Virals Flashcards
What are viruses that live outside of a host cell known as?
Virion
What was the first drug known to effectively stop the growth of herpes in immunosuppressed patients
Vidarabine or Ara-A
What are the three sub families of herpes virus infection infections?
Herpes simplex virus, varicella zoster virus, and cytomegalovirus
Which herpes virus infection can cause Kaposi’s sarcoma
HHV-8
What is the viral genome?
It is the DNA contents that are ejected to the cell nucleus to use the host machinery and replicate HSV one DNA
What are the signs and symptoms and treatment of HSV –1
It is typically asymptomatic, but patients can have oral or Peri oral lesions, ocular infections, non-genital skin lesions, genital skin or mucous membrane lesions and serious, systemic, illnesses, like encephalitis and neonatal disease. It is transmitted from person to person from oral secretions during close contact. The incubation period is one to 26 days and lesions are usually present from one to eight days. It is treated with acyclovir, valacyclovir and famciclovir.
How is the treatment of HSV one determined
What are the infection is the first time or a reactivation the severity of the symptoms and what the site of infection is.
What are the nucleotide analogs for HSV infections?
Acyclovir, valacyclovir and famciclovir
What are the two clinically significant infections that are caused by varicella zoster?
Chickenpox in the primary infection and herpes, zoster and shingles and the reactivation
What is the most common complication of herpes zoster?
Posttherapetic neuralgia
How can cytomegalovirus be transferred?
It can be bisexual intercourse, close contacts of viral shedding by blood or tissue exposure or vertically through pregnancy or childbirth
What are the nucleotide analogs of cytomegalovirus?
Ganciclovir and Valganciclovir
What is the therapeutic goal for treatment of chronic hepatitis b and c
Decrease the risk of cirrhosis and hepatocellular carcinoma by suppressing HBV and HCV replication
What are the non-infectious causes of hepatitis?
Alcohol and drug exposure, autoimmune disease, or metabolic reasons
How is hepatitis C, most commonly transmitted by?
IV drug use unprotected sex with multiple partners surgical exposure, unintended needlestick or sharp exposures hemodialysis HIV and infants of HCV positive mothers.
How soon after infection can you detect hepatitis C on lab work?
One to two months after infection
When can you expect chronic liver disease and HCV infection most likely to appear in an infected patient
In the third and fourth decades after initial infection
Once the hepatitis C virus enters the body what type of cell does it target?
Hepatocytes
What class of oral medication has changed the landscape for HCV treatment so that cure is now possible?
Direct acting antivirals
Which virus does amantadine inhibit
Influenza A
Which virus is a spherical shape with an external lipid membrane that is taken from a host cell, and a virus multiplies similar to a parasite
Influenza virus
What are the steps of the viral replication process
- Attachment of the virus to a susceptible host sell by uniting with a cell surface receptors
- Penetration of the virus or viral genome into the cell and absorbs theenzymes release
- The DNA of the phage penetrates through the hole.
- The virus replicates.
- There’s a release of new infective Verions
What are the two main classes of antiviral drugs used in influenza a and b
Neuraminidase inhibitors which are Tamiflu Relenza and rapivab
And Adamantanes or M2 inhibitors which are flumadine and symmetrel
How do the neuraminidase inhibitors treat influenza?
They target the NA glycoproteins on the outer lipid layer of the influenza virus
How is Zamamivir administered and why?
It has poor bio availability, so it must be administered directly into the respiratory tract by inhalation. It is contraindicated in patient to have Poor inhaler technique and patience with H5N1 virus where extra pulmonary virus replication has been detected.
How soon after symptom on set must all neuraminidase inhibitors for influenza be administered to be effective
Within 48 hours of symptom onset
Which neuraminidase inhibitor can be administered IV to Childrens, two years and older
Peramivir
How do the adamantanes or M2 inhibitors work for influenza treatment?
They block the influx of hydrogen ions through M2 proton channel of influenza a and inhibit the un coating and release of free, viral ribbonuclear proteins in the cells cytoplasm
What are the concerns with the use of amantadine and rimantadine for influenza?
It can cause dizziness, nervousness, insomnia, and gastrointestinal toxicities
What is a trivalent or quadrivalent influenza recombinant vaccine?
A vaccine that’s not prepared with influenza virus or eggs
At what age can children get the influenza vaccine?
Six months and older
How soon after administration of the influenza vaccine is it effective?
Two weeks
What are the side effects of the inactivated influenza vaccine?
Fever, myalgia, mace, and it typically last one to two days
What are the side effects of the live attenuated influenza vaccine?
Rhinorrhea, nasal congestion, headache, vomiting, muscle aches, fever, sore throat, and cough
When is the influenza vaccine contraindicated
When there is an anaphylactic allergy to chicken eggs or Guillain barre syndrome
What class of antivirals is recommended for treatment of influenza in the United States?
Neuraminidase inhibitors
Which class of antivirals is effective only against influenza a
Admanatanes
What is the mechanism of action for Oseltamivir?
It inhibits the neuraminidase enzyme and reduces viral replication
What is the physical traits of the HIV structure?
It is spherical and shape and has a diameter of one 10,000 of a millimeter with an outer coat or viral composed of a lipid by later they have protein copies that produce spikes on the surface of the Verion and each copy consists of a cap made of three molecules called glycoprotein 120 and a stem consisting of three molecules called glycoprotein 41 that anchor of the structure in the viral envelope
What are the seven steps of HIV replication cycle?
- Fusion of the HIV cell to the host CD4 lymphocyte cell service.
- HIVRNA reverse transcript test integration and other viral proteins host CD for sale by a process similar to pinocytosis
- Reverse transcript days the enzyme that makes DNA copies of HIVRNA forms viral DNA.
- Viral DNA is then transported across the nucleus and integrates into the host DNA.
- New viral RNA is used as the genomic RNA or the genetic material carrying all the hereditary information of the new virus to make viral protein
- Viral RNA and proteins move to the cell surface and a new immature HIV virus forms.
- The virus matures by proteins and enzyme that leaves the longer HIV proteins into individual proteins and then are released into the house bloodstream.
What is the primary HIV infection phase?
It is the acute phase of infection of HIV to AIDS
In what phase of HIV infection do 70% of people suffer flu like symptoms
The acute primary phase
How long after exposure to the HIV virus does the immune system fight back with killer T cells and B cells
2 to 4 weeks after exposure
What is the clinical latency period of HIV?
The person infected with HIV may remain free of HIV related symptoms for years, even though HIV continues to replicate and they can still transmit HIV to others.
What appears in an HIV patient’s labs after gradual destruction of the immune system?
The HIV viral load in the blood dramatically increases and the number of CD4 T cells drops
At what point is an HIV infected person diagnosed with AIDS
When they have one or more opportunistic infections, like pneumonia or tuberculosis and fewer than 200 CD4T cells
What was the first antiretroviral drug?
Zidovudine for HIV
What is the goal treatment for HIV and AIDS?
To extend and improve the quality of life by decreasing viral load to undetectable levels and prevent resistance to antiretroviral drugs and decrease vertical transmission of HIV from a pregnant woman to her child
What can you use to prophylactically prevent an HIV infection in the high risk populations
Prep has reduce the risk of getting HIV by 74% or you can do topical microbiocides like gels and creams and foams that can be applied in the genitalia prior to sexual intercourse
What are the two key types of HIV screening blood tests?
HIV antigen – antibody test that can detect HIV 18 to 45 days after exposure or a nucleic acid test that will detect HIVRNA 10 to 33 days after exposure
What is the earliest that viral RNA can be detected after an HIV infection?
10 days after transmission
What should you monitor in patients that are getting antiretroviral therapy?
At baseline in every six months, you should do a CBC and CMP a CD4 cell count and correlate it with immune response. You should also assess BUN creatinine and LFT levels.
In viral suppression, what do you typically see on labs at about 4 to 8 weeks after treatment is initiated for HIV patients
An increase in CD4 counts
When is viral load typically checked after starting treatment and what should you expect to see
2 to 4 weeks after starting treatment and you should expect to see a significant decrease
How often is viral load rechecked in patients with HIV treatment
Every one to two months until the level falls below the limit of detection or 50 copies and then it is checked every six months for 2 to 3 years if the patient is stable
When should a patient with HIV start therapy?
At the time of diagnosis, regardless of their CD4 counts
Before starting therapy and HIV positive patients, what should you test for?
Genetic mutations that can reverse transcriptase and Proteus genes you should do a genotype HIV drug resistance test
In which situations should patients with early HIV infection not delay treatment while waiting on genetic testing
In an acute infection or impact pregnant HIV infected women
After failed ART for HIV positive patients, what should the following regiment include?
Two or three fully active agents
What does a person’s initial HIV treatment regimen include
Three HIV medication’s from at least two different HIV drug classes
What are the reverse transcriptase inhibitor classes for HIV treatment?
NRTI and NNRTI and they prevent the HIV enzyme reverse transcriptase converting single-stranded HIVRNA into double-stranded HIVDNA
How did the protease inhibitors work for the antiretroviral drugs?
They interfere with the HIV enzyme Proteus, which normally cuts or Cleaves long chains of HIV proteins into smaller individual proteins and it stops new viruses from being assembled
How does INSTI work in the antiretroviral drug class?
It blocks the HIV enzyme integration, which the virus uses to integrate its genetic material into the DNA of the cell it has infected
How did the HIV treatment fusion inhibitors work?
It interferes with the viruses ability to fuse with cellular membrane prevent preventing HIV from entering the cell
How does CR5 antagonist inhibitors work for HIV treatment?
It interferes with the viruses ability to bind to receptors on the outer surface of the cell that it tries to enter, and when the binding fails, the HIV cannot affect the cell
How did the CD4 attachment inhibitors work for HIV treatment?
They block HIV from attaching to CCR5 and CXCR4 co-receptors and entering the cell
How do capsid inhibitors work for HIV infection?
It interferes with the HIV cap that protects HIV’s genetic material and enzymes needed for replication
which treatments are not recommended in the initial treatment of newly diagnosed HIV patients that are treatment naïve
Fusion inhibitors CR5 inhibitors and CD4 post attachment inhibitors
What can cause resistance in HIV treatment?
Genetic drug resistance, previous exposure to prep
How is failure of antiretroviral therapy defined
Sub optimal, viral suppression or loss of suppression or inability to maintain appropriate CD for cell count or clinical disease progression
What are the possible reasons for ART regimen failure
No adherence, drug toxicity, drug drug interactions, development of resistance, etc.
What is the basic strategy for treatment failure due to suspected resistance in ART
Choose a new regimen, including at least two new drugs, but three is preferred and test for genetic drug resistance
What is the most common given NRTI for HIV treatment?
Lamivudine (epivir or 3TC)
What are the common adverse effects of lamivudine
Headache, malaise, fatigue, nausea, vomiting, diarrhea, abdominal pain, cough, and nasal congestion, and rarely could cause pancreatitis, aplastic anemia, and lactic acidosis
What is the most common NNRTI given for HIV
Efavirenz (sustiva)
What are the adverse effects of efavirenz
Rash liver toxicity, CNS effects fetal malformation and it can interact with many CYP450 drugs
What pregnancy category is efavirenz
Pregnancy category D and it showed teratogenic effects in animals
How does NNRTI affect other HIVART drugs?
It increases the metabolism of the
ARTs
What is the most common HIV protease inhibitor
Ritonavir or norvir
What are the adverse effects ritonavir
GIF effect endocrine and metabolic effects hepatotoxicity neuromuscular and skeletal effects and CNS effects.
What does ritonavir interact with?
CYP 450 substrate inhibitors and inducer and it enhances or boosts the efficacy of other HIV drugs
What is the most common HIV integrate strand inhibitor?
Raltegravir or isentress
What are the adverse effects of raltegravir
CNS effects, metabolic and endocrine effects, G.I. and hepatic effects and hematologic effects
How does raltegravir affect PPI and statin drugs?
It increases an enhances their effects
What is the most common fusion inhibitor for HIV treatment?
Enfuvirtide or fuzeon
What are the adverse effects of enfuvirtide
Injection site reactions GI effects, fatigue and pneumonia
Which HIV drug increases the risk for bacterial pneumonia
The fusion inhibitor enfurvirtide
What drug increases the concentration of protease inhibitors
Fusion inhibitors like enfurvirtide
What is the most common CCR5 antagonist?
Maraviroc or selzentry
What are the adverse effects of CCR5 antagonist?
Cough, upper respiratory infection, rash, liver injury, cardiovascular events like postural hypotension, and CNS effect.
What drugs should you monitor carefully when giving a CCR5 antagonist
Any CYP3A4 isoenzymes
What is the most common CD4 for attachment inhibitor
FOSTEMSAVIR or rukobia
What are CD 4 attachment inhibitors used in
Treatment and experienced patients with multi drug resistant, HIV and limited treatment options
What are the adverse effects of the CD four attachment inhibitor fostemsavir
Hepatotoxicity and QT prolongation
What drugs does fostemsavir interact with?
Drugs metabolized by CYP3A
What is the most common capsid inhibitor?
Lenacapavir or sunlenca
What are the adverse effects of the capsid inhibitor?
Nausea and injection site reactions
What drugs should you avoid with capsid inhibitors?
Strong and moderate CYP3 a inducer digoxin anticonvulsants and statins
Which two of the ART drug classes are not recommended to treat naïve patients
Fusion inhibitors and CCR5 antagonist
Can patients taking ART for HIV take holidays from their daily drug regimen and how do you advise?
No, they cannot take holidays and stopping therapy can lead to a decrease in CD4 cell counts and increase HIVRNA
What is the earliest possible time that primary HIV can be detected and what type of test can be used?
The earliest is 10 to 33 days after exposure and a NAT test must be used
How do viruses replicate?
They attach and penetrate the host cell and then use the host cell to produce multiple copies of their genome, then assemble the genetic material into packets and finally create new viruses that are released from the host cell
How is the risk for viral transmission among humans determined
By characteristics of the virus and the host population
What is the treatment options for HSV 1?
Acyclovir for 5-10 days within 72 hours of symptom onset or topical acyclovir.
Which class of HAART has the least drug interactions?
NRTI lamivudine
Which class of HAART is pregnancy category D and should only be given if absolutely necessary in pregnancy
NNRTI efavirenz
Which class of HAART causes insulin resistance?
Protease inhibitors like ritonavir
Which three classes of HAART are nog recommended in 1st line treatment
FI, CCR5 antagonist and CD4 post attachment inhibitor
