MYCVIR L6 CNS

Aseptic Meningitis

Infection of pia/arachnoid mater and subarachnoid space presenting with fever, nuchal rigidity, and photophobia; >85% caused by Enteroviruses.

Viral Encephalitis

Infection of brain parenchyma proper characterized by altered sensorium, focal seizures, and confusion/coma; caused by Arboviruses, HSV-1, and Rabies.

Myelitis

Infection of spinal cord gray matter motor neurons resulting in acute flaccid paralysis (AFP) and hyporeflexia; caused by Poliovirus, EV-D68, and West Nile Virus.

Hematogenous Route (Viremic Seeding)

Mechanism of CNS neuroinvasion where virus replicates in lymphoid tissue, spills into bloodstream, and breaches blood-brain barrier at capillaries or choroid plexus.

Neural Axonal Route (Retrograde Axonal Transport)

Mechanism of CNS neuroinvasion where virus enters peripheral unmyelinated nerves at neuromuscular junctions and travels centripetally inside axoplasm at 12-24 mm/day.

Picornaviridae Architecture

Small (25-30 nm), non-enveloped, positive-sense single-stranded RNA (+ssRNA) virus with icosahedral symmetry; resistant to ether/lipid solvents and acid-stable down to pH 3.0.

CD155 / PVR

Specific primate cell surface receptor required for Poliovirus attachment and entry.

D or N Antigen

Native, infectious poliovirus particle trigger that induces protective neutralizing antibodies.

C or H Antigen

Non-infectious, coreless empty poliovirus capsid lacking viral RNA.

Abortive Poliomyelitis (Mild Disease)

Most common symptomatic form of poliovirus infection presenting as a mild febrile illness with fever, headache, and sore throat.

Nonparalytic Poliomyelitis

Poliovirus manifestation presenting as aseptic meningitis syndrome with stiffness in back and neck, recovering fully in 2-10 days.

Paralytic Poliomyelitis

Form of poliovirus infection caused by destruction of anterior horn motor neurons in spinal cord, leading to asymmetric acute flaccid paralysis without sensory loss.

Salk Vaccine (IPV)

Formalin-inactivated injected polio vaccine that stimulates circulating serum IgG to prevent viremic CNS invasion, but does not prevent gut shedding.

Sabin Vaccine (OPV)

Live-attenuated oral polio vaccine that induces mucosal secretory IgA and IgG, blocking viral replication at intestinal entry portal and preventing transmission.

Echoviruses (Orphan Viruses)

Enteric Cytopathogenic Human Orphan viruses; major cause of aseptic meningitis in children/adults and neonatal sepsis-like syndrome.

Enterovirus 68 (EV-D68)

Acid-labile, rhinovirus-like enterovirus (optimum growth at 33°C) that causes severe respiratory wheezing followed by Acute Flaccid Myelitis (AFM) in children.

Enterovirus 70 (EV-D70)

Cause of pandemic Acute Hemorrhagic Conjunctivitis (AHC) featuring an ultra-short 24-hour incubation period.

Enterovirus 71 (EV-A71)

Agent causing severe Hand, Foot, and Mouth Disease (HFMD) complicated by brainstem encephalitis and neurogenic pulmonary edema.

5'-Noncoding Region (5'-NCR)

Conserved molecular target amplified in multiplex CSF RT-PCR for gold-standard diagnosis of Enterovirus meningitis.

Dead-End Hosts

Status of humans in arboviral transmission cycles due to low, transient viremia insufficient to infect biting mosquito vectors.

Eastern Equine Encephalitis (EEE)

Most severe Alphavirus (Togaviridae) neuroinvasive infection, causing high mortality (~45%) in humans and horses.

Japanese Encephalitis Virus (JEV)

Flavivirus transmitted by Culex mosquitoes breeding in rice paddies; leading cause of arboviral encephalitis worldwide.

Dengue Hemorrhagic Fever (DHF)

Severe Dengue manifestation (thrombocytopenia, plasma leakage, shock) triggered by secondary heterologous infection via antibody-dependent enhancement.

West Nile Virus

Flavivirus causing neuroinvasive disease (meningitis/encephalitis) predominantly in adults over 50 years old.

CSF IgM MAC-ELISA

Serological gold standard for arbovirus laboratory diagnosis, detecting intrathecal IgM synthesis when PCR fails due to cleared viremia.

C6/36 and LLC-MK2

Specialized mosquito (Aedes albopictus) and rhesus monkey kidney cell lines used for arbovirus culture and isolation.

Lyssavirus (Rabies)

Bullet-shaped, enveloped, negative-sense single-stranded RNA (-ssRNA) virus belonging to Rhabdoviridae family.

Nicotinic Acetylcholine Receptor (nAChR)

Host receptor at motor endplates bound by Rabies Glycoprotein G spikes during initial infection.

Furious Rabies

Clinical form (80% of cases) characterized by limbic invasion, intense terror, autonomic instability, hydrophobia/aerophobia, and foaming at the mouth.

Dumb / Paralytic Rabies

Clinical form (20% of cases) presenting as ascending flaccid paralysis starting in bitten limb; frequently misdiagnosed as Guillain-Barré Syndrome (GBS).

Negri Bodies

Pathognomonic eosinophilic cytoplasmic inclusion bodies in hippocampal and Purkinje neurons, detected by post-mortem brain Direct Fluorescent Antibody (DFA) testing.

Nuchal Skin Biopsy

Ante-mortem diagnostic procedure taking full-thickness skin at posterior hairline to detect Rabies viral antigen in cutaneous nerve twigs.

Rabies Post-Exposure Prophylaxis (PEP)

Immediate 3-step intervention: thorough wound washing + Human Rabies Immunoglobulin (HRIG) infiltrated at wound site + Active Vaccine series (days 0, 3, 7, 14).