Viral Infections Flashcards
Virus that causes measles
Paramyxoviridae (RNA VIRUS)
Period of communicability of measles
4 days before and 4 days after the onset of rash
Prodrome of measles
High grade fever
Conjunctivitis
Colds
Branny desquamation
Measles (rash)
What do you give to prevent measles complications?
Vitamin A single dose
100,000 iu orally for 6-12month old
200,000 iu > 1 yr old
Post exposure prophylaxis for measles
- Measles Ig witihin 6 days (0.25 ml/kg) Im
2. Measles active vaccine for > 1 yr old within 72hrs
This is a chronic complication of measles with delayed onset
Subacute sclerosing panencephalitis (SSPE)
Stage 1 SSPE
Irritable
Temper outbursts
Reduced attention span
Stage 2 SSPE
Myocolnus (inflammation of the basal ganglia)
Consciousness is maintained
Stage 3 SSPE
Choreoathetosis Immobility Dystonia Lead pipe rigidity Deterioration of sensorium
Stage 4 SSPE
Loss of critical centers for breathing, HR, BP
DEATH
Three day measles
Rubella
German measles
Viral Cause of rubella
Togaviridae (RNA virus)
Period of communicability of rubella
7 days before and 7 days after onset of rash
Most characteristic sign of rubella
Retroauricular, posterior cervical and postoccipital lymphadenopathy
Forscheimer spots
Rubella
Discrete rose spots on the soft palate
Blueberry muffin skin lesions
Congenital rubella
IUGR, congenital cataracts, microcephaly, sensorineural hearing loss, structural heart defects, later sequelae of motor and mental retardation
Congenital rubella
Viral cause of mumps
Paramyxovirodae
Usual presenting sign of mumps
Painful enlargement of parotid glands
Period of communicability of mumps
1-2 days before onset of parotid swelling until 5 days after its onset
Alarming manifestations of mumps
Edema of homolateral pharynx and soft palate
Edema of larynx
Edema over manubrium and upper chest wall
Most frequent complication of mumps
Meningoencephalitis
Other less common complication of mumps
Orchitis and epididymitis
Oophoritis
Dacryoadenitis or optic neuritis
Nagayama spots
Roseola
Ulcers in the uvulopalatiglossal jx in asians
Cause of roseola
Human herpes virus type 6
Latent type of roseola
Type A
Type of roseola that causes > 99% of cases
Type B
Fever for 3-5 days with fussiness
Roseola
Primary varicella infection
Chicken pox
Reactivation of varicella infection
Herpes zoster/shingles
Dewdrop on a rose petal
Rash of varicella zoster
Starts on trunks
Vesicular centrifugal rash
Cause of varicella
Neurotropic Human herpes virus
Period of communicability of varicella
1-2 days before onset of rash until 3-7 days adter its onset and when all lesions have crusted
Skin lesion with zigzag scarring associated with atrophy of the affected limb
Cicatrix
In congenital varicella
Stigmata of VZV fetopathy
Skin
Extremities
Eyes
Brain
Lifetime risk for herpes zoster
10-15%
With 75% of cases occuring after 45 yo
Ramsay hunt syndrome
Aka herpes zoster oticus
Sx: facial nerve paralysis, vesicles over the ears
Involvement of the geniculate ganglion
When best to give acyclovir in herpes zoster
Most effective within 24 hrs of onset of rashes
Post exposure prophylaxis for herpes zoster
Active vaccine within 3-5 days exposure
Anti vzv Ig for immunocompromised, pregnant, newborns exposed to maternal varicella: within 96 hrs ( 125 units/10kg IM)
Newborns with moms positive for varicella infection 5 days before to 2 days after delivery
Cause of hand foot mouth disease
Coxsackie virus A16
Gold standard in the diagnosis of HSV infection
Virus culture
Management for disseminated HSV infection
Acyclovir 30mg/kg/day 3 doses as one hr IV infusion for 14-21 days
Management for genital herpes
Topical acyclovir
Valacyclovir
Famciclovir
Cause for poliomyelitis
Enterovirus from picornaviridae
Cause of herpangina
Coxsackievirus A
Cause of erythema infectiosum
Parvovirus B19 (only single stranded DNA virus)
Fifth disease
Erythema infectiosum
Slapped cheek as hallmark sign
Erythema infectiosum
Lacy reticulated appearance esp on extensors
Erythema infectiosum
Central clearing of macular erythema
Exanthem subitum
Aka roseola
Sixth disease
Roseola
Rashes appear when fever abates
Roseola
Rash and aplastic crisis
Erythema infectiosum
Parts of brain affected by HSV
Frontal lobe
Temporal lobe
Limbic system
Hallmark: Skin vesicles and shallow ulcers
Herpetic gingivostomatitis
Mode of transmission of poliomyelitis
Fecal oral
Most common clinical form of poliomyelitis
Abortive (nonspecific febrile illness)
Specimen of choice when diagnosing poliomyelitis: end of 1st week
Blood (virus isolation)
Specimen of choice when diagnosing poliomyelitis: end of 2nd week
Throat
Specimen of choice when diagnosing poliomyelitis: end of 3rd week
Feces
Cause of infectious mononucleosis
Epstein-barr virus (member of herpesvirus)
Man is the SOLE SOURCE
Mode of transmission of infectious mononucleosis
Sexual intercourse; oral secretions
Classic triad of infectious mononucleosis in adolescents
Fatigue
Pharyngitis
Generalized lymphadenopathy
Best known clinical syndrome due to Epstein-Barr virus
Infectious mononucleosis
Serologic test to confirm infectious mononucleosis
Heterophile antibody (Paul- Bunnell antibodies)
Or
Specific EBV antibodies
Most feared complication of infectious mononucleosis
Splenic rupture
What syndrome?
- Symmetrical rashes on cheek
- Multiple erythematous papules
- Looks like atopic dermatitis
- Associated with infectious mononucleosis
Gianotti-Crosti syndrome
MCC of congenital infection
Cytomegalovirus
Hepatosplenomegaly Jaundice Petechiae Purpura Microcephaly
Cytomegalic inclusion disease
Pathognomonic for CMV infection
Strikingly enlarged epithelial or mesenchymal cells with large intranuclear inclusions
Influenza virus -from what family
Orthomyxoviridae
Influenza type: causes epidemic; primary; has animal host; causes myocarditis
Type A
Influenza type: primary; causes epidemic; no animal host; myocarditis and myositis
Type B
Influenza type: causes sporadic cases of URTI
Type C
Diagnosis to confirm influenza
Hemagglutination inhibition
Prophylaxis and treatment for Type A influenza outbreaks
Amantadine and Rimantadine
Vector of dengue fever
Aedes aegypti
Generalized maculopapular rash that spares palms and soles, appears 1-2 days after defervescence
Hermann’s rash
Dengue with warning signs
Abdominal pain Persistent vomiting Mucosal bleed Clinical fluid accumulation Lethargy, listlessness Liver enlargement > 2 cm Inc Hct with dec PLT
In rabies, the most severe disease is evident in which part of the nervous system?
Pons and floor of 4th ventricle
Seen in brain of rabid animal
Negri bodies
Category of bites
Category 1:Licking, Nibbling of intact skin
Category 2: superficial abrasians without bleeding
Category 3: lacerations, transdermal bites, puncture wounds with bleed, all wounds on HEAD AND NECK with or without bleeding
Active anti-rabies vaccination
0.5 ml IM on days 0,3,7,14,28
5th dose is optional
Antibiotic prophylaxis for category 3 bites
Coamoxiclav 40 mkD x 7 days
Cells affected by HIV
Cells expressing CD4+ molecules and cells of monocyte-macrophage lineage
Confirmatory test for HIV
Western immunoblot or IF assay
Best single porgnostic indicator in HIV
Viral load
Dengue without warning signs
Rashes Aches and pains Nausea and vomiting Tournique test positive Leukopenia
