If you or a loved one has had a stomach flu in the past few weeks, you are not alone.
Cases of norovirus – or the ‘stomach flu’ – hit a 12-month high in February and are still wreaking havoc, especially in schools.
At the same time, cases of bacterial Shigella infections are on the rise and health officials are concerned about an antibiotic-resistant strain growing in the US.
The two bugs — which are the leading cause of gastroenteritis in American schools — cause very similar symptoms, making it difficult to tell them apart.
But there are ways to tell the difference between the two:
Norovirus tends to start with a lot of vomiting and then progress to diarrhea, or sometimes they both start at the same time. But shigella tends to be more diarrhea than vomiting. You may get stomach cramps. Diarrhea caused by shigella is usually more watery or bloody, medics say, while diarrhea caused by norovirus tends to be vomiting
The chart above shows the number of shigella outbreaks reported this year (red line) and previously. The season started early but has since declined. It remained below pre-pandemic levels
This map shows the number of outbreaks reported by state. It was most common in Virginia, California, Ohio and Michigan – with pending cases. Virginia schools advise parents to keep children home for 48 hours after symptoms subside to help stop the spread of norovirus
Dr. Marci Drees is the chief infection prevention officer at ChristianaCare in Delaware, who regularly treats patients with the diseases.
Asked how to tell the diseases apart, she said ABC6: ‘The norovirus usually starts with a lot of vomiting and then progresses to diarrhea, or sometimes they both start at the same time.
‘[But] shigella tends more towards diarrhea rather than vomiting. You may have stomach cramps.’
Diarrhea caused by shigella is usually more watery or bloody, medics say, while diarrhea caused by norovirus tends to be vomiting.
The two can also be told apart by how long they last. Norovirus cases normally clear up within three days, but shigella usually lasts four to seven days.
In severe cases, it can take weeks to months for the bowels of patients with the bacterial infection to return to normal.
Other differences include that shigella patients are more likely to have a fever than people with norovirus.
The diseases can also strike at different year species.
Norovirus is also known as the “stomach bug” because of its tendency to peak in the cold months of November to April before releasing again.
Shigella, on the other hand, tends to broadcast at a constant rate throughout the year.
Norovirus causes up to 21 million cases in the United States each year, 109,000 hospitalizations and 900 deaths, statistics suggest.
The number of cases peaked earlier than usual this year, data shows, peaking at 30 outbreaks per week in early January.
But they have since refused. They remained below the levels recorded between 2012 and 2020 before the pandemic.
Virginia, California, Ohio and Michigan have experienced the most norovirus outbreaks this year, data shows.
Earlier this month, schools in Chesterfield, outside Richmond, Virginia, told parents to keep children home for another 48 hours after their symptoms subsided — suggesting norovirus was behind the illness.
Shigella, on the other hand, causes fewer diseases each year than norovirus.
Surveillance data from the Centers for Disease Control and Prevention (CDC) suggests that the bacterial infection causes about half a million cases each year, leading to 5,400 hospitalizations and 38 deaths.
A “serious public health alert” was issued last month about cases of the superbug across the country becoming resistant to antibiotics, making them more difficult to treat.
Drug-resistant strains now account for about five percent of all cases, compared to just six or seven years ago.
Medics say that in most cases, the best treatment for sick children is getting enough rest and making sure they are hydrated.
Some patients can also eat small amounts of bland foods, they suggest, such as soup, rice, pasta or bread.
Children only need to see a doctor if they start showing symptoms such as bloody diarrhea, prolonged fever, severe stomach cramps or dehydration.
In these cases, stool testing is done to determine whether an infection is caused by shigella or norovirus.
Because shigella is caused by a bacteria, it can be treated with a course of antibiotics.
But there is no comparable treatment for norovirus, which is caused by a virus, with doctors focusing instead on managing the symptoms.