Sunday, June 24, 2012

in Humans and Dogs

Human scabies is caused by a parasitic insect (a really small insect) known as an arthropod of the mite genus. They can be Eyelash mites, hair mites or a nasty skin mite. The mite is specific to its host, that is to say that the animal infective mites can not survive on human skin (in other words the animal mites think we taste nasty).

The mite causing scabies can only survive on human skin, the human eating parasite can not survive beyond 2 to 3 days outside of the skin (so if you are treating scabies then why not go away for a long weekend whilst you treat yourself, and then the mites in your house on your carpets and beds will have starved to death).

The female mite will start digging a furrow (like a trench) in the stratum corneum (the outermost layer of your skin) to lay between 10-27 eggs before expiring (kicking the bug bucket). The larvae hatch after 3 or 4 days out of the grooves to become mature in about two weeks. Only 10% of each batch of eggs survive, but considering the numbers laid in scabies infected skin, you are talking between hundreds and thousands.

The prevalence of scabies varies throughout the world, with some developing countries the prevalence (how frequently they find it) is as high as 6% to 27% of the population, especially in children. That is the same as having a class of 30 kids and 8 of them being infected. Transmission is by direct human contact (persons living in the same house, attending the same classes or persons within a close relationship), and it can also be passed through sharing clothing, towels, beds, etc. (Lets hope that hotels wash and dry their sheets correctly). They can be anywhere on the body, from eyelash mites, hair mites to skin mites.

As such this means that scabies can be included in the growing list of sexually transmitted diseases as the mode of contamination (way of catching it) is possible/likely through sexual contact. In institutions such as at work and in classrooms, transmission from one room to another (through door handles, chairs, tables, etc) is very unlikely unless the person is highly infected on their hands and arms.

Improved hygiene does not protect from contamination but gives a more atypical symptomatology (it will give symptoms slightly different to normal scabies infection, such as larger flakes of skin and red and blue vein patches). Unlike the chickenpox, initial infestation does not confer immunity later (you are not immune if you have them once, they may just as easily come back).



Cutaneous (skin) manifestations (you can see something like redness or scabs) are related either directly to the presence of the mite grooves or a through an immunologic reaction to their presence, or their actions (eating) or their waste (some people are allergic to their poop). The incubation period is about three weeks, or as little as a few days if re-infestation occurs. Washing your body and hair with a formula that has a mite killing agent within is normally the best way to prevent infestation if you have been around people with scabies. Don’t forget that it can take up to three weeks for symptoms to show, so there is no way of knowing if your contact has caused infection straight away.

Treating the scabies involves going after the mites and killing them, but then also making sure that you are not re-infected from the person(s) who gave it you in the first place, and also by the mites that have transferred to your clothes, sofa, carpets and bed sheets. Wash as much as you can at 60 degrees, apply mite killing agents, or better still, leave your house for 4-5 days. The mites will simply starve to death. Hoover up every thing in your house and wash your clothes and bed sheets. Dispose of the hovering remains carefully and then leave the house. That way the mites have no dust or oil to feed on and die off within 2-3 days. There are lots of remedies out there for curing scabies and mite infestations (but don’t forget to consult your doctor if you think you have scabies).



0 comments:

Post a Comment