LONDON, Jan 9: Experts have highlighted the key differences between the various winter viruses currently circulating in the UK, helping the public differentiate between the flu, a cold, and a new potential threat to the health services — Human Metapneumovirus (HMPV).

As flu cases continue to surge, overwhelming hospitals and triggering 'critical incidents' at several facilities across the country, concerns have also been raised about the rise of HMPV. This virus, which has already overwhelmed hospital waiting rooms in China, is drawing comparisons to the early days of the COVID-19 pandemic.

Experts are calling on Chinese authorities to share more information about the strain of HMPV in circulation so that UK health officials can assess the potential threat to the British public. While symptoms of HMPV are generally mild for most people, resembling a common cold, certain vulnerable groups—such as the elderly, young children, and the immunocompromised—could face more severe complications from the virus.

In most cases, HMPV symptoms closely mirror those of a common cold. These include coughing, a blocked or runny nose, sore throat, and a slight fever. Nausea and vomiting may also occur. For the majority of people, symptoms usually clear up after about five days.

However, in some cases, HMPV can cause more severe respiratory issues such as bronchitis, bronchiolitis, or pneumonia, especially in individuals with weakened immune systems. This may lead to shortness of breath, a severe cough, or wheezing.

Professor John Tregoning, an expert in vaccine immunology at Imperial College London, explained that when HMPV infects children, it often presents similarly to respiratory syncytial virus (RSV), another common winter virus that usually causes mild, cold-like symptoms. He emphasized that, like other respiratory viruses, HMPV spreads through coughs, sneezes, and droplets.

Patients are typically not tested for HMPV unless they are hospitalized, where rapid antigen tests or PCR tests are used to detect the virus.

Recent data from the UK Health Security Agency (UKHSA) shows that one in ten children tested for respiratory infections in hospitals have tested positive for HMPV as of December 23, more than double the number of cases seen in late November. While case numbers are consistent with expectations for this time of year, experts warn that vulnerable groups, such as babies, the elderly, and those with weakened immune systems, are at greater risk of more severe episodes.

Flu, caused by influenza viruses, tends to be more severe than a cold or HMPV. Common symptoms include a cough, fever, chills, headaches, muscle aches, and fatigue, with some cases leading to gastrointestinal issues such as vomiting and diarrhea.

Flu can also lead to serious complications like pneumonia, which can be fatal for vulnerable groups. Professor Ron Eccles, former head of the Common Cold Centre at Cardiff University, stated that flu symptoms are more intense because they affect the entire body, not just the upper airways, as with colds.

Flu cases in the UK have been rising sharply, with flu-related hospital admissions quadrupling in the past month. Latest NHS data shows that 4,500 hospital beds were occupied by flu patients every day as of December 29, up 3.5 times from the same week last year. At least 211 patients were in critical care, marking a 69% increase from the previous week. Over 5,000 people were hospitalized with the flu by December 29, and the virus continues to put pressure on NHS services, alongside other respiratory illnesses like RSV and norovirus.

Colds, typically caused by rhinoviruses, are the mildest of the winter viruses. Symptoms are usually restricted to the upper airways and include a runny nose, sneezing, sore throat, and congestion. Cold symptoms develop gradually and may cause fatigue, but they are generally not as severe as the flu.

Dr. Ann Nainan, a London-based GP, explained that colds tend to start with mild symptoms like a runny nose or sore throat, becoming more noticeable as congestion and coughing set in. Unlike flu, which can leave people bedridden, colds are more of a nuisance and usually resolve within a few days.

There is no cure for a cold, but there are several ways to alleviate symptoms. Rest, fluids, steam inhalation, and warm drinks with lemon and honey can help soothe a sore throat and clear nasal congestion.

Although flu, HMPV, and the common cold share some overlapping symptoms, experts advise that the intensity and duration of the symptoms can help distinguish between them. While a cold is typically a mild infection with upper respiratory symptoms, flu tends to affect the entire body, with more severe symptoms and the potential for complications. HMPV, while usually mild, can cause more severe respiratory issues in vulnerable individuals.

Dr. Conall Watson from UKHSA encouraged people to practice good hygiene to prevent the spread of these viruses, including regular handwashing and using tissues to catch coughs and sneezes. He also recommended wearing a mask if respiratory symptoms persist, especially when out in public, to prevent further transmission.

In summary, while winter viruses like HMPV, flu, and the common cold are circulating at high levels, experts urge the public to monitor their symptoms and seek medical attention if they worsen or persist beyond a week. In particular, vulnerable individuals, including young children, the elderly, and those with weakened immune systems, should be vigilant and seek prompt care if necessary.