16  Pneumonia

16.1 Introduction

Pneumonia is an acute infection of the lung parenchyma, leading to inflammation and consolidation of the alveoli. It remains a major cause of childhood morbidity and mortality worldwide and is especially significant in low- and middle-income countries such as Ghana. Despite progress in immunization and child health services, pneumonia continues to account for a large proportion of paediatric hospital admissions and deaths, particularly among children under five years of age.

Understanding its causes, clinical presentation, and management is essential for medical students and young clinicians. The disease spectrum ranges from mild, self-limiting illness to severe, life-threatening conditions requiring intensive care.

16.2 Epidemiology and Burden

Globally, pneumonia is responsible for approximately 14% of all deaths in children under five. In sub-Saharan Africa, the burden is disproportionately high due to limited access to healthcare, malnutrition, and environmental risk factors such as indoor air pollution.

In Ghana, pneumonia is among the top five causes of under-five mortality. Both viral and bacterial pneumonias are common, and coinfections such as malaria, tuberculosis, or HIV-associated infections complicate the picture. The disease shows a seasonal pattern, often peaking during the rainy seasons when respiratory viruses are more prevalent. Neonates and young infants, malnourished children, and those with underlying chronic conditions such as congenital heart disease or HIV are at greater risk.

16.3 Aetiology

The causes of pneumonia vary with age, immune status, and environment.

16.3.1 In Neonates:

• Bacterial: Group B Streptococcus, Escherichia coli, Klebsiella species, Listeria monocytogenes.
• Viral: Respiratory syncytial virus (RSV) and cytomegalovirus (in congenital infection).

16.3.2 In Infants and Young Children:

• Bacterial: Streptococcus pneumoniae (pneumococcus) is the most common; Haemophilus influenzae type b (Hib) is important where vaccination coverage is low. Staphylococcus aureus causes severe, necrotizing pneumonia with empyema.
• Viral: RSV, parainfluenza, influenza, adenovirus, and human metapneumovirus are frequent, especially in the first two years of life.
• Atypical: Mycoplasma pneumoniae and Chlamydia pneumoniae appear more often in older children and adolescents.

16.3.3 In Immunocompromised Children:

• Opportunistic infections such as Pneumocystis jirovecii, cytomegalovirus, and fungal pneumonias may occur, particularly in HIV-positive children.

Environmental exposures, malnutrition, passive smoking, and crowded living conditions amplify susceptibility.

16.4 Pathophysiology

The lungs normally maintain sterility through effective mucociliary clearance, immune defenses, and cough reflexes. Pneumonia develops when these defenses are breached — by overwhelming microbial inoculation, impaired clearance, or immune compromise.

Microorganisms reach the alveoli by inhalation, aspiration, or via the bloodstream. The host immune response leads to inflammation, exudation of fluid and cells into the alveolar spaces, and impaired gas exchange.

Typical bacterial pneumonia leads to alveolar consolidation — a process in which alveoli are filled with exudate containing neutrophils and fibrin. This impedes oxygen diffusion and causes hypoxaemia.

Viral pneumonia, in contrast, causes interstitial inflammation, airway oedema, and epithelial necrosis, predisposing to secondary bacterial infection.

The degree of impairment depends on the virulence of the organism and host factors such as nutritional status, immunization history, and presence of comorbidities.

16.5 Clinical Features

The presentation of pneumonia varies with age and severity.

General symptoms include:

• Fever, often high-grade.
• Cough, which may be dry or productive in older children.
• Difficulty in breathing, nasal flaring, and grunting in infants.
• Poor feeding, irritability, or lethargy.

Physical findings:

• Tachypnoea is the most sensitive clinical sign. The WHO defines tachypnoea as:
  • >60 breaths/min in infants <2 months
  • >50 breaths/min in 2–12 months
  • >40 breaths/min in 1–5 years
• Chest indrawing, nasal flaring, or grunting indicate severe disease.
• Auscultation may reveal crackles, bronchial breath sounds, or decreased air entry.
• Cyanosis, hypoxia, and altered sensorium are signs of respiratory failure.

Infants and neonates may have nonspecific presentations; temperature instability, apnea, or poor feeding, making a high index of suspicion essential.

16.6 Differential Diagnosis

Several other conditions can mimic pneumonia, and distinguishing them is crucial for correct management:

• Bronchiolitis (in infants under 2 years) — wheezing and diffuse crackles rather than localized findings.
• Asthma or viral-induced wheeze — recurrent episodes with reversible airway obstruction.
• Pulmonary tuberculosis — chronic cough, weight loss, and failure to thrive, often with contact history.
• Severe malaria — fever and respiratory distress due to metabolic acidosis.
• Congestive heart failure — history of cardiac disease and signs of cardiomegaly or murmurs.

Clinical judgement, aided by investigations, guides differentiation.

16.7 Investigations

Diagnosis is often clinical, especially in resource-limited settings. However, investigations help confirm and classify pneumonia, identify complications, and guide therapy.

Basic Investigations:

1. Pulse oximetry — to assess oxygen saturation; hypoxaemia (<92%) indicates severe disease.
2. Chest X-ray — shows lobar consolidation, interstitial infiltrates, or pleural effusion.
3. Full blood count — leukocytosis with neutrophilia suggests bacterial infection; lymphocytosis may indicate viral infection.
4. Blood culture — useful for identifying pathogens but often low yield.
5. Nasopharyngeal aspirate or PCR testing — for viral pathogens where available.

Further investigations in selected cases:

1. Sputum culture or tracheal aspirate (in ventilated patients).
2. HIV testing in children with recurrent or severe pneumonia.
3. Ultrasound or CT scan if empyema, abscess, or foreign body is suspected.

In Ghana, reliance is often on clinical diagnosis supported by simple tests due to cost and availability limitations.

16.8 Treatment

The management of pneumonia involves supportive care, antimicrobial therapy, and treatment of complications.

16.8.1 1. Supportive Management

• Oxygen therapy for hypoxaemia using nasal prongs or face mask.
• Hydration: maintain fluid balance; overhydration may worsen pulmonary oedema.
• Antipyretics (e.g., paracetamol) for fever.
• Nutritional support to prevent catabolism.
• Monitoring of respiratory rate, SpO₂, and consciousness level.

16.8.2 2. Antibiotic Therapy

Empiric treatment is based on the likely pathogen and local resistance patterns:

• Neonates: Ampicillin plus gentamicin for 7–10 days.
• Infants and older children:
  • Outpatient: Oral amoxicillin for 5–7 days for mild pneumonia.
  • Inpatient (severe): IV ampicillin (or penicillin) plus gentamicin; add cloxacillin or ceftriaxone if S. aureus or Gram-negative sepsis is suspected.
  • Macrolides (e.g., azithromycin) for atypical infections.

Treatment is modified based on clinical response or culture results.

16.8.3 3. Management of Complications

• Pleural effusion/empyema: chest tube drainage and antibiotics.
• Lung abscess: prolonged antibiotic therapy; drainage if necessary.
• Septicemia: aggressive IV antibiotics and supportive care.
• Respiratory failure: CPAP or mechanical ventilation as indicated.

16.8.4 4. Discharge and Follow-up

Discharge once afebrile, feeding well, and maintaining oxygen saturation in room air. Follow-up in 1–2 weeks ensures full recovery and detects post-pneumonia complications such as bronchiectasis.

16.9 Complications

Complications occur more commonly with delayed treatment or virulent organisms. They include:

• Parapneumonic effusion or empyema
• Lung abscess
• Pneumatocele formation
• Septicemia and metastatic abscesses
• Bronchiectasis or chronic lung disease
• Acute respiratory failure and death

Prompt recognition and intervention are vital to prevent long-term morbidity.

16.10 Prevention

Preventive measures are among the most cost-effective interventions in child health.

Immunization plays a key role:

1. Pneumococcal conjugate vaccine (PCV13)
2. Haemophilus influenzae type b (Hib) vaccine
3. Measles and pertussis vaccines
4. Annual influenza vaccination in at-risk groups

Nutrition: Exclusive breastfeeding for the first six months, adequate complementary feeding, and vitamin A supplementation strengthen immunity.

Environmental control: Reducing exposure to tobacco smoke and indoor air pollution from biomass fuels.

Early treatment of illnesses such as malaria, HIV, and malnutrition decreases susceptibility to pneumonia.

Community education on danger signs and early health-seeking behavior significantly reduces mortality.

16.11 Prognosis

The outcome depends on the child’s age, nutritional status, immune function, causative agent, and timeliness of treatment.

Most children with uncomplicated pneumonia recover fully with appropriate therapy. However, mortality remains high among neonates, severely malnourished children, and those with HIV or delayed presentation.

Recurrent or chronic infections may lead to lasting lung damage. Strengthening preventive strategies and early intervention are therefore crucial to reducing the burden of pneumonia in Ghana.

16.12 Conclusion

Pneumonia remains one of the most important paediatric health challenges in Ghana and across Africa. Understanding its pathophysiology, timely diagnosis, and appropriate management are fundamental skills for every medical student.

While antibiotics and supportive care remain the mainstay of treatment, prevention through vaccination, nutrition, and improved living conditions offers the greatest hope for sustainable reduction in disease burden. A holistic approach that integrates clinical excellence with strong public health measures is the surest way to protect Ghana’s children from this preventable killer.