Definition Meningitis is inflammation of the meninges, the protective membranes covering the brain and spinal cord. Causes Bacterial Meningitis Viral Meningitis Other Causes Pathophysiology Clinical Features Common symptoms include: In infants: In meningococcal infection, a characteristic purpuric or petechial rash may appear. Diagnosis CSF findings help distinguish bacterial from viral causes. Treatment Bacterial Meningitis Viral Meningitis Early treatment significantly reduces mortality and long-term complications. Complications Prevention Vaccination Vaccines available against major bacterial causes: Public Health Measures Public Health Significance Meningitis is a serious inflammatory condition of the central nervous system requiring prompt recognition, rapid medical intervention and strong vaccination strategies to reduce its public health burden.

Overview The MenB vaccine protects against invasive disease caused by Neisseria meningitidis serogroup B. Why a Separate Vaccine for Serogroup B Type of Vaccine MenB vaccines are recombinant protein vaccines. Mechanism of Action Indications Recommended for: Dosage Schedule Schedules vary by national immunisation policy. Efficacy Safety Profile Public Health Significance The MenB vaccine represents an advanced immunological approach targeting protein antigens to prevent invasive meningococcal disease caused by serogroup B, complementing the broader protection offered by MenACWY vaccines.

Overview MenACWY is a meningococcal conjugate vaccine that protects against four major serogroups of Neisseria meningitidis: It is used to prevent invasive meningococcal disease, including meningitis and meningococcemia. Type of Vaccine The conjugation improves immune response, especially in children, by inducing T-cell dependent immunity and immunological memory. Mechanism of Action Indications Recommended for: In some countries, vaccination is mandatory for pilgrims travelling for Hajj. Dosage Schedule National schedules vary by country. Efficacy Safety Profile Public Health Importance The MenACWY vaccine plays a critical role in preventing invasive meningococcal infections and is an essential component of adolescent and high-risk group immunisation programmes worldwide.

Taxonomic Classification It is a Gram-negative, aerobic diplococcus that typically appears as kidney-shaped paired cells under the microscope. Microbiological Characteristics The capsule helps the bacterium evade host immune responses and is central to disease severity. Serogroups Neisseria meningitidis is classified into serogroups based on capsular polysaccharides. The most clinically significant are: Different serogroups predominate in different geographical regions. Transmission Crowded environments such as hostels, military barracks and schools increase risk. Diseases Caused Meningococcal Meningitis Meningococcemia Rapid progression can make the infection life-threatening within hours. Pathogenesis Diagnosis Treatment Prevention Vaccination Chemoprophylaxis Public Health Significance Neisseria meningitidis is a medically significant pathogen with epidemic potential, requiring rapid diagnosis, early treatment and strong vaccination strategies to prevent severe morbidity and mortality.

Institutional and Programme Context Operational Mandate Technical Configuration Strategic Implications These four vessels collectively represent a doctrinal shift toward strengthening littoral anti-submarine warfare capabilities and enhancing India’s maritime security architecture in the Indian Ocean Region.

Programme Background Design Philosophy Combat and Surveillance Systems Defence and Maritime Strategy

Institutional Context Operational Doctrine Technical Capabilities Strategic Relevance

Institutional Background Strategic Rationale Technical and Operational Architecture Defence Significance

Overview Operation Vijay was the codename given to India’s military operation to evict Pakistani intruders from Indian territory during the 1999 Kargil conflict. Background Objectives Military Operations Indian Army Indian Air Force Indian Navy Outcome Strategic Significance Broader Impact Operation Vijay remains a significant episode in India’s military history, demonstrating operational resolve under extreme terrain and geopolitical constraints.

Overview Abhay is an Anti-Submarine Warfare Shallow Water Craft built for the Indian Navy. Purpose Technical Specifications Operational Capabilities Sensors and Surveillance Armament Strategic Significance Abhay ASW SWC represents a significant step in strengthening India’s coastal defence architecture through advanced indigenous naval platforms.