Researchers are hoping to halt the spread of the fastest growing parasite-transmitted disease in the northern hemisphere by reducing tick numbers, writes
MICHELLE McDONAGH
AS OUTDOOR recreational activities increase during brighter days and longer evenings, so too does the risk of being bitten by a tick and developing a potentially serious disease.
Lyme disease is the fastest growing parasite-transmitted disease in the northern hemisphere and the main period of risk in Ireland is between mid-March and mid-October. However, through taking simple and sensible precautions, you can reduce your risk of contracting the disease to a very low level.
Dr Eoin Healy, a research associate in the Department of Zoology, Ecology and Plant Science at University College Cork, is involved in research into the biochemical drivers of tick behaviour. The goal of this work is to contribute to the development of baiting and trapping methods to reduce tick numbers and, as a consequence, the incidence of Lyme disease in humans.
“In Ireland, Lyme disease is not a notifiable disease and so there are no official data to inform us about its prevalence. However, based on laboratory data in the Cork/Kerry area, it is very likely that several hundred cases a year occur in Ireland. In addition, many more cases may go undiagnosed or misdiagnosed,” he explains.
The risk of coming into contact with ticks is likely to be high in areas where there is a significant number of deer and sheep grazing in rough, non-pasture land, explains Healy. Counties Wicklow, Kerry and Cork are known high-risk areas.
“Only a very small proportion of people who are bitten by ticks develop Lyme disease, but given that thousands of people will be bitten between now and autumn, it’s important to be aware of this risk,” says Healy.
The first indication of Lyme disease is usually a red expanding weal around the site of the tick bite, followed shortly by fatigue and chronic flu-like symptoms in the second phase of the illness.
Healy says: “If untreated, the third phase of Lyme disease is a chronic arthritis in the vast majority of sufferers. This is extremely painful and particularly affects the knee joints.
“The late conductor of the Berlin Philharmonic, Herbert von Karajan, spent much of his last months of life in a wheelchair because of severe attacks of Lyme disease.”
However, Healy stresses that as well as being preventable, Lyme disease can be effectively treated with antibiotics. He points out that the risk of being bitten by a tick can be reduced by taking sensible precautions, the most obvious of which is to wear appropriate clothing.
Ticks are more visible and can be easily removed from light-coloured clothing. Wear trousers tucked into socks and long-sleeved shirts to try to prevent direct access to the skin. A general purpose insecticide used on the wrists and ankles can provide a decent degree of protection.
“When in recreational forest parks, stay on the paths and discourage children from straying into knee-high vegetation, heather and long grass that is likely to harbour ticks. Walkers and backpackers may be tempted to lie back on the heather and look at up the sky, but they should be aware that they could pick up a few or even hundreds of ticks if they are in a high tick area.”
Healy stresses the importance of conducting an all-over body examination of the skin within a few hours of spending time in outdoor activities in high-risk areas as the parasites do not begin to release the bacteria Borrelia for about six hours after they start feeding. The tick is flat and dark in appearance and cannot fly.
Remove any tick visible with a tweezers and crush it between a coin and hard surface just to be safe. Dab the site of the bite with antiseptic ointment and make a written note of the date and location where the bite occurred.
“Check the site of the bite daily and if you notice any sign of a red weal widening around the site, consult your GP within the next couple of days,” advises Healy.
“Given that 25 per cent of people do not develop this rash, keep an eye out for other signs of flu-like symptoms. Lyme disease may not be the obvious reason for your symptoms, so if you have been bitten by a tick, you should make that clear to your GP.”
LYME DISEASE: WHAT IS IT?
Lyme disease in humans is caused by infection with bacteria of the genus Borrelia. Infection can happen as a result of a person being bitten by a tick. As a tick sucks blood from its victim, the bacteria enter the bloodstream and may, in certain cases, result in the development of a condition called Lyme disease or borreliosis.
In cases where infection progresses to the disease state, symptoms usually begin with flu-like indications. Inflammation of joints is common and, in untreated cases, severe chronic arthritis may develop.
People who live and work in areas with significant tick numbers and those who visit tick-infested localities for recreational use are at a much higher risk of being bitten.
The risk is highest in children in the under-12 age group as they are more likely to be bare-legged, closer to the ground and in contact with tick-infested vegetation as they run around in woodland. Unless taught and supervised by parents, they will be less likely to rigorously examine themselves for ticks.
