Surveillance data from China CDC (30 Dec 2024 - 5 Jan 2025) shows influenza, not hMPV, as the dominant respiratory virus in China, while India appeared poised for another pandemic
Published Jan 11, 2025 | 7:00 AM ⚊ Updated Jan 11, 2025 | 7:00 AM
A few days ago, news about human metapneumovirus (hMPV) was everywhere. No television viewer or social media user in India could escape reports of hMPV cases in China, with lingering fears from the Covid-19 outbreak fuelling public unease.
During the first week of January, widespread coverage caused panic, with a case reported in Bengaluru being labeled as India’s “first.” The news even triggered a dip in the Indian stock market. A total of eight cases were reported before the topic seemingly disappeared from public discourse.
However, surveillance data from the China CDC for 30 December, 2024 – 5 January, 2025, reveals a different picture of the same period. Influenza, not hMPV, was the dominant respiratory virus in China during this period, even as India seemed braced for another pandemic.
On other hand, on Thursday, 9 January, China also identified another long-forgotten disease, shifting focus away from hMPV and underscoring the evolving health landscape.
In the first week of 2025, respiratory specimens from outpatient influenza-like illness (ILI) cases and hospitalised severe acute respiratory infection (SARI) cases were collected from sentinel hospitals across mainland China. These samples were tested for ten viral pathogens, including the novel coronavirus, influenza virus, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), and others.
The analysis indicated that the influenza virus remained the most frequently detected pathogen. Among outpatient ILI cases, the positive detection rate rose by 3.8 percent from the previous week, reaching 35.5 percent. In hospitalised SARI cases, the detection rate increased by 2.5 percent, reaching 21.4 percent. The positive detection rate for human metapneumovirus (hMPV) remained stable at 6.2 percent in outpatient cases, showing no increase.
Despite the rise in influenza cases, overall detection rates were lower than during the same period last year. Influenza activity is expected to gradually decline by mid to late January, though regional variations are anticipated.
In hospitalised SARI cases, influenza virus and Mycoplasma pneumoniae emerged as leading pathogens. Significant regional differences were observed: northern provinces showed a slowing detection rate, while cases among children aged 14 and below began to decline. In contrast, RSV showed a fluctuating upward trend among children aged 0 to 4 years.
Detection rates for rhinovirus, adenovirus, and Mycoplasma pneumoniae continued to decline, while other respiratory pathogens, including the novel coronavirus, remained at low epidemic levels.
Age-specific patterns showed influenza, human metapneumovirus, and RSV were predominant among children aged 0 to 4 years. In those aged 5 to 14 years, Mycoplasma pneumoniae and influenza were the dominant pathogens, with human metapneumovirus also common.
Among individuals aged 15 to 59 years, influenza and rhinovirus were most frequently detected, while human metapneumovirus continued to be a significant contributor. For those aged 60 and above, influenza and rhinovirus remained most common, followed by coronaviruses and human metapneumovirus.
The China CDC predicts a short-term rise in respiratory infections but expects influenza activity to decline by mid-month. Human metapneumovirus detection rates remain stable but continue to warrant attention.
Public health officials recommend strict hygiene practices, mask use in crowded places, and timely vaccinations for vulnerable groups to curb disease transmission and safeguard public health.
While recent discussions in India have centered on rising concerns about human metapneumovirus (hMPV) cases in China, Chinese health authorities have reported a different pressing health development.
On Thursday, the China Centre for Disease Control and Prevention (CDC) announced the detection of a newly mutated strain of mpox, identified as clade Ib, which has sparked a localised outbreak.
The cluster reportedly began with a foreign national who had traveled from, and previously lived in the Democratic Republic of the Congo (DRC), where the strain is endemic. Following close contact with the individual, four additional cases were detected in China. The infected patients exhibited mild symptoms, including skin rashes and blisters.
Mpox, which spreads through close contact, often presents with flu-like symptoms and pus-filled lesions. Although typically mild, it can occasionally lead to severe outcomes. The new clade Ib variant is noted for spreading more efficiently through routine interactions, including sexual contact, compared to the earlier clade I strain that led to an outbreak in the DRC.
The global health community has kept a watchful eye on mpox since the World Health Organisation (WHO) declared it a public health emergency last year.
In response, China has classified mpox as a Category B infectious disease, allowing authorities to impose emergency measures, such as restricting public gatherings and suspending work or school, during outbreaks. Screening protocols have also been reinforced for travellers and imported goods to curb the virus’s spread.
As concerns over hMPV persist, the emergence of this new mpox strain highlights the complexity of monitoring and managing respiratory and viral infections in a season marked by heightened health vigilance.
(Edited by Ananya Rao)
