HHV8

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Retroviruses

• Family of viruses that
• carry reverse transcriptase (RTase)
• ssRNA - dsDNA via RTase (error prone)
• replicate through DNA provirus intermediate
• Many carry integrase - can integrate into host
  genome
• Oncoviridae carry oncogenes, can cause malignant
  transformation
• Lentiviridae exogenous transmission, generally
  cytopathic (ex. HIV)

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HIV

• Envelope lots of Ag variation
• gp120 binds CD4, coreceptor(CXCR4 on T cells,
  CCR5 on macrophages)
• gp41 may bind coreceptor
• Capsid p24 core protein
• ssRNA genome
• 5 cap, ployA tail, flanked by LTRs (RQ for
  integration)
• gag - capsid proteins
• pol - RTase, protease, integrase
• env - envelope glycoproteins
• tat - transactivator, regulates virion
  production
• nef - positive regulator of virus production,
  down-regulates CD4
• CD4 cells
• Latent infection provirus is integrated into
  cell
• When these cells are activated, produce
  infectious virions
• Established early in course of infection

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HIV infection

• Acute infection
• Wide dissemination and organ seeding,
  establishment of latent reservoirs
• Contained by CD8 response subsides in a few
  weeks
• Establishment of viral load steady state by 4-6
  months post infection level influences course
• Persistent replication from infection - death
• Latency
• Clinically asymptomatic
• Progressive destruction of CD4 cells
• memory cells selectively depleted
• AIDS CD4
• Fever, weight loss, night sweats
• Opportunistic infections candida, PCP, Kaposis
  sarcoma, histoplasmosis, toxoplasmosis, CMV

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HIV

• Acquired by sexual contact, parenterally,
  vertically
• Low efficency of transmission
• Some people innately resistant or acquire
• Post-exposure prophylaxis reduces maternal-fetal,
  needlestick transmission
• Dx
• ELISA screening test - detects Abs lots of false
  
• Western Blot - detects p24, gp120
• Viral load - measure RNA copies in plasma
• Rx RTase inhibitors (nucleoside and
  non-nucleoside), protease inhibitors - combo Rx

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Oncoviridae

• ssRNA (diploid)
• HTLV-1
• See in S Pacific, W africa, Caribbean African
  populations
• adult T-cell leukemia
• Most are smoldering, some acute
• Skin lesions, hepatosplenomegaly
• tropical spastic paraparesis
• Insidious onset of spinal cord demyelination
• HTLV-2 no known disease (yet)
• More common than -1 see in IVDA, Native
  Americans
• Rx AZT, prevention by screening blood organs

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• Hepatitis A
• ssRNA, no envelope, icosahedral capsid
• Picrornavirus
• Hepatitis
• Fever, vomiting, RUQ pain, jaundice
• No chronic carriers or carcinoma
• Fecal - oral transmission
• Hepatitis B
• dsDNA, circular genome, enveloped hepadnavirus
• Virion contains DNA polymerase with RTase
  activity
• Parenteral/sexual/vertical transmission

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Possible outcomes of infection in Hep B
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Hepatitis D

• Viroid with ssRNA, circular, helical capsid
• Parasite of HBV - steals HBsAg, envelope
• Coinfection with or superinfection of HBV
• Increase incidence of acute fulminant hepatitis
• More rapid cirrhosis
• Parenteral acquisition
• IVDAs in US
• Dx serology - IgG or IgM
• Rx prevent with HBV vaccine

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Hepatitis C

• ssRNA, enveloped, icosahedral Flavivirus
• Parenteral transmission (maybe sexual)
• Does not integrate persists in hepatocytes,
  macrophages, latent in WBCs

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Hepatitis C disease spectrum
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• Hepatitis E
• ssRNA, naked Calcivirus
• Self-limiting hepatitis, like HAV
• High fatality in pregnant women
• No chronic carriers
• Hepatitis G
• ssRNA, enveloped, no visible capsid
• Flavivirus
• No known disease

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Poxviridae

• Linear dsDNA in dumbbell shape 2 envelopes
• Differs from most DNA viruses - replicates in
  cytoplasm
• Thus carries all enzymes needed for RNA synthesis
• Produces cell lysis to release virions
• VariolaSmallpox
• Humans only reservoir all infections produce
  overt disease
• Spread via inhalation, close contact
• Secondary viremia
• Seeds liver, spleen, BM, dermis
• Characteristic pustular rash
• Vaccine vaccinia (cowpox avirulent, mostly but
  occasional dissemination, mortality in
  immunosuppressed)
• Monkeypox
• Disease looks a lot like smallpox
• Get from direct contact with animals in Africa
• Nodular to wartlike lesions
• Spread by direct contact or fomites
• More common in kids, AIDS pts

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Herpes viruses

• Transmitted by saliva other stuff - sex, etc.
• All herpes viruses can develop a latent state
  lytic and latent cycles
• HSV-1
• Reactivation from trigeminal ganglia
• Cold sores, fever blisters
• Herpatic keratitis - corneal blindness
• Encephalitis
• Disseminated infection in immunocompromised
• Can cause genital neonatal herpes, but HSV-2
  more likely
• HSV-2
• Reactivation
• Genital herpes - Painful vesicles on genitals
  burning, itching, dysuria
• Neonatal herpes - transplacental or perinatal
• Meningitis
• Disseminated disease in immunocompromised
• Can cause eye/skin/oral disease, but usually
  HSV-1

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VZV

• Primary disease
• Chicken pox
• rash starting on face trunk - dewdrops on a
  rose
• In adults immunocompromised, can have serious
  disease
• Reactivation
• Shingles
• Reactivates from latency in dorsal root ganglia
• Burning, painful vesicles, restricted to
  dermatome
• Increasing incidence with age
• Dx cytology, Ag/DNA detection
• Live attenuated vaccine

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• HHV-6 Roseola
• Febrile seizures
• Latency in B cells
• Common in infants
• CMV
• Primary infection
• Mononucleosis - Heterophile negative
• Congenital disease
• Microcephaly, rash, retardation, deafness
• Reactivation disease in immunocompromised
• In BMT pneumonia
• In HIV retinitis
• Latency in monocytes, T-cells, BM stroma
• Dx cytology - nuclear AND cytoplasmic inclusions

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HHV-8

• Kaposis sarcoma
• Especially in males, immunosuppressed
• NOT ubiquitous
• Infects B cells, spindle cells

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EBV

• Mononucleosis
• Heterophile positive
• Lymphocytosis, hepatosplenomegaly, pharyngitis
• Encephalitis
• Lymphoprolifertative disease
• Infects transforms B cells
• Burkitts lymphoma
• Nasopharyngeal cancer
• Hairy leukoplakia in AIDS pts
• Disease post transplants
• Dx Downey cells, heterophile Abs
• Rx only leukoplakia (acyclovir)

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adenoviruses

• Direct/oral contact, fomites
• Many serotypes
• Upper respiratory illnesses
• Rhinitis
• Pharyngitis conjunctivitis
• Pertussis-like illness
• Gastroenteritis
• Keratoconjunctivitis
• Hemorrhagic cystitis nephritis
• Pneumo, hepatitis in immunocompromised
• Lytic, latent and oncogenic infections
• Dx smudge cells
• Oral live vaccine in military

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Polyomavirus

• Ubiquitious, worldwide
• Respiratory transmission
• BK virus
• Mild/asymptomatic infection in kids
• Hemorrhagic nephritis in immunosuppressed
• Latently infects kidney cells
• JC virus
• Progressive multifocal leukoencephalopathy in
  immunosuppressed
• Demyelination in CNS - impaired speech,
  paralysis, death
• Latent in B cells, replicates in oligodendroglia
  in reactivation infection

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HPV

• Spread by direct contact, sex, fomites
• Lots of serotypes with tropism for various
  anatomic regions
• Cutaneous warts
• Genital warts
• Perinatal transmission - laryngeal papillomas
• Cervical cancer (HPV16, 18)
• Integration of DNA in cervical epithelial cells
• Dx koliocytes on pap smear, PCR
• Tx surgical removal

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B19

• Fifths disease
• Slapped cheeks, lacy rash on arms, fever
• Rash caused by immune complex deposition
• Congenital infection - hydrops fetalis
• Aplasic crisis in chronic hemolytic anemia pts
• Persistant anemia in immunocompromised
• Replicates in BM cells - RBC, platelet lineage

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rotavirus

• Fecal/oral, fomites, nosocomial
• Most common in winter
• 1 cause of infectious diarrhea
• Segmented genome - gene reassortment
• Gastroenteritis
• Vomiting, diarrhea - dehydration
• Kids adults
• Causes lytic infection - destroys vili
• Vaccine recalled due to intussusception

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Flaviviruses

• One group of the arboviruses (arthropod
  transmitted) - cause encephalitis, fever
• Yellow fever
• Mosquito transmission
• Severe systemic disease - hepatitis,
  coagulopathy, hepatic necrosis
• Dx councilman bodies
• Live virus vaccine
• Dengue virus
• mosquito transmission
• Hemorrhagic fever or breakbone fever
• Rash, fever, back and bone pain
• A small develop hemorrhagic shock upon
  rechallenge with another strain

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Flaviviruses

• Encephalitis meningitis
• Mosquito transmission, bird reservoir humans are
  incidental hosts
• St. Louis - US, summer
• Japanese B - inactivated vaccine available
• West Nile - East coast, esp elderly pts
• Tick transmission
• Powassan - Canada
• Russian

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Coronaviruses

• SARS
• Common cold, mainly in kids
• Second most common cause
• Winter spring
• Rare pneumonia
• Transmitted by aerosols, droplets
• Dx not usually done ELISA
• Rx supportive

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Rubella

• Transmitted by respiratory droplet
• German measles
• Mild febrile illness with rash, lymphadenopathy
• If mom is infected when fetus is
• Cataracts
• Heart disease
• Deafness
• Retardation
• No cell lysis kid excretes virus for years
• Live viral vaccine

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Alphaviruses

• Transmitted by mosquitoes
• Enters cells by endocytosis, fuses with endosome
  on acidification, replicates in cytoplasm,
  released by cell lysis
• Bird reservoir human is incidental host
• Flu-like syndrome and encephalitis
• WEE - W. US, Canada
• VEE - S/Central America, S. US
• EEE - E. US severe encephalitis
• Occasional paralysis, seizures, death
• Dx serology
• No Rx
• Killed vaccine

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Poliovirus

• Fecal/oral, fomites primarily
• Peaks in summer, early fall
• Polio
• Mild illness - most common asymptomatic or
  febrile
• Meningitis
• Paralytic poliomyelitis
• Anterior horn cells destroyed
• Increase risk with age
• Lytic infection
• Dx PCR, cell culture, Ab assay
• Vaccines
• Salk - inactivated
• Sabin - live oral

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Cocksackie

• Fecal/oral
• A hand, foot and mouth disease
• B
• Myocarditis/pericarditis
• Meningitis/encephalitis
• Neonatal sepsis
• Pleurodynia - sudden fever, unilateral pleurisy
• Juvenille diabetes?
• Infects GALT- viremia - infects organs
• Lytic infection
• Dx PCR of CSF, direct isolation
• Rx immunoglobulin as last ditch

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Echoviruses

• Fecal/oral
• Diseases a lot like cocksackie
• Meningitis
• Rash/fever
• Neonatal sepsis
• Mycoarditis
• Lytic infection
• Dx PCR
• Rx plecornaril for meningitis

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Rhinovirus

• Aerosols, fomites, hands
• Fall and spring
• Common cold
• Rhinorrhea, sneezing, sore throat, HA
• Grows best at 33 degrees
• Replicates in cytoplasm, lyses cells
• Dx clinical, cell culture
• Rx none

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Norwalk

• Fecal/oral, shellfish, contaminated food
• Year-round
• Gastroenteritis
• Adults kids
• Diarrhea with vomiting fever (like rotavirus)
• Replicates in cytoplasm, lyses cells
• Dx ELISA, cant culture

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Astrovirus

• Fecal/oral via contaminated foods
• Gastroenteritis
• Kids adults
• Diarrhea without vomiting
• Replicates in cytoplasm, lyses cells
• Dx ELISA, cell culture
• Rx none

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influenza

• Orthomyxovirus types A B
• Segmented genome
• Hemagglutinin - mediates attachment, fusion
• Neuraminidase - mediates virion release
• M2 - proton channel, promotes uncoating and
  release
• Transmitted by respiratory droplet in winter
• Causes the flu - fever, cough
• Complications
• Bacterial/viral pneumonia
• Reyes syndrome
• Post infectious encephalitis
• Endocytosis, fusion with endosome on
  acidification, transcription of genome in
  nucleus, release by lysis
• Dx serology, hemagglutination
• Rx zanamivir (NA), amantadine (M2, type A only)
• Killed vaccine

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Sin Nombre virus

• Hantavirus pulmonary syndrome
• High fever, cough, vomiting, pulmonary edema, CV
  collapse
• Endocytosis, fuses with endosome on
  acidification, replicates in cytoplasm
• Dx RT-PCR, IgM
• Rx ribavirin
• Found in Western US

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Measles virus

• Transmitted by respiratory droplet
• Winter spring
• Rubeola
• High fever, photophobia, cough, Kopliks spots
• Complications
• Pneumonia, hepatitis
• Encephalitis
• Acute
• Post-infectious
• Subacute sclerosing - 5-9 years later
• Persists without lysis in neurons
• Dx clinical, cytoplasmic inclusions and giant
  cells
• Rx Ig post exposure
• Live attenuated vaccine

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Mumps virus

• Mumps
• Parotitis
• Epididymitis/orchitis
• Meningitis, encephalitis
• Pancreatitis
• Carries own RNA-dependent RNA polymerase
• Rx none
• Live vaccine

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RSV

• Very contagious by resp droplet, hands, fomites
• Winter outbreaks
• Disease
• Kids febrile rhinitis pharyngitis
• Adults URI, rhinorrhea - common cold
• Pathogenesis
• F protein - fusion
• G protein - attachment
• Replicates in cytoplasm
• Dx fluorescent Ab, Ag detection
• Rx nebulized ribavirin in premies/immunocompromis
  ed. Maternal Ig not protective

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Parainfluenza

• Respiratory droplet
• 1,2 - autumn 3 - year around
• Disease
• Croup (laryngotrachobronchitis) - infants
• Subglottal edema, tachypnea, tachycardia
• Cold-like Sx - pharyngitis, bronchiolitis,
  pneumonia
• Path
• F - fusion protein
• HN - attachment
• Replicates in cytoplasm
• Dx syncytia, immunofluorescence
• Rx humidity, steroids, epi

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Rabies virus

• Bullet shaped
• Transmitted by inhalation of aerosol, bite of
  infected animal bat reservoir in NW, cats dogs
• World-wide, year around
• Rabies
• Incubation weeks - months
• Prodrome 2-10 days - fever, HA, lethargy, pain
  at bite site - virus is in CNS
• Neurologic phase hydrophobia, encephalitis,
  paralysis, death
• Endocytosis, fuses w/endosome on acidification,
  replicates in cytoplasm, released by budding
• Carried to dorsal root - CNS - salivary glands
• Dx Negri bodies - cytoplasmic inclusions
• Rx vaccine, human If for post-exposre
• Inactivated vaccine

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Filoviruses

• Ebola marburg
• Fulminant hemorrhagic fever
• Flu-like Sx then n/v, diarrhea, rash
• Bleed from everywhere
• Death in up to 90, ebolamarburg
• Fast replication in cytoplasm, cell lysis
• Causes vascular injury, necrosis
• Dx Level 4 containment, RT-PCR, ELISA
• Rx quarantine, Ig, IFN
• Endemic in Africa

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arenaviruses

• Transmited from rodents - people by eating
  contaminated food, fomites, aerosols
• LCM
• Lymphocytic choriomeningitis
• Febrile illness, meningitis
• Dx level 3 containment, serology
• No person-person spread
• Lassa fever
• Fever, coagulopathy, petechiae, hepatic/splenic
  necrosis no vasculitis or CNS lesions
• Dx Level 4 containment, urine serology
• Person - person by bodily fluid contact,
  nosocomial
• Infects macrophages, replicates in cytoplasm,
  released by budding
• Rx supportive

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Some lists

• viruses transmitted by mosquito
• WEE, EEE, VEE
• Dengue
• Yellow fever
• Flaviviruses - St. Louis, Japanese B, W. Nile
• Stuff you cant culture
• Clostriduim tentani
• M. leprae (except in mouse foot pads)
• Coxiella
• Treponema pallidum
• Pneumocystis carinii
• Norwalk virus

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Virus calendar

• Winter spring summer fall
• Rota Rhino St. Louis Rhino
• Measles polio
• Corona
• RSV
• Influenza para 12
• Para 3
• Norwalk
• rabies

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Protazoa

• Free-living, single-celled, eukaryotic
• Ameba (sarcodina)
• Crawl around using pseudopods
• Reproduce by binary fission (asexual)
• Ciliates
• Reproduce by binary fission
• Flagellates
• Can live either in body tubes (gut or GU tract)
  or invade into tissues
• Reproduce by binary fission
• Sporozoa
• Sporogony - sexual
• Schizogony - asexual

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Entamoeba histolytica

• Most prevalent in tropics
• Fecal-oral transmission via food contaminated
  with cysts
• In colon, transforms into trophozoite (motile,
  feeding form)
• Attaches to gut wall (via GIAP-lectin)
• Forms amoeba pore - cytolysis
• Proteolytic enzymes destroy mucosa (flask-like
  ulcers), PMNs
• Ingests RBCs (only protazoan that does)
• Occasionally, gets into portal circulation

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Entamoeba histolytica

• Intestinal amebiasis
• Majority are asymptomatic
• Non-dysenteric
• Intermittent diarrhea, abdominal pain, localized
  ulcer
• Dysenteric
• Bloody diarrhea, tenesmus, widespread ulcerations
• Complications
• Ameboma, stricture
• Perforation
• Cutaneous spread
• Postinfectious colitis

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Entamoeba histolytica

• Extraintestinal amebiasis
• Portal circulation - liver sets up camp
• liver abscess, subdiaphragmatic abscess
• Erodes through diaphragm into thoracic cavity
• Empyema, pericarditis, infection of lung
• Hematogenous spread to lung, brain, spleen
• Increased risk with immunosuppression
• Dx stool OP X3, sigmoidoscopy, Bx, serology for
  invasive disease, EM - RBCs
• Rx metronidazole drug to eliminate cyst passage

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Naegleria fowleri

• Free-living in fresh H2O
• Water-up-the-nose transmission in S. US,
  inhalation in dust storms in Africa
• Mainly healthy kids, young adults
• Meningoencephalitis
• Fever, HA, stiff neck, n/v, seizures, coma dead
  in a week
• Dx look for motile trophs in CSF
• Rx pretty much hopeless, but try Ampho B,
  miconazole rifampin

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Acanthameba

• Free-living in soil, tap water can colonize
  mouth nose
• Spit-on-your-contacts transmission to eyes,
  reaches CNS via upper respiratory tract
• Meningoencephalitis
• Especially common fatal in immunosuppressed
  necrotic granulomas in CNS
• Keratitis uveitis - blindness
• In healthy hosts
• Dx cysts trophs in corneal scrapings, CSF
• Rx hard - topical miconazole, try itraconzole

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Giardia lamblia

• fecal- oral ingestion of food and water
  infected with cysts (or direct b/w people)
• Converts to troph in gut, adheres to small bowel
  wall
• Rarely invades
• Causes malabsorption - steatorrhea
• Persists by Ag variation
• T-cell damage, increased cell turnover
• Giardiasis
• Asymptomatic in many (2/3 endemic, 1/3 epidemic)
• Sx more likely in kids, primary infection,
  gastrectomy
• Explosive, stinky, greasy diarrhea
• Can be chronic
• Dx - stool OP/Ag cysts, trophs with 2 nuclei,
  falling leaf motility
• Rx metronidazole

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Trichomonas vaginalis

• Troph form only - sexual transmission
• Attaches by axostyle doesnt invade
• Persists by Ag variation
• WomenVaginitis
• frothy discharge, dysuria, dyspareunia
• Men usually asymptomatic
• Occasional urethritis, prostatitis, epididymitis
• Prostatic secretions, urine movement clear
• Dx wet mount of vaginal or prostatic fluid
  (Herky jerky movement), Ag detection
• Rx metronidazole

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Leishmania spp.

• Reservoirs rodents, humans, others
• Promastigote - infectious form
• Sandfly injects into humans phagocytosed by
  macros, converts to
• Amastigote - intracellular form
• Replicates by binary fission
• Replicates in RE system rupture, releases bugs,
  invades new macros
• Infected cells ingested by another sandfly
• Disease determined by host response
• Th1 - protective
• Th2 - more disseminated disease
• Dx Leishmania skin test - localized, -
  disseminated artificial liquid culture, PCR
• Rx pentavalent antimonial ampho B, azoles.
  Resistance ?

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Cutaneous leishmaniasis

• L. tropica (urban) L. tropica major (rural)
• Mediterranean, Middle E, India, Africa
• Oriental sore - indurated, painless ulcer
• L. tropica single facial lesion can disseminate
  cutaneously (like leprosy) or into viscera
• L.t. major multiple leg lesions can have more
  chronic infection - leishmaniasis recidiva
• L. mexicana
• Central America
• Chicleros ulcer - single ear lesion, destroys
  pinna
• Lesions usually self-limiting, heal in 6 months
• Dx scrape ulcer base culture, serology skin
  test

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Mucocutaneous leishmaniasis

• L. braziliensis
• Latin America
• Espundia
• Primary dermal ulcer at bite site satellite
  lesions, lymphangitis, lymphohematogenous spread
• Secondary 1-2 years later get ulceration of
  mucus membranes of nose mouth slowly destroys
  septum, soft palate, lips over 20-40 years
• Complicated by bacterial infection
• Dx skin test

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Disseminated leishmaniasis

• L. donovani
• E. Africa, India, S. America, Mediterranean
• Kala azar - disseminated visceral disease
• Th1 response is deficient, get chronic infection
  of RE cells
• see in malnourished kids
• Massive hepatosplenomegaly, abd pain, diarrhea,
  weight loss, fever, severe anemia,
  glomerulonephritis
• Dx - skin test amastigotes in macros from Bx
• Even w/Rx, kills 10-25. Frequent relapses

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Trypanosoma brucei

• Vector tse tse fly
• Metacyclic trypomastigote is innoculated form
  replicate in human blood stream, then picked up
  by new fly
• African Sleeping Sickness
• Acute chancre, fever, lymphadenitis, rash, HA
• Recurrent parasitemia escapes by Ag variation
• Parasites localize in small vessels of heart, CNS
• T. b. rhodesiense
• savannah tse tse, E. Africa
• cattle, antelope reservoir
• Subacute weakness, myocarditis, death in 6-9
  months
• T. b. gabiense
• riverine tse tse, W. Africa
• human reservoir
• Chronic gradual meningoencephalitis, death in
  mo-yrs
• Dx direct exam of blood CSF
• Rx Melaroprol, DFMO (really toxic)

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Trypanosoma cruzi

• Vector reduviid bug
• Epimastigote - in reduviid gut
• Trypomastigote - in reduviid poo
  (extracellular) infectious form
• Amastigote - in human cells
• Reservoir dog, cat, human, rodents, opposum
• Central/South America, S. US
• Chagas disease - American trypanosomiasis
• Chagoma at entry site - hard, red lesion local
  replication
• Invades blood, spreads to heart, smooth muscle,
  glia
• Recurrent fever, rash big liver, spleen, nodes
• Romanas sign unilateral conjunctivitis
  periorbital edema
• Chronic disease years later cardiac enlargement,
  arrhythmias, megacolon, megaesophagus
• Increased risk with immunosuppression
• Dx serology, direct exam of LN Bx, blood
• Rx acute - nitrofuramox, benznidazole

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Sporozoa transmitted by ingestion

• Oocyst
• Isospora, Cyclospora, Cryptosporidium
• All acid-fast
• All transmitted fecal- oral via contaminated
  water, food
• All cause diarrhea
• Tachyzoite
• Toxoplasma

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Cryptosporidium

• Ubiquitous
• Human- human transmission, zoonoses
• Ingest oocyst - sporozoites invade brush border
  - trophs in superficial vacuole - multiply
  asexually - merozoites
• Merozoites can invade new gut cells or form
  gametocytes - fertilized - oocysts passed in
  stool
• Does NOT require embryonation to be infective
• Gastroenteritis
• Normal host self-limited diarrhea (? absorption)
• Compromised host unremitting diarrhea, weight
  loss, fever
• Dx stool OP
• Rx albendazole or paromomycin for
  immunocompromised

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Isospora

• Found worldwide, esp in AIDS, Haiti
• Sexual asexual reproduction in intestinal
  epithelium
• Pass oocysts in feces
• Require embryonation in soil to be infective
• Gastroenteritis
• Can be asymptomatic - severe diarrhea
• Steatorrhea - mimics giardiasis
• Chronic intermittent diarrhea in
  immunocompromised
• Dx stool OP - ovoid oocysts
• Rx trimethoprim/sulfamethoxazole

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Cyclospora

• worldwide
• Inhabits upper bowel
• pass oocysts in feces
• Requires embryonation in soil
• Cyclosporiasis
• Asymptomatic - severe diarrhea
• More severe, prolonged in immunocompromised
• Dx stool OP - round oocysts
• Rx not usually needed

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Toxoplasma

• Alternating sexual asexual replication
• Definitive host cats
• Sporogony In GI tract, reproduce sexually -
  oocysts passed in stool
• Incubate in cat box for a few days - infective
• Intermediate host humans ( others)
• ingest - tachyzoites ( trophozoite) can infect
  any nucleated cell, especially like lung, heart,
  lymph, CNS, eye
• replicate by schizogony - tissue cysts
• Transmission
• Kitty litter, cat feces
• transplacental (TOrches)
• eat tissue cysts in another intermediate host
  (pork, beef)

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Toxoplasmosis

• Congenital
• 1st trimester - stillbirth
• Later - epilepsy, anemia, retardation, pneumo
• Reactivation chronic chorioretinitis - 2nd-3rd
  decade
• Acquired
• Primary infection
• asymptomatic
• Febrile lymphadenopathy
• Rarely, disseminated disease - myocarditis,
  pneumo
• Immune hosts cysts form intermittent rupture
• Relapsing chorioretinitis
• Encephalitis with immunosuppression (AIDS)
• Immunosuppressed get encephalitis, disseminated
  disease
• Dx serology, Bx - demonstrate trophs, cysts
• Rx pyrimethamine sulfadizaine for
  disseminated, immunocompromised, pregnant

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Plasmodium

• Vector Anopheles mosquito (definitive host,
  sporogony)
• Female mosquito ingests male female gametes -
  sporozoites - injected into humans (intermediate
  hosts)
• Attach to penetrate hepatocytes
• Some transform into dormant hypnozoite - can
  relapse
• Non-dormant - schizogony - merozoites released
• Merozoites endocytosed by RBCs - ring shaped
  trophozoite - rupture, releases more merozoites
  - invade new RBCs or produce gametes
• Gametes ingested by new mosquito

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Plasmodium

• Malaria is characterized by
• Rigors, fever - due to cytokine release with
  rupture of RBCs
• Fevers can become synchronous, especially in
  semi-immune hosts (high temps kill schizonts)
• May have paroxysms - cold then hot then wet
• Splenomegaly - infection of RBCs decreases
  plasticity - increased removal in spleen
• Anemia - due to increased clearance of RBCs in
  spleen, intravascular hemolysis
• Relapsing course - antigen variation, strain
  diversity
• Dx thin thick smears
• Rx chloroquine if sensitive

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Plasmodium falciparum

• Asia, Africa, Latin America tropics
• Malaria persists up to 1 year due to persistant
  trophs in blood
• Complication
• Rare paroxysms
• Synchrony - 36-48 hours
• Pernicious syndromes
• ARDS, shock, cerebral malaria, renal failure,
  blackwater fever (due to ICs, hemolysis)
• Dx banana shaped gametes, rings in RBCs IFA
• Rx often chloroquine resistant

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P. vivax P. ovale

• Subtropics, temperate Africa, Asia, L. Am
• Have hypnozoite (dormant) forms - can relapse
  for up to 5 years
• Tertian synchrony (48 hours)
• Dx rings in RBCs
• Rx mostly chloroquine sensitive need primaquine
  to kill hypnozoites

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P. malariae

• Uncommon in Africa
• Quatran synchrony (72 hours)
• Persists up to 30 years due to persistant blood
  forms (no hypnozoites)
• Rx mostly chloroquine sensitive

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Babesia spp.

• Vector Ixodes tick (hard tick) - definitive host
• Intermediate hosts - deer, mice, cattle, us
• NE U.S.
• Like malaria, but doesnt infect liver cells
• Babesiosis
• malaise, non-periodic fever
• Complications Hemolytic anemia, renal failure
• At risk with asplenia, immunosuppression
• Dx thick thin smear - maltese cross
• Rx quinine

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Microspora

• Worldwide
• Primitive eukaryotes
• Lack mitochondria, peroxisomes, golgi
• Genera that can infect humans
• Encephalitozoon, enterocytozoon, nosema,
  pleistophora, microsporidium
• Fecal - oral, swimming pools?
• Causes diarrhea, biliary disease, pneumo, eye
  infections, meningitis
• Most severe in immunocompromised, esp HIV
• Dx stool OP spores are acid fast
• Rx Albendazole

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A couple of things

• transmitted by ingestion - cysts (except
  toxoplasmaand even then, its sort of a cyst)
• Parasites that cause diarrhea
• Entamoeba
• Giardia
• Cryptosporidium
• Isospora
• Cyclospora

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Bugs that cause meningitis

• S. Pneumo
• N. Meningitidis
• H. Flu
• Cryptococcus
• Coccidioides
• LCM virus
• W. Nile
• Cocksackie
• Acanthameba
• Naeglaria
• Microspora

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Bugs that cause UTIs

• E. Coli
• S. Saprophyticus
• Klebsiella
• Proteus
• In the hosptital
• enterococci
• Psuedomonas

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Bugs that cause pneumonia

• S. pyogenes, pneumo influenza
• H. Flu toxoplasma
• Mycoplasma toxocara
• Klebsiella Echinococcus
• Psudomonas and many more
• Chlamydia pneumo, psittaci
• PCP
• Aspergillosis
• Histoplasma
• Coccidioides
• Cryptococcus

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Some rashes

• S. Pyogenes scarlet fever
• B. Burgdorferi erythema migrans
• R. Rickettsii RM spotted fever
• S. Typhi rose spots
• HHV-6 roseola
• Rubeola Kopliks spots
• B-19 slapped cheeks

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Bugs that like the eye

• C. trachomatis - trachoma
• Adenovirus - pink eye
• Rubella - congenital cataracts
• Toxoplasma - chorioretinitis
• Loa loa
• Onchocerca - river blindness
• Leptospira - conjunctival hemorrhage

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Bugs that can cause cancer

• H. pylori - gastric CA
• HTLV-1 - T-cell leukemia
• HBV, HCB, HDV - HCC
• EBV - Burkitts
• HHV-8 - kaposis
• HPV - cervical
• Clonorchis - cholangioCA
• S. haematobium - bladder

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The top 5 things I learned in microbiology
82
The top 5 things I learned in microbiology

• 5. Always get vaccinated against everything

83
The top 5 things I learned in microbiology

• 5. Always get vaccinated against everything
• 4. Wash my hands after I touch any part of my
  anatomy

84
The top 5 things I learned in microbiology

• 5. Always get vaccinated against everything
• 4. Wash my hands after I touch any part of my
  anatomy
• 3. Never walk barefoot in Africa or the American
  South

85
The top 5 things I learned in microbiology

• 5. Always get vaccinated against everything
• 4. Wash my hands after I touch any part of my
  anatomy
• 3. Never walk barefoot in Africa or the American
  South
• 2. Never, EVER eat anything raw

86
The top 5 things I learned in microbiology

• 5. Always get vaccinated against everything
• 4. Wash my hands after I touch any part of my
  anatomy
• 3. Never walk barefoot in Africa or the American
  South
• 2. Never, EVER eat anything raw
• 1. Stay away from indiscriminately defecating
  children

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Thats ityouve been wonderful

• Have a great summer
• Rest up! Second year is coming