Viral Infections Part I Flashcards
What are some alpha herpes viruses that stay latent in neurons?
HHV1 = HSV - 1 HHV2 = HSV - 2 HHV3 = VZV
What does latency allow viruses to do?
- Life-long infection
- Intermittent reactivation
- Lifelong shedding
- Long term infection
(Can lead to cancer)
What are some beta herpes viruses that stay latent in T Cells?
HHV5 = Cytomegalo CMV
HHV6 =
HHV7 =
What is the Gamma herpes virus that stays latent in B Cells?
HHV8 = KSV
Karposi Sarcoma Associated Herpes Virus
What gamma virus is HHV4 ?
- Epstein Barr Virus (EBV)
What are the two gamma herpes viruses?
- HHV4 = (EBV)
- HHV8 = (KSV)
What is the most common primary herpatic infection?
- HSV-1
- Acute Gingivostomatitis
What are some S&S of HSV-1 ?
- Pain
- Bleeding of the gums
- Ulcers with necrotic bases
- Adenopathy
- Fever
- Self limited disease
- Lasts around 14 days
What is herpes labialis?
- Cold Sore
- Re-occurrence of Oral HSV (Primary infection)
- Reactivation
What are some prodrome signs of HSV-1?
- Tingling
- Warmth
- Itching
After the prodrome signs of HSV-1, what occurs next?
- 12 hours later
- Redness
- Papules
- Vesicles
What are some associated diseases or complications with HSV-1 ?
- Herpetic Whitlow (Distal fingers)
- Encephalitis
- Ocular herpes
What are some characteristics of HSV 2?
- Vesicular Lesions (Clean base)
- Pustular
- Ulcerative
- Involves the penis, vagina, cervix, Anus
- Painful
- Tender adenopathy
T of F
Primary infection worse than reactivation secondary infection?
- True
- Primary infection typically worse than reactivation
What is the best test (Highest Sensitivity) for active skin lesions of HSV?
- PCR > 90% sens
Most Sensitive - Ag Detection 70% sens
- Cx 30-80% sens
- Tzanck Smear 40% sens
What is the best test (Highest Sensitivity) for Dx HSV encephalitis ?
- PCR with CSF Fluid
T of F
HSV 1 and HSV 2 are the easiest viruses to cultivate?
- True
- 1 to 5 days results available
Why is serology not useful in Dx HSV in acute phases ?
- Takes 1-2 weeks before antibodies appear
When can you use serology to Dx a pt with HSV?
- Only use IgG if you need to Dx a pt with a latent infection without skin lesions
What are the main reasons to treat HSV?
- Primary infection is severe
- Dissemination
- Vision threatened
- HSV encephalitis
Drug of choice to treat HSV currently?
- Valacyclovir (New #1)
- Acyclovir (Was #1)
- Famciclovir
HSV perinantal infections occur during?
- 1st trimester = Miscarriage
- 2nd & 3rd trimester = Premature labor
Can the infant contract HSV during birth?
T of F
- True
- Even in the absence of vesicles
- Viral shedding 30 days after resolution of lesion)
Treatment of neonatal HSV infections consist of ?
- Acyclovir
- Systemic and Localized
- Systemic high mortality
Varicella Zoster Virus characteristics?
- Primary infection 4 - 10 y/o
- Highly communicable
- Attack rate of 90% seronegative pt’s close contact
- Secondary attack rate 70-90% in siblings
When are you contagious with Varicella Zoster Virus?
- 48 hrs prior to vescicles
- Contagious
until all lesions crust over
When was the VZV vaccine introduced?
- Vaccine available since 1995
What is the point of entry of VZV?
- Respiratory tract
- Spread into lymphoid system
What is the main target of the VZV ?
- The skin
- Take 14 days (2 weeks) from date of inoculation
Where does the VZV remain latent following the primary infection?
- Cerebral or Posterior root ganglia
The primary VZV rash
starts where and then spread where ?
- Face
- Spreads to the trunk and Extremities
Herpes Varicella Virus?
- Children
- Dew drops on a rose petal
Herpes Zoster Virus?
- Adults and Elderly
- Reactivation of Varicella = Shingles
How many dermatomes does herpes zoster usually affect?
- Single dermatome
- Wont cross mid-line
Where does the latent VZV reactivate?
- Sensory ganglion and tracks down the nerve to the skin innervation
What is postherpetic neuralgia?
- Vesicles in the dermatome often accompanied by intense pain
- Last for months
Complications of Herpes Zoster Shingles?
- Encephalitis
- Disseminated Zoster
Management of Varicella ?
- Self limited
- Clinically DX, labs rarely used
Management of Varicella in immunocompromised or with serious complications (Pneumonia & Encephalitis) ?
- Acyclovir / Valacyclovir
- Promptly
Treatment of Varicella eye complications?
- Ganciclovir
Management of Zoster?
- Manage post herpetic neurological (Pain)
- Antiviral offered to all pt’s > 50 y/o (Acyclovir, Valacyclovir or Famciclovir)
- Vaccination
Varicella Zoster Virus Perinatal Infections early in pregnancy can cause?
- Miscarriage
- Congenital infection with growth restriction
- Microcephaly
- Hepatosplenomegaly leading to Neurological disabilities
Varicella Zoster Virus Perinatal Infections late in pregnancy (3 to 5 days before delivery) can cause?
- Disseminated infections at days 5-10 after birth
- High mortality 30%
Treatment of mother is symptomatic unless pneumonia develops?
- Acyclovir
- Isolation
S&S of the prodrome phase of VZV?
- Fever
- HA
- Malaise
- Followed by a pruritic vesicular rash
What is another name for HHV4 ?
- Epstein Barr Virus
How is EBV transmitted?
- Via saliva
- Long kissing events
What is the most notable EBV disease?
- Mononucleosis
What other diseases is EBV associated with?
- Burkitt Lymphoma
- Nasopharyngeal carcinoma
- Pediatric Leiomyomas
- Lymphoma in immunosuppressed
- Oral leukoplakia in AIDS patients
- Chronic interstitial pneumonitis in AIDS
What are the two peaks of infection in developed countries?
- Preschool 1-6 y/o
- Adolescents / young adults 14-20 y/o
What percentage of the population is currently infected?
- 90%
In developing countries the EBV infection occurs earlier, by what age?
- 90% of 2 y/o
- Seropositive & Asymptomatic
EBV is associated with what type of cell?
- B Cell
What are some S&S of EBV?
- Fever
(Cytokine release due to B- Cell invasion) - Pharyngitis
(B- Cell infected lymphocytes in Oropharynx) - Lymphocytosis
(Proliferation of EBV infected B cells)
What does EBV do to B-Cells?
- Immortalize B-lymphocytes
- Continue in circulation
Incubation period of EBV?
- 30 to 50 days
Triad of most common symptoms in an EBV infection ?
- Fever
- Lymphadenopathy
- Sore Throat
Sore throat in an EBV infection can consist of ?
- Pharyngitis
- Tonsilitis
- Gingivitis
- Soft palate petechiae
Other S&S of EBV infection?
- Malaise
- Muscle aches
T of F
High risk of Splenomegaly with EBV?
- True 50% of cases
- Pt must not play contact sports
- High risk of Splenetic rupture
PE findings with EBV ?
- Dramatic appearing pharyngitis or tonsillitis
- Tender enlarged posterior cervical nodes
Pt develops a maculopapular rash with EBV?
- Pt was accidentally treated with Amoxicillin with caused the rash
Serious Complications of EBV?
- Bacterial pharyngitis
- Splenetic rupture
- Pericarditis
- Meningitis
- Encephalitis
Less common complications of EBV?
- Hepatitis
- Mono-neuropathy
- Aseptic meningitis
- Myositis
- Renal failure
Differential Dx for EBV in a pt with
Fever, Pharyngitis & Lymphadenopathy ?
- Streptococcal infection
- Cytomegalovirus
- Acute HVI
- Toxoplasma infection - RARE
Dx of EBV includes?
- Increase in granulocytes - Followed by lymphocytic leukocytosis
- Atypical lymphocytes
- Hemolytic anemia and thrombocytopenia
- Mono spot positive in 4 weeks
- Increase in LFTs and Total bilirubin
Treatment of EBV?
- 95% self limited without therapy
- NO ANTIBIOTICS
- Corticosteriods only for certain cases
- Antivirals only for certain cases
- NSAIDS for Pain and Fever
- No contact sports
When are corticosteriods used when treating EBV?
- Pts with mononucleosis EBV
- and
1) Airway obstruction
2) Severe Thrombocytopenia
or
3) Severe hemolytic anemia
When are antivirals used to treat EBV?
- Acyclovir or Ganciclovir
in Transplant patients - Not for treatment of simple mononucleosis
What is mumps?
- Highly contagious
- Preventable by vaccination
- Belongs to the genus Rubula virus
When is the peak incidence of mumps?
- Late winter to Early spring
Who is at high risk of mumps?
- Most commonly infected school-aged children and young adults
T of F
Maternal antibodies protect infants from mumps?
- True
Mumps S&S include?
- Fever
- Headache
- Myalgia
- Fatigue
- Followed by Parotitis
Most common symptom of mumps?
- Swollen Parotid gland (Parotitis)
Most common complication of Mumps?
- Orchitis (Swollen testicle or both Inflammation)
Other complications of mumps?
- Meningitis
- Encephalitis
- Deafness
How do you test for mumps?
- Buccal swab with PCR (preferred)
or
- Serum mumps immunoglobulin (Ig)M antibody
What is the treatment for mumps?
- Supportive care
- Self limited
What is measles?
- Measles is a respiratory disease
- Very contagious
- Preventable with vaccination
Number of measles cases reported in 2014, 2018 and so far as of March 2019?
- 2014 = 667
- 2018 = 372
- 2019 = 387
Measles hallmark sign?
- Koplik Spots Pathognomonic for measles
Symptoms of measles included?
- Fever
- Cough
- Runny nose
- Red watery eyes
- Tiny white spots in mouth (Koplik Spots)
- Rash from head to toe
- 3-5 days after symptoms, rash breaks out
Complications of Measles?
- Diarrhea
- Otitis media
- Pneumonia
- Encephalitis
- Blindness
- Subacute Sclerosing Panencephalitis (Progressive Neurological disorder)
How do you test for Measles?
- IgM AB serum assay standard
- May also do viral culture / PCR
Treatment of Measles includes?
- Symptomatic
- Children & infants, high dose Vitamin A
When can you give a prophylaxis treatment for suspected measles post exposure?
- Given within 72 hours of exposure in unvaccinated pt’s
