Neonatal Sepsis and Congenital Infections Quiz

Neonatal Sepsis and Congenital Infections

• Neonatal period is the time of highest risk for invasive bacterial infection in childhood.
• Neonatal infections (first few weeks) are categorized as early-onset or late-onset sepsis.
• Early-onset sepsis (within 72 hours of birth) results from vertical exposure or high bacterial load during birth (after membrane rupture).
• Common organisms in early-onset sepsis include Group B Streptococcus, Gram-negative organisms (E. coli, Klebsiella, Pseudomonas), and Listeria monocytogenes (less common).
• Late-onset infection (after 72 hours) originates from the infant's environment (often hospital related).
• Common late-onset pathogen is coagulase-negative staphylococcus (CONS), but organisms can vary widely, such as Gram-positive bacteria (Staphylococcus aureus, Enterococcus fecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas, Klebsiella, Serratia species).

Risk Factors for Neonatal Sepsis

• Preterm infants, especially those with prolonged rupture of membranes.
• Prolonged rupture of membranes (more than 18 hours) or pre-labor rupture of membranes.
• Intrapartum fever over 38°C, or chorioamnionitis.
• Previous child with Group B Streptococcus infection.
• Group B Streptococcus bacteriuria during pregnancy.
• Indwelling central venous catheters for parenteral nutrition.
• Invasive procedures that break skin barrier (e.g., tracheal tubes).
• Ineffective hand hygiene measures.

Clinical Presentation of Neonatal Sepsis

• Respiratory distress
• Fever/temperature instability or hypothermia
• Poor feeding
• Vomiting
• Apnea and bradycardia
• Abdominal distention
• Jaundice
• Neutropenia
• Hypoglycemia/hyperglycemia
• Shock
• Irritability
• Seizures
• Lethargy, drowsiness
• Meningitis (bulging fontanelle, head retraction)
• Poor feeding, drowsiness, lethargy, and possible seizures are also common symptoms.

Lab Tests for Sepsis

• Septic screen (blood cultures, chest X-ray).
• Complete blood count (CBC) to check for neutropenia (low white blood cells).
• Acute-phase reactant (C-reactive protein) test. One normal result is not conclusive, but two consecutive normal results are strong evidence against infection. Test takes 12-24 hours to rise.

Treatment for Neonatal Sepsis

• Antibiotics initiated immediately, regardless of culture results.
• Intravenous antibiotics to cover Group B strep, Listera monocytogenes (e.g., benzylpenicillin or ampicillin). Combine with aminoglycoside (e.g., gentamicin) to cover Gram-negative organisms.
• If cultures and C-reactive protein tests are negative and infant has no other signs of infection, treatment may be stopped after 36-48 hours.
• If blood cultures are positive or infant shows neurological/generalized signs, cerebrospinal fluid (CSF) examination and culture are necessary.
• In late-onset sepsis, initial therapy uses drugs like flucloxacillin and gentamicin, which covers Gram-negative bacilli and staphylococci.
• If the organism is resistant or infant's condition does not improve, specific antibiotics like vancomycin (for coag-neg staphylococci or enterococci) or broad-spectrum drugs like meropenem may be indicated.

Congenital Infections: Overview

• Congenital infections are acquired transplacentally.
• Leading infectious agents are fungal, bacterial, and viral. Those commonly mentioned are toxoplasmosis, rubella, cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus, congenital syphilis, parvovirus, human immunodeficiency virus (HIV), hepatitis B, Zika virus, Neisseria gonorrhoeae, Chlamydia, and Mycobacterium tuberculosis.

Evaluation of Congenital Infections

• Isolating the organism (culture).
• Identifying pathogen antigens (e.g., for hepatitis B, Chlamydia trachomatis, RUBELLA).
• Identifying pathogen's genetic material using polymerase chain reaction (PCR).
• Identifying pathogen-specific antibodies (IgM or increasing IgG titers for relevant pathogens).

Toxoplasmosis

• Causative agent: Toxoplasma gondii
• Maternal epidemiology: Exposure to cats, raw meat, or immunosuppression (10-24th week of gestation is high-risk).
• Clinical presentation in the infant typically includes hydrocephalus, abnormal spinal fluid, and intracranial calcifications. Jaundice and hepatosplenomegaly may also be observed.

Congenital Rubella

• Causative agent: Rubella virus
• Maternal epidemiology: Fever and rash in unimmunized, seronegative mothers. High probability of virus transmission via the mother to the infant within 8 weeks.
• Prevention: Rubella vaccine
• Clinical presentation in the infant is variable but includes intrauterine growth restriction, microcephaly, microphthalmia, cataracts, glaucoma, "salt and pepper" chorioretinitis, hepatosplenomegaly, and jaundice.

Congenital CMV (Cytomegalovirus)

• Causative agent: Cytomegalovirus
• Maternal epidemiology: Often a sexually transmitted disease that is primary genital or asymptomatic in the mother. The infant may have viruria for a period of 1-6 years.
• Clinical presentation includes sepsis, intrauterine growth restriction, chorioretinitis, microcephaly, periventricular calcifications, and blueberry muffin rash. Anemia, thrombocytopenia, and hepatosplenomegaly can also occur.

Congenital Herpes

• Causative agent: Herpes simplex virus (type 1 or 2)
• Maternal epidemiology: Sexually transmitted disease, primary genital infection often asymptomatic. Intrauterine infection is rare, but infection at time of birth is more common.
• Clinical presentation may involve intrauterine infection such as chorioretinitis, skin lesions, microcephaly or postnatal encephalitis, localized or widespread disease, skin vesicles, and keratoconjunctivitis.

General

• Many infants are asymptomatic at birth, but long-term issues can arise.
• Treatment considerations for congenital infections and sepsis are complex.
• Prevention of infection in pregnant women and newborns is important. There are vaccine options in some cases.
• It is important to note that many infants display symptoms at or after birth, and congenital infections can have severe and lifelong consequences.

Test your knowledge on neonatal sepsis and congenital infections. This quiz covers early-onset and late-onset sepsis, their causes, and major pathogens involved. Understand the risk factors associated with neonatal infections to better comprehend their impact on infant health.