Staphylococci, or staph, are widely prevalent bacteria commonly responsible for hospital and community-acquired infections. Early recognition and appropriate treatment can help decrease the length of illness and possible complications. Tests for C-reactive protein play a role in both early diagnosis and monitoring for the success of treatment of staph infections.
Staphylococcal Infections
Multiple strains of staphylococcal bacteria can cause infections, most notoriously the species Staphylococcus aureus. Despite their ability to cause disease, staph can be found at any given time in 20 to 30 percent of healthy adults either in the nose or on the skin, according to the Merck Manuals Online Medical Library. Your risk of developing a staph infection increases if you have a serious underlying medical condition, influenza, chronic lung disease, burns, recent surgery, are immunocompromised or have an implanted medical device. Common staph infections include skin cellulitis or boils, abscesses, pneumonia, heart valve infection or endocarditis, osteomyelitis, toxic shock syndrome and food poisoning. Symptoms can vary widely depending on the severity and type of staph infection you experience.
C-Reactive Protein
C-reactive protein, or CRP, is one of several proteins known as acute phase reactants that your body produces in response to infections, inflammatory disorders, malignancy, burns and other types of tissue damage. CRP levels in your blood rise rapidly in response to any of these conditions; they can be detected within six hours of the start of a serious bacterial infection, according to an April 2008 article in "Clinical Laboratory International." Blood levels rise dramatically with these infections, and also decrease quickly once effective antibiotic treatment is begun. CRP is considered a non-specific test, because it simply reflects the presence of an inflammatory reaction occurring in your body without indicating the specific cause.
Diagnosing Staph Infections
Fever, pain, x-ray changes and a variety of other symptoms can signal staph or other types of bacterial infections. A CRP level can often indicate the presence of infection earlier than other laboratory tests such as an elevated white blood count or other acute phase reactants. Cultures of fluid, tissue or blood from the site of suspected infection are the key to a specific diagnosis, plus allow for identification of the strain of bacteria involved and susceptibility testing to different antibiotics. Knowing which antibiotics will effectively treat your infection becomes particularly important with staphylococcal bacteria, as many species are now resistant to multiple antibiotics.
Treatment and Follow-Up
As with symptoms, the treatment of staph infections depends on the type of infection, severity of your illness and the body site involved. Local measures can include debridement, involving the removal of dead tissue, abscess drainage or removal of infected medical devices. The type of infection and the results of culture and susceptibility testing similarly determine the right antibiotic and appropriate dosages. As methicillin-resistant and vancomycin-resistant strains of staph become increasingly common, susceptibility testing becomes ever more important. Once a successful course of treatment for an uncomplicated infection is begun, your CRP levels should quickly begin decreasing and return to near normal within about a week.
References
- Merck Manuals Online Medical Library; Staphylococcal Infections; December 2009
- Patient.co.uk; Acute Phase Proteins, CRP, ESR and Viscosity; Dr. Colin Tidy; April 2010
- "Clinical Laboratory International"; CRP: An Important Biomarker for Infectious Disease and its Role in POC; Dr. Kirstin Kriz, et al.; April 2008
- Lab Tests Online: Staph Wound Infections and Methicillin Resistant Staphylococcus aureus
