Neonatal Sepsis

Bacteremia

Bacteremia is the presence of viable bacteria in the blood. It is a microbiological finding, detectable by laboratory tests. However, not all cases of bacteremia cause symptoms or complications.

Septicemia

Septicemia is a clinical state in which there is bacteremia along with associated signs and symptoms. Symptoms can vary depending on the bacteria involved and the patient's health. Common symptoms include fever, chills, rapid breathing, rapid heart rate, low blood pressure, and confusion.

Sepsis

Sepsis is the systemic inflammatory response (SIRS) to an infectious agent. SIRS is a set of clinical signs and symptoms caused by various factors, including infection, trauma, and burns. Symptoms of SIRS include fever, tachycardia, tachypnea, and leukocytosis.

The definitions of bacteremia and septicemia are often used interchangeably, but there is a subtle difference. Bacteremia is simply the presence of bacteria in the blood, while septicemia is bacteremia with associated symptoms.

Sepsis is more severe and can lead to organ failure and death. Early identification and treatment are crucial for improving survival chances.

SIRS Manifestations (SIRS is manifested by 2 or more of the following):

• Thermal Instability: Body temperature below 35°C or above 38.5°C.
• Respiratory Distress: Includes tachypnoea (rapid breathing) or hypoxaemia (low oxygen levels in the blood).
• Cardiac Dysfunction: Characterized by tachycardia (elevated heart rate), poor capillary refill, and hypotension (low blood pressure).
• Perfusion Abnormality: Indicated by oliguria (reduced urine output), acidosis (abnormal blood pH), and altered sensorium (changes in mental awareness).
• Abnormal White Blood Cells (WBC) or Increased Immature Forms: Elevated levels of immature white blood cells or other abnormalities in white blood cell counts.

• Varies from one environment to the other and even from nursery to nursery.
• In developed countries: 1 - 5 per 1000 live births
• In developing countries: 5 - 45 per 1000 live births

• Haematogenous / Transplacental: This route involves the transmission of infection from the mother to the fetus through the bloodstream or across the placenta.
• Ascending Infection: In this scenario, infection ascends from the birth canal into the amniotic fluid and can be associated with conditions like PROM (Premature Rupture of Membranes) or prolonged ROM (Rupture of Membranes).
• Post-natal Infections: These infections occur after birth and can result from various sources, including contact with hospital personnel, contaminated equipment, practices related to caring for the umbilical cord, traditional scarifications, circumcision procedures, and more.

• Newborn Immune Competence:

Even as a newborn, the immune system displays remarkable competence. It begins producing antibodies as early as 20 weeks into gestation, showcasing the innate capability to respond to potential threats.

• Maternal Antibody Transfer:

During the third trimester of pregnancy, maternal antibodies are actively transferred to the developing fetus. This maternal immune support helps provide early protection to the newborn, as the infant's immune system is still maturing.

• Complement Levels at Term:

Complement proteins play a critical role in immune defense. It's important to note that complement levels are relatively low at term, which is a consideration in the overall immune function of newborns.

• Challenges in Infection Localization:

Newborns lack efficient chemotaxis, a process that allows immune cells to navigate toward sites of infection. This limitation can make it more challenging for their immune systems to localize and target infections effectively.

The newborn's immune system is not fully developed at birth, but it does have some innate immune defenses.

• Skin: The skin is a physical barrier that helps to protect the newborn from infection.
• Mucous membranes: The mucous membranes lining the respiratory tract, digestive tract, and urinary tract also help to protect the newborn from infection.
• Natural killer cells: Natural killer cells are a type of white blood cell that can kill infected cells.
• Complement system: The complement system is a group of proteins that help to fight infection.
• Maternal antibodies: The newborn receives some passive immunity from the mother's antibodies, which are transferred to the fetus through the placenta during the third trimester of pregnancy.

However, the newborn's immune system is still not fully developed, and they are more susceptible to infection than adults.

• Complement levels are low at term, which means that the newborn's body is not as good at fighting infection.
• The newborn lacks chemotaxis, which means that they cannot localize infections.
• The newborn's immune system is still developing, so it may not be able to respond to infections as effectively as an adult's immune system.

• Prematurity:

One significant predisposing factor for infections in newborns is prematurity. Premature infants often have underdeveloped immune systems, making them more susceptible to infections.

• Maternal Infection:

Maternal infections during pregnancy can pose a risk to the newborn. Certain infections, such as rubella or cytomegalovirus, can be transmitted from mother to child, potentially leading to congenital infections.

• PROM (Prolonged Rupture of Membranes):

Prolonged rupture of membranes, where the amniotic sac breaks before labor, can increase the risk of infection as it provides a direct pathway for microorganisms to enter the fetal environment.

• Cultural Practices and Lack of Colostrum:

Cultural practices can also influence the risk of infections in newborns. Some practices, such as traditional customs or rituals e.g for cord care, may expose the newborn to potential sources of infection.

Cultural practices that may discourage breastfeeding or delay the provision of colostrum can impact the newborn's immune system negatively. Colostrum, the initial breast milk, contains essential antibodies and nutrients vital for the infant's immune development.

• Sanitation and Hygiene:

Poor sanitation and hygiene practices can expose newborns to harmful pathogens. Maintaining clean surroundings and proper hand hygiene are crucial in preventing infections.

• Crowded Living Conditions:

Overcrowded living conditions can facilitate the spread of infections among newborns. Close contact with infected individuals in crowded settings increases the risk of disease transmission.

• Low Birth Weight:

Low birth weight is another factor that can compromise a newborn's immune system. Babies born with low birth weight may have underdeveloped organs and a weaker immune response, making them more susceptible to infections.

• Early-Onset:

Early-onset infections occur within the first 72 hours of life. In these cases, the organisms responsible for the infection are typically acquired from the mother, either during pregnancy, labor, or delivery. Maternal-to-fetal transmission is a significant factor in early-onset neonatal infections.

• Late-Onset:

Late-onset infections manifest from the 4th to the 28th day of life. Unlike early-onset infections, these organisms are primarily acquired from the community. The baby's environment, including exposure to family members, caregivers, or community settings, becomes more relevant in late-onset infections.

• Nosocomial (Hospital-Acquired):

Nosocomial infections also occur between the 4th and 28th day of life, but they are acquired within the hospital setting. These infections are often associated with healthcare interventions, such as medical procedures, catheterizations, or the presence of invasive medical devices.

The causative agents of neonatal infections can vary depending on the geographic location and specific nursery or healthcare facility. Here are some notable factors related to the aetiology of neonatal infections:

• Early Onset:
• In developed countries, early-onset infections are often attributed to Group B Streptococcus (GBS).
• In our environment, gram-negative bacteria such as Escherichia coli (E. coli) and coliforms are more common causes.
• Late Onset:
• Late-onset infections are relatively rare in developed countries.
• In our environment, Staphylococcus aureus is more frequently associated with late-onset neonatal infections.
• Nosocomial (Hospital-Acquired):
• In our environment, Staphylococcus epidermidis is a common cause of nosocomial neonatal infections.
• Additionally, gram-negative bacteria like Klebsiella, Proteus, and Pseudomonas are notable pathogens in hospital-acquired infections.
• Other Causative Agents:
• Aside from the mentioned pathogens, other causative agents of neonatal infections can include Listeria monocytogenes and Streptococcus pneumoniae, although they may be less common.

Neonatal infections can manifest through various signs and symptoms, and it's essential to recognize them for timely intervention. Here are some key indicators:

• Early Signs:
• Early signs of neonatal infections can be subtle and include:
  • Thermal instability
  • Lethargy
  • Poor feeding
• Late Signs:

As the infection progresses, more noticeable signs and symptoms may appear. These can include:

• Fever
• Irritability
• Respiratory distress
• Diarrhea
• Vomiting
• Paralytic ileus
• Abdominal distension
• Omphalitis (inflammation of the umbilical stump)
• Acidosis
• Seizures
• Hepatomegaly (enlarged liver)
• Petechiae (small red or purple spots on the skin, indicative of bleeding)

Diagnosing neonatal infections involves a series of essential investigations to confirm the presence of infection and identify the causative agent. Key investigations include:

• Blood Culture (Confirmatory):

A blood culture is a critical test for confirming the presence of bacteria in the bloodstream. It helps identify the specific pathogen responsible for the infection, allowing for targeted treatment.

• Urine Culture:

Urine culture helps detect urinary tract infections, which can be a source of neonatal infection. It aids in identifying the causative bacteria and determining the appropriate antibiotics for treatment.

• Lumbar Puncture:

Lumbar puncture involves collecting cerebrospinal fluid from the spinal canal. This test is crucial for diagnosing central nervous system infections and assessing for meningitis.

• Full Blood Count (FBC):

It can reveal signs of infection, such as an elevated white blood cell count.

• Chest X-ray:

A chest X-ray may be performed to assess lung involvement in cases of respiratory distress or suspected pneumonia.

• Polymerase Chain Reaction (PCR):

Polymerase Chain Reaction is a molecular diagnostic technique that can identify the DNA of specific pathogens, providing rapid and accurate results for certain infections.

Effective treatment of neonatal infections involves a combination of medical strategies to address the underlying infection and provide supportive care. Here are the key components of treatment:

• Empirical Antibiotics:

Empirical antibiotics are administered initially to cover a broad spectrum of potential pathogens. This initial treatment aims to control the infection while awaiting culture and sensitivity results.

• Change Antibiotics If Required:

If culture and sensitivity results indicate a specific pathogen, the treatment plan may be adjusted accordingly to target the identified pathogen effectively.

• For Gram-Positive Bacteria:
  • 1st Generation Cephalosporins (e.g., Cefazolin)
  • 2nd Generation Cephalosporins (e.g., Cefuroxime)
  • Amoxicillin-Clavulanic Acid (Amoxyclav)
• For Gram-Negative Bacteria:
  • 3rd Generation Cephalosporins (e.g., Cefotaxime)
  • 4th Generation Cephalosporins (e.g., Cefepime)
• Prescription for 7-10 Days:

Neonatal infections typically require a course of antibiotics for 7 to 10 days to ensure complete eradication of the infection. Compliance with the prescribed treatment duration is essential to prevent relapse.

• Supportive Care:

In addition to antibiotics, supportive care plays a crucial role in neonatal infection treatment. This may include:

• Intravenous Fluids (IVF): Maintaining proper hydration is essential for the infant's recovery.
• Oxygen Therapy: Oxygen may be provided if the infant experiences respiratory distress.
• Anticonvulsants: In cases where seizures occur, anticonvulsants may be administered to manage them effectively.

Preventing neonatal infections is crucial to ensure the well-being of newborns. Different strategies are employed to prevent various types of neonatal infections:

• Early Onset:

To prevent early-onset neonatal infections, it's essential to identify mothers who may carry pathogens and screen their babies at birth to detect any potential infections.

• Late Onset:

For late-onset neonatal infections, health education plays a vital role. Informing parents and caregivers about infection prevention measures can reduce the risk of transmission.

• Nosocomial (Hospital-Acquired):

To prevent nosocomial infections in the Neonatal Intensive Care Unit (NICU), specific measures are essential, including:

• Avoiding overcrowding in the NICU to reduce the risk of cross-infection.
• Maintaining strict asepsis during invasive procedures like IV insertion, UVC (Umbilical Venous Catheter) placement, and venepuncture.
• Individualizing equipment to prevent cross-contamination between patients.

Good Hand Washing

Hand hygiene is a fundamental measure in preventing neonatal infections in newborn units. Here are important guidelines for effective hand washing:

• Importance of Hand Washing:

Hand washing is the most critical measure for preventing neonatal infections in newborn units. It involves using a germicidal soap and washing under running water for at least 3 minutes before handling any baby.

• Proper hand washing includes:
• Washing hands with germicidal soap under running water for 3 minutes before contact with infants.
• Continuing to wash hands in between handling different babies to prevent cross-contamination.
• Ensuring that hospital wash basins have long handles that can be turned off with elbows to maintain hygiene.
• Avoiding the use of towels except for disposable or individualized ones to prevent the spread of germs.