Human Diseases That Originated in Animals

By Shreesha Ghosh

July 05, 2022

Ebola

Scientists believe that the African fruit bats are likely involved in spreading the Ebola virus and may even be the source animal (reservoir host) but are yet to get conclusive evidence. It is a rare and deadly disease in people and nonhuman primates. People can get the virus through direct contact with an infected animal or a sick or dead person infected with it.

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COVID-19

Coronaviruses are zoonotic, meaning they are transmitted between animals and people. Detailed investigations found that SARS-CoV was transmitted from civet cats to humans and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.

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Monkeypox

In cases of Monkeypox, animal-to-person transmission occurs through broken skin, like from bites or scratches, direct contact with an infected animal's blood, bodily fluids or pox lesions (sores). It is a viral zoonotic disease that occurs primarily in tropical rainforest areas of central and west Africa, occasionally exported to other regions.

Image source:  Pixabay

Rabies

Rabies is a zoonotic viral disease transmitted through the bite of a rabid animal and occurs in both domestic and wild animals. The rabies virus infects the central nervous system of mammals, ultimately causing brain damage and death and is fatal to both humans and animals. Humans get rabies when the saliva of infected animals enters the body, usually through a bite.

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The Plague

Plague is an infectious disease that affects animals and humans. It is caused by the bacterium Yersinia pestis, found in rodents and their fleas in several parts of the world. Humans usually get the plague after being bitten by a rodent flea carrying the bacterium or by handling an infected animal. It is infamous for killing millions of people in Europe during the Middle Ages.

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Lyme disease

Lyme disease (Lyme borreliosis) is an illness that affects animals and humans – known as a zoonotic disease – and is the commonly reported vector-borne illness in the US. The black-legged tick (or deer tick, Ixodes scapularis) spreads the disease, and humans are infected through the bites of immature ticks called nymphs.

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West Nile fever

West Nile fever is a zoonotic disease caused by the West Nile virus (WNV), which is a flavivirus that also causes encephalitis in humans, and yellow fever. The virus is transmitted among birds via the bite of infected mosquitoes, and incidentally, humans and other mammals may get infected. The virus can also cause a fatal neurological disease in humans.

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Cat scratch disease

Cat scratch disease is a bacterial infection spread by cats. The disease spreads when an infected cat licks a human’s open wound or bites or scratches a person hard enough to break the skin surface. It is the most common zoonotic infection caused by Bartonella bacteria. Transmission of the bacteria actually occurs through cat fleas and possibly other biting flies or ticks.

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