Meningococcal disease is the leading infectious cause of death in children in the UK. Around half of cases occur in children aged four years or under, although peaks are seen in teenagers and the elderly.
There are at least 13 different serotypes of Neisseria meningitidis, the causative agent, although most cases of meningococcal disease in the UK are caused by B or C strains. Introduction of the MenC vaccine in 1999 resulted in a marked decrease in the number of cases.
Meningococcal disease may cause septicaemia, meningitis or both. The organism may also cause arthritis, osteomyelitis or ophthalmic complications.
The early stages of meningococcal disease may present as non-specific flu-like symptoms so it is important to look for signs of septicaemia or meningitis in all febrile patients without obvious infection.
Meningococcal septicaemia is an emergency and is fatal in around 20 per cent of cases. A high index of suspicion and thorough examination are required when children present with signs of septicaemia.
A diagnostic tool such as the Glasgow meningococcal septicaemia prognostic score can help identify those children requiring immediate emergency treatment.
Bacterial death in the blood triggers a massive inflammatory reaction with failure of the endothelium and the clotting cascade. This produces the classic non-blanching purpuric rash of meningococcal septicaemia. In up to a third of cases the rash is maculopapular.
Early symptoms include tachycardia, increased respiratory rate and peripheral vasoconstriction. Signs include hypoxia and oliguria. Abdominal pain, sometimes with diarrhoea, may be a feature and joint and bone pains can be severe.
The peripheries may be cool and mottled. A capillary refill time greater than two seconds on the sternum or forehead is abnormal while one of four seconds or more in the peripheries is suggestive of shock.
Hypotension and altered consciousness are late signs in children. Without treatment, organ failure and cardiovascular collapse will eventually lead to death in these cases.
Meningitis has a different presentation to septicaemia and a much lower mortality rate at less than 5 per cent.
Symptoms include severe headache, impaired consciousness, photophobia and neck stiffness, although in young children both neck stiffness and photophobia occur later in the illness and up to a third do not even develop neck stiffness.
Kernig's sign may be positive. Babies may also present with a tense fontanelle, vacant stare, high pitched cry, poor feeding or a change in tone.
In older children and teenagers meningitis can cause changes in behaviour such as confusion or aggression. These signs are sometimes presumed to be alcohol related.
Meningitis may also cause raised intracranial pressure, which can eventually lead to cardiorespiratory compromise and death.
Signs of this include declining consciousness; unequal, dilated or poorly responsive pupils; hypertension; and relative bradycardia.
A child presenting with meningitis or a fever and purpuric rash should be treated for meningococcal disease without delay. Blood tests to confirm the infection can be carried out after antibiotics have been administered.
Antibiotics should be given intravenously where possible. Benzylpenicillin or cefotaxime are first-line agents.
Chloramphenicol may be used if there is a definite history of allergy to these agents. Oxygen should be given.
Treatment for sepsis may also include fluid resuscitation and inotropic support, usually within a hospital setting.
A lumbar puncture should be taken when meningitis is suspected. Treatment should also be administered where the diagnosis is unclear.
A child with worrying symptoms should be transferred to a paediatric unit via a blue-light ambulance, with a receiving team on standby.
Meningococcal disease is a notifiable disease. The consultant in communicable disease control is responsible for ensuring that anyone who has been in close contact with the patient receives prophylaxis.
Drugs used to clear carriage include rifampicin, ciprofloxacin and ceftriaxone.
Contacts should be informed that these drugs are not used to treat infection and the signs of established meningococcal disease should be discussed with them.
Dr Thakkar is a GP in Wooburn Green, Buckinghamshire.