What is the common cause of infective carditis?

A. Fever: Fever is a common sign of pericarditis, often indicating inflammation or infection in the pericardial sac. This symptom is typical in patients with this condition.

B. Mild chest pain: Mild chest pain is a typical symptom of pericarditis. Patients often experience sharp, pleuritic chest pain that may worsen with inspiration or coughing.

C. No evidence of fatigue: Fatigue can be a common symptom in patients with pericarditis due to the body's response to inflammation. Therefore, the absence of fatigue is not typical, making this an appropriate choice.

D. Myalgias: Myalgias or muscle aches can occur in pericarditis as part of the systemic inflammatory response. This symptom is not unusual in patients with this condition.

E. Pericardial friction rub: A pericardial friction rub is a characteristic finding in pericarditis, heard during auscultation. It results from the movement of inflamed pericardial layers against each other.

F. Radiating substernal pain felt in the left shoulder: This type of radiating pain is more characteristic of myocardial ischemia or angina rather than pericarditis. While pericarditis can cause chest pain, it does not typically radiate in the same manner as that seen in cardiac conditions, making this an appropriate choice.

A. Hospital-acquired pneumonia: Pneumonia that develops 48 hours or more after hospital admission is classified as hospital-acquired pneumonia (HAP). It is caused by pathogens acquired in the hospital setting, often involving multidrug-resistant organisms such as Pseudomonas aeruginosa, Staphylococcus aureus (including MRSA), and Klebsiella pneumoniae. Patients who are intubated, have prolonged hospital stays, or have weakened immune defenses are at higher risk.

B. Immunocompromised pneumonia: Pneumonia in immunocompromised patients occurs due to weakened host defenses, such as in individuals with HIV/AIDS, those undergoing chemotherapy, or transplant recipients on immunosuppressive therapy. While these patients can develop HAP, pneumonia due to opportunistic infections like Pneumocystis jirovecii or fungal infections is categorized separately.

C. Community-acquired pneumonia: Pneumonia acquired outside the hospital or within the first 48 hours of admission is classified as community-acquired pneumonia (CAP). Typical pathogens include Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae. CAP is usually less resistant to antibiotics compared to HAP.

D. Viral pneumonia: Pneumonia caused by viral pathogens such as influenza, respiratory syncytial virus (RSV), or SARS-CoV-2 is classified based on the causative agent rather than the setting in which it was acquired. Although viruses can cause both CAP and HAP, the classification of pneumonia is determined by the timing of onset and exposure risks.