Infection takes place when foreign organisms such as bacteria, viruses, or fungi invade the body. If an infection is suspected, antibiotics will be given before a definitive diagnosis is made because a premature baby's body may already be weakened and even a minor infection is potentially dangerous.
Premature babies are highly susceptible to infection for several reasons:
- Their immune systems are both immature and inexperienced. This means that every encounter with a possible infectious agent is new to the baby, who may be slow to develop the means to combat the foreign organism.
- The usual transfer of maternal antibodies through the placenta to the fetus during the third trimester of pregnancy was less than optimal reducing the baby's immediate immunity once born.
- The possibility for infection can be great for a premature baby in the Neonatal Intensive Care Unit (NICU). Because premature babies are frequently ventilated or have indwelling lines or feeding tubes, these can serve as point of entry for infectious agents.
Although most infections are not serious, even a minor infection is potentially dangerous because a premature baby’s body may already be weakened, either in the immune system or elsewhere. In general, if an infection is suspected, antibiotics will be given before a definitive diagnosis of infection is made.
Infections in premature babies may occur in the lungs, blood, urinary tract, or cerebrospinal fluid, which is the fluid in the spine and surrounding the brain, and other parts of the body. Infection may be initially suspected if the baby has an abnormal temperature, breathing difficulties, lethargy, irritability, or other subtle clinical signs.
Since infection can result from complications during pregnancy and birth, doctors will look at the immediate history prior to the birth of the child. Early or prolonged rupture of the amniotic sac, infection of the mother’s urinary tract, a long and difficult delivery, and other infections the mother may have had can all cause infection in the premature newborn baby.
A definitive diagnosis of infection requires blood and possibly urine cultures. A lumbar puncture, also called a spinal tap, may be performed to look for signs of meningitis. Meningitis is a type of infection found within the cerebrospinal fluid. Cultures are taken to identify the organism causing the infection and the best antibiotic to use. Since treatment must start before the results are available, the initial choice of antibiotics must cover the most likely possible causes of the suspected infection.
Many infections can be treated with an antibiotic called ampicillin or a drug from the group of antibiotics called aminoglycosides; however, there are some organisms that are not affected by these medications. Other antibiotics that might be used include vancomycin, cefotaxime, acyclovir, and fluconazole. Some infections are severe and can have serious consequences if they are not resolved quickly. These include meningitis, an infection of the bone called osteomyelitis, and septic arthritis, an infection of the joints causing severe inflammation.