ID - Viruses

Genetic material of viruses is either ___ but never both

DNA or RNA

Which viruses have DNA?

Herpes (HSV, CMV, EBV, VZV, HHV)

Hepadna (hepatitis)

Adeno

Papova

Parvo

Pox

What type of outcomes are possible for a virally infected host?

Death, transformation (malignancy), latency, chronic slow infection

Interferons, macrophages, fever and mucociliary clearance are examples of ___ immune responses

innate (non-specific)

Which antibody is formed during the primary response?

IgM

3 multiple choice options

Which antibody is formed during secondary response and can cross the placenta?

IgG

3 multiple choice options

Which antibody is present in mucous membranes?

IgA

3 multiple choice options

Which antibody is responsible for allergic reactions?

IgE

3 multiple choice options

Name the main viruses in the herpesviradae family:

CMV, EBV, HSV, VZV, HHV

All herpes viruses have ___ DNA

double stranded

Where are HSV and VZV if latent?

neural ganglion

Where does EBV remain latent?

B cells

What is seen on histology in cytomegalovirus?

multinucleated giant cells and intranuclear inclusion bodies

What does CMV get its name from?

Swelling of infected white cells (cytomegaly)

About ___% of people infected with CMV are asymptomatic

80

3 multiple choice options

Which areas have higher incidence of CMV?

Developing countries

CMV transmission is facilitated by ___

poor hygiene and communal living

M/C congenital infection of developing countries?

CMV

About ___% of newborns with CMV will be symptomatic

10

3 multiple choice options

Jaundice, hepatosplenomegaly, purpura, thrombocytopenia, microcephaly, motor disability, hearing loss and mental retardation are s/s of ___

CMV

3 multiple choice options

Bluberry muffin spots are indicative of ___

CMV inclusion disease

Dx of CMV inclusion disease?

- PCR assays (dried blood)

- ELISA (urine, saliva, blood in first 3 weeks of life) = congenital dx

In immunocompetent patients CMV will present similar to ___

mono

Differentiating CMV from EBV?

No heterophil AB formed on mono spot test

Mean duration of symptoms of CMV?

7-8 weeks

Complications of CMV?

Encephalitis, Hepatitis, Peri/Myocarditis, Thrombocytopenia, GI damage, and Guillain-Barre syndrome

Complications of CMV in patients with AIDS?

Esophagitis, pneumonitis, retinitis (blindness), and encephalitis

Tx for CMV?

- mono = supportive

- Ganciclovir (IV) if GI or CNS

- Ganciclovir (IV) + vitreous w/ PO Valganciclovir for sight threatening retinitis

- Post transplant infection (Severe IV Ganciclovir, non-severe Valganciclovir PO or Ganciclovir IV)

EBV is HHV___

4

3 multiple choice options

EBV is present in what percent of the population?

90

3 multiple choice options

How is EBV transmitted?

Saliva (sometimes genital secretions)

EBV causes most cases of ___ in which EBV invades human B cells

Infectious mononucleosis

EBV is implicated in ___ which is more common in Africa

Burkitt's lymphoma

Incubation period of EBV?

30-50 days

3 multiple choice options

Classic triad of mono?

pharyngitis, fever, posterior cervical lymphadenopathy

How do mono and diphtheria differ in presentation?

mono has patchy tonsillar exudates, diphtheria is blanket like and gray

If a rash presents with EBV after taking amoxicillin what does it look like?

papular scarlatina rash with sandpaper texture

Dx of EBV/mono?

(+) heterophil agglutination test

Why do we not allow contact sports with a mono diagnosis?

splenomegaly - can cause rupture

Blood smear of someone w/ EBV will show:

up to 30% atypical lymphocytes and more than 50% mononuclear cells, as well as thrombocytopenia

How long does it take for a mono test to be positive after infection?

2-4 weeks

What diagnoses can cause a false positive monospot?

HIV, Lymphoma, rubella, hep B

Tx of mono?

- supportive (fever reduction and hydration)

- no contact sports

- steroids if airway threatened

Clinical syndromes of EBV: trigger NOT cause

- hairy leukoplakia

- nasopharyngeal cancer

- Hodgkin's lymphoma

- Burkitt's lymphoma

90% of cases of HSV infection are ___

subclinical

Complications of HSV?

- neonatal transmission

- enhanced HIV transmission

- psychosocial issues

Primary infection of HSV is typically asymptomatic for ___ after contact

3-7 days

Prodrome of ___ includes low grade fever, myalgias, adenopathy, localized pain, itching and tingling

HSV

Vesicles in HSV are ___

uniform in size and grouped

How long do HSV lesions typically last?

2-6 weeks

Dx of HSV?

- viral culture most definitive

- Serology (IgG/IgM)

- Tzanck prep

Factors like sunlight, bacterial infection or hormonal changes can cause a flare up in latent ___

HSV

Tx of first clinical episode of HSV?

- acyclovir ointment

- cool compresses w/ burrow's solution

- PO acyclovir, famciclovir, valacyclovir 7-10 days

Tx of genital herpes?

- Acyclovir 400/800mg TID

- Valacyclovir 500mg/1g

- Famciclovir 125mg BID

When should daily medication be considered in genital herpes?

6 or more recurrences per year

Tx for severe cases of HIV/HSV

Acyclovir IV

Potential complications of HSV?

- ocular disease

- CNS encephalitis

- Bell's

- Esophagitis/proctitis

- erythema multiforme

- liver failure

- pneumonia

Neonatal herpes infection can be split into three categories:

localized, disseminated (highest mortality) or systemic (highest morbidity)

VZV is also known as HHV___

3

3 multiple choice options

VZV causes two distinct disease forms:

- herpes zoster

- varicella

How is varicella zoster transmitted?

respiratory droplets or contact with lesions

Incubation period of Varicella

9-21 days

3 multiple choice options

Which virus has a centripetal distribution of lesions?

Varicella

Patients with ___ usually present with lesions at different stages at the same time

Varicella

Complications of varicella in adults?

- adults = monitor for pneumonia, acyclovir PO if at risk

- immune compromised = at risk for complications such as encephalitis, hepatitis and Reye's syndrome

Tx of Varicella?

- calamine lotion for itch

- avoid scratching

- acetaminophen for fever/myalgias (avoid aspirin)

- Acyclovir PO if older than 13 and healthy

- Acyclovir IV if immunocompromised

Shingles tends to appear with ___

increasing age and immune compromise

Most common cranial nerve involved with shingles?

Trigeminal

Hutchinson sign indicates ___ nerve involvement

Trigeminal

Ramsay-Hunt syndrome (rash on external ear) indicates ___ nerve involvement

Facial

Tx of herpes zoster within ___ will shorten duration and incidence of post herpetic neuralgia

72

Tx of herpes zoster?

- Valacyclovir & famciclovir if immunocompetent

- IV Acyclovir and vidarabine if immunocompromised

Zostavax should not be given to ___ patients because it is a live virus

immunocompromised

Tx of post herpetic neuralgia?

- topical capsaicin ointment or lidocaine patches

- regional blocks

- amitriptyline & gabapentin

HHV6 causes ___

Roseola

HHV___ is a major cause of infantile febrile seizures

6

3 multiple choice options

HHV___ causes Kaposi's Sarcoma

8

3 multiple choice options

Paramyxovirus causes ___

mumps

Paramyxovirus is a ___ virus

RNA

1 multiple choice option

Incubation period of paramyxovirus?

14-21 days

Painful, swollen parotid gland with redness of stinsons duct indicates ___

mumps

Complications of unvaccinated patients with mumps?

Meningitis, orchitis/oophoritis, pancreatitis, and salivary gland issues

Tx of mumps?

- symptomatic care (fever)

- isolation and bed rest while febrile

HPV is a ___ virus

DNA

1 multiple choice option

HPV infects the ___ or the skin or mucous membranes

keratinocytes

Persistent infection of HPV can lead to cancers of:

the cervix, penis, vulva/vagina, anus, and oropharynx

M/C STD in the US?

HPV

Which types of HPV cause genital warts?

6&11

Which types of HPV cause cancer?

16, 18, (31, 33, 45 cervical)

Symptoms of HPV develop within ___ of inoculation

3-6 months

3 multiple choice options

Tx of genital HPV?

- imiquimod cream to affected area

- podofilox solution

- provider administrated: cryotherapy, podophyllin, trichloroacetic acid, or surgical removal

HPV is detected in over ___ of squamous cell anal cancers

80%

Over 60% of oral squamous cell cancers are HPV (+) and over 90% is HPV ___

16

3 multiple choice options

Gardisil 9 coverage:

- cervical vaginal and vulvar cancers

- anal cancers (M/W)

- genital warts (M/W) 6/11

- HPV 16, 18, 31, 33, 45, 52, 58

Rabies is a ___ that causes encephalitis which is fatal if untreated

Rhabdovirus

SS RNA virus w/ bulletshaped capsid

Rabies

Incubation period of rabies:

10-90 days

3 multiple choice options

Rabies virus attaches to the ___ receptor causing neuron death and demyelination

ACh

Common rabies reservoirs in the US

Raccoon, skunk, fox and cat