THEblood culture is a bacteriological examination which consists of looking for the presence of germs (germs) in the blood.

You should know that the blood is normally sterile. When infectious agents pass through the blood repeatedly, they can cause serious infection (bacteremiaor sepsis in the event of significant and repeated passages in the blood of pathogens).

To detect their presence, it is necessary to put a blood sample “in culture”, that is to say on a medium conducive to the multiplication (and therefore to the detection) of the various germs.

Blood culture can be done in several situations, including:

• in case of suspicion of septicemia (symptoms of severe sepsis or septic shock)
• a cas de fever prolonged and unexplained
• in the event of complications in a person suffering from abscess, An boil or a tooth infection important
• in case of fever occurring in a person with a catheter, a catheter or a prosthesis

The purpose of this analysis is to confirm the diagnosis (isolation of the germ responsible for the infection) and to orient the treatment (by choosing an antibiotic to which the germ in question is sensitive).

THEblood culture consists above all in taking a blood sample (blood test).

It is very important that this sample be taken under sterile conditions, to avoid any contamination of the sample by skin germs, for example, which would falsify the results. Transport should also take place under sterile conditions.

The concentration of bacteria in the blood being generally very weak in adults, it is necessary to collect a sufficient quantity of blood (approximately 20 ml per sample).

The examination is carried out when the doctor suspects the presence of bacteremia, and it is advisable to take the sample at the time of peaks of fever (> 38,5 ° C) or hypothermia reflecting a serious infectious state (<36 ° C), or in the presence of chills (sign of "bacterial discharge " in the blood). The sample should be repeated three times in 24 hours, at intervals of at least one hour, as many bacteraemias are “intermittent”.

In the laboratory, the blood sample will be cultured aerobically and anaerobically (in the presence of air and without air), so as to identify aerobic or anaerobic pathogens (whether or not they need oxygen to develop) . Two vials will therefore be taken. Incubation usually lasts 5-7 days.

Un antibiogramme (test of different antibiotics) will also be carried out to determine which treatment is effective on the germ in question.

If the blood culture is positive, that is, if the presence ofPathogens is detected in the blood, treatment will be started urgently. If the symptoms suggest the existence of sepsis, doctors will not wait for the results and will prescribe antibiotic therapy immediately, which they will adjust if necessary.

The blood culture will identify the microorganism involved (for example a staphylococcus, an enterobacterium or a yeast of the Candida type) and therefore to implement an effective treatment (antibiotic or antifungal in the case of a pathogenic fungus).

The duration of treatment varies, but can be up to 4-6 weeks.