Echoing the observations of doctors treating thousands of patients in the pandemic, the federal health agency changed its website to cite the following symptoms as possible indicators of Covid-19, the infection caused by the coronavirus:
repeated shaking with chills
and, new loss of taste or smell.
Previously it had listed just three symptoms: fever, cough and shortness of breath.
The C.D.C. added the six symptoms earlier this month after new recommendations were issued by an organization of public health epidemiologists that is responsible for defining which infectious diseases are tracked and reported to the agency. The organization, the Council of State and Territorial Epidemiologists or C.S.T.E., recommended that Covid-19 be considered a nationally reportable illness and gave guidelines about how cases should be defined and identified.
The group’s recommendations say that cases should be reported if there are positive lab tests, but also if there are clinical symptoms that meet one of several thresholds. One category involves people who have cough, shortness of breath or difficulty breathing. Another involves people with two of the following symptoms: fever, chills, shivers, muscle pain, headache, sore throat or new dysfunction of taste and smell. Cases of people in both categories should be reported as likely Covid-19 only if there is no other more plausible diagnosis, the recommendations say.
While people who become seriously ill from coronavirus infection primarily have acute respiratory distress, other symptoms that accompany the disease can vary widely, doctors and researchers have reported.
It has turned out, for example, that many people with Covid-19 don’t have fevers or that their fevers wax and wane and are sometimes accompanied by chills.
Shortness of breath can emerge at the same time as other symptoms or it can crop up suddenly a week or even 10 days after a person has been experiencing more manageable symptoms like cough and aches.
Some people report a notable loss of smell and taste, an effect that can also occur with other respiratory infections.
The revised C.D.C. list differs somewhat from the symptoms described by the World Health Organization on its website. The W.H.O. says the most common symptoms are fever, dry cough and tiredness. “Some patients may have aches and pains, nasal congestion, sore throat or diarrhea,” the W.H.O. says. “These symptoms are usually mild and begin gradually.”
Both agencies recommend that people seek emergency medical attention if they have trouble breathing or persistent pain or pressure in the chest. The C.D.C. also says that immediate medical attention should be sought if people experience sudden confusion, cannot be aroused or if their lips or face turn a bluish color.