When the world locked down to prevent the spread of COVID-19, it took a few extra illnesses down with it – including influenza, also known as flu. The Centers for Disease Control and Prevention (CDC) reported that rates of flu were “unusually low” in the 2020-2021 season both in the United States and globally, despite high levels of testing. However, as sanctions in certain parts of the world start to ease up, the question of what might happen to a person simultaneously infected with influenza and COVID-19 becomes more pressing.

Last week, it was revealed that a person had tested positive for both illnesses in Israel – a condition that’s been dubbed “Flurona”. The report comes from the city of Petah Tikva, where a young pregnant woman was found to have both influenza and COVID-19 when tested at Beilinson Hospital. The patient was not vaccinated against either virus.

Fortunately, the patient’s symptoms were mild, says EuroNews, and they have since been able to go home. While some outlets are reporting the "Flurona" case as a world-first, the disease presentation isn’t actually all that new. Similar cases were detected by researchers from the University of Columbia, US, in early 2020, The Atlantic reports.

The decline in flu rates in the 2020-2021 season was likely the cumulative effect of COVID-19 restrictions like wearing face masks, social distancing, plus school, workplace, and hospitality closures. As such restrictions relax in certain parts of the world, and with fewer people accessing flu vaccines, it has been suggested that we could be at risk of a “Twindemic” if Flurona catches on, so to speak.

While preliminary studies suggest that the current dominant strain Omicron appears to be milder, a mashup with flu could set us back to Delta disease severity. This would once again put a catastrophic strain on hospitals and other health care services and increase the motivation to reintroduce harsher restrictions on daily life.

At the time of writing, little is known about the severity of Flurona – but with flu on the rise, it’s likely we’ll start seeing more cases of the dual infection. Health officials say more investigation is needed to better understand if Flurona may be more deadly for certain patients, and if (or how) the presence of the two diseases might influence a patient’s treatment plan and expected outcome.

“It’s a little mysterious as to what’s going to happen,” said Monica Gandhi, an infectious disease specialist at the University of California, San Francisco, to National Geographic. “We don’t have influenza immunity from last year and we’re going to be mingling more. We need to be prepared for both [viruses] coming up at once.”