Viruses and parasites Flashcards

Question

Adenoviruses | DNA virus

Answer 1

Clinical: * URIs- pharyngitis and cold * LRI- atypical pneumonia and bronchitis * Keratoconjunctivitis * gastroenteritis * UTI, hemorrhagic cystitis * stimulate proliferation of adipocyte stem cells Asym or self limitnig PCR is lab test Adenovirus 14= LIFE THREATENING

Answer 2

>100 serotypes aerosal of resp droplets affects nose and conjunctiva= UPPER RESPIRATORY- mostly just nose SxS: sneezing, nasal discharge, sore throat, cough, headache **may play a role in asthma exacerbations in kids** | NO GI tract bc kill it

Answer 3

SARS-COV-1- severe acute respiratory syndrome * ATYPICAL PNEUMONIA MERS-COV (middle east respiratory syndrome) * SEVERE PNEUMONIA- camel is reservoir Sxs: coryza, scratchy sore throat, low fever no antiviral therapy or vaccine

Answer 4

Patho: RNA virus **Virus binds to ACE-2 thru the receptor binding domain of its spike protein**- present in many tissues Resp manifestations: * **Killing of alveolar cells -> accumulate cellular debris blocking diffusion of o2 into capillaries causing hypoxia * Killing of endothelial cells in capillaries lining alveoli-> causes blood clots and cytokine storm** Symptomatology: 1/3 pt asymp cough, fever, myalgia, headache, dyspnea, sore throat, anosmia and ageusia in less than 10% Disease severity: mild= 81% severe= 14 critical= 5% fatality rate = 2.3%

Answer 5

1. Intrinsic factors- age, male, ethnicities 2. Social factors- smoking, inactivity, substance use disorders 3. Immune compromise- cancer, HIV, use of steroids 4. Pulmonary conditions- asthma, chronic lung disease, cystic fibrosis, tb 5. cardio/hemat conditions-heart failure, CAD, cardiomyopathies, TYPE A BLOOD 6. neuro- cerebral palsy 7. Endocrine- DM1&2, obesity, pregnancy 8. Other- chronic kidney/liver disease

Answer 6

* Cardiac- arrhythmia, myocardial injury, heart failure, shock * thromboembolic- DVT and PE * Neurologic- encephalopathy- increased depression * inflammatory- **cytokine release syndrome** * long term sequelae- long Covid- fatigue, memory problems, dyspnea, chest pain, cough, cognitive deficits

Answer 7

1. Poliovirus 2. Coxsackie virus- Group A, B 3. Norovirus 4. Rotavirus

Answer 8

Transmit: **fecal-oral route-> replicates in oropharynx and gut** travels to CNS via bloodstream ->motor neurons of spinal anterior horn cells->**death of these neurons causes paralysis** Affects brainstem ("bulbar" polio)-> leads to respiratory paralysis spectrum of infection: 1. **asymptomatic 99%** 2. abortive- mild fever, headache .8% 3. non-paralytic- aseptic meningitis w/ meningismus .15% 4. **paralytic: flaccid paralysis .05%- signs of viral meningitis, back, neck, and muscle pain** Postpolio syndrome- yrs after acute illness-> deterioration of residual fxn of affected muscles Vaccine: **Killed IPV (salk)** live attenuated vac OPV- DC bc rare reversion to virulence, can't be given to immunodeficient, coinfection of GI tract

Answer 9

trans: fecal oral, resp aerosols *summertime virus* Type A: **23 serotypes 1-24 missing 23-> predilection for skin and mucous mem**- handfootandmouth, hemorrhagic conjunctivitis Type B: 6- for organs-myocarditis, pericarditis, pleurodynia A&B: **aseptic meningitis and common cold** Causes: acute flaccid paralysis-> **resembles poliomyelitis**

Answer 10

Pleurodynia- infxn of intercostal muscles fever, severe pleuritic type chest pain **Myocarditis and Pericarditis** * fever * chest pain * signs of congestive heart failure rare: pancreatitis and hepatitis

Answer 11

Norovirus- Norwalk virus: * **most common cause of VIRAL GE in adults, MC in kids** * Transmission: fecal oral- close quarters **cruise ships** * Sudden onset vomiting and watery diarrhea, low grade fever and abdominal cramping Complications: **CNS involvement- headache, meningismus, photophobia, obtundation** Rotavirus: * **common cause of viral GE in kids- vaccine has lowered incidence** * transmission: fecal oral * sxs: n/v/d * management: fluids * vaccin avail

Answer 12

1. Rabies virus 2. Arbovirus 3. West nile virus

Answer 13

Transmission: saliva with bite of rabid animal aerosolized bat excrement transplanted corneas Incubation: 2-16 wks depending on site of bite **retrograde axonal transport in sensory neurons to CNS** sxs: * prodrome- fever, anorexia, paresthesia at bite site * Progression- Furious and Dumb * Furious form- agitation, delirium, seizures and hydrophobia= pharyngeal spasms - dont want to swallow * Dumb form- ascending paralysis * Eventual coma and death Negri bodies in brain- intracellular masses of virions, unassembled viral components Post exposure: passive (Ig in bite) and active immunization- vaccine

Answer 14

Clinical picture: 1. encephalitis- eastern, western equine encephalitis, st. louis, california encephalittis, colorado tick fever, **west nile encephalitis** 2. Hemorrhagic fever: Yellow fever and Dengue hemorrhagic fever 3. Fever w/ systemic sxs: Zika fever, chikungunya fever Yellow fever- afria and SA- mosquito * sudden onset fever, headache, myalgias, photophobia, jaundice **dengue:** break bone fever, SE USA Sxs: **flu like illness w fever, lymphadenopathy, severe myalgias and arthralgias, leukopenia, rash** can progress to hemorrhagic fever

Answer 15

US: encephalitises Outside: Yellow fever, dengue, zika virus

Answer 16

1. West nile fever * fever +/- low grade, headache, malaise, back pain, lack of appetite, myalgias 2. west nile neuroinvasive disease * fever + meningitis (kids), encephalitis (older adults), flaccid paralysis, or mixed pattern of dx

Answer 17

SXS: **80% asymp** * **common: fever, myalgia, arthralgia, nonpurulent conjunctivitis, pruritic rash, headache, dyesthesia, retroorbital pain** * Occasional: **gi sxs, mucous membrane ulcerations** Incidence: found in miami beach -> recommended that pregnant women avoid travel to these areas during epidemics

Answer 18

Severe MICROCEPHALY w/ partially collapsed skull * ventriculomegaly- large * thin, hypoplastic corpus callosum * insuff proliferation and defective migration of early neurons * concern for later congnitive issues even in bnabies without obvious problems | all in purple

Answer 19

**Retrovirus- changes viral RNA to viral dna with REVERSE TRANSCRIPTASE** HIV- infects and kills CD4 t cells-> loss of cell mediated immunity **CXCR & CCR5 chemokine receptors- required for entry of HIV into cd4 cells** Sxs: Acute HIV syndrome= Flu like/mono like illness with high viremia **fever, weightloss, malaise, headache, myalgia, rash, lymphadenopathy, n/v, organomegaly, pancreatitis, sore throat, lethargy** Epidemiology: 82% male and 18% female-> bc msm and iv drug use SEX DRUGS AND TRANSFUSIONS Untreated infection: latency period varies tremendously, some**develop AIDSA IN AS LITTLE AS A YEAR OR LESS** AIDS indicator disease: fungal, protozoal, viral and bacterial | Cant fight anything so catch everything

Answer 20

1. Kaposi sarcoma 2. Pneumocystis jirovecii pneumonia- diffuse through lungs

Answer 21

1. screening: HIV 1&2 AB AND p24 Ag-> positive 2. HIVab differentiation immunoassay-> Positive on screening and Negative on AB diff= NAT 3. Reactive NAT w/ negative or indeter. Ab diff= HIV1 infxn or Negative NAT w/ indeter. Ab diff= False positive 1st: screening and testing 2nd: HIV RNA viral load (PCR), CD4 count, and ART resistance assay (see what drugs to use)

Answer 22

Parasites: 1. Protozoa- unicell 2. Helminths- multicell- **Eosinophilia**

Answer 23

1. Entamoeba histolytica- Amebic dysentery 2. Giardia lamblia- Giardiasis 3. Cryptosporidium hominis- Cryptosporidosis 4. Trichomonas vaginalis- Trichomoniasis 5. P. Falciparum or P. vivax- Malaria 6. Toxoplasma gondii-Toxoplasmosis 7. Trypanosoma cruzi- Chagas disease

Answer 24

Amebic dysentery- fecal oral 90% asymp 10% GI sxs: * bloody mucus diarrhea * lower abdominal discomfort RF: MSM DX: stool O&P

Answer 25

Ingestion of cysts in fecal contam 50/50 asym and sxs: * watery foul smelling diarrhea * nausea * anorexia * flatulence * abdominal cramps DX: stool O&P with ELISA purify water when camping

Answer 26

Fecal oral occurs in outbreaks SXS: **opportunistic infx in immunocomp-> watery diarrhea** **self limited in immunocomp hosts** Chlorine tolerant

Answer 27

Sexually transmitted sxs: **watery, foul smelling pale green frothy discharge with itching/burning** Dx: wet mount tx: metronidazole

Answer 28

1. P. falciparum (blackwater fever)-> most severe 2. P. vivax 3. P. ovale 4. P. malariae Anopheles female mosquito SXS: **fever (spikes to 105.8 F) & chills, headache, myalgia, arthralgia** **fever progress to periodic cycles** Cycles= fever spikes, rigors, n/v, abdominal pain PE: splenomegaly, hepatomegaly, prominent anemia **DX: Giemsa stain** **untreated P. falciparum= brain and renal damage can lead to death**

Answer 29

Domestic cats infxn: ingest cysts in meat, CAT FECES Immunocompetant= Asymp or resembles mono (heterophile negative) Immunocompro= life threatening disseminated disease, encephalitis Congential= abortion, stillbirth: **chorioretinitis or intracranial calcifications** T in TORCH- mother must be infected during pregnancy ## Footnote BAD FOR PREGO

Answer 30

Trans: Reduviid bug **latin american countries-> immigrants and refugees come to US** Acute: **nonspecific= malaise, fever and anorexia OR anorexia OR Asymp** Chronic: **Cardiac: HF, dysrhythmia, thromboembolism, chest pain syndrome GI: more common in southernmost geo, huge variation** if untx: **cardiac complications** MC cause of non ischemic cardiomyopathy in Latin America Testing: **serology**

Answer 31

1. Tapeworms * T. solium and T. saginata * E. granulosus 2. Intestinal roundworms * whipworm- trichuris * Ascarias - ascaris * Hookworm- necator * Pinworms- enterobius vermicularis * Trichinosis- trichinella spiralis 3. Tissue roundworm * Larva migrans- toxocara or ancylostoma

Answer 32

Taenia solium- pork tapeworm: 1. Taeniasis (caused by adult worm)- asymp to anorexia and diarrhea-> undercooked pork 2. Cysticercosis (from larvae)- ingestion of eggs-> systemic infxn including brain Taenia saginata- beef tapeworm Asymp to mild GI sxs undercooked beef DX: O&P to find proglottids

Answer 33

Dog tape worm- dogs definitive host Causes: liver cysts, lung cysts, cerebral cysts (abdominal, chest pain, hemoptysis, headache and focal neuro signs) **rupture of cyst-> anaphylaxis due to massive ag release**

Answer 34

Whipworm- trichuris- asx to diarrhea==== **ingestion of worm eggs from food/water contam w/ human feces** Ascariasis-ascaris- GI sxs============== Hookworm- necator- walking barefoot in soil= gi and pulmonary | South/southest USA, areas of contaminated soil

Answer 35

Enterobius vermicularis- exclusively human parasite ingestion of worm eggs **perianal pruritis** Scotch tape technique to remove eggs

Answer 36

Trichinella spiralis- raw pork, **bear meat** Diarrhea few days after consuming undercooked meat 1-2 wks later: **fever, myalgia, eosinophilia, periorbital edema with subconjunctival hemorrhage** cardiac and cns disease

Answer 37

Visceral larva migrans: toxocara larvae * dog as host * ingestion of soil containing eggs-> migrate to brain, liver, and eyes Cutaneous larva migrans: ancylostoma larvae * penetration of skin by larvae-> walking barefoot in feces soil * **southern US**

Answer 38

1. Scabies 2. Pediculoses

Answer 39

* **intense, generalized pruritic rash- worse at night** * **inflammatory pruritic papules, pustules, vesicles, and nodules** * **pathognomonic fiding is a burrow in hands, feet, or finger webs**

Answer 40

Capitis: mostly children * pruritus MC * small red papules under hairline * erythema w/ honey colored crust Pubis: sexually active