Wednesday, 14 July 2010
ABC Wednesday Z is for Zoonosis
Zoonoses are infections that can be passed from vertebrate animals to humans and vice versa. Infection passed from human to non-human is sometimes called reverse zoonosis or anthroponosis. When you live in close proximity to animals it is impossible to ignore the relationship between illness in humans and a similar pattern of illness in companion animals. For most people, however, the emphasis is usually on those diseases that occur as a direct result of contact with an infected animal or through vectors of infection between non-human vertebrates, not necessarily mammals, and humans. Some infections are serious, potentially fatal, like Ebola or anthrax, while others are self-limiting, uncomfortable for a short period and possibly contributing to a stronger immune system.
Many modern diseases arose in animals. Measles, smallpox, HIV, diphtheria and influenza were all zoonoses. Bubonic plague and Rocky Mountain Spotted Fever are zoonotic and it is thought that the common cold and tuberculosis may also be zoonotic.
Most people know that rats, fleas, lice, ticks and mosquitoes carry disease. Cat and dog owners and those who keep horses or parrots will know of the potential infections that may be passed on - leptospirosis, ringworms, toxoplasmosis, psittacosis. Fish and snails can also harbour zoonoses – salmonella and yersinia. Walking in areas where wild animals roam poses dangers, too – Lyme disease from deer ticks, for example. (There are other dangers associated with wild animals but they don't usually involve infection unless you live to tell the tale of the tiger or elephant attack and the wounds become infected!)
Thanks are due to Denise Nesbitt and her zealous team who host this weekly meme. Click here to see more Zs - and they won't make you push out the ZZZs