Animals, Humans, and Lyme Disease
You may think that the transmission of Lyme disease is very simple - you get it from a deer tick bite. That information is essentially true, and if you just want to avoid Lyme disease, that’s all you really need to know. What goes on in the woods, however, is interesting, and it helps to explain why Lyme disease is spreading and becoming more common.
Lyme transmission starts with the White-footed mouse, a common forest creature that carries Borrelia burgdorferi, the organism responsible for Lyme disease. In the most common scenario, newly hatched larval Ixodes sp. ticks feed on the mice and become infected with the organism. The ticks then develop through a nymphal stage to an adult tick, feeding on other hosts as they get older.
At both the nymph and adult stage, ticks are found clinging to the tall grasses in open forests and forest edges, the same type of environment favored by White-tailed Deer. When a deer wanders by, the ticks climb on and take another blood meal. If it’s a human that wanders by, or a dog, a raccoon, or even a bird, the tick is not fussy - deer ticks will readily feed on all of these hosts as well as other warm blooded animals.
Borrelia burgdorferi gets passed on to the new host as the tick feeds. Many animals aren’t affected by the organism and their immune systems simply kill it. White-tailed deer and some bird species are among the lucky animals that don’t get Lyme disease. Humans, however, can suffer a long and debilitating illness.
Deer are responsible for supporting large numbers of ticks; one deer can have hundreds of ticks feeding on it at any one time. Anyone who has driven the roads of North Eastern North America at dusk and dawn in the summer months knows that the White-tailed deer population is booming like never before. Deer graze by the roadsides and wander into cities and gardens. Lots of deer means lots of ticks, and deer in human communities means Lyme transmission to humans.
Deer don’t spread Lyme disease over large geographical distances however - birds do that. When a deer tick bites a bird, two things can happen: if the bird is already infected, having been bitten by an infected tick somewhere else, the new tick becomes infected and can spread the organism to other hosts. If the tick is already infected and the bird is not, the organism gets passed the other way, and because ticks take days to finish their meal, both tick and bird can be many miles away from their starting point before the tick drops off. Both can now continue to Lyme transmission. Migrating birds are thought to have spread B. burgdorferi to many new locales.
A final factor to consider is global warming. Warmer climates have opened up new territory for deer ticks, and they are now surviving and reproducing in areas where they were previously unable to withstand cold winter temperatures. Thus, ticks carried in on migrating birds are more and more likely to survive the trip.
Rosemary Drisdelle is a freelance writer focusing on technical and science writing and creative non-fiction. She writes about birds for Suite101.com. She also writes a blog about parasites and people.
Tags: lyme disease, Lyme transmissionLyme Disease and Ticks - How is it Transmitted
Lyme disease is transmitted through deer ticks when they bite someone. It has a bacteria called spirochete. If it is diagnosed and treated early on with antibiotics it is easy to stop.
They say a tick that is infected can’t transmit Lyme disease until it has been attached to the host for 36 to 48 hours. So if you are in an area where these ticks are, check yourself and others at lease once a day.
If a tick has attached itself to you and it has been a few hours, chances are it has not had enough time to be able to transmit the disease. You should be aware of the symptoms though. If rashes appear around the bite, joint pain or flu-like symptoms in the first month or so, it could be signs of Lyme disease.
Northern California, Oregon and parts of the east coast are slowly being “invaded” by Lyme disease. Some say it is due to deer or other large animals and bird migrations. Check with local agency’s to see what the tick and Lyme disease situation is like.
Some more symptoms are chills, fever, fatigue, aches, tingling or numbness, headaches and swelling of lymph glands. If you think you may have Lyme disease, see your doctor as soon as possible.
To help limit exposer to ticks here are some tips to help you. Keep the area around your property clear of leaves and brush. Light colored clothing can help you spot ticks easily. Use a insect repellent that contains DEET. If you hike, stay on cleared paths and avoid sitting directly on walls or the ground. Wear pants and long sleeves. After coming back from a hike you should check yourself and others for ticks. They usually get onto your lower half first. Then they travel up the body looking for areas they can kind of hide in. Armpits, groin area and top of the head are some places they like to go.
David Getchel runs http://ticks.worldcondition.com More great information is available there.
Tags: deer ticks, LD, Lyme, lyme disease, rashes, ticks
