When bacteria enter the bloodstream, bacteremia is present. Normally, a healthy immune system eliminates the bacteria before they can spread widely and reach vital organs through the blood. However, in patients with poor immune systems, bacteremia can result in severe sepsis.
What is bacteremia?
Bacteria are everywhere: in the air, on objects of everyday use, and on your own skin. At the latest when bacteria are washed into the bloodstream, the immune system becomes active. In the bloodstream, elimination of the microorganisms usually takes place. If this elimination by the immune system fails to occur, bacteremia may result. Bacteria are part of the healthy flora of the skin and mucous membranes of humans. Bacteria that are generally considered pathogens and cause harm to humans when they colonize must be distinguished from these. The phenomenon of bacteremia is present when bacteria are detected in serum. It may be temporary or chronic over a long period of time. To be distinguished from bacteremia is viremia, in which viruses spread in the blood. A related phenomenon is fungemia or mycemia, in which fungi cause similar conditions. The human immune system takes over the fight against bacteria in the aftermath of their introduction into the blood. A healthy defense system recognizes bacteria as foreign to the body and attacks them, so immunologically healthy people often suffer only from temporary bacteremia. Chronic bacteremia presents itself far more often in immunodeficient patients and can be caused in them by commensals alone, which generally do not harm a healthy person.
Causes
Sepsis in the sense of blood poisoning with systemic signs of inflammation of the entire organism may be the result. Septicopyemia often occurs, in which the pathogens spread further and further in the blood, reaching vital organs where they cause foci of inflammation. The cause of bacteremia is thus the spread of bacteria into the blood. Existing wounds form a portal of entry. In addition, bacteria can enter the bloodstream via bacterial abscesses as soon as fistula tracts form. Abscesses play an important role in clinical practice. They result from inflammatory tissue fusions triggered in the course of bacterial infections. The abscess cavity of the melted tissue is filled with pus consisting of dead cells, neutrophil granulocytes and bacteria. Along fissure spaces, untreated abscesses continue to spread. After the formation of a fistula, the abscess cavity empties into internal or external body surfaces. Bacteremia following invasive medical procedures was also common, especially in the past. The bacteria either reach the bloodstream during bacteremia, which is the result of a bacterial infection elsewhere, during diagnostic or therapeutic procedures, or are carried from the skin into the blood through minor wounds.
Symptoms, complaints, and signs
Bacteremia is present whenever cultural evidence of bacteria in the blood can be obtained. Some patients do not show any symptoms other than fatigue with short-lived bacteremia. Sepsis or septic shock do not necessarily occur. Sepsis corresponds to an infection with general signs of inflammation. Once sepsis affects organs, it is referred to as severe sepsis. In septic shock, in turn, the patient’s circulation collapses. In a healthy person, bacteremia is the temporary presence of bacteria within the bloodstream, which often resolves itself with attacks from the immune system. Excessive proliferation of bacteria or the settlement of pathogens in organs does not usually result from bacteremia for healthy people. As soon as they reach the blood, they are recognized by the healthy immune system as foreign to the body and fought, so that they cannot metastasize to organs. Thus, bacteremia is usually associated with sepsis only when the affected person’s defenses are excessively poor, such as in HIV patients or immunocompromised individuals. If the bacteria from an infectious focus are constantly or periodically washed into the bloodstream, they multiply strongly and thus cause sepsis.What other symptoms are present depends on the type of bacteria and the aggressiveness of the pathogens. For patients with poor immune systems, bacteremia can lead to serious multiplication of microorganisms. Various organs can be affected. For example, a disease caused by bacteremia in predominantly immunodeficient patients is bacterial endocarditis.
Diagnosis and course
Bacteremia is diagnosed by serologic detection of bacteria in the blood. The diagnosed patient is further observed to estimate the duration of bacteremia and to promptly identify any signs of sepsis. The prognosis depends on the patient’s immunologic constitution and the nature of the invading pathogens.
Complications
In most cases, bacteremia can be treated relatively well. The treatment itself is done with the help of antibiotics and in most cases leads to a relatively quick success. It becomes problematic when the bacteria are multiresistant. Here, extensive treatment and possibly a blood transfusion is necessary. If the bacteria cannot be removed from the body, all of the patient’s organs must be monitored. Here, severe infections and inflammations can occur, which can be life-threatening. Usually, the patient must be transferred to the intensive care unit in the hospital. Without treatment, bacteremia does not necessarily lead to complications. In many cases, the body can fight off the symptom and defeat the bacteria itself. However, with bacteremia, the body becomes more susceptible to various diseases. The immune system and circulatory system are both weakened, making them more likely to break down. This results in a general sluggish attitude toward life and lassitude. In the worst case, the spread of bacteremia in a person can lead to death if the symptom is not treated in time. Especially in older people, bacteremia poses an increased risk and should always be treated by a physician.
When should you see a doctor?
If a wound becomes infected or other infections are noticed, the primary care physician should be consulted. The physician can quickly determine whether bacteria have entered the blood by examining the inflamed area and performing a blood test and, if necessary, initiate treatment directly. If inflammation remains untreated, bacteremia becomes apparent at the latest in the form of increasing fatigue. If this symptom is noticed, an immediate visit to the doctor is recommended. Especially people with immunodeficiency (e.g. HIV patients or immunosuppressed persons) should talk to a doctor in case of unusual symptoms. Above all, serious infections and increasing cardiovascular complaints indicate the onset of sepsis. An external warning sign is a reddish stripe on the skin leading from the inflammation toward the heart. If fainting or cardiac arrhythmias occur, the emergency physician must be called. In severe cases, first aid measures must be taken until emergency medical services arrive. Since advanced bacteremia requires prolonged hospitalization, accompany this should also inform the relatives.
Treatment and therapy
In cases of bacteremia, patients are promptly given an appropriate drug to keep the pathogens from multiplying. In most cases, at least one of the currently used antibiotics shows success. In order to select an antibiotic for treatment, identification of the microorganisms is required. Most strains of bacteria are resistant to at least one of the medically used antibiotics. Treatment of bacteremia is particularly difficult when the bacterium involved is multidrug resistant. In such cases, conventional antibiotics are usually ineffective and the bacterium can hardly be stopped from multiplying. Multidrug-resistant bacteria have sometimes been reported in the setting of various hospital-acquired infections. In bacteremia, they can cause life-threatening infections of various organs, especially for immunodeficient patients, without medical control. If the bacterium, and thus the cause of the infection, cannot be eliminated, medicine is primarily concerned with damage control.In this case, the focus is on preserving all vital bodily functions. Patients are usually monitored in the intensive care unit, where life-sustaining measures such as resuscitation can be performed more quickly.
Outlook and prognosis
The prognostic outlook of bacteremia depends on the bacterial culture that has entered the organism. Normally, the invading germs are treatable with medication. The multiplication of the pathogens is stopped and within a few days the bacteria die off. At the same time, health improves again until the patient has fully recovered after a few weeks. Some patients suffer from intolerance to the medicine. This leads to a challenge in fighting the bacteria and can significantly complicate the healing process. Alternative medications are available, but are less effective than antibiotics in their active ingredients. Most types of bacteria die even without medical treatment. After their invasion of the organism, the immune system gradually builds up sufficient defenses and thus has the strength to remove them from the bloodstream. However, this process usually takes much longer than with medical care. Moreover, the body is usually very weakened afterwards. The prognosis worsens, with resistant germs. These do not react to the drugs and continue to multiply unhindered. Patients with a weakened immune system can suffer from severe complications in these cases. In the worst case, the pathogen cannot be killed and the patient dies from the resulting consequences.
Prevention
Bacteremia can be prevented to the extent that the spread of bacteria into the blood can be prevented. Thus, in addition to wound disinfection, timely treatment of abscesses, for example, is considered a preventive measure.
Aftercare
Prevention is the best measure to avoid recurrence of bacteremia. Patients should make sure that they have a strong immune system. They achieve this through a balanced diet, physical activity, and adequate sleep. If the immune system is already weakened, care should be taken with minor injuries. Bacteria must not be allowed to enter the bloodstream. Protection of the corresponding areas with plasters or gloves is advisable. There is no immunity after bacteremia. Patients can become infected again and again. Diagnosis is made by a blood test. The doctor then orders drug treatment. Usually an antibiotic is used. Complications can arise if the pathogen proves resistant to the active substances. Doctors then have to resort to unconventional approaches. The main aim is to preserve vital organs. This is not always successful. In the worst case, bacteremia can lead to death. If the symptoms worsen, it is recommended to visit the doctor again. The most important aspect represents to prevent the spread of bacteria into the blood.
What you can do yourself
Untreated bacteremia can lead to sepsis and, in the worst case, to septic shock with a fatal outcome. Although the latter rarely occurs, patients should always seek medical attention. A healthy immune system usually prevents bacteria that enter the bloodstream from multiplying unhindered and attacking vital organs. If there is an excessive concentration of bacteria in the blood, the immune system is usually weakened. A healthy lifestyle is the main way to strengthen the immune system. This includes a plant-based diet rich in vitamins and fiber, and abstaining from excessive consumption of alcohol, tobacco and refined sugar. Sufficient sleep and regular physical activity are also important. Light endurance sports such as swimming, cycling or walking are particularly beneficial. Constant stress can also weaken the immune system and should therefore be avoided. In naturopathy, an active ingredient from the red coneflower (Echinacea Purpurea) is also used to strengthen the body’s own defenses. Patients who already know that their immune system is weakened should also take preventive measures. Bacteria can also enter the bloodstream through small injuries that are imperceptible to the affected person. Gloves should therefore always be worn during high-risk activities.In everyday life, the preparation of (raw) meat in particular is a risk factor that is often overlooked. Disposable gloves can protect against infections here.
