian zoologist Élie Metchnikoff in 1882, who received the 1908 Nobel Prize in Physiology or Medicine for the discovery that established the science of immunology.

An additional observation of Griffith was that in some horses, some horses had parasites in their blood and respiratory tract. Those were roundworms, but he did not know them. He suggested them to be kinds of worms, as he reported:

I saw n the blood samplewhat I thought were bacteria swarming in it. I made a rather hasty conclusion, because I was thinking of Anthrax, and as this disease is commonly identified with it, I was really looking for bacteria. On closer inspection, I thought they were more likely to be blood-crystals: they resembled very closely the small prismatic crystals of Haematoglobulin nowiki/>haemoglobin">haemoglobin.html" ;"title="nowiki/>haemoglobin">nowiki/>haemoglobin I have since come to the conclusion that they are worms in a very early stage of development... Now, I do not know what these things are,—whether they belong to the animal or vegetable kingdom. I call them worms, because they are worm-like. I know very little about parasites.

''The Veterinary Journal'' commented the discovery as: "Should his discovery turn out to be a real one, then we shall have the key to the etiology of a very serious and hitherto mysterious disease, and this may lead to our ascertaining that other obscure disorders of animals are due to a similar cause."

Parasite of surra

In August 1880, Griffith was transferred to Dera Ismail Khan to investigate cases of surra (from the Marathi language">Marathi