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Classic meningitis signs present in only half of cases, study finds

Only around half of babies under three months who have bacterial meningitis present with fever, which has for decades been the trigger for further medical investigation, new research has revealed.

Other associated signs like a bulging fontanelle, coma, seizures and neck stiffness were also found to be uncommon in infants – the group at highest risk of the disease.

The study showed that clinical presentation in young babies is often non-specific and hard to distinguish from mild illnesses. Common features of the disease were found to be poor feeding, lethargy and irritability.

The researchers from St George’s, University of London are warning practice nurses and GPs that they may miss correctly diagnosing babies with deadly bacterial meningitis if they assume that infants without a fever do not have the illness.

One of the researchers, Professor Paul Heath, said: ‘The classic features of meningitis were uncommon in many cases. The symptoms displayed by young infants are often non-specific and only half of cases showed signs of a fever.

‘Guidelines focusing on serious infections in children - including meningitis - have been introduced in the UK and the USA but all specify fever as a key feature of infection.

‘Unfortunately, neither the rates of bacterial meningitis in babies, nor the numbers of deaths, has changed since the 1980s.

‘Clinicians must therefore still consider bacterial meningitis in the diagnosis of an unwell infant that doesn’t present with fever.’

The study looked at 263 infants across the UK and Ireland and found that fever (temperature above 38C) was reported in only 54% of cases, seizures in 28%, bulging fontanelle in 22%, coma in 6% and neck stiffness in only 3%.

The study revealed that infants who did present with fever tended to be older than infants without fever. The median age for this symptom was around 21 days old.

Over half (52%) of the infants without fever did have other features suggestive of bacterial meningitis, such as apnoea (33%), seizures (32%), bulging fontanelle (16%), coma (7%) and neck stiffness (3%).

The study suggests that there should be a low threshold for referral and performing investigations on young infants, especially in the first month.

As a result of the findings, the Meningitis Research Foundation has collaborated with the researchers to create a teaching package aimed at health professionals to aid rapid diagnosis and treatment.

The package includes an e-tool to help clinicians recognise bacterial meningitis in young infants, a lumbar puncture information sheet to help explain this procedure to parents and an algorithm to aid management of bacterial meningitis.

The Pediatric Infectious Disease Journal 2018; available online 29 January