Human metapneumovirus, HMPV: Virus you’ve likely never heard of suddenly surges in Australia – with thousands feared to have it right now

A potentially deadly respiratory virus that few people even know exists is surging in Australia, with at least 1,168 people infected last week in NSW alone.

Human metapneumovirus (HMPV) can cause upper and lower respiratory disease in all age groups, but poses a greater danger to young children, older adults and people with weakened immune systems. 

Though it usually causes a mild infection similar to the common cold – with nasal congestion, coughs, shortness of breath and a fever – complications can lead to bronchitis or pneumonia and can be fatal, especially among those who are immunocompromised, such as people with cancer. 

According to NSW Health data, only influenza, which was detected in 1,424 people, was more prevalent in the state than HMPV last week. 

Confirmed cases of HMNPV have risen from 648 three weeks ago to 1,008 a fortnight ago, before reaching 1,168 infections last week.

The cases of HMPV – which are highest in winter and early spring – are also likely to be underestimated as testing is sometimes not done if a patient is already positive for Covid or flu.

A potentially deadly virus that few people even know exists is surging in Australia, with 1,168 people infected last week in NSW alone. Two women are pictured wearing face masks

‘We’re not only seeing increased numbers, but we’re also seeing people who we typically would think have a mild illness tending to have a more severe illness,’ University of NSW Professor William Rawlinson told the Sydney Morning Herald.

According to the CSIRO, children under five are the largest group of patients that are hospitalised in Australia for respiratory viruses such as HMPV. 

There are no antiviral medications that treat human metapneumovirus, but most people can manage their symptoms at home until they feel better – and most will not even realise that HMPV is the cause of their discomfort, mistaking it for a cold. 

But Professor Rawlinson warned that ‘people need to be aware that we are seeing a little bit more severe illness (now from HMPV). 

‘But we are also diagnosing it more now because we’re using much better testing,’ he said.

Dr John Williams, a paediatrician at the University of Pittsburgh who has spent his career researching vaccines and treatments for HMPV, said it was ‘the most important virus you’ve never heard of’. 

Leigh Davison, 59, came down with HMPV in early April after attending a family gathering.

Her symptoms were so bad that she could no longer talk on the phone.

She told CNN: ‘I couldn’t get out more than a couple of words. I would go into violent, violent coughing to the point where I was literally almost throwing up.’

HMPV usually causes a mild infection similar to a cold with symptoms such as a blocked nose, coughs, shortness of breath and a fever. But complications can lead to bronchitis or pneumonia and can be fatal (stock image)

Human metapneumovirus (pictured) can cause upper and lower respiratory disease in all age groups, but it poses a greater danger to young children, older adults and people with weakened immune systems

She was sure she had Covid, but after six negative rapid tests became nervous about pneumonia instead as she is immunocompromised.

Her doctor sent her to a hostpital for tests, which showed she had HMPV. ‘I was like, ‘What?’ Because it sounds really dire,’ she said.

The virus gave her severe bronchitis and she was admitted to the hospital for observation.

It took a month for her to fully recover and she said of all the respiratory infections she has had in her lifetime, HMPV was ‘the worst I’ve ever experienced’.