Meningitis and Tetanus Quiz

Structure and Function of the Nervous System

• Central Nervous System (CNS): Comprises the brain and spinal cord.
• Peripheral Nervous System (PNS): Includes nerves that branch from the CNS.
• Meninges: Protective layers surrounding the brain and spinal cord, consisting of three layers:
  • Dura mater (outer)
  • Arachnoid mater (middle)
  • Pia mater (innermost)
• Subarachnoid space houses cerebrospinal fluid (CSF), which cushions the brain and spinal cord.
• Blood-brain barrier: A physiological barrier separating circulating blood from the brain, maintaining CNS homeostasis.

Meningitis

• Infection of CSF surrounding the brain and spinal cord, caused by bacteria and viruses.
• Viral meningitis: Typically less severe and often resolves without specific treatment.
• Bacterial meningitis: More severe, can lead to brain damage, hearing loss, or learning disabilities.

Bacterial Meningitis

• Causative agents:
  • Historically, Haemophilus influenzae (HiB vaccine introduced).
  • Current leaders: Streptococcus pneumoniae and Neisseria meningitidis.
• Transmission:
  • Neisseria meningitidis: Direct person-to-person transmission in crowded environments (schools, military camps, prisons).
  • H. influenzae and S. pneumoniae: Spread through respiratory droplets.
• Signs/Symptoms:
  • Typical in individuals over 2 years old: High fever, headache, stiff neck, nausea, vomiting, photophobia, confusion, sleepiness.
  • Progression may lead to seizures.
• Diagnosis & Treatment:
  • Diagnosed via lumbar puncture (culturing CSF).
  • Treated with antibiotics like penicillin, cefotaxime, and ceftriaxone.
• Prevention:
  • Vaccines recommended for H. influenzae, certain N. meningitidis strains, and Streptococcus pneumoniae.

Tetanus

• Acute and often fatal disease characterized by muscular rigidity and convulsive spasms.
• Reported 37 cases in the U.S. in 2001.
• Causative agent: Clostridium tetani.
• Transmission: Usually occurs through puncture wounds, handling contaminated objects (e.g., bedpans, diapers).
• Mechanism: Tetanospasmin toxin from vegetative cells inhibits GABA release from inhibitory neurons, preventing muscle relaxation.
• Signs/Symptoms:
  • Early: Lockjaw, neck and abdominal stiffness, difficulty swallowing.
  • Later: Fever, heightened blood pressure, severe muscle contractions.
• Complications: Approximately 11% mortality, especially in individuals over 60.
• Treatment: Involves IV penicillin, tetanus IgG, and tetanus antitoxin.
• Prevention: DTaP vaccine, developed from inactivated toxin, significantly reduced tetanus incidence in the U.S.

Botulism

• Average of 110 annual cases in the U.S.
• Causative agent: Clostridium botulinum.
• Occurs in three forms: foodborne, infant, and wound botulism.
• Botulism is toxin-mediated, with the toxin blocking the release of acetylcholine, leading to paralysis.
• Notably, botulinum toxin is considered the most acutely lethal toxin known, with an L.D.50 lower than that of other toxins.

Test your knowledge on meningitis and tetanus, including their causes, symptoms, and treatments. This quiz covers key concepts related to these important medical conditions, including the role of bacteria and the effects of toxins on the nervous system.