Brief on Human Metapneumovirus (hMPV), January 2025


Short overview of the hMPV and its impact in South Africa. By Prof Tulio de Oliveira, Director of CERI & KRISP & Dr. Richard Lessells, Senior ID specialist, KRISP.


What do we know about hMPV?

Human metapneumovirus (hMPV) is common virus that causes acute respiratory tract infections. It was discovered in 2001 by researchers in the Netherlands, but genetic analyses suggests that hMPV emerged over 200 years ago (de Graaf et al. J Gen Virol. 2008). hMPV is distributed worldwide; in many parts of the world, it circulates in late winter through to spring and it can circulate at around the same time as other respiratory viruses such as influenza and respiratory syncytial virus (RSV). It is thought that most people are infected by hMPV by the age of 5 years, but immunity is incomplete and re-infections can occur throughout life.


What are the clinical manifestations of hPMV?

Clinical disease ranges from mild upper respiratory tract infection to more severe problems such as bronchiolitis and pneumonia. The most common symptoms associated with hMPV infection are the same as other respiratory viruses: fever, cough, sore throat and rhinorrhoea (runny nose). The severity of disease depends on the age and the health of the host, so the more severe manifestations can be seen in young children, older adults and people with underlying health problems (particularly those with weakened immune systems).


Why is there interest in hPMV now?

The interest in hPMV is mostly related to social media showing full hospital emergency departments in some parts of China. The reality is that, especially after COVID-19, any information on increasing respiratory infections in China tends to generate global interest.


What do the Chinese authorities says about hPMV?

The Chinese authorities have acknowledged that hMPV cases are increasing in some parts of the country, but have emphasized that the virus is a known entity and that disease patterns are not unusual for this time of year. China, like many other countries, has a robust respiratory pathogen surveillance system - trends in respiratory pathogens are reported transparently by the China CDC on a weekly basis (China CDC 2025). The latest results (from the last week of 2024) show that acute respiratory infections have increased during recent weeks and detections of several viruses (influenza, rhinovirus, RSV, and hMPV) have increased, particularly in northern provinces of China. Nationally, influenza was the most common cause of both outpatient influenza-like illness and hospitalised severe acute respiratory infection (China CDC 2025).


WHO comments on hMPV and China?

The WHO have released clear information about the current situation in China and around the world (World Health Organization 2025). They confirm that what is being seen is as would be expected for this time of year, that they have not received any reports of unusual outbreak patterns, and that the health care system in China is not overwhelmed.


Should South Africa be worried about hPMV?

South Africa has no reason to be worried about the increase in hMPV infections in China. hMPV already circulates in South Africa and causes infections throughout the year, particularly in late winter and spring. Most people in South Africa will have some immunity to hMPV. There is therefore no additional risk from the virus being imported from other parts of the world.

Although the NICD respiratory pathogen surveillance systems do not routinely include testing for hMPV, any unusual increase in respiratory infections or change in disease severity would be detected and additional testing could be performed. Routine diagnostic testing for hMPV is relatively rare in the public sector, but is more common in the private sector where multi-pathogen respiratory diagnostic tests are used more frequently. Trends in respiratory pathogens (including hMPV) are reported usually on a monthly basis by the main private laboratory groups (Lancet Laboratories 2024, Ampath Laboratories 2024 and Pathcate Laboratories 2024).


Citations:


1. de Graaf M, Osterhaus ADME, Fouchier RAM, Holmes EC. Evolutionary dynamics of human and avian metapneumoviruses. J Gen Virol. 2008 Dec;89(Pt 12):2933-2942. doi: 10.1099/vir.0.2008/006957-0. PMID: 19008378.

2. China CDC 2025. National sentinel surveillance of acute respiratory infectious diseases. https://www.chinacdc.cn/jksj/jksj04_14275/ , accessed 07 January 2025.

3. World Health Organization 2025. Trends of acute respiratory infection, including human metapneumovirus, in the Northern Hemisphere. https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON550, accessed 07 January 2025

4. Lancet Laboratories 2024. Respiratory Pathogen Statistics 2024. https://www.lancet.co.za/respiratory-virus-statistics-november/ , accessed 07 January 2025

5. Ampath Laboratories 2024. Respitatory BVirus Statstics, Oct/Nov 2024. https://www.ampath.co.za/storage/538/Respiratory-statistics-OCTNOV.pdf , accessed 07 January 2025

6. Pathcate Laboratories 2024. Respiratory Pathogen Statistics September 2024. https://www.pathcare.co.za/respiratory-pathogen-statistics-september-2024/ , accessed 07 January 2025

News date: 2025-01-09

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KRISP has been created by the coordinated effort of the University of KwaZulu-Natal (UKZN), the Technology Innovation Agency (TIA) and the South African Medical Research Countil (SAMRC).


Location: K-RITH Tower Building
Nelson R Mandela School of Medicine, UKZN
719 Umbilo Road, Durban, South Africa.
Director: Prof. Tulio de Oliveira