WALKERS and campers in the New Forest are being warned to watch out for signs of a disease which can cause blindness and paralysis.

Ticks - tiny blood-sucking insects -spread Lyme disease, which is on the increase.

The Chartered Institute of Environmental Health (CIEH) is pressing the Government to tackle, what it describes as, a growing threat to public health.

The institute says 800 laboratory cases of Lyme disease are confirmed annually, plus up to 2,000 cases which are diagnosed and treated by family GPs.

A CIEH spokesman said: "Lyme disease is caused by infected ticks and can cause symptoms from a rash to blindness and paralysis.

"Treating the disease is often complicated by the fact it's frequently misdiagnosed and underreported.

"The spread of Lyme disease in Europe and America has signalled the need to assess the potential threat to public health."

Ticks are on the increase because of warmer and wetter summers. In 2006, there were 768 reported cases of Lyme disease compared with 292 in 2003.

People walking in the countryside can guard against the threat by making sure their arms and legs are covered. Tucking the bottoms of your trousers into your socks can significantly reduce the risk of a tick attaching itself to your leg.

A Department of Health spokesman said: "Clinicians have ready access to the best Lyme disease diagnostic tests available. Tests are freely available in the NHS.

"A short course of antibiotics is the usual treatment for Lyme disease, and this is also freely available.

"It is for primary care trusts to ensure appropriate services are in place to meet local needs."

Lyme disease is caused by infection with spiral bacteria called Borrelia burgdorferi.

Most ticks are not infected with the bacteria which causes Lyme disease.

Most people with Lyme disease develop a reddish skin rash in a ring shape, and this may be the only sign of infection.

The rash spreads out from the site of a bite after three to 30 days. Other common symptoms with early Lyme disease include tiredness, headache, joint pains, and flu-like symptoms.

Without treatment, these symptoms may last for weeks or even longer. Rarely, there are serious complications and, in some cases, these can occur several years later.