Multiple sclerosis 'might be caught by sexual contact'

Multiple Sclerosis, the creeping paralysis that affects 85,000 people in Britain, might be a sexually transmitted infection, a new study claims.

The changing incidence of the disease across the world shows that it is more common in sexually permissive societies and where there has been a sudden influx of young men, as in wartime.

It is more common among young, sexually active people and a Danish study showed its incidence increased around the time the contraceptive pill was introduced and women abandoned barrier methods of contraception. An American study found the incidence of MS doubled after six years of oral contraceptive use.

The new theory is proposed by Christopher Hawkes, a consultant at the Essex Centre for Neuroscience in Romford, in the Journal of Neurology. It was criticised yesterday by other specialists as offensive.

Among the evidence cited by Dr Hawkes is that the incidence of MS in children under 16 is two to three times higher in girls than in boys and that this might be due to child sexual abuse.

"Most abuse victims are female in a ratio of three to one ... the predominance of girls in childhood multiple sclerosis would support the concept of childhood sexual transmission," he writes.

Alastair Compston, professor of neurology at Cambridge University, dismissed the claim as "mischievous and deeply wounding, especially for relatives in families with several cases of the disease".

Dr Hawkes cites clusters and epidemics of MS over the past 50 years as evidence. In the Orkney and Shetland Islands, the incidence of MS increased fourfold between 1954 and 1974, after the arrival of 20,000 British troops in 1940. There was a similar increase in Iceland from 1945 to 1954, where 50,000 Allied troops were stationed, and in the Faeroe Islands.

Studies of migrants show that their risk of the disease increases when they move to countries where the incidence disease is higher, suggesting an environmental cause. MS is rare among people physically or culturally isolated from white populations, such as Aborigines, Maoris, Inuits, black South Africans, Norwegian Sami and native North Americans, Dr Hawkes says.

The disease is similar to tropical spastic paraplegia, which is known to be sexually transmitted and is linked to HTLV-1, a virus that attacks the nerve sheaths. Dr Hawkes says he is not claiming MS is caused exclusively by sexual contact but that genetic factors increase susceptibility to a sexually transmitted infection that damages the nerves. He hopes his hypothesis "might encourage a new direction of neurological research".

The theory is challenged in an editorial in the journal by Professor Graeme Stewart, of the Institute for Immunology and Allergy Research in Sydney, Australia, who calls it pure speculation. "The data cited in support of the hypothesis are open to different interpretations and there are no new data to back up the argument," he says.

Professor Compston said in a statement issued by the MS Society: "As no new facts have been reported, this paper has little if any scientific value. The hypothesis falls down quickly."