Virology

• Naked RNA viruses are a type of virus that belongs to the Picornaviridae family.
• Picornaviridae viruses include Poliovirus, Coxsackie virus (A and B), ECHO (Enteric Cytopathic Human Orphan) virus, and Rhinovirus.
• Polioviruses are naked, single-stranded RNA (ssRNA) viruses with icosahedral symmetry and are transmitted through the oral-fecal route.
• Polioviruses cause paralysis by replicating in motor neurons in the anterior horn of the spinal cord.
• Picornaviridae viruses cause diseases such as Poliomyelitis and Meningitis.
• Poliomyelitis can be of three types: Abortive poliomyelitis, Non-paralytic poliomyelitis, and Paralytic poliomyelitis.
• Coxsackie virus (A and B) are also naked, single-stranded RNA (ssRNA) viruses with icosahedral symmetry and are transmitted through the oral-fecal route.
• Picornaviridae: A family of naked RNA viruses with icosahedral symmetry.
• Poliovirus: A naked RNA virus that replicates in motor neurons in the anterior horn of the spinal cord, causing paralysis.
• Coxsackie virus: A naked RNA virus transmitted through the oral-fecal route, causing a spectrum of diseases including herpangina, acute hemorrhagic conjunctivitis, and aseptic meningitis.
• ECHO virus: A naked RNA virus transmitted through the oral-fecal route, causing aseptic meningitis, URTI, febrile illness, infantile diarrhea, and hemorrhagic conjunctivitis.
• Rhinovirus: A naked RNA virus with over 100 serotypes, primarily affecting the nose and conjunctiva, causing the common cold.
• Rotavirus: Morphology - Naked double-layered capsid with segmented dsRNA, Pathogenesis - Villous destruction with atrophy, Spectrum of disease - Viral gastroenteritis
• Norwalk virus (Norovirus): Morphology - Naked + ssRNA (icosahedral symmetry), Transmission - Oral-fecal route, Spectrum of disease - Viral gastroenteritis
• Influenza Virus (A, B, and C): Morphology - Enveloped virus with a helical nucleocapsid and segmented, ss-negative RNA, Transmission - Respiratory droplets, Spectrum of disease - Influenza or Flu
• Hepatitis A virus: A naked RNA virus transmitted through the oral-fecal route, causing hepatitis with symptoms ranging from self-limited hepatitis to anicteric hepatitis.
• Measles Virus: Morphology - Enveloped, helical, non-segmented ss-negative RNA, Transmission - Respiratory droplets, Disease - Red measles, rubeola, "first disease"
• Hepatitis E virus: Morphology - Naked + ssRNA (icosahedral symmetry), Transmission - Oral-fecal route, Spectrum of disease - Hepatitis E
• Spectrum of disease: (see next page)
• Prevention: MMR vaccine
• Transmission: respiratory droplets and transplacental
• Arbovirus is an acronym for arthropod-borne virus
• Spectrum of disease: encephalitis
• Transmission: bites of Culex mosquito
• West Nile Virus Morphology: enveloped, icosahedral, non-segmented, (+ ssRNA)
• Rubella virus Morphology: enveloped, icosahedral, non-segmented, (+ ssRNA) [1 serotype]
• Most arboviruses are classified in three families: togaviruses, flaviviruses, and bunyaviruses
• Mumps virus Morphology: Enveloped - ssRNA (helical symmetry; non-segmented)
• Rabies virus Morphology: Bullet-shaped enveloped helical non-segmented (-ssRNA)
• Transmission of Rabies virus: Animal (dogs, cat, skunks, racoons, and bat) - via animal bite (retrograde transport)
• Measles Virus Diagnosis: Multinucleated giant cells (Warthin-Finkelday bodies)
• Transmission of Parainfluenza virus 1 and 2: Respiratory droplet
• Treatment and Prevention for Ebola virus: Supportive care; strict isolation
• Ebola virus Morphology: Enveloped, helical, non-segmented ssRNA
• Treatment and Prevention for Measles: Vitamin A supplementation, Measles vaccine, MMR vaccine, Post-exposure prophylaxis
• Natural host of Ebola virus: Fruit bat (Pteropodidae family)
• Treatment for Parainfluenza virus 1 and 2: Racemic epinephrine
• Parainfluenza virus 1 and 2 Morphology: Enveloped - ssRNA (helical symmetry; non-segmented)
• Pathogenesis and Diseases caused by Mumps virus: Parotitis, Orchitis, Meningitis, Pancreatitis
• Transmission of Ebola virus: Direct contact, fomites, infected bats or primates