Studied by 3 people
Which DNA viruses are single- stranded?
Parvoviruses
Which RNA viruses are double-stranded?
Reoviruses
What three criteria divide human viruses into families?
Type of nucleic acid they carry, type of capsid, presence of an envelope
What effect on the host cells account for the pathology and loss of function associated with viral infections?
Lytic effect destroys them
Name the 2 types of persistent viral infections.
Chronic and latent
Define a chronic viral infection.
Virus is detectable in tissues samples, multiplying at a slow rate; Sx are mild or absent Ex: HIV, HBV, HCV
Define a latent viral infection.
After a lytic cyle, the virus enters a dormant pahse inside the host cells remaining inactive and typically undetectable, but can reactivate and result in recurrent infections Ex: HSV, VZV
What cancer is associated with human papillomavirus?
Cervical and penile cancer
What cancer is associated with hepatitis B & C?
Hepatic carcinoma
What cancer is associated with human herpesvirus 8?
Kaposi sarcoma
When did routine vaccination end for Smallpox?
1972
Why was the Smallpox vaccine reintroduced in 2002?
Prevent bioterrorism
What virus causes Smallpox?
Variola
Describe the clinical presentation of molluscum contagiosum.
Flesh-colored, smooth, waxy, dome-shaped papules/nodules w a central umbilication or indentation; axillae and trunk commonly affected
What is the most common patient population this molluscipoxvirus is seen in?
Children
How is Molluscum contagiosum transmitted?
Skin-to skin contact and fomites
How many viruses make up the Herpes virus family?
8 (HSV-1, HSV-2, VZV, CMV, EBV, HHV-6, HHV-7, HHV-8)
What disease is associated with HHV-6 and HHV-7?
Roseola
Why do all members of the Herpes viruses show latency and cause recurrent infection?
After entry of the viral DNA into the nucleus of the host cell, it becomes an extrachromosomal particle
Describe the primary infection of HSV1 including the location and typical patient population.
Lesions on the oropharynx (can by optic); typically occurs in early childhood – early adulthood
Describe the primary infection of HSV2 including the location and typical patient population.
Lesions on the genitalia; primary infection often occurs in ages 14-29
What is the typical transmission of HSV1 and HSV2?
Direct exposure to secretions containing the virus
Name three different medications used to treat the HSV and how soon treatment should begin.
Acyclovir, famicyclovir, valacyclovir; treat w/in 72 hours of Sx onset
Which nerve ganglia do the HSV1 and HSV2 virus enter?
HSV1 enter 5th cranial nerve; HSV2 enters lumbosacral spinal nerve
Provide a brief review of Herpes in the newborn.
Spread during or before birth if lesions are present; Potentially fatal, can infect the CNS; C-secition may help prevent this
Describe the classic pattern of the HSV infection in a premature infant.
Cigarette burn lesions
Describe the clinical presentation of herpetic whitlow and the most common patient population you would see this in.
Usually a location infection on one finger, may become inflamed and necrotic; seen in healthcare workers in OB/GYN, dentristry, and respiratory therapy
If a patient has HSV, what would you see on a Tzanck smear?
Multinucleate cells, giant cells, and inclusion bodies w/in the nucleus
Name the 2 diseases caused by VZV and the mode of transmission.
Chicken pox and Shingles; spread via respiratory droplets and contact w/ fluid from lesions
What does VZV stand for?
Varicella-Zoster Virus
Describe the typical presentation of chicken pox.
Fever, rash, macules -> itchy vesicles that encrust and drop off, all over the body, “dew drops on a rose petal”; more common in children
Describe the typical presentation of shingles.
Vesicles localized to distinctive dermatomes, often preceded by pain; more common in pts over 60
What 2 complications can VZV cause?
Post-herpetic neuralgia and Zoster opthalmicus (EMERGENT)
What is the typical presentation of a cell infected with CMV.
Giant cells, distortion of nucleus, “owl’s eye”
What virus causes infectious mononucleosis and what is the mode of transmission?
Epstein-Barr (EBV); direct oral contact and contamination with saliva, blood transfusion, organ transplant
Describe the typical presentation of mononucleosis.
Sore throat w/ gray-white exudate, high fever, LAD, splenomegaly
What 2 cancers are associated with Epstein-Barr virus?
Burkitt’s lymphoma and Nasopharyngeal carcinoma
Describe the pediatric presentation of Roseola infantum.
Fever followed by a pink maculopapular rash on trunk and extremities
What virus is associated with Roseola infantum?
Human Herpes Virus 6 (HHV-6) (B-lymphotropic virus)
What is the most common malignant tumor in AIDs patients and what virus is it associated with?
Kaposi sarcoma: HHV-8
Which Hepatitis virus is a DNA virus? What organ is primarily involved?
Hepatitis B virus (HBV); liver
How is HBV transmitted?
Small amounts of blood, blood products, sexually transmitted
Describe the common clinical features associated with HBV.
Mild sx, malaise, fever, chills, anorexia, abd discomfort, diarrhea; severe: jaundice, rash, glomerulonephritis
Standard screening for HBV occurs in which situations?
Blood for transfusion, semen for sperm banks, organs for transplant, routine prental testing of all pregnant women
What is the primary prevention of HBV?
Vaccination
What is a condyloma acuminata?
Skin-colored or pink lesions, range from smooth, flattened appules to verrucous papilliform; most common STI
What is a condyloma lata?
Skin-colored, moist lesions, vary is size and appearance
What lesion is associated with secondary syphilis?
Condyloma lata lesions
Which HPV types are most commonly isolated in patients with cervical cancer?
HPV 16 and HPV 18
What vaccine can protect an individual from HPV?
Gardasil 9
What virus causes erythema infectiosum?
Parvovirus B19
What is another name for erythema infectiosum?
Fifth disease
Describe the clinical presentation of Fifth disease.
Low-grade fever followed by a rash, “slapped face” appearance, lacy, maculopapular rash
What months do we usually experience epidemics of influenza?
November – April
Which influenza type is the most virulent?
Type A due to antigenic shift
What is the primary mode of transmission of influenza?
Inhalation of aerosols and droplets
What is the most common complication experienced after being infected with the influenza virus?
Secondary bacterial pneumonias
Name the two influenza glycoproteins discussed in class and their action.
Hemagglutinin: binds to host Neuraminidase: hyrolyzes respiratory mucus and assists viral budding and release
Define antigenic drift.
Gradual minor antigenic change w/in the H or N that decreases ability of host memory cells to recognize them; responsible for epidemics
Define antigenic shift.
Major antigenic change w/in H or N resulting in a new subtype, one gene is substituted w/ a gene from another flu virus; responsible for pandemics
Name the neuraminidase inhibitors used to treat influenza and how soon they should be initiated after developing influenza symptoms.
Zanamivir, Oseltamivir, Peramivir; w/in 24-30 hrs, no benefit if >48hrs
Name 4 arenavirus diseases.
Lassa fever, Argentine hemorrhagic fever, Bolivian hemorrhagic fever, Lymphocytic choriomeningitis
What are the sydromes associated with the American bunyavirus?
Hantavirus pulmonary syndrome (HPS) and Hemorrhagic fever w/ renal syndrome (HFRS)
Paramyxoviruses have glycoprotein spikes and fusion spikes. What do the fusion spikes initiate and how does this increase the virulence?
Initate the fusion of infected cells w/ neighboring cells -> syncytium or multinucleate giant cells; allows virus to pass undetected from infected cells to non-infected cells
Croup is a pediatric illness caused by the parainfluenza virus. Describe the typical clinical presentation of a child with croup.
Inspiratory stridor, tachypnea, barking seal-like cough, inflamed and narrow airway, hypoxemia
What medication can be prescribed to lessen the symptoms of croup?
Dexamethasone
Describe the typical presentation of a patient with mumps.
Fever, painful swlling of one or more salivary glands (typically parotid), usually bilaterally, malaise, HA, muscle pain
What are the most common complications of the mumps?
Orchitis, epididymitis, oophoritis, aseptic menigitis, pancreatitis
How can mumps be prevented?
MMR vaccine
Measles (Rubeloa) is caused by a morbillivirus. What is another name for this infection?
Red Measles
How is Rubeola transmitted?
Via respiratory droplets
Describe the rash associated with Rubeola.
Erythematous, maculopapular, blotchy rash appears first on the head -> trunk and extremities; spares palms and soles
What clinical finding of Rubeola is pathognomonic?
Koplik’s spots: Whitish, grayish, bluish small elevations w/ an erythatous base, typically on buccal mucosa; present 48hrs prior to the rash
How many vaccinations are needed to obtain 95% ser-conversion?
Usually 2
What is the most serious complication of Rubeola?
Subacute sclerosing panencephalitis; presents 7-10 yrs after infection
What causes RSV?
Pneumovirus
RSV typically presents in what population?
Children < 6 mo
When is the peak seasonal outbreak of RSV?
Winter and early spring
Describe the clinical presentation and symtpoms of RSV.
Fever, rhinitis, pharyngitis -> couth, wheezing, tachypnea, dyspnea
What infection does the Rhabdovirus cause?
Rabies
What are the three phases of Rhabdovirus?
Prodromal, Furious, Dumb
What S/sx are associated with the Prodromal phase of a Rabies infection.
Fever, nausea, vomiting, HA, fatigue; some pain, burning, paraesthesias at wound site
What S/sx are associated with the Furious phase of a Rabies infection.
Agitation, disorientation, seizures, twitching, spasmas in the neck and pharyngeal muscles upon swallowing, hydrophobia
What S/sx are associated with the Dumb phase of a Rabies infection.
Paralyzed, disoriented, stuporous, coma, death
Name the most common Rhabdovirus reservoirs in the US.
Bats, raccoons, skunks, foxes
What is the post- exposure prophylaxis of rabies?
Human rabies immune globin (HRIG) or vaccinations w/ human diploid cell vaccin or purified chick embryo cell vaccine
What finding during autopsy is diagnostic of rabies?
Negri bodies -collections of virions in the cytoplasm of brain cells
The Filovirus, Ebola, is one of the most virulent human pathogens that can cause severe hemorrhagic disease. Describe the progress of the disease.
Incubation 2-21 days -> nospecific sx: fever, chills, malaise -> sever diarrhea, nausea, vomiting, uveitis -> nonpruritc rash, can desquamate -> meningoencephalitis, bleeding
What is the mode of transmission of Ebola?
Person-to-person via direct contact of broken skin or unprotected mucous membranes w/ virus containing body fluids
What is the treatment for Ebola?
Inmazeb for the Zaire species; supportive care
What is the mode of transmission of MERS?
Via aerosols and droplets
What are the clinical symptoms of MERS?
Acute respiratory sx, fever, cough, SOB, sore throat, hemoptysis, myalgias, diarrhea, vomiting, abdominal pain, abn CXR; can leads to pneumona and ARDS
What is the treatment for MERS?
Supportive care
List two other names for Rubella.
Three-day measles, third exanthematous disease of childhood, German measles
What is the mode of transmission of Rubella?
Inhalation of droplets
Why is it important for pregnant women to be vaccinated for Rubella? List the possible pregnancy complications.
Can pass to the fetus: infection, intra-uterine death, spontaneous AB, congential Rubella Syndrom (malformation of major organ systems)
Describe the possible clinical presentation of an individual with Rubella.
HA, low fever, malaise, LAD, rash (fine, pink, maculopapular states on face) conjunctivitis, Forcheimer spots (on the soft palate)
What class of medications are used to treat Hepatitis C?
Direct acting antivirals (DAAs)
What is an arbovirus?
Virus that is spread by arthropod vectors (mosquitoes, ticks, flies, gnats)
List the encephalitis-causing diseases associated with ticks.
Colorado tick fever
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