Internal Medicine

Bacteremia - what is it?

What is bacteremia?

Bacteremia is when bacteria get into the bloodstream. This differs from sepsis (blood poisoning), since the bacteria can be detected in the bloodstream, but the patient does not experience any systemic symptoms of inflammation (high fever, body aches, drop in blood pressure, cough, etc.).
Bacteremia occurs more frequently than one might suspect: the pathogens get into the blood in small quantities, for example through examinations of body regions colonized by bacteria (e.g. dental treatments), but are usually eliminated quickly by the immune system. Only when the extent of the bacteremia exceeds the body's defenses, the bacteremia can develop into dangerous sepsis. Since this can be life-threatening, a possible bacteremia should not be taken lightly, but its cause should be found and this should be eliminated if possible.

Treatment of bacteremia

If the immune system is intact and the number of pathogens detected in the blood test is not too high, bacteremia therapy can often be dispensed with.
You then limit yourself to repeating the blood test after a few days in order to monitor the course of the pathogen count.
If, on the other hand, it can be assumed that the body will not manage to eliminate the cause of the bacteremia and eliminate the pathogens on its own, it must be helped. If the bacteremia is triggered, for example, by a bacterial inflammation of a heart valve (endocarditis), an antibiotic therapy appropriate to the pathogen is initiated first. If this does not show a satisfactory effect, surgical replacement of the affected heart valve may have to be considered in order to permanently eliminate the source of bacteremia.

What are the accompanying symptoms?

By definition, bacteremia does not have any physical symptoms. Should symptoms develop in the course of a bacteremia, these should be taken as an indication of the progression of the bacteremia to sepsis (blood poisoning). The first signs of such development are usually fever and chills. Even if one would not speak of sepsis in the case of bacteremia with moderate fever, the physical symptoms should still be interpreted as an alarm signal and taken seriously, since inadequately treated sepsis can have serious or in the worst case even fatal consequences.

fever

A fever occurs when the programmed setpoint for the body temperature in the temperature center of the brain is adjusted as part of an infection (e.g. sepsis).
The increased body temperature is said to limit the vitality of the pathogens and thus support their elimination. To see fever per se as a sensible and desirable mechanism of the body's own defense system, as long as it does not become too strong. If a fever occurs as part of bacteremia, the body has difficulty eliminating the pathogens in the blood. For this reason, the attending physician should be reported immediately about the fever that has developed and measured regularly in order to monitor the temperature profile. The doctor can then estimate how likely the development of sepsis (blood poisoning) is and whether further therapy measures need to be initiated.

You may also be interested in this topic: Causes of fever

chills

To combat the pathogens, the body's temperature must be increased. To do this, heat has to be generated, which is most effectively and quickly achieved through increased muscle tremors, the chills.
As a rule, chills only occur when the fever develops, if the fever is developing very rapidly. Chills are an important alarm signal for the development of sepsis (blood poisoning) and should result in an immediate medical consultation.

Blood poisoning - a dangerous complication

Blood poisoning (sepsis) is a dreaded complication of bacteremia. By definition, it differs from bacteremia in the appearance of physical symptoms such as fever and chills.
Blood poisoning is always preceded by bacteremia, although in some cases the blood poisoning develops so quickly that bacteremia cannot be detected beforehand. However, not all bacteremia ends in blood poisoning! So if you want to protect yourself from blood poisoning in the presence of bacteremia, you should measure your body temperature at least once a day and generally watch out for flu-like symptoms. Blood check-ups should be taken seriously. Bacteremia can be treated with antibiotics. It is important to follow the medical treatment guidelines. In this way, bacteremia can be controlled very well in most cases and the development of blood poisoning.

You can find out more about the symptoms of blood poisoning here: Symptoms of blood poisoning

Therapy of bacteremia

If the immune system is intact and the number of pathogens detected in the blood test is not too high, bacteremia therapy can often be dispensed with.
You then limit yourself to repeating the blood test after a few days in order to monitor the course of the pathogen count. If, on the other hand, it can be assumed that the body will not manage to eliminate the cause of the bacteremia and eliminate the pathogens on its own, it must be helped. If the bacteremia is triggered, for example, by a bacterial inflammation of a heart valve (endocarditis), an antibiotic therapy appropriate to the pathogen is initiated first. If this does not show a satisfactory effect, surgical replacement of the affected heart valve may have to be considered in order to permanently eliminate the source of bacteremia.

Duration and forecast

General statements about the duration of bacteremia cannot be made due to the many possible causes, pathogens and the individual differences in the immune system.
There are cases in which, after bacteremia has been detected for the first time, even without special treatment measures, no further pathogens can be detected in the next blood test after a few days. On the other hand, bacteremia can persist for a very long time, especially if it is based on a chronic disease, for example inflammation of the inner lining of the heart (endocarditis) or chronic inflammatory bowel disease.In the vast majority of cases, regular check-ups and appropriate treatment can prevent the development of sepsis.

Blood test

In the case of bacteremia, a so-called blood culture is created. For this purpose, blood is first taken from the patient and this is transferred directly into two culture bottles that contain nutrient medium.
As a rule, an aerobic (oxygen-rich) and an anaerobic (no oxygen) culture bottle is filled: Since some types of bacteria prefer an oxygen-rich and some an oxygen-poor environment, this enables the whole spectrum of possible causes of bacteremia to be covered. The culture bottles are then incubated in an incubator at 37 ° C. over a period of several days. The evaluation of the blood test is nowadays mostly done automatically and provides a list of the types of bacteria contained in the sample as well as their resistance or sensitivity to different classes of antibiotics. This information is particularly helpful for the selection of a suitable agent for the treatment of bacteremia, if one becomes necessary.