Parents of girls at the 700-pupil Godolphin and Latymer School in Hammersmith, west London, were told of the latest outbreak of the disease by letter yesterday after the girl was admitted to St Thomas's Hospital on Saturday.
In the letter, Dr Tony Ellam, consultant in communicable disease control at Ealing, Hammersmith and Hounslow Health Authority, said parents should be "alert to the possibility that your child is becoming unwell with 'flu- like' symptoms with aches and pains in the joints or muscles or an increasingly severe headache".
Headmistress Margaret Rudland confirmed yesterday that the school remained open. Dr Ellam said pupils had not been given antibiotics because their effect was short-lived and tended to lull parents into believing that their children would be safe from the disease in the long term.
Dr Ellam said that notifications of the disease were "tracking at 20 per cent up on last year" and warned that the increase was likely to be exacerbated by an expected flu epidemic.
The toll in Lincoln stands at five following the deaths of Robert Newlin, also 19, a carpet shop manager, and Kelly Roberts and Samuel Binns, both aged 15 and pupils at the City School.
Caroline East, 14, another pupil at the school who contracted the disease last week, is now off the critical list. Her condition last night was stable. A 40-year-old Lincoln man is still critically ill in Nottingham City Hospital.
In the Leeds case, a 21-year-old girl, who was studying at Leeds University, died from meningococcal meningitis at the same time as three schoolchildren and a baby were hit by what is believed to be the same bacterial strain.
The three children - a boy aged 16 and two girls aged nine and 10 - are recovering from the illness. The infant is still very poorly.
The university student who died has not been named. It is believed she was an exchange student and her parents are flying over from Canada.Reuse content