If you managed to stay healthy this festive season, chances are you still know at least a couple of people who did not. In the days before Christmas and in the weeks that followed, a so-called “mystery virus” has been moving rapidly across the UK. Many people have reported coughing, sneezing, blocked or runny noses, and in some cases stomach-related problems too. So what exactly is behind this wave of illness? Ian Budd, lead prescribing pharmacist at Chemist4U, has explained which virus is currently spreading widely across the country and what steps you can take to safeguard yourself and your family. He also sheds light on its incubation period.What Is Adenovirus?Adenoviruses refer to a large family of viruses that can trigger infections ranging from mild to more serious, affecting different parts of the body. Most often, adenovirus targets the respiratory tract. The symptoms can closely resemble those of a cold or flu. In the majority of cases, adenovirus infections are mild and can be managed with basic care focused on easing symptoms.Adenovirus Incubation PeriodThe incubation period for adenovirus usually falls between 2 and 14 days. For many people, signs such as fever, a sore throat, or coughing tend to appear around five or six days after coming into contact with the virus, although this can differ from person to person. Adenovirus spreads easily through droplets released when someone coughs or sneezes, by touching contaminated surfaces, or through fecal-oral transmission. It is highly contagious, particularly in crowded settings, and people may continue to shed the virus even after they start feeling better, according to the National Institute of Health.One reason the virus appears to be everywhere right now is winter behaviour. Colder weather keeps people indoors for longer periods, increasing close contact with others who may already be unwell.Ian explained, “With COVID-19 restrictions no longer in place and fewer people being exposed to common viruses over the last few years, overall immunity in the community may be lower. That makes people more vulnerable now.“Adenovirus itself is not new. It is simply appearing more frequently at the same time as other winter illnesses.”Adenovirus SymptomsIf you suspect you may have adenovirus, the most common symptoms include:Sore throatRunny or blocked noseCoughFeverFatigueHeadaches or body achesShortness of breath, which is less commonOther possible signs:Pink eye, also known as conjunctivitis, causing red, watery, gritty-feeling eyesEar infections, particularly among childrenDigestive symptoms such as nausea, vomiting, or diarrhoea with certain strainsWho Do Adenoviruses Affect?Adenoviruses can infect people at any age, but they are especially common in children under the age of five. In babies and young children, the virus often spreads in daycare settings, where close contact is unavoidable. Young children are also more likely to put shared objects in their mouths and are less consistent about handwashing.Among adults, adenoviruses tend to spread in crowded living conditions. Those who spend time in dormitories or military housing may face a higher risk. The virus can also circulate easily in hospitals and nursing homes.People with weakened immune systems are more likely to become seriously ill if they contract adenovirus. This group includes individuals who have undergone stem cell or organ transplants, as well as those living with cancer or HIV/AIDS. Those with existing heart or lung conditions also face a higher risk of severe infection.