Covid-19, flu or the common cold: how to make the difference?

Fever, headache, fatigue, runny nose, cough… are all symptoms that can make you think of the flu, Covid-19 or rhinopharyngitis (viral cold). These three viral diseases are sometimes difficult to differentiate. Symptoms, modes of transmission, contagion, treatments … We make the point.

Indeed, the seasonal epidemic of influenza and the reinforced circulation of rhinoviruses complicate the diagnosis of the covid-19.  How to know if your symptoms are related to a cold, to the flu or to the new coronavirus infection? Dr. Jean Pierre Ndayirukiye, Executive Director of the Initiative for the Promotion of Rural Health and Development, explains.

How to differentiate the symptoms of influenza, covid-19 and the common cold?

According to Dr. Jean Pierre, it can be difficult to differentiate between influenza, Covid-19 or rhinovirus infection (responsible for what is commonly called the common cold) based on a simple clinical diagnosis.

“With practice and experience, we manage to distinguish them, and it is especially according to the epidemic context, the contacts that a patient may have had at school, or at work, etc. that we orient ourselves towards a diagnosis (which will have to be confirmed by virological test for Covid-19),” explains Dr. Jean-Pierre Ndayirukiye.

Indeed, each of these diseases is linked to the influenza virus type A or B (family of orthomyxoviridae).

– Influenza is linked to influenza virus type A or B (family Orthomyxoviridae).

– Covid-19 is related to the new coronavirus SARS-CoV-2 (family Coronavirus (Coronaviridae).

– The viral cold (rhinopharyngitis) is generally linked to a rhinovirus (Picornavirus family), of which there are hundreds of variants, and which remains confined to the nose and throat. They circulate more or less all year round,” says Dr. Jean Pierre. 

The intensity of the symptoms, an element to be taken into account

Rhinoviruses circulate throughout the year, which is why we can sometimes catch a cold in the middle of the dry season or other seasons. Most of the time, they induce a simple cold, which sets in slowly and can result in nasal congestion and discharge, sneezing, headache, sore throat and mild fatigue for three to five days. However, some patients may present with a fever that is reminiscent of an influenza-like illness, or even the onset of Covid-19,” says Dr. Jean Pierre. Similarly, some people go through flu or Covid-19 with few, if any, symptoms, Dr. Jean Pierre say.”

The main factor that differentiates the common cold from the flu and Covid-19 clinically is actually the intensity of symptoms. Most patients with a rhinovirus infection are able to work, to do their daily tasks. This is less often the case when a patient has influenza or Covid-19.

Flu or Covid-19, can they be distinguished clinically?

Influenza, caused by influenza A (H1N1) pdm09 or A(H3N2) viruses) and influenza B (B Yamagata and B Victoria) viruses, usually presents with high fever, chills, headache, muscle aches and dry cough. Some patients may have a runny or stuffy nose or even a sore throat. “All of these symptoms appear suddenly and persist for three to seven days, most frequently in the rainy season.

Covid-19 may cause the same symptoms (which appear gradually – not suddenly – and less specifically): fever, persistent cough, loss of taste, loss of smell, fatigue, aches and pains, headache, sore throat, shortness of breath . More rarely, patients may experience nasal congestion or discharge, diarrhea, or even neurological or dermatological symptoms. “Because of the many asymptomatic cases (40% of infected subjects, according to a study published in December 2021? source 1), it is also more difficult to detect,” notes Dr. Jean Pierre .

Anosmia (loss of smell) and agueusia (loss of taste) can occur in Covid patients as well as in patients with a severe cold or flu.

In all cases, Dr. Jean Pierre recommended to consult a doctor as soon as possible if the person presents symptoms because sometimes it is difficult to differentiate the flu from the Covid-19.

                                                           E. Allickan Niragira