(NewsNation) — Staying steadfast successful the New Year presents a caller situation for Americans who are coping with what wellness officials are calling a "quad-demic," which involves a quartet of infectious viruses that are making the rounds.

Each of the maladies tin people antithetic groups and property ranges, but here’s what you request to cognize to debar contracting these illnesses and immoderate tips for remaining healthy.

What is the quad-demic?

Although the trifecta of flu, COVID-19 and respiratory syncytial microorganism (RSV) are commonly paired, norovirus outbreaks astir the United States person added to concerns of a quad-demic.

“All of the viruses are here, it’s conscionable they’re affecting antithetic areas a small spot differently,” Dr. Robert Hopkins Jr., aesculapian manager of the National Foundation for Infectious Diseases, told Fortune.

Flu

Cases of influenza, oregon the flu, reached 40 cardinal betwixt 2023-2024, according to the Centers for Disease Control.

Most radical retrieve from the flu wrong days to a mates of weeks, but immoderate cases tin go severe. Approximately 28,000 radical died past flu season.

Flu symptoms include:

• Fever oregon feeling feverish/chills
• Cough
• Sore throat
• Runny oregon stuffy nose
• Muscle oregon assemblage aches
• Headaches
• Fatigue

COVID-19

COVID-19 has go a portion of beingness conscionable arsenic the flu erstwhile did. Cases are obscurity adjacent arsenic precocious arsenic they were erstwhile the microorganism was archetypal introduced, but the U.S. is inactive seeing affirmative tests, hospitalizations and deaths.

COVID-19 antigen location tests indicating a affirmative effect are photographed successful New York. (AP Photo/Patrick Sison, File)

Between Oct. 1, 2024, and Dec. 14, 2024, the CDC estimates determination were between 2.7 and astir 5 cardinal illnesses. Hospitalizations successful large cities similar Los Angeles, Chicago and New York were each up sharply arsenic the twelvemonth came to an extremity and arsenic 2025 began.

COVID-19 symptoms include:

• Fever oregon chills
• Cough
• Shortness of enactment oregon trouble breathing
• Sore throat
• Congestion oregon runny nose
• New nonaccomplishment of sensation oregon smell
• Fatigue
• Muscle oregon assemblage aches
• Headache
• Nausea oregon vomiting
• Diarrhea

COVID-19 and flu symptoms are similar, but they are caused by antithetic viruses.

“You cannot archer the quality betwixt flu and COVID-19 by symptoms unsocial due to the fact that immoderate of the symptoms are the same,” the CDC advises.

Anyone experiencing symptoms should instrumentality a COVID-19 test, which tin beryllium recovered astatine investigating sites, your doctor’s bureau oregon over-the-counter astatine pharmacies.

RSV

RSV, oregon respiratory syncytial virus, is simply a respiratory unwellness that affects the nose, pharynx and lungs, usually peaking successful December and January.

The symptoms are akin to the communal acold and different respiratory infections similar the flu and COVID-19.

Infants and older adults are astir susceptible. RSV tin origin different illnesses similar bronchiolitis, which is the inflammation of the lungs’ tiny airways, and pneumonia.

RSV symptoms include:

• Runny nose
• Congestion
• Decrease successful appetite
• Coughing
• Sneezing
• Fever
• Wheezing

The CDC warns not each symptoms volition look astatine erstwhile and whitethorn travel successful stages. Infants whitethorn acquisition lone irritability, decreased enactment and breathing difficulties without the different symptoms.

Norovirus

The tummy bug is striking again. Norovirus is highly contagious, spreads done interaction and causes inflammation of the tummy and intestines.

This electron microscope representation provided by the Centers for Disease Control and Prevention shows a clump of norovirus virions. (Charles D. Humphrey/CDC via AP, File)

The CDC reports about 19 to 21 cardinal yearly cases.

People of each ages tin get norovirus, but much terrible infections hap successful children younger than 5 years old, older adults and radical with weakened immune systems.

Norovirus symptoms typically make wrong 12-48 hours of exposure. They include:

• Diarrhea
• Vomiting
• Nausea
• Stomach pain
• Fever
• Headache
• Body aches
• Dehydration

What areas are affected?

The illnesses are hitting assorted pockets of the country, according to Dr. Dana Hawkinson, aesculapian manager for the Infection Control and Prevention programme astatine the University of Kansas Medical Center.

Increases successful flu cases person been the astir problematic astir the country, Hawkinson told NewsNation. New cases of COVID-19 are besides being reported aft the fig of affirmative cases dropped pursuing a spike implicit the summertime months, helium said.

How to forestall getting sick

Doctors are encouraging Americans who person not gotten a flu changeable oregon the latest COVID-19 vaccine to debar contracting 1 oregon much of the prevalent viruses. According to the CDC, 40.8% of adults person gotten the flu vaccine, portion conscionable 20% of Americans person been vaccinated for COVID-19 this season.

A vaccine for RSV is besides disposable for residents who are 75 years of property oregon older oregon those who unrecorded with definite wellness conditions. RSV vaccines are mostly disposable to anyone 60 years of property oregon older, Hawkinson said. However, if residents got the RSV changeable past twelvemonth erstwhile the vaccine was archetypal released, they bash not request to get a 2nd dose.

There is presently nary vaccine for norovirus, but doctors accidental the champion mode to debar this microorganism is to travel bully hygiene practices, including regular handwashing.

Hawkinson told NewsNation it is not excessively precocious to get a flu shot. On average, 10 to 14 days are usually required to physique up immunity to a microorganism aft a vaccine has been administered. Flu shots that are administered present tin inactive beryllium effective, Hawkinson said.

Are masks making a comeback?

Masks became commonplace during the COVID-19 pandemic, and usage successful places similar hospitals, doctor's offices and dental practices remained successful place. Now, some of those requirements are making a comeback.

Amid threats of the quad-demic, hospitals specified arsenic Duke Health successful North Carolina and Mass General Brigham successful Massachusetts updated their masking and visitant guidelines, the Daily Mail reported. Hospitals successful astatine slightest 8 states including Wisconsin, California, Illinois, Indiana, New Jersey and New York are either requiring oregon powerfully recommending masks successful their facilities, the study said.

Exposure and hygiene are cardinal successful preventing each 4 illnesses, including hand-washing and staying location erstwhile ill.

While requirements and mandates successful aesculapian facilities are changing, masks successful nationalist places similar restaurants, bars and gyms stay a idiosyncratic preference.

NewsNation's Ashley Soriano contributed reporting to this story.