People who spend lots of time outdoors are being reminded of the importance of protecting themselves against Lyme disease, which is spread by the bite of a tick.

According to the Health Protection Surveillance Centre (HPSC), in a small number of cases, Lyme disease can cause severe heart and nervous system problems.

"Ticks are tiny insect-like creatures that feed on the blood of mammals and birds and will also feed on humans and occasionally dogs. Ticks are more numerous and more active in the summer months and protecting against tick bites protects against Lyme disease," explained Dr Paul McKeown of the HPSC.

He pointed out that when people are infected, many show no symptoms, and in Europe, as many as one in four people have antibodies in their blood to the disease. This means that they have previously been bitten by an infected tick.

"The commonest feature is a rash, which occurs in about three-quarters of patients. This rash generally develops between three days and a month after a tick bite. It can last up to a month and be several inches in diameter. People can also complain of flu-like symptoms such as headache, sore throat, neck stiffness, fever, muscle aches and general fatigue," Dr McKeown said.

In a minority of cases, there can be serious complications involving the heart, nervous system, joints or other tissues.

However, Dr McKeown emphasised that only a minority of ticks actually carry infection and they usually have to be attached to a person for a number of hours before this infection is passed on, ‘so rapid removal of ticks is important'.

"If a tick is removed within a few hours, the risk of infection is low. The entire tick, including any mouthparts which might break off, should be removed with a tweezers by gripping it close to the skin. The skin where the tick was found should then be washed with soap and water and the area checked over the next few weeks for swelling or redness," he said.

Anyone who develops a rash or other symptoms should attend their GP and explain that they have been bitten by a tick.

"Lyme disease is diagnosed by medical history and physical examination. Diagnosis can be difficult if there has been no rash. The infection is confirmed by special blood tests," Dr McKeown noted.

Lyme disease has been notifiable in Ireland since 2012 and since then between eight and 13 cases have been reported per year. However Dr McKeown emphsised that as some people may not be aware they have been infected or may not seek medical help if unwell, ‘the true incidence is not known'.

"It is likely that there are at least 50-100 cases in Ireland every year," Dr McKeown added.

People can protect themselves by wearing long trousers, long-sleeved shirts and shoes, and using an insect repellent.

For more information on Lyme disease, click here