Viruses Only

Antivirals

Antivirals

Medications used to treat viral infections when there is no vaccine available

Acute Infection

Results in the death of the host cell

Persistent/Chronic

Results in constant viral replication without the death of the host cell

Latent

Viral genome persists and is integrated into the host genome

Neural spread

Gastrointestinal tract to CNS

Hematogenous spread

Transcutaneous to the liver

Fusion Inhibitor

Medication that inhibits the fusion of the virus with the host cell

Human Cancer Viruses (Oncoviruses)

Viruses that enter the host cell and permanently alter its genetic material

Neuraminidase Inhibitor

Medication used for the treatment and prevention of influenza A and B

Immune Evasion

Strategies used by viruses to evade the immune system

Acute Respiratory Infections

Viral infections that primarily affect the respiratory tract

Viral CNS Infections

Infections that affect the central nervous system

Viral skin infections introduced through abrasions

Poxvirus

Viral skin infection introduced through bite

Rabies

Viral skin infections introduced through puncture

HBV and HIV

Neurodegenerative CNS infections

Measles and JC Polyomavirus

Examples of latent viral infections

HSV, EBV, Varciella-Zoster

Viruses that spread through direct contact (droplet or aerosol)

Influenza virus, rhinovirus, measles virus, vaccinia major, SARS-CoV-2

Viruses that spread through direct contact (sexual)

HPV, HBV, HSV type II

Viruses spread through direct contact (hand-face)

EBV

Indirect (fecal-oral) transmitted viruses

Enterovirus, hepatitis A

Indirect (fomite) transmitted viruses

Norwalk virus, rhinovirus

Zoonosis (bite or inhalation) viruses

Rabies virus, hantavrus

Vector-transmitted viruses

Dengue virus, West Nile Virus, La Crose Virus, Yellow fever virus

Viruses that remain and replicate at site of entry

Rhinoviruses, SARS-CoV-2, Rotaviruses, Papillomaviruses

Location of Rhinovirus infection

Upper respiratory tract

Location of SARS-CoV-2 infection

Upper or lower respiratory tract

Location of Rotavirus infection

Intestinal Epithelium

Location of Papillomavirus infection

Epidermis

Viruses that spread through a neural route

Enteroviruses (polio virus), VZV, measles virus, HSV, rabies

Route of Enterovirus dissemination

Gastrointestinal —> CNS

Route of VZV and measles dissemination

Respiratory tract —> PNS

Route of HSV dissemination

Urogenital tract —> PNA & CNS

Route of rabies dissemination

Muscle & connective tissue —> CNS

Viruses that exhibit hematogenous spread

HCV, HBV, HIV

Dissemination route of HCV & HBV

Transcutaneous —> Liver

Dissemination route of HIV

Urogenital tract —> lymph nodes

Examples of oncoviruses

EBV, certain HPV, and some retroviruses

Interferon-alpha & beta

Beneficial: localized “antiviral state” by inhibition of protein synthesis

Adverse: Flu-like symptoms

Pleitropic Inflammatory Cytokines (TNF-alpha & IL-1alpha)

Beneficial: Cellular and immune antiviral response

Adverse: Fever, inflammation, tissue damage, organ failure

Macrophages

Beneficial: secrete pleitropic inflammatory cytokines, phagocytosis

Adverse: tissue damage

NK Cells

Beneficial: Kills virus infected cells

Adverse: Tissue damage

Neutrophils

Beneficial: Phagocytosis, degranulation, respiratory burst

Adverse: Amplify inflammation, tissue damage

Components of the innate immune response

Interferons-alpha & beta, Pleitropic inflammatory cytokines, NK cells, Neutrophils

CTL

Beneficial: kill virus-infected cells

Adverse: Tissue damage

Antibodies

Beneficial: Neutralization, ADCC

Adverse: Immune complex glomerulonephritis, dengue

Inflammatory Cytokines (IL-17)

Beneficial: Synergizes with TNF-alpha & beta, IL-1alpha

Adverse: Fever, inflammation, tissue damage

Viruses that downregulate MHC Class I (inhibiit antigen processing and presentation)

CMV, HSV, HIV

This virus destroys CD4 helper cells

HIV

This virus’s glycoprotein interferes with complement activation

HSV

This virus upregulates Fas ligand on the cell surface

HIV

Cytopathic effects

Necrosis, inclusion bodies, giant cells, cytoplasmic vacuolation

This virus causes giant cells

RSV

This virus causes bullet shaped cells

Rabies

Rotavirus

Common cold

Main symptoms: nasal obstruction and nasal discharge

Causes of common cold in infants

Rhino virus and Adeno virus

Causes of common cold in children

Rhino virus and Adeno virus

Causes of common cold in adults?

Rhino virus and Corona virus

Pharyngitis

Main symptom is sore throat

Main common cause of pharyngitis in infants

Adeno virus and Herpes simplex virus

Most common cause of pharyngitis in children

Adeno virus and coxsackie virus

Most common cause of pharyngitis in adults

Adeno virus and coxsackie virus

Tracheobronchitis

Main symptom is cough

Main cause of tracheobronchitis in infants

Parainfluenza and influenza

Main cause of tracheobronchitis in children

Parainfluenza and influenza

Main cause of tracheobronchitis in adults

Influenza and Adeno viruses

Bronchiolitis

Main symptoms are cough and dyspnea

Main cause of bronchiolotis in infants

RSV and parainfluenza

Pneumonia

Main symptoms are cough and chest pain

Main cause of pneumonia in infants

RSV and Influenza

Main cause of pneumonia in children

Influenza and Parainfluenza

Main cause of pneumonia in adults

Influenza and Adeno virus

GI track viruses in children

Rotavirus, Norovirus, Poliovirus, Hepatitis A, and Calcivirus

GI track viruses in adults

Enterovirus, Coronavirus, and Adenovirus

Pathology of viral CNS infections

necrosis, inflammation, and phagocytosis

Primary congenital viral infections

CMV & Rubella Virus

Secondary Congenital Viral Infections

HSV, VZV, HBV, Measles, Mumps, HIV, Parvovirus, and some Enteroviruses

When Rubella is most serious

Gestation

When Rotavirus in most serious

In Infants

When St. Louis Encephalitis and SARS-CoV-2 is most serious

In elderly