Covid symptoms but testing negative? Here’s how to differentiate between Covid and norovirus

If you’ve felt like you had Covid recently but tested negative, you’re not alone.

A wave of respiratory and stomach bugs have been sweeping the US for months, striking earlier and more severe than usual and causing similar symptoms to the pandemic virus.

An unseasonably early and vicious flu and RSV outbreak largely subsided last month, but now a new familiar nuisance has resurged.

Norovirus is a very contagious stomach bug that causes vomiting and diarrhea. Like Covid it can cause headaches, chills and a fever.

But there are some ways to tell between the two. 

The above graph shows tracking of norovirus cases by year, with this year's data 2022/23 shown in red. Last year's (2021/22) is the blue dashed line, while the previous year is the blue dotted line. The average for the period before the pandemic is shown in gray. It reveals that cases of norovirus are pointing sharply upwards in the 14 states where they are monitored

The above graph shows tracking of norovirus cases by year, with this year’s data 2022/23 shown in red. Last year’s (2021/22) is the blue dashed line, while the previous year is the blue dotted line. The average for the period before the pandemic is shown in gray. It reveals that cases of norovirus are pointing sharply upwards in the 14 states where they are monitored

Norovirus tends to cause nausea, vomiting and diarrhea, but if you have lost your taste or smell, chances are it’s Covid.

Official data shows norovirus infections are up 66 percent in 2023 compared to last year and are rising across the country.

Experts say the virus is taking off earlier than normal, and there are also concerns the illness could be more serious than usual after lockdowns robbed children of vital immunity for fighting viruses.

For norovirus, the main symptoms are nausea, diarrhea and vomiting. Some people also have a high temperature, a headache and aching arms and legs.

Symptoms usually start one or two days after being infected. Dehydration is often the earliest warning sign. A dry mouth and throat, listlessness, dizziness and increased urine output could also occur if the patient is dehydrated.

Covid is a virus that causes mild to moderate respiratory illness, including fatigue, shortness of breath and a dry cough.

There are a lot of overlapping symptoms between the two, but Covid has more upper respiratory symptoms, a cough and the hallmark loss of taste or smell.

Another key differences between the two is that Covid symptoms usually last for two weeks whereas norovirus sufferers usually recover in a couple of days.

People with either can usually manage their symptoms at home, by drinking lots of fluids to avoiding dehydration.

In serious cases, norovirus can lead to dehydration in patients and even death.

Norovirus is spread through close contact with someone with the virus, or eating food that has been prepared by them.

It can also be passed on by touching objects that are contaminated with the virus and then touching your mouth.

Google searches for norovirus have risen more than six-fold since the start of February.

Official data from the Centers for Disease Control and Prevention (CDC) shows that 225 norovirus outbreaks have been recorded since August, already up a third on the 172 recorded in the previous year.

But we do not routinely test for norovirus in the same way of Covid, meaning that the actual case numbers are likely to be much higher.

In the most recent update – including data for the week ending January 9 2023 – more than 20 outbreaks were recorded.

For comparison, during the same week last year, there were 15 outbreaks. Cases are rising in all 14 states that report data to the CDC.

These states include Alabama, Massachusetts, Michigan, Minnesota, Nebraska, New Mexico, North Carolina, Ohio, Oregon, South Carolina, Tennessee, Virginia, Wisconsin and Wyoming.

Dr Simon Clarke, an Associate Professor in Cellular Microbiology at the University of Reading told Mail Online: ‘Good hand hygiene and not putting your fingers in your mouth are really important to reduce chances getting norovirus’.

He added: ‘Nobody knows whether the last person to touch a door handle or lift a petrol pump, unwittingly deposited something unpleasant which could make you sick.’ 

Official data shows norovirus infections are up 66 percent in 2023 compared to last year and are rising across the country.

Medics say the best way to avoid infection is to wash hands regularly, adding that hand sanitizers — which worked against Covid — do not work against norovirus.

Experts also say hand sanitizer does not destroy the virus because it is resistant to alcohol.

This means only thorough hand washing can help someone avoid catching it. 

Norovirus can spread all year round, but cases tend to rise in the late winter driven by more social events spurred by the warming temperatures.

The virus is passed on via fecal matter that gets onto the hands and then transferred to other surfaces people touch. 

Ingesting only a small amount of the virus can trigger an infection.

Patients tend to suffer a mild illness lasting for about one to three days, suffering symptoms including nausea, vomiting and stomach pain or cramps.

Those most at risk of catching norovirus include young children yet to have built up immunity against it, those with underlying conditions and the elderly.

There are no vaccines available, with medics saying it is best to allow the infection to run its course.

A CDC spokeswoman previously told TODAY: ‘While norovirus cases are rising in the US, CDC data as recent as January 2023 shows that reported norovirus outbreaks are within the expected range for this time of year.’

Norovirus causes 19 to 21 million cases of vomiting and diarrhea, 109,000 hospitalizations and 900 deaths.

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Read more at DailyMail.co.uk