Understanding Enterococcal Bacteremia in Children

Introduction

Several infectious agents in the body can cause widespread disease, affecting several basic physiological functions. To eradicate microorganisms and improve body functions, people tend to use a lot of unprescribed antibiotics. This issue is further complicated by the fact that the microbes causing the infection are developing resistance to all kinds of medications. One such serious infection-causing agent in children is Enterococci.

What Is Enterococcal Bacteremia in Children?

Enterococci refers to spherical Gram-positive bacteria (cocci) that reside within the gut as a normal commensal. This bacteria is known to survive in any kind of environment. Disturbance in the balance of gut flora and a weak or immunocompromised state in children can cause Enterococci to proliferate in greater numbers and cause dissemination into the circulating blood.

The widespread dissemination of Enterococci bacteria in the hematological system (blood) is termed Enterococcal bacteremia. This bacteremia is caused by specific species like Enterococcus faecalis and Enterococcus faecium. The most prevalent species among them is E.faecalis. This species is particularly less resistant to antibiotics, and the bacteremia can be cured easily with appropriate antibiotics. However, E. faecium is known to be resistant to almost all antibiotics, including Vancomycin. This makes it very difficult for doctors to treat Vancomycin-resistant Enterococci. The ICD-10 code for enterococcal bacteremia in children is B95.2.

Who Is Susceptible to Develop Enterococcal Bacteremia?

• Immunocompromised children (Children with HIV or type 1 diabetes).

• Children with cancer.

• Preterm neonates.

• Children with congenital heart disease (disease affecting cardiac structures right from birth).

• Children who have chronic illness (secondary to renal failure or genetic disorders).

• Children in their postoperative period.

• Children who have inherent gastrointestinal disorders, like necrotizing enterocolitis (a disease causing inflammation of the gut tissues and associated with intestinal tissue death).

• Children who have other local infections like urinary tract infections or abscesses anywhere in the internal organs.

What Are the Clinical Features of Enterococcal Bacteremia in Children?

The clinical features of Enterococcal bacteremia in children range from very mild fever to organ failure due to septic products. The clinical presentation of Enterococcal bacteremia is:

• Fever - May be persistent or intermittent.

• Lethargy.

• Easy irritability among young kids.

• Poor feeding and immediate vomiting of the ingested contents are the immediate signs seen in Enterococcal bacteremia in infants.

• Abdominal pain.

The growing colonies of Enterococci within the stomach and intestine can cause the release of bacterial products (septic products) within the bloodstream. This causes the infection to reach all parts of the body. Thus, severe manifestation of the bacteremia can be seen in kids as:

• Hypotension.

• Septic shock (widespread infection in the body causing multiple internal organ failure).

• Rashes in the skin.

• Altered state of consciousness.

• Children may go unresponsive.

• Pneumonia (lung infection) due to respiratory system attack.

The source for such widespread bacteremia is considered to arise from a primary infection site, like the urinary tract or intra-abdominal infections. Bloodstream infections secondary to catheter usage are also a common cause of Enterococcal bacteremia.

How to Diagnose Enterococcal Bacteremia in Children?

• The best way to diagnose Enterococcal bacteremia in children is to receive blood samples from affected kids and look for the colonization of such cocci through blood culture methods. The limitation of this method is that there is a need to take repeated blood samples from the affected children to differentiate if the condition is true bacteremia. This is particularly needed for kids who are less susceptible to developing Enterococcal bacteremia.

• Once the presence of Enterococci is confirmed in the blood, appropriate antibiotic sensitivity testing is highly necessary. This is because the specific causative microorganism can be resistant to antibiotics. Thus, the particular antibiotic that has the potential to kill Enterococci should be determined. Only after getting an antibiotic sensitivity testing done, one should proceed with further antibiotic administration.

• Non-specific tests that give an overview of the ongoing inflammatory process secondary to infection are also advised. Some test results providing valuable insights about the infectious disease include elevated neutrophil and leukocyte count and increased levels of C-reactive protein and ESR (Erythrocyte sedimentation rate).

• Local causes of this widespread infection should be certainly identified to eradicate the causative factor. This is achieved with the help of investigations such as abdominal computed tomography or endoscopy. This will give details of abdominal abscesses, endocarditis, or any other infections.

• Since bacteremia can be caused by congenital heart disease in children, an echocardiography must be performed to rule out the presence of endocarditis in affected children.

How to Treat Enterococcal Bacteremia in Children?

Medical Management:

• In conditions where the causative organism for bacteremia is not elicited, empirical therapy consisting of broad-spectrum antibiotics should be given based on the child’s responsiveness and condition. Generally, Ampicillin or Vancomycin will be the preferred choice for bacteremia in children.

• If the causative organism is confirmed to be Enterococci, appropriate administration of the sensitive antibiotic should be done. Enterococcus faecalis is responsive to Ampicillin therapy. However, Enterococcus faecium requires higher antibiotics like Vancomycin. If the particular Enterococci is resistant to Vancomycin, Linezolid or Daptomycin will be preferred. Irrespective of the drug, the duration of administration ranges from 10 to 14 days based on the child’s disease status.

Other Management Strategies:

• Sometimes, the cause of bacteremia can be external instruments like catheters. In such cases, the sources should be removed.

• Local causes of widespread bacteremia like intraabdominal abscesses or necrotizing fasciitis require surgery to be performed to completely cure the primary source of infection.

• Children who have advanced stages of the disease, like septic shock, would require fluids to be restored in the body as there is a profound and abrupt drop in blood pressure (hypotension) along with internal organ failure.

• Even after fluid resuscitation, if children have hypotension, drugs that increase the volume and blood pressure (like vasopressors) will be administered for children.

• Enterococcal bacteremia is a common occurrence in immunocompromised children and children with genetic diseases. Thus, such children will always be kept in the pediatric intensive care unit to monitor and have an overview of all their vitals. This can also help in emergency preparedness that can occur due to septic shock and organ failure.

Conclusion

Enterococcal bacteremia is a life endangering bloodstream infection and the treatment for this infection is becoming a great challenge due to the incidence of antibiotic-resistant species. Currently, there are no vaccines available to prevent this bacteremia. However, with proper infection preventive measures and early diagnosis, bacteremia and resultant septic shock can be avoided.