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41 Cards in this Set
- Front
- Back
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What is the difference in enveloped and naked viruses?
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enveloped - viruses that have a membrane around their capsid; these viruses are more sensitive to drying, heat, and disinfectants
naked - those viruses that have no membrane around their capsid |
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What is the cause of 5th disease/slapped cheek disease?
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parvovirus B19 - erythema infectiosum
bright red cheeks bilaterally in a child and then progresses to also cause a reticular rash of the arms capable of causing aplastic anemia in anyone with bone marrow path |
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Which HPV types are most common in warts (papillomas)? Carcinomas?
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papillomas - 1-4 (plantar and skin), 6 and 11 (genital)
carcinomas - 16, 18, 30s-50s |
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What virus increases children's risk for intussusception?
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adenovirus infections
usually infects URT - causing fever, exudative pharyngitis with sore throat, coryza, and conjunctivitis - can progress to bronchitis or pneumo in children, promotes excessive peyer's patch enlargement - risk for intussusception |
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In the smallpox rash, what stage are the lesions in at any one time?
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all lesions are at the same stage of evolution at any one time
first infects URT, then lymph nodes, then blood, enters organs, re=enters blood, then spreads to skin fever, malaise, then rash on face that later spreads to trunk, then extremities rash - macule to papule to vesicle to pustule |
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What is the infecting dose for Hep B?
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low infectious dose - easily transmitted
vertical transmission during birth and breastfeeding - blood, sex those infected will be (+) HBsAg |
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Where does herpes in the mouth usually rest? Genital herpes?
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mouth - trigeminal ganglion
genital - lumbar and sacral dorsal root ganglion |
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How is HSV1/2 diagnosis made?
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screen with Tzanck smear - will see multinucleated giant cells
followed by fluorescent antibody staining or ELISA painful vesicles; fluid filled with virus and decubitus - very infectious |
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What does herpes encephalitis cause?
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causes necrosis of one temporal lobe
fever, headache, vomiting, altered mental status usually occurs during a current outbreak elsewhere - oral usually high death rate - treat with acyclovir begun immediately - before testing |
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What are the 2 stages of VZV?
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1) chicken pox - infects UR mucosa - spreads by blood to skin causing vesicular rash (dew drop) on trunk first then spreads - crusts and becomes pruritic
2) shingles - re-activation of latent VZV. Vesicles erupt along the sensory nerve course of a dermatome |
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What are the 3 causes of exudative pharyngitis?
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strep pyogenes - strep pharyngitis - PAIN, fever
adenovirus - adenovirus infection - conjunctivitis, red eyes EBV - mono - FATIGUE |
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How is CMV transmitted?
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via body fluids - milk, placenta, birth canal, saliva #1, sexually , blood, organ transplant
does NOT produce heterophile Abs latency site - leukocytes, kidney, cervix Dx - CMV Ab, Owl eye intranuclear inclusions (multinucleated giant cells with very prominent intranuclear inclusions |
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When will you see CMV retinitis
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common in AIDS pts with a CD4 <50.
pizza pie retina - causes blindness Tx - ganciclovir |
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What is caused by HHV-8 infections?
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Kaposi's sarcoma
most common cancer in AIDS pts - inactivates RB gene - uncontrlled cell growth malignancy of vascular endothelium with extravsation of blood - dark purple, float to nodular lesions on skin, in oral cavity, GI tract, on sole and in l ungs B cells become neoplastic too - primary effusion lymphoma |
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WHat RNA virus is responsible for the common cold?
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Rhinovirus (picornaviridae)
transmitted by respiratory droplets and dired droplets |
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What are the 4 types of polio?
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inapparent asymptomatic infection
abortive poliomyelitis - most common - mild, fever, headache, sore throat, n/v, recovery non-paralytic poliomyelitis - fever, headache, stiff neck paralytic poliomyelitis - flaccid paralysis - preceded by painful muscle spasm |
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What does rotavirus cause?
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pediatric gastroenteritis (#1 cause in children)
replicates in small intestine mucosal cells, leading to diarrhea |
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What can influenze A, B lead to?
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atypical pneumo (quickly fatal)
secondary bacterial pneumo (fatal) Reye's syndrome in children (if given aspirin) Flu A is endemic with the potential of causing a pandemic (due to surface glycoproteins H and N) Flu B is epidemic |
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What are the H and N antigens?
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H - hemagglutin - bind to a cell surface receptor to initiate infection. The immune system perceives this as an antigen, thereby producing antibody to it and preventing future diesase
N - neuraminidase - cleave the cells neuraminic acid to allow for release of newly produced virus from the cell. The immune system perceives this as an antigen, thereby producing antibody to it that aids in reducing the severity of the disease |
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What is the progression of measles?
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enters upper resp tract - enters blood - enters RES - enters skin vasculature endothelium - rash (stars on face and goes downward)
koplik spots (red lesions with white center) in mouth - then rash and high fever |
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What xray sign is seen with croup?
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steeple sign - due to swelling of soft tissue around trachea
causes harsh barking cough an stridor |
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What is the #1 lower respiratory infection of infants?
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RSV (respiratory syncytial virus)
also a major cause of OM in children and pneumo in elderly causes URI in adults |
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What is SARS?
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sever acute respiratory syndrome
caused by the coronavirus severe atypical pneumo with high fever, nonproductive cough, dyspnea, headache, and hypoxia xray shows ground glass infiltrates without cavitation |
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What are the 4 families that include arboviruses?
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RNA viruses that are arthropod borne
Togaviridae Flaviviridae Bunyaviridae Reoviridae |
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What are the two different infections from alphavirus (togaviridae)?
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Eastern Equine Encephalitis
V - mosquito R - birds H - humans, horses encephalitis, high fever, 50% fatal - mostly SE US Western Equine Encephalitis V - mosquito R - birds H - humans, horses encephalitis, high fever, may be fatal - Western US |
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What is the difference between Dengue Fever and Dengue Hemorrhagic Fever?
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DF:
V - mosquito R - humans and monkeys world-wide in warm, humid environments - high fever, rash, bone/joint pain, then symptom free for several days, then high fever with new rash DHF same vector, reservoir and range as for DF. Occurs with re-exposure to DF after having a past history of DF high fever, shock due to hemorrhage, SEVERE - often fatal |
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What causes California Enceophalitis?
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Bunyavirus
V - mosquito R - rodents H - humans occurs mostly in north central US - usually mild with headache, but may be evere with headache, confusion, fever; rarely causes death |
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What colorado tick fever?
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Coltivirus
V - wood tick R - small rodents H - humans occurs in rocky mountains - high fever, HA, retro-orbital pain, severe myalgia, then remission x several days - fever for several weeks Reoviridae family |
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What is Hantavirus Pulmonary Syndrome?
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bunyavirus (robovirus - rodent borne)
V/R - deer mice H - humans transmitted via respiratory route occurs thru-out US, but mostly in western US flu-like symptoms, then acute resp failure - 60% mortality rate, even with hospital support |
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What is the MOA of rabies virus?
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virus in saliva of infected mammal - virus injected into skin - multiples at bite site - travels retrograde up sensory neurons to CNS - multiplies in CNS and cause encephalitis - kills neurons and oligodendrocytes - also travels down nerves to salivary glands and other organs - excreted with saliva production
(+) negri bodies |
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What causes norovirus gastroenteritis?
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norovirus (calicivirus) - fecal oral route
usually occurs at schools, camps, cruise ships nausea, vomiting, diarrhea x12-24 hours |
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What is kuru?
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trembling disease
spongiform encephalopathy rigid limbs, pathologic bursts of laughter terminal state marked by placidity and muteness death within 3-12 months secondary to decubitus ulcers or pneumo acquire via cannibalism of human brain |
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What is seen in Crutzfeld-Jakob Disease?
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memory deficits, ataxia, rigidity - 40-60 y/o
terminal state marked by akinesia and muteness - death within 3-12 months of symptom onset - usually by pneumo acquired via tisue transplants (contaminated with CNS tissue) or human growth hormone (from pituitary) or intracerebral electrodes. |
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How do retroviruses infect humans?
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enveloped RNA viruses whose RNA undergoes "reverse transcription" after infection of the target cell.
the RNA is transcribed to make DNA via an enzyme known as reverse transcriptase. |
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What are the major HIV genes and gene products?
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gp 160 - when cleaved becomes gp 41 and 120
gp 41 binds CCR5 or CXCR4 gp 120 binds CD4 receptors gag - gene that codes for the capsid protein of HIV - p24 pol - gene that codes for multiple enzyme for HIV, including reverse trancriptase env - gene that codes for glycoroteins that exist on the envelope of HIV - gp 41 and 120 tat - gene for transactivation of transcription (increases transcription rate) nef - gene that works to decrease class 1 MHC synthesis on infected cells; induces healthy CD8 cell death |
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How is HIV acquired?
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sexually, IV drug use, breast feeding or birth canal, transplacentally, blood transfer
takes many more viral particles to establish an HIV infection compared to Hep B acts as a super Ag, working to actually be physically presented to DC4 T cels by antigen presenting cells. |
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What is the treatment for HIV?
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HAART - highly active antiretroviral therapy
2 nucleoside reverse transcriptase inhibitors (NRTI) + EITHER (1 protease inhibitory OR 1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) or 1 integrase inhibitory |
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Describe the acute stage of HIV
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begins 2-4 weeks after infection and resolves in 2 weeks
fever, lymphadenopathy, sore throat, lethargy - rash on trunk and extremities (not soles and palms) anti-HIV Ab are generally formed within 3-4 weeks after infection eventually a set-point viral load is established |
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Describe the middle, latent stage of HIV
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lasts for years; asymptomatic
clinically latent - virus is not latent (CD4 continues dropping) in later months of latent stage, some symptoms start to arise: increasing frequency of fatigue, weight loss, persistent fevers, lymphadenopathy, as well as infections - HSV, Candida |
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What is the prophylaxis and treatment for Pneumocystis carinii pneumonia (P jirovecie P)
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P - start with CD < 200 - trimethoprim-sulfamethaoxazole
OR dapsone OR dapsone + pyrimethamine + leucovorin 2nd line - pentamidine OR atovaquone T - sulfamethoxazole-trimethoprim OR dapsone + trimethoprim alt: primaquine + clindamycin OR atovaquone alone |
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What is the treatment of CMV retinitis?
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ganciclovir (DOC) + Valganciclovir until CD4 > 100
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