Amid growing fears of a full-blown epidemic, health authorities are trying to wrap their heads around why children have not been struck down by severe symptoms.

Australia’s chief medical officer Dr Brendan Murphy said it was very ‘unusual’ when compared to influenza.

‘We don’t know whether children might be getting the disease but [their symptoms] are so mild they are not being picked up, or they’re not becoming sick, or whether they are somehow less susceptible,’ he said.