Observed under a microscope, it forms the number 8. Pneumococcus, or Streptococcus pneumoniae, is part of the streptococcus family. “It is a commensal bacterium, that is to say it can live on the body without causing the slightest infection”, explains Dr Pierre Abgueguen, infectious disease specialist at the University Hospital of Angers. It is estimated that 5 to 25% of the population carries the bacteria without having any symptoms. But it can also be formidable, causing serious infections and many deaths. “The pneumococcus can be responsible for multiple infections,” warns Dr Abgueguen.

Naturally present in the nose and throat, when it stays there, the bacteria are completely harmless. But if, during a sore throat or the flu, it passes into the blood and migrates to other parts of the body, it can cause a lot of damage, from the mildest to the most serious.

Here are the possible infections:

• Otitis: when it reaches the middle ear, it is the cause of otitis; 
• Sinusitis: it can also cause sinusitis (by touching the sinuses);
• Pneumonia: affecting the lungs;
• Endocarditis: affecting the heart;
• meningitis: by touching the envelopes of the brain and spinal cord or bacteremia (by touching the blood)

“The pneumococcus is a bacterium at the origin of serious infections (pneumonia, meningitis) and frequent deaths (almost three times more than car accidents in France), in particular in young children and the elderly”, alert the Institut Pasteur on its website. “Mortality from invasive pneumococcal infections varies from 10 to 30% depending on the studies and increases with age and the presence of comorbidities”, confirms Public Health France.

Pneumococcal infection can go unnoticed. It can also lead to death. Its severity depends, of course, on the organ it affects, but also on the sensitivity of each (e). “Some people are more at risk of getting an infection, and a more serious infection,” says Dr Abgueguen.

In addition, there are different types of pneumococci. We are talking about serotypes. More than 90 have been identified, and not all of them have the same degree of dangerousness. “Pneumococcal infections most often affect fragile people: people with chronic diseases or who are undergoing treatment which reduces their immune defenses against infections, young children, seniors, etc.”, warns Public Health France.

“The risk of developing a pneumococcal infection is multiplied by 4 in the presence of a chronic pathology, such as diabetes, pulmonary pathology, cardiac pathology or alcoholism, and by 23 to 48 in immunocompromised patients of the has cancer or HIV / AIDS infection. “

Pneumococci are contagious. They can be transmitted by sick people, but also by healthy, asymptomatic carriers. Transmission occurs during close (less than a meter) and long (more than an hour) contact with an infected person. The bacteria are transmitted, for example, by coughing, kissing or sneezing.

Symptoms are specific to each infection. For example, acute otitis media often warns of its onset by ear pain, and fever over 38ºC.

“Meningitis can be signaled by intense headaches, stiff neck, fever, nausea and vomiting, or intolerance to light and noise,” explains Dr Abgueguen. This is an absolute emergency. In fact, if not treated in time, meningitis can lead to serious neurological sequelae, even death of the patient. 

The main symptoms of pneumonia are:

• chest pain
• high fever
• chills
• feeling unwell
• a dry cough.

These symptoms appear suddenly.

As for bacteremia, it is a generalized infection of the body. It is often accompanied by a high fever, extreme fatigue, and malaise.

“To diagnose meningitis, we’ll do a lumbar puncture. »This is the removal of cerebrospinal fluid between two vertebrae, using a fine needle. Systematic, hospitalization of the patient allows treatment to be started immediately. 

“For pneumococcal pneumonia, it is recommended to do blood cultures to look for this bacteria in the blood. The diagnosis will be confirmed by an x-ray of the lungs.

In case of suspicion of bacteremia, a blood sample is taken which will be placed in blood culture in order to determine the presence of infectious bacteria.

“The treatment of a pneumococcal infection is always antibiotics. The dose, duration and route of administration are different depending on the infections and their severity.

• For pneumonia, for example, we can give 3g / day of amoxicillin for seven days.
• For meningitis, it will be 12g / day of amoxicillin, intravenously, for ten to fourteen days. “

In the latter case in particular, the treatment must be started without wasting time, to avoid sequelae and death. Whatever the pathology treated, the antibiotic treatment must be followed to the end, to prevent the bacteria from becoming insensitive to these drugs and thus developing antibiotic resistance.

“The best weapon to prevent these pneumococcal infections is vaccination. »It is compulsory for all children born on or after January 1, 2018.

The vaccination schedule therefore provides for two doses, at the age of 2 and 4 months, followed by a booster at the age of 11 months. The National Reference Center for Pneumococci notes “that in 2016, 91,8% of children aged 24 months received the complete regimen comprising two doses and a booster. “

From the age of 2 years, vaccination is recommended for patients at risk. This category includes young people and adults who are immunocompromised (infected with HIV, transplanted, treated with immunosuppressants, biotherapy and / or corticosteroid therapy for an autoimmune or chronic inflammatory disease, etc.), or having a chronic disease making them more susceptible to infection. pneumococcal (for example, chronic respiratory failure).