Staph infections, caused by the bacteria Staphylococcus aureus, are frustratingly stubborn and difficult to fully eradicate. There are several reasons why staph infections tend to persist or recur after antibiotic treatment.
Staph bacteria can survive on surfaces and skin
Staph bacteria have the ability to survive for extended periods on environmental surfaces and on people’s skin and inside their noses. This allows staph bacteria to persist in a home, hospital or other setting even after cleaning measures and antibiotic treatment. According to a study published in the American Journal of Infection Control, S. aureus can survive on polyester, polyester-cotton blend and 100% cotton fabrics for up to 90 days.
Staph bacteria can live benignly on the skin and inside the noses of an estimated 30% of people at any given time. This carrier state provides a reservoir from which staph can spread and cause recurrent infections. Decolonization regimens involving antibiotics and antimicrobial body washes can reduce, but not always fully eliminate, staph colonization.
Biofilms help staph bacteria persist
Staph bacteria have the ability to form biofilms – slimy colonies of bacteria that adhere to surfaces and provide protection against antibiotics and the immune system. Biofilms can form on medical devices such as catheters, prostheses and heart valves. Staph biofilms act as a source for chronic and recurrent infections that are resistant to antibiotic treatment.
According to a review in Frontiers in Microbiology, up to 80% of microbial infections involve biofilms. Biofilms have an extracellular matrix that impedes penetration of antibiotics. Bacteria in biofilms also have a decreased growth rate and different gene expression patterns that enhance antibiotic resistance.
MRSA infections are antibiotic resistant
Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph that is resistant to many common antibiotics. According to the CDC, about 1 in 3 people carry MRSA in their nose without any illness, which can serve as a reservoir for infection. MRSA infections are more difficult to treat and often require IV antibiotics.
A study in Emerging Infectious Diseases found that about 50% of patients with MRSA soft tissue infections experienced recurrence within a year. Recurrence was associated with inadequate antibiotic therapy and failure to drain infectious fluid collections.
Treatment may be inadequate
In some cases, staph skin infections recur because the initial antibiotic treatment regimen was inadequate or prematurely discontinued. The Infectious Diseases Society of America recommends 7-14 days of antibiotic treatment for a staph abscess or boil.
However, some doctors prescribe antibiotics for shorter durations. A study in Open Forum Infectious Diseases found that about 25% of patients with a staph skin infection had antibiotic treatment durations of less than 7 days. Inadequate treatment can lead to recurrence when residual bacteria are not fully eradicated.
The immune system can’t fully clear the infection
The immune system plays an important role in fighting staph infections through white blood cells, antibodies and inflammatory proteins. However, in some people the immune response is not robust enough to completely clear the infection. Those with weakened immune systems due to aging, illness or medications are at higher risk for recurrent staph infections.
Obesity and diabetes can also impair immune function and predispose people to chronic or recurrent staph infections. Getting blood glucose levels under control can help improve immune function and response to infection.
Steps to get rid of a staph infection
While staph infections can be stubborn, there are steps you can take to get rid of a staph infection and prevent recurrence:
- See your doctor for drainage of any abscesses and a full course of appropriate antibiotics. Take all antibiotics as prescribed.
- Disinfect your home thoroughly by cleaning surfaces with diluted bleach.
- Practice good hand hygiene by washing hands frequently with soap and water.
- Avoid sharing personal items like towels and razors.
- Shower after athletic activities where skin-to-skin contact can spread staph.
- Talk to your doctor about decolonization regimens if you are a known staph carrier.
- Address factors that weaken immunity, such as managing diabetes, quitting smoking, and getting immunizations.
- See your doctor promptly for evaluation of any recurrent infections.
Key Points
- Staph bacteria can live on surfaces, skin and in noses, allowing for recurrence.
- Biofilms help staph evade antibiotics and immune defenses.
- MRSA is more antibiotic resistant.
- Inadequate antibiotic treatment can lead to recurrence.
- A weakened immune system makes it harder to eradicate staph.
- Good hygiene, full antibiotic treatment, disinfection and addressing immunity issues help prevent recurrence.
Conclusion
Staph infections can be extremely frustrating to treat due to bacterial, treatment and host factors that allow the infection to persist. MRSA and biofilms enhance the antibiotic resistance of staph. Bacteria can also live harmlessly on skin and surfaces, seeding new infections. Inadequate antibiotic therapy and impaired immunity further hamper the body’s ability to fully eradicate the bacteria.
However, with a concerted effort to sanitize environments, treat active infections aggressively, address risk factors and boost immunity, it is possible to eventually get rid of even stubborn staph infections. Close follow-up with your healthcare provider is key to ensuring treatment is complete and detecting any recurrences early so they can be addressed.