Sepsis is a serious but rare infection. It's usually caused by bacteria, which can originate in the lungs, intestines, urinary tract, or gallbladder, making toxins that cause the immune system to attack the body's own organs and tissues.

Sepsis can be frightening because if it is untreated, it can lead to serious complications that affect the kidneys, lungs, brain, and hearing. Sepsis can affect a person of any age, but it is more prevalent in infants whose immune systems have not developed enough to fight off overwhelming infections and people whose immune systems are compromised from conditions such as HIV.

If your infant has a rectal temperature of 100.4° Fahrenheit (38° Celsius), seems lethargic, uninterested in eating, or seems to be having difficulty breathing, call your doctor. In an older child, the symptoms of sepsis may include a fever (an oral temperature at or above 99.5° Fahrenheit [37.5° Celsius]); your child may also seem lethargic, irritable, and may complain that his or her heart feels like it's racing.

About Sepsis

Sepsis occurs when the body's normal reaction to inflammation or a bacterial infection goes into overdrive. Bacteria create a toxin that causes a widespread inflammation of the body's organs and causes rapid changes in body temperature and blood pressure, and dysfunction in the lungs and other organs.

Sepsis in newborns produces few concrete symptoms, though symptoms can vary widely from child to child. Frequently, affected babies suddenly aren't feeling well or "just don't look right" to their caretakers.

Common signs or symptoms of sepsis in newborns and young infants include:

• disinterest or difficulty in feeding
• fever (above 100.4° Fahrenheit [38° Celsius] rectally) or sometimes low, unstable temperatures
• irritability or increased crankiness
• lethargy (not interacting and listless)
• decreased tone (floppiness)
• changes in heart rate — either faster than normal (early sepsis) or significantly slower than usual (late sepsis, usually associated with shock)
• breathing very quickly or difficulty breathing
• periods where the baby seems to stop breathing for more than 10 seconds (apnea)
• jaundice

Older children who have sepsis might have a fever (an oral temperature above 99.5° Fahrenheit [37.5° Celsius]), vomit, and complain of feeling like their hearts are racing. A child with sepsis may have started with an infection such as cellulitis that seems to be spreading and getting worse, not better.

What Causes Sepsis?

Bacteria are almost always the cause of sepsis in newborns and infants. Bacteria such as E. coli, Listeria monocytogenes, Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b, Salmonella, and Group B streptococcus (GBS) are the more common culprits in sepsis in newborns and infants younger than 3 months.

Premature babies receiving neonatal intensive care are particularly susceptible to sepsis because their immune systems are even more underdeveloped than other babies, and they typically undergo invasive procedures involving long-term intravenous (IV) lines, multiple catheters, and breathing through a tube attached to a ventilator. The incisions a young infant gets for catheters or other tubes can provide a path for bacteria, which normally live on the skin's surface, to get inside the body and cause infection.

In many cases of sepsis in newborns, bacteria enter the baby's body from the mother during pregnancy, labor, or delivery. Some pregnancy complications that can increase the risk of sepsis for a newborn include:

• bleeding
• maternal fever
• an infection in the uterus or placenta
• premature rupture of the amniotic sac (before 37 weeks of gestation)
• rupture of the amniotic sac very early in labor (18 hours or more before delivery)
• a long, difficult delivery

Some bacteria — GBS in particular — can be acquired by the newborn during delivery. At least 1 of every 5 pregnant women carries the bacterium for GBS in her vagina or rectum, where it can be passed from mother to child during delivery.

Diagnosing and Treating Sepsis

Because symptoms of sepsis can be vague in infants, laboratory tests play a crucial role in confirming or ruling out sepsis:

• Blood tests (including red and white blood cell counts) and blood cultures may be taken to determine whether bacteria are present in the blood.
• Urine is usually collected by inserting a sterile catheter into the baby's bladder through the urethra for a few seconds to remove urine; this will be examined under a microscope and cultured to check for the presence of bacteria.
• A lumbar puncture (spinal tap) may be performed, depending on the baby's age and overall appearance. A sample of cerebrospinal fluid will be tested and cultured to determine if the baby could have meningitis.
• X-rays, especially of the chest (to make sure there isn't pneumonia), are sometimes taken.
• If the baby has any kind of medical tubes running into the body (such as IV tubes, catheters, or shunts), the fluids inside those tubes may be tested for signs of infection.

Sepsis, or even suspected cases of sepsis in infants, will be treated in the hospital, where doctors can closely watch the infection and administer strong antibiotics intravenously to fight the infection.

Typically, doctors start infants with sepsis on antibiotics right away — even before the diagnosis is confirmed. If more symptoms of sepsis appear, they usually start them on IV fluids to keep them hydrated, blood pressure medication to keep their hearts working properly, and respirators to help them breathe.

Can Sepsis Be Prevented?

Although there's no way to prevent all types of sepsis, some cases can be avoided, namely the transmission of GBS bacteria from mother to child during childbirth. Pregnant women can have a simple swab test during the 35th and 37th weeks of pregnancy and again just before the birth to determine if they carry the GBS bacteria.

Women are at higher risk of carrying GBS if they have a fever during labor, if the amniotic sac ruptures prematurely, if they have prolonged labor, or if they had other children with sepsis or other diseases triggered by GBS, such as pneumonia or meningitis. A woman who has one of these risk factors or tests positive for GBS can receive IV antibiotics during labor to lower the risk of transmission to her child.

Immunizations routinely given to infants today include vaccinations against certain strains of pneumococcus and Haemophilus influenzae type b that can cause sepsis or occult bacteremia, an infection of the blood.

When to Call the Doctor

Symptoms of sepsis can be very difficult to identify in newborns and young infants, so call your doctor or seek emergency medical care if your baby shows any of these symptoms:

• difficulty or continued disinterest in feeding
• fever (100.4° Fahrenheit [38° Celsius] and above rectal temperature) in newborns and young infants
• labored or unusual breathing
• change in skin color (paler than usual or mildly bluish)
• listlessness or lethargy
• change in the sound of the baby's cry or excessive crying
• change in baby's muscle tone — either seeming too stiff or especially floppy
• a slower or faster heart rate than usual
• bulging or fullness of the "soft spot" on the baby's head
• any type of behavior or appearance that concerns you

These signs don't necessarily mean your baby has sepsis, but infants younger than 3 months old should be checked out immediately to ensure that nothing else is wrong.

Reviewed by: Barbara P. Homeier, MD
Date reviewed: June 2005