Flu without fever: what you need to know

Flu without fever: what you need to know

Sometimes confused with flu syndrome, the flu is caused by a seasonal virus. What are the symptoms of the flu? Is the fever still present? How long does the illness last? How to treat it? Explanations from Vincent Enouf, deputy director of the national reference center “Virus and respiratory infections” at the Pasteur Institute in Paris.

Every year as winter approaches, seasonal flu infects millions of people. Fatigue, body aches, fever, chills, sore throat are some of the most common flu symptoms. The vaccine and the adoption of barrier gestures (wearing a mask, regular hand washing) make it possible to limit the spread of the epidemic in the population.

Flu without fever, is it possible?

Every winter, it reappears in our latitudes. Until the end of April, the flu will infect 2 to 6 million people per year. “Influenza is a seasonal respiratory virus that spreads very easily within the population. underlines Vincent Enouf, deputy director of the National Virus Reference Center for Respiratory Infections at the Pasteur Institute in Paris.

Particularly resistant to cold and humidity, the influenza virus, of the family of Orthomyxoviridaeis transmitted by the projection of droplets (mainly when sneezing or coughing but sometimes just by talking) or by contact with contaminated surfaces: door handles, tickets, mobile phone, computer keyboard, etc.

After two to three days of incubation, the first symptoms of the flu appear.

Characteristics, the clinical signs of the flu are well known: fever, chills, body aches, headaches, intense fatigue, cough, stuffy nose… “In most cases, a fever is present, although it is possible to be affected by the flu virus without having a fever.specifies the scientist.

Flu without fever or flu syndrome?

If other viruses (such as rhinoviruses, COVID, metapneumovirus or the respiratory syncytial virus responsible for bronchiolitis) can present a similar clinical picture, influenza corresponds to a very specific virus. “Only a diagnostic test will reliably establish the presence of the influenza virus”adds Vincent Enouf.

How long does the flu last?

In healthy people without any complications or particular co-morbidities, the flu generally lasts a week. However, even if the symptoms (muscle pain, fever, etc.) have disappeared by this time, fatigue often persists for one to two additional weeks.

As it is a viral illness, there is no specific treatment for the flu. “Symptomatic treatments can be offered to reduce fever and pain. Rest and good hydration are also important,” adds Vincent Enouf. To avoid transmission of the disease, you should stay at home if possible for the duration of symptoms.

Although it is a very rare situation, it is possible to contract the flu twice in the same year. Just as it is possible to be affected simultaneously by the flu virus and the Covid virus.

Flu in vulnerable people

Every year, the flu causes hospitalization in certain people at risk: people aged over 65, pregnant women, immunocompromised people or people suffering from co-morbidities (diabetes, heart or respiratory problems, etc.). In these people with more fragile health, superinfection can sometimes lead to death. In fact, each year, 9,000 to 15,000 people die from the flu.

Among these vulnerable groups, wearing a mask, especially in public places and public transport, is strongly recommended during the period when the virus is circulating. “Even if it is not completely waterproof, the mask remains very useful. recalls Vincent Enouf. Widespread during the Covid period, hand washing is also very important to protect against viral and bacterial infections in winter.

The importance of vaccination

Intended primarily for these vulnerable groups, flu vaccination represents an effective prophylactic solution. “The vaccine protects for approximately 6 months. As soon as doses are available in pharmacies, it is important that these populations be vaccinated as a priority.”, believes Vincent Enouf. Currently, apart from the general practitioner, other health professionals such as pharmacists and nurses are also authorized to vaccinate. As strains of the virus evolve, a new vaccine is released each year. It includes 4 different strains of inactivated virus. “Although its effectiveness may not be very high, the flu vaccine saves lives every year. recalls Vincent Enouf.

In vulnerable populations, the prescription of antiviral drugs, if it occurs quickly, that is to say within 48 hours after the appearance of the first symptoms, will annihilate the replication of the virus in the body’s cells. “These antivirals will both limit infection and prevent bacterial superinfection”adds the researcher.

Finally, to give yourself every chance of avoiding the flu, make sure to maintain a healthy lifestyle (sufficient rest, regular physical activity, diet rich in vitamins as winter approaches). A tired or weakened body is always more likely to contract a virus.