Modern Pandemic Flashcards
What are our big three modern pandemics?
HIV, influenza, and SARS-CoV-2
What is an endemic?
normal level of infection/spread in certain area among people there
What is an epidemic?
increased levels of infection typically occurs over a large geographic area and generally result of new strain of virus in immunologically naive population
What is a pandemic?
worldwide epidemic, usually from introduction of new virus
Who decides when level of infection goes from endemic to epidemic to pandemic?
depends on agency, WHO declares pandemics
What is a retrovirus?
enveloped, positive sense, single-stranded RNA virus that converts RNA to DNA through reverse-transcription (via reverse transcriptase)
What does HIV bind to?
CD4 cells; and coreceptor CCR5
What are the two forms/states HIV?
metabolically active or dormant; active = productive infection, dormant = long-lived in person
What happens to host cells of HIV?
HIV is cytotoxic to it’s host cells; number of CD4 cells will decrease over time
When does HIV progress to AIDS?
when the person becomes immunocompromised
What actually kills HIV patients?
secondary/opportunistic infections
Where did HIV come from?
they came from ancient world monkeys that humans had crossover events with
How is an HIV molecule structured?
genome in middle, proteins (reverse transcriptase and integrase), capsid, envelop (host derived membrane), more proteins on outside
What do the proteins outside HIV do?
recognize and bind to CD4 cells
What is the HIV virus’ life cycle?
1) binding
2) fusion
3) reverse transcription
4) integration
5) replication
6) assembly
7) budding
Which step in the life cycle is prone to error/mutations?
the reverse transcription stage
How can HIV escape our treatment/intervention?
it rapidly changes due to mutation
What happens in integration?
double-stranded DNA entered into host cell which is IRREVERSIBLE; genome is now a provirus; determines dormant vs active status
What are symptoms of HIV at first?
cold/flu-like symptoms
What is clinical latency?
HIV and our immune system fighting to reach equilibrium
What is AIDS?
having CD4 count < 200 cells/mm OR having an AIDS defining condition (invasive cervical cancer, HIV-related encephalopathy)
What is the stigma around HIV?
one of the most heavily stigmatized such as refusal to interact, refusal of services, loss of relationships; leads to social isolation
What is a problem with HIV stigma?
people become hesitant to disclose/seek help for their HIV status
What is the HIV prevalence 1990-2017?
number of new infections and deaths have decreased while number of people living with HIV has increased
How do you require HIV?
(highest to lowest risk)
blood transfusion, receptive anal sex, needle-sharing during injection drug use, percutaneous (needle-stick), insertive anal sex, receptive vaginal sex, insertive vaginal sex
What can increase risk of HIV infection?
higher viral load, other STIs, tearing and abrasions, menstruation, and some vagial conditions
What can decrease risk of HIV infection?
lower viral load, pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), circumcision, lubrication, and condom use
What age group makes up HIV diagnoses?
people 25-34 account for most infections (younger people)
What populations see HIV infection the most?
2/3 of infections among men who have sex with men, 24% heterosexual sexual conduct, 10% drug users (higher among men)
What race is most affected by HIV?
about half of HIV infections are related with black people
What is the HIV care continum?
new HIV diagnosis/late HIV diagnosis, linkage to care, receipt of HIV care, and viral suppression
How do we commonly test for HIV?
4th generation amino assay (recommended); start with screening test, antibody differentiation test (determines HIV 1 or 2), HIV 1 RNA test (gold standard, definitive HIV test)
What other methods do we use to diagnose HIV?
oraquick point of care testing and nucleic acid amplification testing (viral load monitoring)
What is the influenza virion structure?
orthomyxoviridae, spherical virions
What two glycoproteins does influenza have?
hemagglutinin (HA) and neuraminidase (NA)
What are two important transmembrane proteins for influenza virions?
M1 (anchors) and M2 (proton channel)
What is the influenza life cycle?
across animals as well as humans
What is antigenic drift?
small changes/mutations over time of an endemic strain circulating the human population (less dramatic)
What is antigenic shift?
recombination even in another host (birds,swine), leading to a novel influenza shift (more dramatic, pandemic strains)
What is endemic influenza?
yearly circulation, normal (not increased amount of infection), if there is outbreak it’s considered epidemic, antigen drift
What is pandemic influenza?
caused by recombination of influenza (novel strain), humans are naive to it, increase in mortality and infection rate, antigenic shift
How do we strain type influenza?
by the glycoproteins present on virus surface
What are the strain types?
hemagglutinin (HA) which activates fusion and neuraminidase (NA) which allows new virions to be released
What are the symptoms of influenza?
respiratory illness involving fever, chills, headache, muscle aches, malaise, dry cough, sore throat, and rhinorrhea (runny nose)
What can influenza become?
pneumonia or secondary bacterial pneumonia
How do we detect influenza?
lateral flow POC, PCR, viral culture and serologic diagnosis
What is the spike glycoprotein on SARS-CoV-2?
specific for ACE-2 (on lung and intestine)
What are the variants of concern (VOC) for SARS-CoV-2?
alpha, beta, delta, omicron (current major circulating variant)
What is COVID-19 transmitted by?
respiratory droplets/aerosoles, fomite transmission by pre-symptomatic/symptomatic/asymptomatic individuals
What is the primary COVID-19 infection? Who does it affect?
symptoms range from mild cold to viral pneumonia; affects elderly mainly
What can COVID-19 lead to?
cytokine storm, blood clots, organ damage, and MIS-C (children)
What are the long-term effects of COVID-10?
new/ongoing symptoms, chronic fatigue, “brain fog”, shortness of breath, lung damage, heart damage, development of type 2 diabetes
How do we test for COVID-19?
direct detection (NAAT, rapid antigen), indirect detection
What is flurona?
coinfection = new virus created from SARS-CoV-2 and influenza
