Can MRSA Cause Pneumonia? Treatment of an Antibiotic-Resistant Infection

Can MRSA Cause Pneumonia? Treatment of an Antibiotic-Resistant Infection
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What Is MRSA?

Methicillin-resistant Staphylococcus aureus, also known as MRSA, is a specific bacterial strain that has developed resistance to the most widely used antibiotics, including penicillin and cephalosporins. S. aureus is a common bacteria found on the skin of healthy people without causing infection. In people with weakened immune systems, such as from illness or medical treatment, S. aureus may cause skin infections or more invasive infections of the lungs, blood, or soft tissues. MRSA had been largely limited to hospital settings but is becoming increasingly prevalent in the general community outside of hospital and long-term care settings.

What Is Pneumonia?

Pneumonia is an inflammatory lung infection that may be caused by a variety of infectious agents, including several types of bacteria, viruses, and fungi. Pneumonia usually develops in people with weakened immune systems. Although pneumonia is often associated with serious illnesses such as cancer, it may also occur in association with any type of upper respiratory infection including influenza or the common cold. Because pneumonia interferes with the exchange of oxygen and carbon dioxide in the lungs, it has the potential to become life-threatening.

Can MRSA Cause Pneumonia?

MRSA can cause pneumonia. In a study of the growing incidence of community-acquired MRSA pneumonia, Vardakas and co-authors determined MRSA is a factor in as many as 1 in 200 cases of pneumonia acquired outside of hospital settings. The presence of resistant bacteria greatly increase the severity of the pneumonia, with approximately 75 to 85 percent of people with MRSA-associated pneumonia requiring intensive care and a mortality rate of 20 to 60 percent.

Symptoms

Pneumonia typically develops quickly. Symptoms include high fever and chills, cough that produced yellow or brownish sputum, and chest pain during coughing or when breathing deeply. Sometimes pneumonia causes shortness of breath. The symptoms of pneumonia are the same regardless of the cause or whether MRSA is involved.

Treatment

MRSA-associated pneumonia is unresponsive to certain types of antibiotics, but it is treatable. The antibiotics vancomycin or linezolid should be used as first-line therapy against MRSA pneumonia, recommends the Infectious Diseases Society of American and the American Thoracic Association. However, vancomycin-resistant strains of S. aureus are evolving. Other antibiotics effective against S. aureus include clindamycin, the fluroquinolones, trimethoprim sulfamethoxazole, tetracycline and rifampin. Always take all antibiotics as prescribed and finish the complete course of treatment.

References

Nakou A, Woodhead M, Torres A. Editorial: MRSA as a cause of community-acquired pneumonia. Eur Respir J. 2009;34:1013-1014. https://www.ersj.org.uk/content/34/5/1013.full.pdf

Vardakas KZ, Matthaiou DK, Falagas ME. Incidence, characteristics and outcomes of patients with severe community acquired-MRSA pneumonia. Eur Respir J. 2009;34:1148-1158. https://www.ersj.org.uk/content/34/5/1148.abstract

National Library of Medicine: MedLinePlus: MRSA https://www.nlm.nih.gov/medlineplus/ency/article/007261.htm

NetWellness: Methicillin-Resistant Staphylococcus Aureus https://www.netwellness.org/healthtopics/infectiousdisease/mrsa.cfm

Centers for Disease Control and Prevention. Severe methicillin-resistant Staphylococcus aureus community-acquired pneumonia associated with influenza – Louisiana and Georgia, December 2006-January 2007. MMWR. 2007;56:325-329. https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5614a1.htm

PneumoniaSymptoms.org: Bacterial Pneumonia https://www.pneumoniasymptoms.org/bacterial-pneumonia/bacterial-pneumonia.html