Two respiratory viruses with similar symptoms could be circulating at the same time
It’s the ultimate nightmare - a major outbreak of flu in the months ahead as we also struggle with a potential resurgence of Covid-19.
This is the great unknown that awaits us, along with trying to figure out which patients have flu or Covid-19, as the symptoms are similar.
So, when will the flu vaccine arrive and what can we expect if we suspect we have caught either or both viruses?
The HSE has ordered 1.4 million doses of the flu jab for adults. Another 600,000 vaccines in the form of nasal sprays are due for children. GPs and pharmacies should have the stocks by next month.
It’s difficult to say how severe the flu season will be this year. There is some comfort in reports from the Southern Hemisphere, which has its flu season from April to September. Levels of flu were extremely low compared to other years in countries like Australia. But it also happened when tough lockdowns were in place there. The fact we in Ireland have now opened up the country again may leave us with less defence. But our day-to-day anti-Covid habits, such as handwashing, social distancing and mask-wearing, are likely to reduce the spread of flu also. The problem may be in pockets like nursing homes, workplaces and residential centres.
Every autumn and winter, 200-500 people die in Ireland as a result of flu and around 4,000 need hospital admission. Covid-19 has killed 1,783 people since March and caused 3,440 hospital admissions. Both are more deadly to people over the age of 65.
Flu and Covid-19 are both contagious respiratory illnesses, but they are caused by different viruses. Because some of the symptoms of flu and Covid-19 are similar, it may be hard to tell the difference between them based on symptoms alone, and testing may be needed to help confirm a diagnosis.
Common symptoms that Covid-19 and flu share include fever, or feeling feverish and chills, cough, shortness of breath or difficulty breathing, fatigue, sore throat, runny or stuffy nose, muscle pain or body aches. People with flu may be more likely to have a headache. Some people may have vomiting and diarrhoea, though this is more common in children than adults. Doctors say shortness of breath or loss of taste and smell are seen more in Covid-19 than in flu patients.
Not all people who present with respiratory symptoms will be tested for Covid-19 and flu but it will happen in specific circumstances, according to new guidance from the Health Protection Surveillance Centre. While a Covid-19 test is likely, a flu test would depend on the levels of the virus circulating. But, for instance, both tests would be administered in nursing homes, residential care facilities or workplaces where someone had respiratory symptoms. People diagnosed with flu can be given anti-viral medications.
Dual infection with flu and Covid-19 is likely to lead to worse outcomes, particularly for those at risk, such as older people and people with underlying medical conditions. The impact is still unclear. Some cases in China where there was co-infection found the patient had more heart damage and more and earlier inflammation, and the over-reaction of the immune system can be dangerous.
From next month, all children aged two to 12 years will be offered a free flu vaccine by nasal spray. Up to 10pc of children under 15 visit their GP with flu in an average flu season. Vaccinating them aims to reduce illness and death and reduce the chance of passing it on. Children are among the most susceptible to flu infection. It is estimated that 20-30pc of children develop flu during each flu season compared to 5-10pc of adults.
Children, because they have limited pre-existing immunity, are primary vectors of flu transmission in the community. They transmit the flu virus for a longer period than adults. Children can transmit the virus for 10 or more days, compared to six days in adults, therefore increasing spread of the disease. Between the 2009/10 and 2018/19 flu seasons, more than 4,750 children aged under 14 were hospitalised as a result of flu, including 183 requiring critical care and 41 who sadly died.
The flu vaccine is recommended for a range of groups, including older people, those with underlying diseases, pregnant women and healthcare workers.