Cytokine storm occurs when immune system produces excessive inflammatory signals. Symptoms range from mild flu-like to life-threatening organ failure. Common symptoms include fever, fatigue, shortness of breath, and confusion
Gram-negative diplococcus causing meningitis and meningococcemia. About 10% of adults carry bacteria in nasopharynx. Causes developmental impairment and death in 10% of cases. Spreads through respiratory secretions and close contact
Rotavirus causes most common diarrhoea among infants worldwide. Nine species exist, with Rotavirus A causing over 90% of human infections. Virus is transmitted through faecal-oral route and infects small intestine. Nearly every child infected by age five, with immunity developing
Viral encephalitis is inflammation of brain parenchyma caused by viruses. Viruses first infect outside CNS, reaching it through circulatory system. Most common type of encephalitis, often occurs with viral meningitis. Herpes simplex virus is most common cause at about 50% of cases
VZV is one of nine human herpes viruses, causing chickenpox and shingles. Virus can survive in external environments for few hours. Virus multiplies in tonsils and remains dormant in neurons
Fewer than a hundred pathogenic bacteria exist in humans. Most bacteria are harmless commensals or saprophytes. Pathogenic bacteria can overcome normal body defenses