Neonatal sepsis

Neonatal sepsis is a bacterial infection of the blood, affecting infants during the first 90 days following birth. Infections occurring during the first week of life are considered early-onset. Infections occurring after the first week are classified as late-onset.

Definition & Facts

Cases of culture-proven neonatal sepsis occur in approximately two per every 1,000 births in the United States. Full-term infants are not likely to experience long-term health effects from neonatal sepsis provided they receive early diagnosis and treatment; however, the mortality rate can be as high as 50 percent for babies who are not treated.

Pre-term infants who develop neonatal sepsis are at an increased risk of developing cognitive deficits, cerebral palsy, or other disabilities. Any infant who has a difficult transition from intrauterine to extrauterine life is at an increased risk of developing neonatal sepsis.

Symptoms & Complaints

• Rapid breathing (tachypnea), difficulty breathing, or labored breathing
• Lack of urine output (oliguria)
• Yellow or jaundiced skin or eyes
• Skin rashes or redness around the belly button
• Poor feeding
• Lethargy
• Diarrhea
• Vomit that appears yellow in color
• Unexplained bruising or unexplained bleeding
• An abnormally fast heart rate (tachycardia) or slow heart rate (bradycardia)
• Skin that is cool and clammy
• Abdominal bloating
• Seizures

Causes

Neonatal sepsis can be caused by a variety of bacteria, including E. coli (Escherichia coli infection, Listeria (Listeriosis), Staphylococcus (Staphylococcal infection), and Group B Streptococcus (Group B Streptococcus infection). In cases of early-onset sepsis, the infection is transmitted from the mother to the infant through the placenta or birth canal.

Common causes of early-onset neonatal sepsis include a maternal Group B Streptococcus infection during pregnancy, water breaking more than 24 hours before delivery, preterm delivery, a fetal bowel movement while still in the uterus, and an infection of the amniotic fluid and placental tissue.

Pregnancy complications and maternal health issues can also increase the risk of neonatal sepsis, including taking multiple courses of prenatal corticosteroids, prolonged catheterization during pregnancy, and prolonged internal monitoring during delivery and labor.

Cases of neonatal sepsis that occur more than a week after birth are typically due to an infection obtained from the health care or home environment. The bacteria can enter the infant’s system via the skin, respiratory tract, gastrointestinal tract, conjunctiva, or umbilical cord through any indwelling lines or catheters or even by coming into contact with a caregiver who has a bacterial colonization. The most common organisms implicated in late-onset neonatal sepsis include:

• Coagulase-negative Staphylococcus
• Pseudomonas (Pseudomonas infection)
• E. coli
• Klebsiella (Klebsiella infections)
• Enterobacter
• Staphylococcus aureus (Staphylococcus aureus infections)
• Candida (invasive candidiasis)

Diagnosis & Tests

Fetal distress during labor or delivery often raises a concern regarding neonatal sepsis. This can include abnormalities in the fetal heart rate, the placenta prematurely separating from the uterine wall (endometrium), and cloudy or foul-smelling amniotic fluid. Infants born with these risk factors should have their vital signs carefully monitored during the first few days of life in order to identify the early signs of sepsis.

Any infant less than 28 days old with a rectal temperature of 100.1°F (38°C) should be evaluated for neonatal sepsis. This starts with a physical examination and complete medical history, including details of the pregnancy, labor, and birth.

Various blood tests and laboratory tests are used to confirm the diagnosis, identify the cause of the sepsis, and determine the most appropriate antibiotic therapy. The most common tests used include a complete blood count, blood tests, clinical urine tests, and cerebrospinal fluid cultures, and C-reactive protein, which is a non-specific indicator of inflammation. Blood chemistry panels, including blood sugar tests, liver function tests, and tests to assess renal function, are also useful in identifying neonatal sepsis and ruling out other health conditions.

Images of the chest and abdomen are often necessary and are usually obtained through X-rays or medical ultrasounds.

Treatment & Therapy

Treatment for neonatal sepsis can vary depending on the age of the infant and the severity of the infection. Mild symptoms may simply require careful monitoring. Infants less than a month old or who have severe symptoms typically require antibiotic treatment and hospitalization. In very young infants, treatment is often started before the lab results are back. Treatment for sepsis that is confirmed by laboratory tests typically takes 7 to 21 days. The specific course of treatment and therapeutic measures depends on the nature and location of the infection.

In most cases, intravenous antibiotics are required. The most frequently used antibiotics include ampicillin, cefotaxime, gentamicin, vancomycin, metronidazole, piperacillin, and erythromycin. The choice of antibiotic is based on the sensitivity of the organism as well as the current infection trends in the hospital nursery.

IV fluids containing glucose and electrolytes may be used to prevent dehydration. IV fluids may also be used to support heart function and blood pressure. Since infants with sepsis are often too sick to feed properly, a nasogastric intubation may be used to allow infant formula or breast milk to be administered through the nose.

Infants with infections affecting the respiratory system may require oxygen therapy or ventilator support. Infants with sepsis often have difficulty regulating their temperature, so they may need to be placed in an incubator (neonatal intensive care unit) or radiant warmer.

It is important to note that viral infections, such as herpes simplex, can produce symptoms similar to sepsis. If it turns out that the infection is viral in nature, prompt treatment with acyclovir may help inhibit the replication of the virus.

Prevention & Prophylaxis

Prophylactic antibiotics can be given to women with Group B Streptococcus infections of the genitourinary system, infections of the amniotic fluid or placental tissue, or who have previously given birth to a baby with sepsis.

When possible, women are encouraged to breastfeed their babies for at least the first six months of life. Maternal breast milk contains vital nutrients and antibodies that can help prevent infections in infants while their immune system is still developing.