Viral Diseases Flashcards

Flashcards about human diseases caused by viruses including pathogen, transmission, symptoms, and treatments.

Chickenpox & Shingles Pathogen

Varicellovirus human herpesvirus 3; also called Varicella-zoster virus (ds DNA virus)

How is chickenpox acquired?

Droplet inhalation into the respiratory system

What are the glycoproteins associated with chickenpox?

gB, gE, gH, gK, gL

What is the function of gE glycoprotein in chickenpox?

viral replication, cell-to-cell spread, entry

What causes shingles (herpes zoster)?

Dormant viral DNA within cranial nerves that migrates down sensory nerves

How is Chickenpox/Shingles Diagnosed?

Clinical diagnosis, PCR, ELISA (detects IgM and IgG), viral culture, direct fluorescent antibody test

What is the treatment for chickenpox and shingles?

Vaccine prevents or shortens illness for chickenpox; antiviral drugs for shingles

What is COVID-19 caused by?

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2); ssRNA Genome

How does the spike protein in COVID-19 function?

Spike binds to human angiotensin-converting enzyme ACE2

How is COVID-19 Diagnosed?

reverse transcriptase quantitative PCR, detecting viral antigen, and antibody testing

What is the treatment for COVID-19?

Acetaminophen or ibuprofen, antiviral in severe cases, oxygen therapy

What is the pathogen for Influenza?

Orthomyxoviridae; Influenza A, B, C virus

How is Influenza transmitted?

Inhalation or ingestion

How do Hemagglutinin (HA) and Neuraminidase (NA) function in relation to influenza?

Hemagglutinin (HA) allows for attachment and invasion of respiratory tract cells; Neuraminidase (NA) allows for newly formed viral particles to escape host cell

What are Antigenic Drift and Shift?

Mutations and recombinations in genes coding for HA and NA spikes; Major genetic change causes pandemics

What is the treatment for Influenza?

Neuraminidase inhibitors (Oseltamivir, Zanamivir, Peramivir)

What is the pathogen for Measles (Rubeola)?

Measles Virus (MeV); Measles morbillivirus; Negative-stranded, enveloped RNA virus

How does Measles (Rubeola) enter the body?

Respiratory tract

What are the symptoms of Measles (Rubeola)?

Cough, fever, headache, and conjunctivitis; Koplik’s spots

What is the treatment/prevention for Measles (Rubeola)?

No treatment; MMR vaccine

What is the pathogen for Rubella (German Measles)?

Rubivirus; Enveloped positive-strand RNA virus

How is Rubella (German Measles) spread?

Respiratory secretions

What are the symptoms of Rubella (German Measles)?

Swollen lymph nodes, red spot rash lasts 3 days

What are the effects of Congenital Rubella syndrome?

Virus crosses placenta, causes disease in the first trimester leading to fetal death, premature delivery, or congenital defects

What is the prevention for Rubella?

MMR Vaccine

What is the pathogen for Mumps?

Mumps virus (MuV); Pleomorphic, enveloped, negative-strand RNA

How is Mumps Transmitted?

Saliva and respiratory droplets

What are the clinical manifestations of Mumps?

Swelling and tenderness of salivary glands 16-18 days after infection

What is the treatment/prevention for Mumps?

Symptomatic and supportive measures; MMR vaccine

What is the pathogen for Respiratory Syncytial Virus (RSV)?

Respiratory syncytial virus (RSV); Negative-strand RNA virus

What are the clinical manifestations of Respiratory Syncytial Virus (RSV)?

Rhinitis, tonsillitis, laryngitis, bronchitis

How is Respiratory Syncytial Virus (RSV) spread?

Direct contact with respiratory secretions

What happens with syncytium formation in relation to RSV infections?

Syncytium forms when RSV triggers infected cells to fuse with uninfected cells

What are the RSV Clinical Manifestations?

Fever, cough, rhinitis, and nasal congestion

What is the treatment/prevention for Respiratory Syncytial Virus (RSV)?

Fluid replacement and fever reducers; vaccines available

What is the pathogen for Smallpox (Variola)?

Orthopoxviruses; Brick shapes; Linear dsDNA

How is Smallpox (Variola) transmitted?

Direct and prolonged face-to-face contact

What happens in relation to cytokine production during Smallpox (Variola)?

The virus produces fake receptors that bind to host cytokines and prevent signaling

What is the prevention for Smallpox (Variola)?

Live vaccine eradicated disease

What are the symptoms of Smallpox (Variola)?

Malaise, severe body aches, and high fevers; small red spots get larger and fill with thick opaque fluid

What transmits Arboviruses?

Arthropods

What are the clinical syndromes associated with Arboviruses?

Undifferentiated fevers, encephalitis, hemorrhagic fevers, joint pain

What is the pathogen for Chikungunya?

Togaviridae family; Positive-strand, enveloped RNA virus

How is Chikungunya transmitted?

Aedes aegypti and Aedes albopictus mosquitoes

What happens with the A226V mutation in E1 protein in relation to Chikungunya?

A226V mutation in E1 protein enhances transmission

What are the clinical manifestations of Chikungunya?

Joint pain, fever, headache, rash, resolving in 7 to 10 days

What is the treatment/prevention for Chikungunya?

No specific treatment or vaccine; prevention through insect repellent, light-colored clothes, mosquito netting

What is the pathogen for Dengue and Dengue Hemorrhagic Fever?

Flavivirus; Enveloped, positive-strand RNA virus

How is Dengue and Dengue Hemorrhagic Fever transmitted?

Mosquito vector (Aedes)

What happens with antibody-dependent enhancement in relation to Dengue and Dengue Hemorrhagic Fever?

Occurs when person has previously been infected with a different DENV

What are the clinical manifestations of Dengue (Classic)?

Fever, rash, joint and bone pain, muscle aches, mild bleeding of gums and easy bruising

What are the clinical manifestations of Dengue Hemorrhagic Fever?

Bruises, epistaxis, gum and GI bleed

What happens in Dengue Shock Syndrome?

Hypotension

What is the pathogen for Equine Encephalitis?

Eastern Equine Encephalitis virus (EEEV); Positive-stranded, enveloped virus

How is Equine Encephalitis transmitted?

Aedes and Culex spp. mosquitoes

What are the clinical manifestations of Equine Encephalitis?

From fever and headache to meningitis and encephalitis; EEE is the most severe mosquito-borne disease in the US

What is the prevention for Equine Encephalitis?

Current vaccine available for horses

What is the pathogen for West Nile Fever (encephalitis)?

Flavivirus; positive-strand RNA virus; West Nile Virus (WNV)

How is West Nile Fever (encephalitis) transmitted?

Culex spp. Mosquitoes that feed on infected birds

What are the clinical manifestations of West Nile Fever (encephalitis)?

Most remain asymptomatic or mild flu-like symptoms

What is the treatment/prevention for West Nile Fever (encephalitis)?

No treatment; no vaccine

What is the pathogen for Zika?

Zika Virus (ZIKV); Enveloped positive-strand RNA virus in the Flavivirus family

How is Zika transmitted?

Many species of Aedes mosquitoes; through bodily fluids

What are the clinical manifestations of Zika?

Mild fever, rash, joint pain, and conjunctivitis

What are the effects of Zika in newborns?

Causes birth defects like microcephaly with diminished brain tissue

What Virus causes Acquired Immune Deficiency Syndrome (AIDS)?

Human immunodeficiency virus (HIV)

How is Acquired Immune Deficiency Syndrome (AIDS) transmitted?

Infected blood, semen, vaginal secretions, or breast milk contact with an uninfected person’s mucous membranes

How does HIV attach to host cells?

Viral protein gp120 facilitates attachment to host immune cells (macrophages-CCR5, T-cells-CXCR-4)

How does HIV replicate?

RNA virus carries reverse transcriptase, converts RNA to dsDNA, integrates into human genome, remains latent or releases through budding

What are the later effects on the body from Acquired Immune Deficiency Syndrome (AIDS)?

T-helper cell count reduces, opportunistic infections begin, CNS disease develops

What are the methods for diagnosing HIV?

Detection of specific anti-HIV antibodies and antigens in blood, PCR test, level of virions of blood, concentration of CD4+

What is the treatment/prevention for HIV?

No cure; treatment used to decrease symptoms; no vaccine due to high mutation rate

What is the pathogen for Cold Sores?

Herpes simplex virus type 1 (HSV-1); Enveloped dsDNA virus

How is Cold Sores transmitted?

Direct contact of epithelial tissue surfaces

What happens during an active Cold Sore infection?

Explosive multiplication of virus

What is the treatment for Cold Sores?

Acyclovir and other antivirals; Idoxuridine for herpes infection of eye

What happens during latent Cold Sore infection?

Virus moves to trigeminal ganglion, is nondetectable unless reactivated

What are the clinical manifestations of Cold Sores?

Characteristic blister at site of inoculation, herpetic keratitis of cornea

What is the pathogen for Cytomegalovirus Inclusion Disease?

Cytomegalovirus (CMV); Herpesviridae family; Enveloped, dsDNA icosahedral capsid

How does is CMV infectious?

CMV can infect any cell of the body, causing cell to swell

What does an abnormally enlarged 'owl's eye' cell indicate?

An abnormally enlarged 'owl's eye' cell indicates CMV infection

What is the pathogen for Genital & Neonatal Herpes?

Herpes simplex type 2 (HSV-2); Linear dsDNA, enveloped

How is Congenital (neonatal herpes) transmitted?

Congenital herpes is transmitted from mother to infant during vaginal delivery

What can Congenital (neonatal herpes) result in?

Neurological involvement and blindness

How is Congenital (neonatal herpes) prevented/managed?

Cesarean section recommended

What is the pathogen for Human Betaherpesvirus 6 infection?

HSV-6; Enveloped dsDNA

Where are the viral replication sites for infections caused by infections with strains of the Human Betaherpesvirus 6?

CD4+ T cells are the main site of viral replication; monocytes are in an infected, latent state; proviral DNA in human chromosomes

What is the treatment/prevention for infections caused by strains of the Human Betaherpesvirus 6?

No antiviral therapy or prevention

What is the pathogen for Human Parvovirus B19 Infection?

Human Parvovirus B19; Icosahedral, naked virus with ssDNA genome

How does Human Parvovirus B19 replicate?

Uses host enzymes, self-complementary sequence at the ends of the viral DNA folds back to form a primer

What are the clinical manifestations of Human Parvovirus B19 Infections?

Mild symptoms, Erythema infectiosum (fifth disease) / slapped face syndrome in children, joint disease in adults

What severe complications can Human Parvovirus B19 Infections cause?

Can cause aplastic crisis in sickle cell disease, anemia, fetal hydrops, and spontaneous abortion in fetuses

What is the pathogen for Mononucleosis?

Epstein-Barr Virus (EBV); dsDNA, icosahedral with envelope

What type of cells does Mononucleosis infect?

B cells

How is Mononucleosis spread?

Mouth-to-mouth contact

What is the treatment/prevention for Mononucleosis?

Rapid diagnostic tests available, symptomatic/supportive therapy with rest

What is Viral Hepatitis?

Infections and inflammation of liver caused by 11 different viruses (5 well-characterized: A-E)

How is Viral Hepatitis (A-E) transmitted?

Hepatitis A-E transmitted by fecal-oral contamination

What is the pathogen for Hepatitis B?

Hepatitis B virus (HBV); dsDNA virus, enveloped with Dane particle

How is Hepatitis B transmitted?

Body fluids and contaminated equipment; transmitted to baby during birth and contact with vaginal secretions