The bacteria only rarely give rise to meningococcal disease, but when they do infection spreads rapidly and is fatal in about 10% of cases. If disease is diagnosed early and treated promptly most people make a full recovery.
About 1 in 8 people who recover experience some long term effects. These can include headaches, stiffness in the joints, epileptic fits, deafness and learning difficulties.
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The victim, who was wearing her uniform at the time, was found knocking on doors nearly four hours after she was abducted.
There will be gales across Scotland and northern England this morning, but these will gradually ease through the afternoon.
A 14-year-old boy was taken into custody following the attack in South Carolina in the US.