Micro Lecture Cards Viruses Flashcards
What stain do you use for TB? What happens with this stain?
Acid Fast, it Glows
Individual coughing with acid-fast positive is likely what diseases*?
TB
What causes TB?
Pulmonary Lesions, Mycobacterium
Where does TB disseminate?
Kidney, Liver, Testes
When are you infectious with TB if you previously were infected?
After your body walls off the bacteria, if the bacterium penetrates the wall and comes out of latency you will become infectious
Who is most susceptible to TB?
AIDs patients, crowded populations, homeless people
Is TB always highly contagious?
Not if your body walls off the bacteria and it is latent, uncontained it is highly communicable.
What was the reason for the spike of TB in the 1980s?
Due to the Spike of HIV
What happens during Primary TB infections?
Macrophages migrate to local lymph nodes, CMI slows the growth of bacteria, the bacteria become contained in epithelioid giant cell granules
What happens to tubercles at the end of TB infections?
They can become calcified with sequestered bacteria that produce a positive skin test, negative X-ray.
What is the main difference between primary TB and Latent TB
Primary = First Exposure
Latent = Controlled exposure in granules
What is Secondary TB?
Skin test positive, X-Ray Positive, Sputum Positive
Clinical TB
Two ways Active TB interferes with lipid metabolism?
Night Sweats, Weight Loss
What is the Ghon complex?
Enlarged Tubercles rupture into airways and blood vessels ( Cheesy Spread ) [Pos, skin test Pos, X-ray]
What are the physiologic reactions due to the Macrophages in secondary TB?
Fever and weight loss
What is the most likely form of TB infection?
Latent
What patients are at risk for Rapid failure of CMI due to TB?
Immunocompromised patients.
How do we test for TB?
Inject PPD in the skin, observe the response of CMI by the diameter of TB ‘bump’
How do we get around TB’s drug resistance when treating patients?
Use 2,3,4 drug combos
What is the MAC?
Mycobacterium avium - intracellulare
What is disseminated miliary TB?
Miliary = milit seed disseminated = pass out
Radio graph = Lesions spread out all throughout the body
(Prevalent in immunocomplex. pts)
Associated with Secondary TB
What two stains are used for MAC?
Acid Fast + fluorochrome
A pt with a CD4 count that is extremely high with positive skin test, lesions all over the body what could be the cause?
TB
What causes syphilis? how is it transmitted?
Treponema Palladium , infectious chancre lesion
-sexually transmitted
If your pt does not have lesions, but syphilis symptoms do you use RPR tests or immunofluorescence?
RPR blood test, testing for a spirochete.
Explain the stages of syphilis.
[Spirochete]
Primary - Chancre lesion (21 days) painless, heals w/o treatments
Secondary - Rash over a wide area ( 1 - 6 months later)
Tertiary - Multi-organ failure, death if not treated (>6 months)
What does Borrelia Burgdorferi cause?
Lyme Disease, tick bite. [Spirochete]
Asymptomatic—>Non Specific flu symptoms—-> Rash—->Neurologic /Cardio/Arthritic involvement
What is the shape of the skin rash in lime disease?
Bullseye
How do you transmit Leptospira interrogans? what are the symptoms?
contact with infected animal urine or contaminated water
[spirochete]
What is a unique feature of the Ab response in leptospira interrogans?
Over the course of time, the Ab response rises (rising ab titer)
What is the difference between an increasing titer and a constant titer?
increasing = recent infection
constant = either not infected or not a recent infection
Burkholderia malia
Associated with horses (animal blood transmission) , HIGH fatality if not treated
Burkholderia psuedomalia is a _____ threat that causes _________.
Biological threat, melioidosis
[gram neg bacilli]
[south east asia, pacific, australia]
Unique features of Burk. cepacia
- Hard to kill
- Common in soil and water
- Nosocomial infections
[Gram Neg Bacili]
Infectious properties of Burkholderia species
- lung , airways affected
- pneumonia
- quickly can lead to death in the immuno compromised
[gram neg bacili]
Where is peptostreptococcus normal vs. abnormal body microbiota?
Normal = vagina Abnormal = Bone and Joints
Key features of Fusobacterium
Anaerobic, periodontal infections, skin ulcers
Faecalibacterium is normal when? and abnormal when?
Normal in high numbers as a boost to the immune system
Abnormal in low numbers as an indication of clinical disorders
Bifidobacterium
Probiotic, normal bacteria of the vagina and mouth and gut
[Gram pos bacili, non spore forming]
Propinobacterium sets the stage for what?
Acne
Lactobacillus spp. characteristics
Gram pos bacillus, normal in digestive and genital tract
a common probiotic in food
Influenza is what kind of virus?
Myxovirus
The flu is transmitted mostly by what 3 things?
Droplets, contact, inhalation
Who is affected most by the flu?
The young and old
If your body can’t fight off viral influenza what are you most likely to die from? vs. a secondary bacterial pneumonia infection
More likely to die from the viral influenza URT infection.
What is the purpose of Hemagluttin and Neuraminidase in flu infection?
Attachment and virulence.
Vaccines try to match up to these for attack.
Which type of flu has high variability?
Type A
H and N of the flu come from what?
Surface Proteins that vary with virulence
How should we treat for the flu?
Antivirals and treat early
Which strain is the most important to get right when predicting for the flu vaccine?
Type A
Type B and C of the flu are _________ stable.
Antigenically
Common human subtypes of the flu
H3N2 , H1N1
Early in the flu season you get flu ___ late you get flu ___
A, B.
What is RSV?
Respiratory Syncytial Virus
What can cause the common cold?
Respiratory Syncytial Virus, Respiratory Syncytial Virus, Corona Virus
RNA virus
What is the primary cold infection of infants and children?
RSV, Respiratory syncytial virus
What is the transmission of Covid?
Person to person, contaminated surfaces, droplets
Symptoms of covid
Fever, Cough, Shortness of breath, loss of smell taste, MISC in children
What is significant about the covid virion structure
Virus codes its own replicase (RNA polymerase) and proofreading enzymes
What is an ACE-2 / NRP-1 ?
They are docking site receptors in nasopharyngeal and bronchial tissues. Antigen spikes attack here.
About how many viruses can be made from one infected cell of covid?
~2100
With a covid infection at what point are you contagious vs. symptoms?
2.5 days to 4 days after exposure you are contagious until day 12
Symptoms go from day 4 to about day 7.5
After exposure to the Covid virus, what happens to surface receptors?
There is an increase which can lead to an increase in infection
What does NRP-1 do?
Blocks pain signaling pathways, allows infection to spread w/o inflammatory pain.
What is the effect of blocked interferon response
Decrease in immune efficiency
Common pathology of Covid?
Vascular system damage= Bradykinin storm [bp lowers] Co opt of ACE-2
Parainfluenza
Enveloped causing croup, member of parmyxovisu
Human metapneumovirus is common when?
Early spring
Adenovirus
DNA non enveloped can cause atypical pneumonia with a vaccine in types 4 and 7 which cause acute respiratory disease
Herpes chracteristics
DNA enveloped, latent and reoccurring. type 1 and 2
What does a syphilis legion look like?
Canchre
Which legion is painful? Herpes vs. syphillis
Herpes, canchre is hard not painful
Why is herpes recurrent?
Branches off the ganglion so you normally get a legion in the same spot
How is the herpes virus normally held in check?
Cell-mediated immunity
Herpes Zoster (Varicella-Zoster) causes what 2 infections?
Chickenpox, Shingles
Why can chickenpox turn into latent recurring shingles?
Because your CMI gets keeps it in check most of your life, as you get old it gets old as well, HZV remerges from the nerve ganglia.
If you get shingles where is the rash typically?
One specific area following the ganglion.
Who gets the shingles vaccine?
Anyone over 50
Epstein Barr Virus affects what cells?
B Cells
How is EBV transmitted
Saliva, oral secretions
[kissing disease]
infectious mono
How does the EBV convert from lysogenic to lytic?
Latent viruses are reactivated upon B cell stimulation
[converts into lytic phase]
Cytomegalovirus causes what?
Congenital cytomegalic inclusion disease from infected vaginal microbiota during the birthing
[CMV mono]
What is CMV associated with clinically?
Impairs CNS and can develop mental/physical retardation of the affected child
Latent CMV is expressed in what cases?
Immunosuppressed malignancy, AIDS, organ transplant, causes expression.
Rotavirus is a _____ virus.
RNA
Transmission of Rotavirus
Fecal to oral
Norwalk virus Characteristics
RNA virus.
Worldwide cause of Gastrentereritis. 18-48 hours of incubation / 12-60 hrs of symptom.
[transmitted by food, water, vomitus- difficult to prevent spread] Think crews ship ( everyone gets sick )
What generally happens to immunity in HIV infections?
Decreased and increased opportunistic infections
Why are there so many different variants of the HIV virus?
Because it is an RNA virus
Virion properties of HIV
Glycoprotein -41 / -120 attaches to CD4 and CXCR4.
CCR5 is for macrophages
P24 is the capsid protein
HIV-1 is prevalent where vs. -2?
1 = world wide 2 = african countries
What is reverse transcriptase?
produces a DNA copy of the RNA genome
What is the purpose of reverse transcriptase in HIV
RNA enters a host cell then Reverse transcriptase makes new viral DNA.
[CD4 cells cant produce cytokines]
What are key details of the 4 stages of HIV
1= Primary infection w spike in viral count [p24 antigen detectable] asymptomatic (1 to 4 months)
2= Latent (asymptomatic period) fought off the virus most of the time here. get a decrease in CD4 cells at the very end,
3 = Persistent infection [subclinical immune dysfunction, p24 spike at the end here.
[Kaposis sarcoma]
4 = AIDS , no longer have any CMI, decrease in CD8 here too.
CD4 count under 200 suspects HIV. What else can happen?
More susceptible to other infections
Symptoms of Viral Hepatitis
Anorexia
Hepatic tenderness
Jaundice and dark urine
Hep B is what kind of virus
Viral enveloped DNA virus
Blood transmission
What do HBsAg, HBcAg, and HBeAg stand for
Hep B
Surface - earliest chronic infection [long term infection]
Core -
Envelope - early acute infection [active virus]
Anti-HBe = indicates? Anti-HBs = indicates?
= seroconversion late acute resolution
=convalescence recover immunity [protective Abs]
Seroconversion =
when Ab appears
Is Hep B curable?
Yes it is an acute infection that resolves in 3-6 months
What does the HBV vaccine solicit, or help create?
Anti-HBs for protection
Hep C characteristics
Small, Enveloped RNA virus
Blood transmission
High co-infection with HIV
No vaccine, too many variants
Hep A characteristics
Small, non enveloped RNA virus
Not chronic
Fecal to oral route
A vaccine is available.
Bunyaviridae includes what viruses
Hantavirus , CCHF , RVF , [Hem fever]
Filoviridae includes what viruses
Ebola and Marburg , [Hem fever]
Flaviviridae includes what viruses
Dengue, yellow fever , [Hem fever]
Togaviriddae includes what viruses
Chikungunya , [Hem fever]
Common symptoms of Dengue fever
joint pain = break bone fever
conjunctivitis
headache
rash
[Hem fever]
Transmitted by mosquitos, not common in the USA
Yellow fever is transmitted by
Mosquitos, not common in the USA because of the vaccine
[Hem fever]
Places in the US that you can find Chikungunya
TX and Florida
Congo - Crimean Hemorrhagic fever = ____ transmission
Tick
[Hem fever]
What is the vector for ebola?
Fruit bats and bushmeat
At risk areas for ebola
direct contact with blood and body fluids.
Mucosal tissue
eyes
breaks in skin
What ar e Ebola supersspreaders
A small number of people that get the virus infect most of the people with total infection of ebola.
What is Encephalitis viral transmission?
Zika = Mosquito-borne and semen
EV = Tick Borne
West Nile = Mosquito
Which virus is associated with Guillain Barre Syndrome
Zika , can cause microcephaly in fetus
Which virus is associated with Guillain Barre Syndrome
Zika can cause microcephaly in the fetus
Does Zika have a vaccine?
No
General areas you can find the following infections :
- St. Louis Encephalitis
- West Nile fever
- Japnese Enceph.
- Murray Valley Fever
- California / South America
- Africa / Europe / small[mid USA]
- Japan
- Australia
Where does Rabies virus replicate?
tissue at bite travels in PNS
How do you die from rabies?
Often due to respiratory paralysis
HPV is associated with what cancer
cervical cancer, genital warts Type 6 & 11.
not all are sexually transmitted
Enterovirus is a __ Virus
RNA
Enter. virus transmission
fecal to oral , resp. secretions, contact with vesicle fluid
What type of enter. virus is an emerging cause of polio like illness (acute flaccid paralysis)
Enter. virus D68
What type of enter. virus causes myocarditis , pleurodynia, vesicular rash
Coxsackie
What does poliovirus invade
The CNS = muscle deterioration / paralysis
How are measles transmitted
Person to person highly contagious
What is re-emergent rubeola?
Red measles [re-emergent measles virus]When you are contagious with the measles, serious infection
Cough, rhinitis, high fever, red eyes, Koplik spots, rash
When are you contagious with the measles
4 days prior to 4days after rash onset
Vaccine effective
Meningitis, first tests you do
Blood culture and spinal tap
[imunnocompromised]
What causes fungal ringworm? how can they be visualized
Microsporum, Trichophyton, and Epidermophyton
KOH wet prep
Sporothrix has _______ that travels along with the lymph and gives you ulcerated ______.
With a history of what?
Nodules
Bumps
Working in soil/ rose garden, few weeks later.
Histoplasma is associated with what transmission and what locations?
Bird droplets that you inhale and it gives you flu lesions
[systemic mold pathogen]
Ohio, Mississippi, Asia
Where is coccidiosis located most commonly?
Southwest USA, North Mexico
Candida Auris is an ____ . How is it identified?
emerging threat.
hard to identify
hospital infections
How do you identify cryptococcus neoformans
India ink CSF
immunodiagnostic test
If you have rabies, polio , and entero d68 , what are the differences
- rabies = dog , vaccinations
- polio = paralysis vaccinations
- 68= more frequent in kids
Difference between smallpox and chickenpox
vesicles in small pox are synchronous, chickenpox has different vesicles in different stages at a given time.
What is a unique way that zika is transmitted
sexually
What type of virus is HPV. Is the vaccine 100% affective?
DNA , no many strains.
Mumps , rubella, and measles are all ____ viruses.
RNA
What virus is associated with rodents and Asia?
Hantavirus
Dengue is aka what? what symptoms are associated with this? Where is it endemic?
Breakbone Fever , associated with severe joint pain and hemorrhagic fever
Tropical Africa
What is the vector for congo Crimean hemorrhagic fever
Ticks
What does a high p24, capsid protein, mean in HIV?
It means the virus is active and replicating
What virus causes upper and lower respiratory tract infections
HUMAN METAPNUEMOVIRUS
[enveloped rna virus]
adenovirus is a ___ virus.
WHAT ARE THE COMMON SYMPTOMS
DNA
COLD, PINK EYE, GI, SORE THROAT
What most commonly gives kids diarrhea from fecal to oral contact?
Rotavirus
[rna virus]