Eelaththu Nilavan
Medical Researcher
“My mission is to contribute global medical perspectives through Tamil-rooted thinking.”
Introduction
Pneumonia is a severe lung infection that causes inflammation in the alveoli—the small air sacs of the lungs—which fill with fluid, pus, or mucus, impairing oxygen exchange and potentially threatening life. It remains a major respiratory illness globally and a leading cause of hospitalization and mortality.
According to 2025 WHO data, pneumonia is among the top causes of death in children under five and adults over 65. In low- and middle-income countries, limited access to clean water, poor nutrition, and low immunization coverage make the disease even deadlier.
Types of Pneumonia
Pneumonia is classified based on where it is acquired and what microbes cause it.
➊. Community-Acquired Pneumonia (CAP) – Acquired outside healthcare settings.
➋. Hospital-Acquired Pneumonia (HAP) – Occurs 48 hours or more after hospital admission.
➌. Ventilator-Associated Pneumonia (VAP) – Affects patients using mechanical ventilation.
✺.Based on causative agents:
• Bacterial: Streptococcus pneumoniae, Haemophilus influenzae
• Viral: Influenza viruses, RSV (Respiratory Syncytial Virus), SARS-CoV-2
Fungal: Pneumocystis jirovecii, particularly in immunocompromised individuals (e.g., HIV patients)
Pathophysiology
The infection enters the lungs through the airways and triggers an inflammatory response. Alveoli fill with exudate, obstructing gas exchange and leading to hypoxia. In children, narrower airways and immature immunity make them more vulnerable. In elderly patients, weakened immunity and comorbidities (like diabetes, COPD, or heart disease) make pneumonia more life-threatening.
Clinical Manifestations
Symptoms vary by age and severity:
• In adults:
Productive cough, fever, chills, shortness of breath, chest pain, and fatigue
The elderly may present with confusion or an altered mental status instead of fever.
• In children:
Rapid breathing, nasal flaring, chest indrawing, and refusal to feed.
A key red flag is the inability or reluctance to breastfeed or drink fluids.
Diagnosis
Diagnosis includes a combination of clinical evaluation and laboratory tests.
• Basic assessments: Respiratory rate, auscultation (lung sounds), oxygen saturation
• Imaging: Chest X-ray for detecting alveolar infiltrates or fluid accumulation
• Laboratory tests: CBC, C-Reactive Protein (CRP), and Procalcitonin levels
• Microbial culture & sensitivity: For identifying bacterial cause and antibiotic resistance
Notable 2025 Advancement:
Researchers at King George’s Medical University, India, have introduced a molecular detection test capable of identifying the pathogen and its antibiotic resistance profile within 6 hours, greatly improving early and targeted treatment.
Artificial Intelligence (AI) Use:
AI-driven interpretation of chest X-rays now achieves up to 88% accuracy in pneumonia classification using deep learning models, aiding diagnosis even in resource-limited settings.
Treatment
Treatment depends on the type and severity of pneumonia and the patient’s profile.
• Outpatient CAP (Community-Acquired):
Oral antibiotics such as Amoxicillin, Doxycycline, or Azithromycin are often sufficient.
• Inpatient or resistant infections:
Require IV antibiotics and hospital care. Severe infections may demand broad-spectrum agents.
2023–2025 Drug Developments:
• Sulbactam/Durlobactam: FDA-approved for treating multi-drug-resistant (MDR) Acinetobacter infections
• Zosurabalpin: A promising new agent in Phase 3 trials, effective against carbapenem-resistant superbugs
• Omadacycline: A new-generation tetracycline used for resistant atypical pathogens
Complications
Without timely intervention, pneumonia can lead to serious complications:
• In adults: Sepsis, pleural effusion, acute respiratory failure
• In children: Empyema (pus in the pleural space), growth delays, or long-term respiratory weakness
Chronic cases may result in permanent lung damage if not aggressively treated.
Prevention
Prevention is key and includes:
• Vaccination:
For children: Pneumococcal Conjugate Vaccine (PCV), Hib vaccine
For adults: PPSV23, annual Influenza vaccine
Pregnant women: Immunization helps protect the newborn via passive immunity
• Nutrition and Hygiene:
Adequate nutrition, exclusive breastfeeding for infants, handwashing, and smoke-free environments are essential public health measures.
Recent Research & Global Health Strategy
The World Health Organization (WHO) and UNICEF have accelerated their GAPPD initiative (Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea), aiming to eliminate preventable childhood pneumonia deaths by 2030.
New Therapies on the Horizon:
• Zosurabalpin (Roche): A highly effective therapy for MDR Gram-negative infections
• Bacteriophage Therapy: Engineered viruses that target resistant bacteria
• Nanoparticle Drug Delivery: Enhancing targeted antimicrobial therapy
• Antimicrobial Peptides: Bioengineered molecules to overcome drug resistance
Conclusion
Pneumonia continues to be a major global health burden despite medical advances. However, early diagnosis, proper classification, targeted therapy, and aggressive vaccination programs have significantly reduced fatality rates. New diagnostics and antimicrobial innovations offer hope for controlling even the most drug-resistant cases.
With integrated public health strategies, continued global research, and equitable access to vaccines and care, pneumonia can be prevented, managed, and even eradicated as a major health threat.
Eelaththu Nilavan
Medical Researcher | Tamil Health Writer
“Even when medical science crosses boundaries, it reaches people best through their native language.”
The views expressed in this article are the author’s own and do not necessarily reflect Amizhthu’s editorial stance.
