Pneumocystis pneumonia in HIV infection
In patients with advanced HIV infection (AIDS) and profound immunodeficiency (CD4+ lymphocyte count less than 50 cells/µL), the respiratory syndrome is most often caused by opportunistic flora. A classic example is Pneumocystis pneumonia, caused by the fungus Pneumocystis jirovecii.
The clinical picture is characterized by the following manifestations:
- Complaints: severe dyspnea occurring even with minimal physical exertion, and a dry, hacking cough.
- Objective status: tachypnea (respiratory rate may exceed 30 breaths per minute), tachycardia, fever (up to 38.2°C and above). Auscultation reveals harsh breath sounds and scattered dry rales.
- Radiological signs: images show bilateral interstitial infiltrates.
An important diagnostic criterion is the medical history: such pneumonia is completely resistant to standard antibacterial drugs (penicillins, macrolides, fluoroquinolones), but demonstrates high sensitivity to empirical administration of Biseptol (co-trimoxazole) and pentamidine. Recurrent atypical pneumonia combined with wasting syndrome is a strict indication for screening the patient for HIV.
Differential diagnosis and management tactics
When severe pneumonia is detected in an immunosuppressed patient, the diagnostic workup must include ruling out HIV infection, pulmonary tuberculosis, atypical mycobacteriosis, and cytomegalovirus (CMV) pneumonitis. Risk factors such as intravenous drug use or the presence of parenteral viral hepatitis are necessarily taken into account.
Action algorithm:
- Hospitalization: Severe respiratory failure is an absolute indication for transfer to an infectious diseases hospital. Transportation is carried out by a specialized team with mandatory respiratory support (administration of humidified oxygen).
- Preliminary diagnosis: During transportation, a syndromic diagnosis is established — "Fever of unknown origin".
- In-hospital examination: Specific HIV diagnostics (screening ELISA and confirmatory immunoblotting), a comprehensive assessment of immune status (CD4+), and a search for markers of opportunistic infections are performed.
- Treatment: First and foremost, specific therapy for identified opportunistic infections is prescribed. Antiretroviral therapy (ART) is initiated only after stabilization of the condition to minimize the risk of immune reconstitution inflammatory syndrome (IRIS).
Neonatal respiratory distress syndrome (NRDS)
In the neonatal period, infectious and non-infectious respiratory tract lesions have their own specific features. Respiratory distress syndrome manifests extremely severely and requires immediate medical attention.
Main clinical manifestations of NRDS:
- Severe dyspnea with retraction of compliant areas of the chest wall.
- Episodes of apnea, arrhythmia.
- Pallor of the skin and cyanosis.
- If pulmonary edema develops, seizures appear or intensify, and sucking and swallowing reflexes are impaired.
Radiography shows blurring of pulmonary structures and decreased tissue aeration (especially in the root and perihilar zones). In massive edema, a homogeneous opacification of the entire lung is visualized.
Preterm infants may develop chronic respiratory failure. It is characterized by prolonged dependence on oxygen therapy and mechanical ventilation, persistent hypoxemia and hypercapnia even after initial improvement, and the inability to extubate for several months.
Lung damage in intrauterine infections (IUI)
Specific symptoms are absent in the majority of newborns with IUI. The infectious process manifests with general non-specific syndromes, among which respiratory disorders, toxicosis, CNS damage, jaundice, and anemia play a leading role.
Pneumonia can be one of the manifestations of congenital rubella syndrome (CRS). This disease demonstrates a pronounced teratogenic effect of the virus. In addition to respiratory system damage, CRS includes:
- Organs of vision: cataract, glaucoma, chorioretinitis.
- Cardiovascular system: congenital heart defects (patent ductus arteriosus, septal defects).
- CNS: microcephaly, encephalitis, developmental delay.
In 75% of cases, the infected child shows combined damage to multiple organ systems simultaneously.
To remember the typical picture of pneumocystosis in HIV-infected patients, use the "Three NOs" rule: NOn-productive (dry) cough, NOn-responsiveness to standard antibiotics, NO air (dyspnea on minimal exertion).
Class and exam questions
Which antibiotics are ineffective in Pneumocystis pneumonia?
Standard drugs such as penicillins, macrolides, and fluoroquinolones yield no results. The drug of choice is co-trimoxazole (Biseptol).
With what diagnosis is a patient with severe respiratory syndrome hospitalized before the cause is clarified?
At the transportation stage and in the admission ward, the syndromic diagnosis of "Fever of unknown origin" is valid.
How does severe pulmonary edema in NRDS manifest radiologically?
Homogeneous opacification of the entire lung, blurring of pulmonary structures, and a marked decrease in tissue aeration are observed.
What else to study on this topic
- Cytomegalovirus infection and CMV pneumonitis
- Atypical mycobacteriosis and pulmonary tuberculosis in the context of immunosuppression
- Immune reconstitution inflammatory syndrome (IRIS) upon initiation of ART
- The impact of intrauterine infections on the formation of congenital malformations
- Chronic respiratory failure in preterm infants
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