Vial infection (A-D) Flashcards
what is B-virus?
Macacine herpesvirus 1 - enveloped, double-stranded DNA virus
- family Herpesviridae, genus Simplexvirus.
- commonly referred to as herpes B, monkey B virus, herpesvirus B, herpesvirus simiae
B virus is commonly found among macaques, a genus of Old World monkeys.
how are B virus transmitted?
- bites or scratches from an infected macaque
- contact with body fluids or tissues of an infected macaque
- human-to-human possible
what is fatal ratio of B virus not treated?
70%
who is at greatest risk for B virus infection?
lab workers, vet
chidren
what are symptoms of B virus infection?
occurs within 1 month of exposure
- influenza-like symptoms
- vesicular lesions near the exposure site
- localized neurologic symptoms (pain, numbness, itching)
- abdominal pain
- spread to CNS - acute ascending encephalomyelitis –> death or serious complication
- respiratory failure associated with ascending paralysis is the most common cause of death
how to diagnose B virus infection?
- collect specimens - only at National B virus resource center
- B virus-specific antibodies in serum is also diagnostic: at time of injury and 14-21 days later for serological testing
for suspected exposure of B virus, what antiviral tx should be started as postexposure prophylaxis in high-risk exposures?
valacyclovir, alternative - acyclovir
how to treat B virus infection if confirmed?
IV acyclovir or ganciclovir
what family and genus is chikungunya virus belong to?
family Togaviridae, genus Alphavirus - single stranded RNA
what species of mosquito cause chikungunya?
Aedes spp - Aedes aegypti and Ae. albopictus
when do you become viremic after a bite of chikungunya causing mosquitoes?
2-6 days of illness
what are other ways of transmission of chikungunya virus ?
bloodborne transmission, maternal-fetal - greatest risk in perinatal period when the mom is viremic at the time of delivery!
what % of people infected with chikungunya virus will remain asymptomatic?
3-28%
what is incubation period of chikungunya virus?
3-7 days (range 1-12 days)
what are the symptoms of chikung?
sudden onset of high fever 39 and joint pains
-fever can be biphasic
-joint symptoms are severe, can be debilitating, and usually involve multiple joints, typically bilateral and symmetric
-conjunctivitis, headache, myalgia, nausea, vomiting, rash (maculopapular usually on trunk and extremities, but can be on palms, soles and face)
what lab findings can you expect when you have chikingu?
increased creatinine and liver function tests, lymphopenia, thrombocytopenia
what are the serious complications of chikingu?
hepatitis, myocarditis, neurologic disease (cranial nerve palsies, Guillain-Barre syndrome, meningoencephalitis, myelitis) , ocular disease (uveitis, retinitis), acute renal disease, severe bullous skin lesions
how long dose the actue symptoms last when you have chikung?
7-10 days
what are the relapse symptoms of Chikung?
rheumatologic symptoms in months after acute illness
how to diagnose Chikung?
- clinical features
- serum detection of virus, viral nucleic acid or virus-specific IgM and neutralizing antibodies
what is the vaccine for Chikung? age indication?
IXCHIQ (manufactured by Valneva)- live attenuated vaccine ; 18 years and older
what are the adverse reactions with IXCHIQ vaccine?
> 10% rate - injection site tenderness, headache, fatigue, myalgia, arthralgia, fever, nausea;
severe or prolonged chikung-like adverse reactions in some persons
precaution and contraindication of IXCHIQ vaccine?
contraindication - immunocompromised conditions, history of severe allergic reaction to any component of the vaccine
precaution - pregnancy or breastfeeding
what is coronavirus?
single-stranded, positive-sense RNA virus
family Coronaviridae
genus Betacoronavirus
people with Covid-19 can be infectious from which days up to which days?
1-2 days before and up to 8-10 days after symptoms begins.
who is at increased risk of severe illness from Covid-19?
-50 years and older
-immunocompromised
-with certain underlying medical conditions
-pregnant - preterm birth, stillbirth, or other pregnancy complications if infected while pregnant
what is multisystem inflammatory syndrome (MIS) associated Covid-19?
rare but serious condition in which different parts of the body become inflamed, 2-6 weeks after acute infection.
what are the testings for Covd-19?
- nucleic acid amplication testing (NAATs) - highly sensitive and specific, takes 1-3 days, PCR test
- antigen test - less sensitive than NAATs, particularly among asymptomatic people.
FDA recommends repeat testing following a negative antigen test for a total of 2 antigen tests for people with symtoms or 3 antigen tests for people without symptoms, each performed 48 hours apart.
name the covid treatments available
paxlovid - nirmatrelvir with ritonavir - within 5 days of symptom onset BID for 5 days
Velkury - remdesivir - within 7 days of onset - IV for 3 days
Lagevrio - Molnupiravir - within 5 days of onset - 4 pills bid for 5 days
what virus cause dengue?
single stranded RNA
genus Flavivirus, dengue virus 1, 2, 3, or 4 (DENV1-4)
which mosquitoes species transmit Dengue virus?
Aedes aegypti,
Aedes albopictus
how long does viremia last for dengue?
7 days - bloodborne transmission is possible
is perinatal DENV transmission possible?
yes, near the time of birth
where is dengue enedmic to?
tropics and subtropics - Puerto Rico, US Virgin Islands, US-affiliated Pacific Islands
Sub-Saharan Africa, Latin America, Asia
how many people are affected by Dengue per year?
> 50 million cases
compared to malaria, Dengue is more of a risk in which areas?
urban and residential areas
what % of DENV infections are asymptomatic?
40-80%
about what % develop severe, life-threatening disease from dengue?
5% or less
what is the incubation period of Dengue?
5-7 days
what are 3 phases of dengue?
- febrile phase - 2-7 days, can be biphasic; other symptoms are headache, retro-orbital pain, bone, joint, muscle pain; macular or maculopapular rash, minor hemorrhagic manifestations, including ecchymosis, epistaxis, bleeding gums, hematuria, petechiae, purpura, or a positive tourniquet test result
- critical phase -
- convalenscent phase
what are the symptoms of febrile phase of Dengue?
- fever 2-7 days, can be biphasic; other symptoms are headache, retro-orbital pain, bone, joint, muscle pain; macular or maculopapular rash, minor hemorrhagic manifestations, including ecchymosis, epistaxis, bleeding gums, hematuria, petechiae, purpura, or a positive tourniquet test result
what are the warning signs of progression to severe dengue in febrile phase?
occur in the late febrile phase around the time of defervescence (38 degree) - severe abdominal pain, difficulty breathing, extravascular fluid accumulation, progressive incresae in hematocrit (hemoconcentration), postural hypotension, lethargy or resetlessness, liver enlargement, mucosal bleeding, persistent vomiting.
when does the critical phase start and what are the symptoms of critical phase of dengue?
begins at defervescence, and typically lasts 24-48 hours
plasma leak (marked increase in vascular permeability) - ascites or pleural effusions, hemoconcentration, hypoproteinemia
hypotension, severe hemorrhagic manifestations (hematemesis, melena, menorrhagia), irreversible shock and death; uncommon - encephalitis, hepatitis, myocarditis, pancreatitis
lab finding: elevated aspartate aminotransferase, alanine aminotransferase, hyponatremia, leukopenia, lymphopenia, thrombocytopenia, normal erythrocyte sedimentation rate
why is dengue in pregnancy more risky for infants?
placental transfer of maternal IgG against DENV from a previous maternal infection might increase risk for severe dengue among infants infected at 6-12 months of age when the protective effect of antibodies wanes.
how to diagnose dengue for patients presenting 7 or less days after fever onset?
> 7 days?
0-7 days - nucleic acid amplification tests and IgM
> 7 days - IgM testing
how long does IgM detected after dengue?
90 days
which medications should be avoided when infected with dengue?
aspirin, NSADs, meds with anticoagulant properties
how to treat dengue?
no antiviral, IV fluid when plasma leakage; no steroid except in cases of autoimmune-related complications
what is the name of dengue vaccine and what age and condition is it indicated?
Dengvaxia vaccine; age 9-16 years with lab-confirmed previous dengue infection who are living in areas of US where dengue is endemic - American Samoa, Puerto Rico, US Virgin Islands, Federated States of Micronesia, Republic of Marshall Islands, Republic of Palau
