Staphylococcus bacteria are the leading cause of death among causes of community-acquired pneumonia. According to statistics, the mortality rate due to methicillin-resistant staphylococcus (MRSA) pneumonia can exceed 50%. Staphylococcal pneumonia often occurs as a secondary infection after a viral infection.
Staphylococcal pneumonia requires prompt diagnosis because it can lead to serious complications such as necrotizing pneumonia, sepsis or septic shock. Early recognition of clinical signs for timely intervention is especially important in the treatment of staphylococcal pneumonia.
What is staphylococcal pneumonia?
Pneumonia is an infection that affects one or both lungs. It causes the alveoli (tiny air sacs where gas exchange takes place) of the lungs to fill with fluid or pus.
What diseases does Staphylococcus aureus cause? Staphylococcus aureus (full name: Staphylococcus aureus – abbreviated: S. aureus ) is a gram-positive bacterium that can cause many diseases in humans. This type of bacteria is present everywhere in the natural environment, especially in hospitals. Most cases of Staphylococcus aureus infection are skin and mucosal infections . However, this type of bacteria can also cause lung infections and cause staphylococcal pneumonia.
S. aureus accounts for approximately 3% of community-acquired pneumonia (CAP) in hospitalized patients. For hospital-acquired pneumonia , S. aureus is one of the major pathogens with infection rates ranging from 7-60% depending on the location.
Symptom
Symptoms of staphylococcal pneumonia often begin suddenly and include:
- High fever (occurs in 80% of patients, however, older adults often do not have this symptom or may have hypothermia).
- Severe cough, coughing up mucus or yellow pus
- Chest pain
- Signs of respiratory distress include difficulty breathing, rapid breathing, wheezing, cyanosis, and muscle twitching.
- Vomiting, diarrhea, and bloating (sometimes)
- Rapid exhaustion
- Skin damage at the point of bacterial entry.
Reason
Causes of staphylococcal pneumonia
S. aureus is the cause of the disease. This is the most dangerous type of bacteria due to its high toxicity, its ability to produce protease, lipase, hyaluronidase, etc., which weakens the host and increases the bacteria’s ability to survive. Some strains also have the ability to produce proteins that are resistant to the antibiotic methicillin – called drug-resistant Staphylococcus aureus (MRSA).
A person gets staphylococcal bacteria in the lungs through two routes:
- Inhalation of staphylococci through the respiratory tract
- Staphylococci from skin or other organ infections enter the lungs through the bloodstream, causing pneumonia.
Risk factors
- S. aureus pneumonia is common in the elderly and patients after influenza or measles infection .
- Intravenous drug abuse: Because of the risk of contamination of the skin or injection equipment, intravenous drug abuse can lead to a variety of systemic infections caused by S. aureus such as tricuspid valve endocarditis , bacteremia , and septic pulmonary embolism .
Several other medical conditions also increase your risk of developing staph pneumonia, including:
- Lung diseases: chronic obstructive pulmonary disease, lung cancer, cystic fibrosis, tuberculosis, etc.
- Chronic internal medicine: diabetes, kidney failure, hypertension, ischemic heart disease, etc.
- Viral infections: flu, measles.
Complications
A common complication of staphylococcal pneumonia is severe necrotizing pneumonia. If necrotizing pneumonia is suspected, your doctor may order a chest CT scan for further evaluation.
Other complications may include:
- Pleural effusion , pleural empyema.
- Sepsis, systemic infection, septic shock .
- Severe respiratory failure, requiring invasive ventilation.
The prognosis of staphylococcal pneumonia depends largely on the patient’s comorbidities, underlying lung disease, and possible complications.
Although mortality rates for most forms of pneumonia have decreased due to better treatment with current drugs, because the bacteria are resistant to treatment, Staphylococcus infections still have a relatively high mortality rate.
Diagnose
A clinical examination will be the first diagnostic step that the doctor performs. Staphylococcal pneumonia is often associated with influenza, measles, and is often found in people with chronic diseases, immunocompromised people, and intubated patients. In this case, the symptoms of the disease depend on the age and health status of the patient. The doctor may suspect staphylococcal pneumonia if the symptoms of pneumonia suddenly start a few days after a person has the flu. On the other hand, when pneumonia occurs, the symptoms of measles (if any) often worsen. Common symptoms are high fever, rapid pulse, rapid breathing, and cough.
The doctor will also evaluate travel history, current epidemiological situation, history of skin infections, central venous catheter placement… Other tests that may be ordered include:
- Chest X-ray showed multi-localized and rapidly changing lung lesions, with many small abscesses in both lungs.
- Blood test
- Blood, sputum, and pleural fluid cultures are used to determine whether the cause of the disease is S.aureus bacteria .
Treatment
Treatment of staphylococcal pneumonia depends on whether the strain of bacteria is methicillin-resistant. If staphylococcal infection cannot be confirmed or is pending confirmation, the physician will use an empirical treatment regimen that includes broad-spectrum antibiotics to cover a wide range of pathogens.
For example, for CAP, a β-lactam antibiotic with a β-lactamase inhibitor (eg, amoxicillin/clavulanate, ampicillin/sulbactam) or a broad- spectrum cephalosporin (cefpodoxime, cefdinir, cefotaxime, ceftriaxone) is often recommended in combination with a macrolide/doxycycline antibiotic.
Respiratory fluoroquinolones (levofloxacin, moxifloxacin) also meet the criteria, however, they are new antibiotics, have not yet developed much resistance, and are therefore reserved for limited use. For hospital-acquired pneumonia, the regimen is more complicated due to the resistance of hospital-acquired bacteria.
1. Treatment of pneumonia caused by drug-resistant staphylococcus (MRSA)
If MRSA is suspected or confirmed, treatment with vancomycin, teicoplanin , or linezolid may be initiated and discontinued if MRSA is ruled out. These two agents have similar efficacy and the choice should be based on patient tolerability, antibiotic allergy, renal function, drug interactions, and the ability to administer the drug intravenously.
- Linezolid is available in oral form and is preferred if intravenous administration is a problem.
- Vancomycin is preferred if the patient has cytopenias or is taking a selective serotonin reuptake inhibitor (SSRI).
- Ceftaroline (a fifth-generation cephalosporin antibiotic) may be used if vancomycin or linezolid are contraindicated, however, it is not FDA-approved for the treatment of hospital-acquired or ventilator-associated pneumonia.
- Clindamycin is also an alternative, but it is less effective for hospital-acquired pneumonia and ventilator-associated pneumonia.
2. Treatment of pneumonia caused by susceptible staphylococci (MSSA)
If culture results indicate MSSA and other causes of pneumonia are excluded, therapy can be reduced to beta-lactam antibiotics (nafcillin, oxacillin, or cefazolin) combined with an aminoglycoside or quinolone.
3. Supportive treatment
Supportive treatment measures may include:
- Use paracetamol to reduce fever.
- Rehydration by mouth, intravenous route or nasogastric tube when the patient is unable to eat or drink.
- Bronchodilator to help people with chronic lung diseases such as asthma or chronic obstructive pulmonary disease (COPD).
- Supplemental oxygen (by nasal cannula, mechanical ventilation) may also be necessary.
- If there is pleural effusion, perform thoracentesis.
Prevent
General pneumonia prevention includes :
- Thoroughly treat infections in the ear, nose, throat and oral areas.
- Control underlying medical conditions
- Keep your neck and chest warm in cold weather
- Eliminate stimulants such as alcohol and tobacco
- Flu vaccination once a year, indicated for people with chronic heart and lung disease, diabetes, severe kidney failure, immunodeficiency. Flu vaccine can be given to all subjects, the earliest children from 6 months.
- Pneumococcal vaccination is indicated in people with chronic heart and lung disease, diabetes, alcoholism, chronic liver disease, cerebrospinal fluid fistula, splenectomy, and immunodeficiency. Currently, people 2 years of age and older only need to receive a single pneumococcal injection.
