What is a Streptococcal Infection?

It is difficult to discuss streptococcal infection without first making it clear that there are many types of strep bacteria. Those most commonly causing illness in children (not newborns) and adults include what is known as Group A strep (GAS) or Streptococcal pyogenes. Another type of streptococcal infection often most dangerous to newborns is Group B strep (GBS) or S. agalactiae. Some other forms of streptococcal infections may be caused by other groups of strep bacteria and may be more commonly found on animals but won’t typically affect humans.

It’s thus important to understand that streptococcal infection can mean much more than a bout of the common strep throat, or its complication, scarlet fever. Instead, GAS can result in many different types of infections and affect many different parts of the body. It would be fair to state that some of the following areas could be affected by streptococcal infection with GAS:

Group B streptococcal infection is most commonly associated with infection in newborns, particularly in causing certain types of pneumonia. It may also cause pneumonia in people who are elderly or who have suppressed immune systems. Method of transmission for babies tends to occur if a mother harbors this bacteria in the vagina or anus, and she may have no outward sign that she has this form of strep.

Many obstetricians now routinely look for Group B strep and may treat a laboring mom with intravenous antibiotics to prevent this streptococcal infection in newborns. Though babies who develop Group B strep may recover with treatment, there still exists an alarming 3% death rate associated with this infection, and it is most dangerous to babies born prematurely. A mom who labors quickly and doesn’t have time for at least four hours of IV antibiotics before delivering may be able to prevent this infection by having a Cesarean section instead.

There are numerous species of strep that can cause infection. What’s complicated about some of these is that they have been reclassified into other groups of bacteria as strep has been more closely studied and understood. For most people, with the exception of infants, the greatest danger comes from streptococcal infection of the GAS type. Most serious forms of these infections invade the blood stream and become systemic. They will require extensive treatment with intravenous antibiotics, and some forms are increasingly antibiotic resistant. The average, and certainly one of the most common strep infections may simply be the classic strep throat, which is usually easily treated with a course of antibiotics.