A virus that can cause paralysis in children has been circulating in New South Wales during autumn, and has recently spread to Victoria.
Around 30 young children, mainly from Sydney’s northern and southeastern suburbs, were admitted to hospital with neurological complications last month.
The cause is a new strain (C4a) of enterovirus EV71, which has infected hundreds of thousands of mostly preschool-age children in China, Cambodia, and Taiwan in recent years. In Australia, five cases of EV71 paralysis were reported in New South Wales and Victoria in early June. Two deaths have been confirmed, and test results are pending for a third case.
While the paralysis caused by EV71 is similar to that caused by poliovirus, the two viruses are not related. Polio has been eradicated from Australia by immunisation; the last cases of polio in Australian children was around 40 years ago.
Outbreaks from different strains of EV71 occur regularly in Australia and normally cause a mild illness in children. The most common of these illnesses is hand, foot, and mouth disease (HFMD).
Children with HFMD develop a fever and rash, and blisters localised to the foot, hand, and throat. It’s important to let the blisters to try out naturally, rather than burst, as the fluid within them is infectious. The incubation period for the disease is three to five days, and the illness lasts around five days.
But some strains of EV71, such as C4a, can cause much more serious illness.
Most cases initially develop fever and a rash. More serious signs are sudden weakness in the limbs, excessive drowsiness or irritability, or evidence of heart and lung inflammation, such as being out of breath.
In some cases, the virus causes inflammation of the brain and spinal cord. The heart and lungs may also be affected, leading to life-threatening encephalitis or heart failure. Children under two years of age are especially at risk of complications.
Victoria's Chief Health Officer, Dr Rosemary Lester, has told hospitals and health workers to be on the lookout for the virus.
"Any child presenting with a febrile [feverish] illness and neurological features (including irritability) should have a diagnosis of EV71 considered and should be discussed with an emergency consultant or paediatrician."
The virus is confirmed after analysis of stool samples and throat swabs. Medical staff have been told to isolate children with suspected EV71 complications in "a single room with contact precautions in place".
How does the virus spread?
Like many viruses, EV71 is transmitted by faecal contact and by coughs and sneezes (droplet infection). Spread from respiratory droplets can be limited by use of tissues.
Careful hand hygiene is important. Parents toileting children or changing nappies should be particularly careful to routinely wash their hands with soap and to use disinfectants where needed.
Children who have EV71 should be isolated to stop the spread. Those with HFMD should be kept at home until the blisters have cleared up.
There is as yet no vaccine or curative treatment available on the market, but a Chinese company is working on a HFMD vaccine.
Visit Essential Kids to learn more about hand, food and mouth disease.
This article first appeared on The Conversation. Charles Watson is a neurobiologist and public health physician, and is currently a research fellow at the Prince of Wales Medical Research Institute and Curtin University.