Pneumococcal Disease Diagnosis

Laboratory Tests

Microbiological Diagnosis

• Blood cultures: gold standard for diagnosing invasive pneumococcal disease
• Sputum or tracheal aspirate cultures: can be used for non-invasive pneumococcal disease
• Urine antigen test: detects pneumococcal antigen in urine, useful for diagnosing pneumococcal pneumonia
• PCR (polymerase chain reaction): can detect pneumococcal DNA in blood, sputum, or other specimens

Serological Diagnosis

• Quellung reaction: detects pneumococcal capsular polysaccharide in cerebrospinal fluid or blood
• Latex agglutination: detects pneumococcal antigens in urine or cerebrospinal fluid

Symptoms

Respiratory Symptoms

• Cough: often productive, with rust-colored or bloody sputum
• Chest pain: can be severe, pleuritic
• Dyspnea: shortness of breath
• Tachypnea: rapid breathing rate

Systemic Symptoms

• Fever: often high, can be accompanied by chills
• Headache: can be severe
• Confusion: especially in elderly or immunocompromised individuals
• Nausea and vomiting: can occur, especially in children

Meningitis Symptoms

• Severe headache
• Stiff neck
• Fever
• Confusion
• Seizures: can occur in severe cases

Laboratory Tests

• Blood cultures are the gold standard for diagnosing invasive pneumococcal disease
• Sputum or tracheal aspirate cultures can be used to diagnose non-invasive pneumococcal disease
• Urine antigen test detects pneumococcal antigen in urine, useful for diagnosing pneumococcal pneumonia
• PCR (polymerase chain reaction) can detect pneumococcal DNA in blood, sputum, or other specimens

Serological Diagnosis

• Quellung reaction detects pneumococcal capsular polysaccharide in cerebrospinal fluid or blood
• Latex agglutination detects pneumococcal antigens in urine or cerebrospinal fluid

Symptoms of Pneumococcal Disease

Respiratory Symptoms

• Productive cough with rust-colored or bloody sputum
• Severe, pleuritic chest pain
• Dyspnea (shortness of breath)
• Tachypnea (rapid breathing rate)

Systemic Symptoms

• High fever, often accompanied by chills
• Severe headache
• Confusion, especially in elderly or immunocompromised individuals
• Nausea and vomiting, especially in children

Meningitis Symptoms

• Severe headache
• Stiff neck
• Fever
• Confusion
• Seizures in severe cases

Laboratory Tests for Pneumococcal Disease

• Blood cultures are the gold standard for diagnosing invasive pneumococcal disease, with a sensitivity of 50-70%.
• PCR is a rapid and sensitive test for detecting pneumococcal DNA in blood, cerebrospinal fluid, or other sterile sites.
• Urine antigen test is useful for diagnosing pneumococcal pneumonia, especially in adults, by detecting pneumococcal antigen in urine.
• Sputum Gram stain is a rapid test for identifying Gram-positive diplococci, but its sensitivity and specificity are variable.
• Latex agglutination detects pneumococcal antigen in cerebrospinal fluid, blood, or urine, and is useful for diagnosing meningitis.
• Serotyping is important for identifying specific pneumococcal serotypes, which is crucial for epidemiological surveillance and vaccine development.

Symptoms of Pneumococcal Disease

• Pneumonia symptoms include fever, chills, cough, chest pain, shortness of breath, and confusion or disorientation in elderly patients.
• Meningitis symptoms include severe headache, fever, stiff neck, nausea and vomiting, photophobia, and confusion or disorientation.
• Bacteremia symptoms include fever, chills, weakness, confusion or disorientation, and sometimes petechiae or purpura.
• Other symptoms of pneumococcal disease include otitis media (ear infection), sinusitis, and rarely, meningococcal disease.