Week 3 Micro
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Questions and Answers

What is a DNA virus that does not replicate in the nucleus?

  • Adenovirus
  • Papillomavirus
  • Poxvirus (correct)
  • Herpesvirus

    • What is tropism?

  • What cells/tissues the virus can infect (cell target) (correct)
  • The rate at which a virus replicates
  • The process by which viruses escape host immune responses
  • The genetic makeup of a virus

    • What is tropism linked to in viruses?

  • Disease and outcome (correct)
  • The replication speed of viruses
  • The size of the viral particles
  • The type of genetic material in the virus

    • What is an example of a non-enveloped, DNA virus?

    <p>Adenovirus</p> Signup and view all the answers

    What is an example of a non-enveloped, RNA virus?

    <p>Poliovirus</p> Signup and view all the answers

    What is an example of an enveloped RNA virus?

    <p>Newcastle disease virus</p> Signup and view all the answers

    What is an example of an enveloped DNA virus?

    <p>Herpes Simplex Virus</p> Signup and view all the answers

    Which of the following is a necessary component of an infectious virus particle? (2)

    <p>Genome</p> Signup and view all the answers

    Which of the following is not a required component of an infectious virus particle?

    <p>Envelope</p> Signup and view all the answers

    What is an example of an adenovirus?

    <p>Common cold</p> Signup and view all the answers

    What disease can be caused by papillomaviruses?

    <p>Cervical cancer</p> Signup and view all the answers

    Which of the following is not an example of a Naked dsDNA virus?

    <p>Parvovirus</p> Signup and view all the answers

    Which disease can Polyomaviruses cause?

    <p>BK polyoma (immune compromised)</p> Signup and view all the answers

    What disease can hepadnaviruses cause?

    <p>Hepatitis B</p> Signup and view all the answers

    What diseases can herpes viruses cause? (Select all that apply)

    <p>HSV1</p> Signup and view all the answers

    What disease can poxviruses cause?

    <p>Smallpox (variola major)</p> Signup and view all the answers

    Which of the following is not an enveloped dsDNA virus?

    <p>Adenovirus</p> Signup and view all the answers

    Which of the following is a ssDNA naked virus?

    <p>Parvovirus</p> Signup and view all the answers

    What disease can picornaviruses cause?

    <p>Hepatitis A</p> Signup and view all the answers

    Which of the following is not a ssRNA positive naked virus?

    <p>Flavivirus</p> Signup and view all the answers

    What ssRNA positive enveloped virus is responsible for Hep C infections?

    <p>Flavivirus</p> Signup and view all the answers

    Which of the following is not a positive-sense single-stranded RNA (ssRNA) enveloped virus?

    <p>Measles virus (Paramyxovirus)</p> Signup and view all the answers

    What disease is caused by bunyaviruses?

    <p>Hantavirus Pulmonary Syndrome</p> Signup and view all the answers

    What is an example of a dsRNA (+/-) naked virus?

    <p>Reovirus</p> Signup and view all the answers

    Match each virus to its shape

    <p>Helical = Tobacco mosaic virus Polyhedral = Adenovirus Spherical = Influenza virus Complex = Bacteriophage</p> Signup and view all the answers

    What is the cytopathic effect?

    <p>The structural changes in host cells caused by viral infection</p> Signup and view all the answers

    Which of the following is not a virus with hemagglutinin?

    <p>HIV</p> Signup and view all the answers

    Which virus life cycle step is defined as the first encounter of virus particles with host cells and requires attachment proteins and cellular receptors?

    <p>Attachment</p> Signup and view all the answers

    What mediates endocytosis and penetration of DNA viruses into host cells?

    <p>Clathrin</p> Signup and view all the answers

    What is the second step in the virus life cycle?

    <p>Penetration</p> Signup and view all the answers

    What is the critical 3rd step in the viral life cycle?

    <p>Uncoating</p> Signup and view all the answers

    What is the fourth step in the virus life cycle? (2)

    <p>Replication</p> Signup and view all the answers

    What is an example of a negative sense RNA virus?

    <p>Influenza virus</p> Signup and view all the answers

    What are the final steps in the virus life cycle?

    <p>Assembly and release</p> Signup and view all the answers

    Which virus's life cycle is special and unique?

    <p>Hepatitis D Delta</p> Signup and view all the answers

    What are inclusion bodies?

    <p>Products of viral replication that aggregate in the host cell</p> Signup and view all the answers

    What is syncytia?

    <p>A phenomenon where multiple cells fuse to form a single cell with multiple nuclei</p> Signup and view all the answers

    Which of the following is an example of an oncogenic virus?

    <p>Human Papillomavirus (HPV)</p> Signup and view all the answers

    What is vertical transmission?

    <p>Transfer of viruses from parent to offspring</p> Signup and view all the answers

    Match each virus to its mode of vertical transmission

    <h1>Transplacental = CMV, parvovirus B19, Rubella, Measles, HIV (Treponema pallidum and listeria monocytogenes; toxoplasma gondii) At time of birth = HepB, HepC, HSV-2, HIV, HPV (N. gonorrhoeae, Chlamydia trachomais and group B strep) Breast Feeding = CMV, HTLV, HIV</h1> Signup and view all the answers

    What is horizontal transmission?

    <p>Transmission of viruses between individuals in the same generation (person-person)</p> Signup and view all the answers

    Match each virus to its horizontal transmission route

    <p>Respiratory = Influenza, Rhinovirus, RSV, EBV, VZV, HSV-1, CMV, Measles, Mumps, Rubella, Hantavirus, Adenovirus, Parvovirus B19 GI Tract = HepA, Poliovirus, Rotavirus, Norovirus Skin = Rabies, Yellow Fever virus, Dengue virus, Human papillomavirus Genital Tract = HPV, HepB, HIV, HSV-2</p> Signup and view all the answers

    What is an example of a blood-borne virus?

    <p>HIV</p> Signup and view all the answers

    Which virus avoids immune defenses by restricting its expression of viral antigens?

    <p>HIV</p> Signup and view all the answers

    Which virus avoids immune defenses in the following way: Antiviral antibody-induced internalization and modulation of viral antigens?

    <p>Measles</p> Signup and view all the answers

    Which virus uses its viral antigenic variation to evade immune detection?

    <p>HIV</p> Signup and view all the answers

    Which virus prevents the binding of neutralizing antibodies to evade immune cells?

    <p>Measles virus</p> Signup and view all the answers

    Which virus decreases the expression of MHC to evade immune cells?

    <p>Herpes Simplex Virus</p> Signup and view all the answers

    Which virus restricts expression of cell adhesion molecules LFA-3 and ICAM-1 to evade immune cells?

    <p>Herpes Simplex Virus</p> Signup and view all the answers

    What virus can infect immune privileged sites?

    <p>Herpes virus</p> Signup and view all the answers

    What is dissemination?

    <p>The process of spreading information or disease</p> Signup and view all the answers

    What is viremia?

    <p>The presence of viruses in the bloodstream</p> Signup and view all the answers

    Match each acute infection to its severity

    <h1>Mild = Cold virus Moderate = Influenza, SARS-COV-2 Severe = Rabies, ebola, MERS, avian influenza, SARS1</h1> Signup and view all the answers

    Match each chronic infection to its severity

    <h1>Mild = CMV Moderate = HepB, herpes simplex Severe = untreated HIV, HepC</h1> Signup and view all the answers

    What virus binds C3b (the opsonin)?

    <p>Herpes Simplex Virus</p> Signup and view all the answers

    What virus blocks IL-2, which is known as the activating T cell growth factor?

    <p>Measles</p> Signup and view all the answers

    What indicates the formation and breaking down of clots in the Renin-Angiotensin-Aldosterone System (RAAS)?

    <p>All of the above</p> Signup and view all the answers

    What disease can prions cause in cattle?

    <p>Bovine Spongiform Encephalopathy</p> Signup and view all the answers

    What can prions cause in sheep?

    <p>Scrapie</p> Signup and view all the answers

    What can prions cause in humans?

    <p>Fatal CNS disease</p> Signup and view all the answers

    Prions can be inactivated in a steam autoclave.

    <p>True</p> Signup and view all the answers

    Prions cause initiation of inflammatory response.

    <p>False</p> Signup and view all the answers

    What is the typical length of a prion?

    <p>5-100 nm</p> Signup and view all the answers

    What can prion disease in humans cause the proliferation of?

    <p>Astrocytes</p> Signup and view all the answers

    What is the infectious prion gene?

    <p>PrPsc</p> Signup and view all the answers

    What disease fits this description: Discovered in 1957 in the Fore people of New Guinea who practiced cannibalism? When the practice stopped, the disease also stopped.

    <p>Kuru</p> Signup and view all the answers

    Which disease fits this description: difficulty in sleeping, progressive dementia, and is fatal?

    <p>Fatal familial insomnia</p> Signup and view all the answers

    What disease fits this characteristic: progressive fatal disease, often seen in patients over 60, characterized by forgetfulness, disorientation, dementia affecting gait, seizures, with a progression of 4-6 months leading to eventual paralysis, wasting, pneumonia, and death?

    <p>Creutzfeldt-Jakob Disease</p> Signup and view all the answers

    What disease fits the following description: "mad cow" disease, life expectancy after diagnosis is 14 months?

    <p>Bovine Spongiform Encephalopathy</p> Signup and view all the answers

    Match each organisms to its classification description

    <p>Amoebozoa = move via pseudopodia/phagocytic/mitochondria have tubular cristae Ciliophora = have coordinate movement of rows of cilia only human parasite is Balantidium coli ( has 2 nuclei; large macronucleus and small micronucleus) Flagellate = Metamonada, Parabasala, Percolozoa, Euglenozoa Apicomplexa = organisms are called Sporozoa or Coccidia; sexually reproducing, spore-forming and have organelles at apical end that help organism penetrate host cells</p> Signup and view all the answers

    Which organism has the following characteristics:

    • Nutritional Requirement: Amebae, ameboflagellates and others use pinocytosis or phagocytosis of particulates; Some use simple diffusion or store food in vacuoles (granules)
    • Respiration: Facultative anaerobic process
    • Elimination of waste: extrusion of material at cell surface
    • Survival: Can form cysts
    • Immunoevasion: Change surface antigens to avoid detection
    • Reproduction: Binary fission; multiple fission?

    <p>Protozoa</p> Signup and view all the answers

    What organisms have the following description?

    • Complex multicellular: elongated and bilaterally symmetric
    • Usually macroscopic: 1mm – 1 m or larger
    • Worm external surface has a protective cuticle
    • Protective covering of a flatworm is called a tegument
    • Have attachment structures: hooks, suckers, teeth
    • Primitive nervous and excretory systems
    • Some have alimentary tracts: no circulatory system
    • 2 phyla: Nemathelminthes and Platyhelminthes

    <p>Helminths</p> Signup and view all the answers

    Which organisms fit the following description:

    • Nutritional requirements: Active ingestion of host tissue, fluids or both via tissue destruction; Passive absorption from environment; Rapidly metabolize carbs need energy for movement; Glycogen is stored fuel
    • Respiration: anaerobic, some larval forms require oxygen
    • Reproduction: most are oviparous; some have live births (viviparous)?

    <p>Helminths</p> Signup and view all the answers

    What organisms have the following characteristics? - Largest group of animals in kingdom Animalia, Complex multicellular organisms, Cause invasive or superficial (infestation) disease, Also a host and vector of infectious agents, Envenomation via biting or stinging arthropods results in allergic and hypersensitivity reactions that can lead to anaphylactic shock/death.

    <p>Arthropods</p> Signup and view all the answers

    What organisms have chitin covering exoskeletons, separate sexes, and gills for aquatic respiration?

    <p>Arthropods</p> Signup and view all the answers

    What is the structure of Plasmodium spp.?

    <p>Coccidia (sporozoan)</p> Signup and view all the answers

    What is the transmission mechanism of Plasmodium spp.?

    <p>Via Anopheles mosquito bites</p> Signup and view all the answers

    What is the pathogenesis of Plasmodium spp.?

    <p>Invasion of red blood cells and multiplication by merozoites</p> Signup and view all the answers

    In which geographic regions can Plasmodium spp be found? (Select all that apply)

    <p>Tropical and subtropical regions</p> Signup and view all the answers

    Which species of Plasmodium causes the most severe symptoms?

    <p>Plasmodium falciparum</p> Signup and view all the answers

    Which species of Plasmodium can establish a dormant liver phase?

    <p>Plasmodium vivax</p> Signup and view all the answers

    In which cell do Plasmodium spp. asexually reproduce?

    <p>Erythrocytes</p> Signup and view all the answers

    In which organism can Plasmodium sexual reproduction be initiated?

    <p>Anopheles mosquitoes</p> Signup and view all the answers

    For which of the following parasites is the Giemsa stain utilized?

    <p>Plasmodium</p> Signup and view all the answers

    Which parasite exhibits resistance to chloroquine?

    <p>Plasmodium</p> Signup and view all the answers

    Which viral infection has Negri bodies?

    <p>Rabies virus</p> Signup and view all the answers

    What viral infection is characterized by the presence of owl's eye inclusions?

    <p>Cytomegalovirus (CMV) infection</p> Signup and view all the answers

    What is the most sensitive method for detection and identification of parasites, but is not used widely?

    <p>Nuclear Acid Amplification Test</p> Signup and view all the answers

    Which organism displays the following structure:

    -Oval or pear-shaped protozoa -Similar to Plasmodium: infects RBC -Can be misinterpreted to be malaria?

    <p>Babesia</p> Signup and view all the answers

    Which of the following organisms has the following transmission: -Bite of an infected blacklegged (deer) tick, Ixodes scapularis -Transfusion of contaminated blood -Transfer from mother to baby during pregnancy or delivery?

    <p>Babesia microti</p> Signup and view all the answers

    Which of the following pathogens has the following pathogenesis:

    -The definitive host is the tick – sexual reproduction. Humans are infected when bitten by a tick – introduce sporozoites into human blood. -Sporozoites enter RBC and undergo asexual reproduction (budding). -Multiplication of the parasite produces clinical signs/symptoms.

    • Humans are dead-end hosts?

    <p>Babesiosis (Babesia spp.)</p> Signup and view all the answers

    Which of the following pathogens has the following clinical presentation:

    -Fever, chills, sweating, myalgias, fatigue, hepatosplenomegaly, hemolytic anemia -Symptoms occur 1 to 4 weeks post infection and lasts several weeks -Asymptomatic to life threatening – immune status of host is important?

    <p>Babesia Microti</p> Signup and view all the answers

    Which of the following pathogens is found in the US Northeast and upper Midwest, peaking during warm months?

    <p>Babesia microti</p> Signup and view all the answers

    Which of the following organisms has the following structure: -Phylum Sporozoa related to Plasmodium -Tachyzoites: groups or clusters -Bradyzoites: tissue cysts -Sporozoites: in oocysts?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms is transmitted to humans by eating undercooked contaminated meat (pork, lamb, and venison) or shellfish (oysters, clams, mussels) and by inhalation of cysts or spores (such as from cat litter), where only one species exists and cats are the essential reservoir?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms has the following pathogenesis: Following exposure, rapid proliferation of tachyzoites, destruction of tissue, and dissemination of the parasite throughout the body. Tachyzoites convert to bradyzoites, and tissue cysts are formed, leading to chronic infection. Congenital toxoplasmosis can occur, causing fetal infection, miscarriage, mental retardation, or hearing problems?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms is known to present with swollen lymph nodes around the neck, headache, muscle ache, fever, and inflammation of the lungs, heart muscle, and eye, and may be asymptomatic until later in life when immunocompromised?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms is located worldwide and affects 25-39% of the world's population?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    In which organism do the Trophozoites of the oocyst develop tachyzoites (slender crescent) as the infectious form?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms can be diagnosed through serology or microscopic detection of cysts in infected feces?

    <p>Toxoplasma gondii</p> Signup and view all the answers

    Which of the following organisms are free-living amoeba?

    <p>Naegleria spp</p> Signup and view all the answers

    Which organism has the following epidemiology:

    • Worldwide distribution
    • Common in soil and fresh water lakes and rivers
    • Infection common after exposure to trophozoites in water
    • Parasite enters the body through the nose and migrates to the brain?

    <p>Naegleria fowleri</p> Signup and view all the answers

    Which of the following organisms is associated with primary amebic meningoencephalitis, characterized by rapid progression and fatal destruction of brain tissue?

    <p>Naegleria fowleri</p> Signup and view all the answers

    Which organism is diagnosed through postmortem detection of a parasite in cerebrospinal fluid (CSF)?

    <p>Naegleria fowleri</p> Signup and view all the answers

    Which organisms is the experimental drug miltefosine available to treat?

    <p>Acanthamoeb spp</p> Signup and view all the answers

    Which organism has the following epidemiology:

    • Worldwide
    • Common in soil, fresh water lakes/rivers, tap water, and bottled water
    • Can contaminate dialysis fluid and contact lens cleaners?

    <p>Acanthamoeb spp</p> Signup and view all the answers

    Which organism causes the following clinical diseases: Keratitis symptoms and Granulomatous amebic encephalitis (primarily in immunocompromised patients)?

    <p>Acanthamoeba</p> Signup and view all the answers

    Which of the following viruses can be diagnosed using the following methods?

    -Keratitis: eye scrapings microscopic -Encephalitis: microscopic examination of brain tissue

    <p>Acanthamoeba spp</p> Signup and view all the answers

    Which organism can cause infections associated with contact lenses?

    <p>Acanthamoeba spp</p> Signup and view all the answers

    Which of the following is not an intestinal and urogenital protozoa?

    <p>Naegleria fowleri</p> Signup and view all the answers

    Which organism has the following description?

    • Structure: Amoeba; Trophozoite is the motile form
    • Transmission: Cyst ingested via fecal/oral, water, or anal sex
    • Pathogenesis: In stomach releases trophozoite; cytospore
    • Clinical presentation: Flask-shaped ulcer in gut lining
    • Geographic location: Worldwide; tropics, sub-tropics, poor hygiene areas

    <p>Entamoeba histolytica</p> Signup and view all the answers

    What is the most common amoeba responsible for diarrheal disease?

    <p>Entamoeba histolytica</p> Signup and view all the answers

    Both cysts and trophozoite (motile form) are found in stool specimens for Entamoeba histolytica.

    <p>True</p> Signup and view all the answers

    Which organism is responsible for the following clinical presentations: Intestinal amebiasis and extraintestinal amebiasis?

    <p>Entamoeba histolytica</p> Signup and view all the answers

    Which organism produces flask-shaped ulcers of intestinal mucosa?

    <p>Entamoeba histolytica</p> Signup and view all the answers

    Which organism do the following diagnostic techniques detect?

    • Intestinal amebiasis diagnosed by microscopic detection of trophozoites and cysts in stool
    • Nucleic acid amplification tests (NAATs) are available
    • Extraintestinal amebiasis: serology

    <p>Entamoeba histolytica</p> Signup and view all the answers

    Which organism displays the following characteristics:

    • Structure: Coccidia with a crescent-shaped body; an apicomplexan who has an apical structure that allows for penetration of the host cell while remaining outside
    • Transmission: Oocyst ingestion
    • Pathogenesis: Sporozoites replicate in brush border
    • Diarrhea to enterocolitis can be severe in immune compromised individuals
    • Geographic: Worldwide; large outbreaks associated with drinking or recreational water?

    <p>Cryptosporidium parvum</p> Signup and view all the answers

    What is the most common cause of water-borne outbreaks of enterocolitis?

    <p>Cryptosporidium oocyst</p> Signup and view all the answers

    Which organism causes the following clinical diseases:

    -Mild to severe diarrheal disease (nausea, anorexia, abdominal cramping, watery diarrhea) self-limiting in immune competent patients though can last for weeks

    • Enterocolitis with remission after 10 days in immune competent patients
    • Severe enterocolitis in immune compromised patients that can become chronic?

    <p>Cryptosporidium spp.</p> Signup and view all the answers

    For which organisms is the following diagnostic technique utilized: Detection of oocysts in stool via microscopy, immunoassay, or NAATs?

    <p>Cryptosporidium spp.</p> Signup and view all the answers

    What is the most common flagellate responsible for diarrheal disease?

    <p>Giardia duodenalis</p> Signup and view all the answers

    Which organism is described by the following characteristics:

    • Structure: Flagellate; pear-shaped with 2 large nuclei visible; features a sucking disk and 8 flagella
    • Transmission: Requires 10-25 cysts; cysts are resistant to chlorine and must be boiled?
    • Pathogenesis: Attach to villi with sucking disk
    • Clinical: Giardiasis of small intestine: symptoms from diarrhea to malabsorption syndrome; diagnosed with trophozoites in stool or NAATs
    • Geographic:Worldwide; fecal/oral with outbreaks at daycare centers and long-term care facility; asymptomatic carriers are an important reservoir; wild animals are reservoir

    <p>Giardia duodenalis</p> Signup and view all the answers

    Which organism has the following two forms: infectious cysts and non-infectious replicating trophozoites?

    <p>Giardia duodenalis</p> Signup and view all the answers

    Which organism has the following clinical presentation:

    -Asymptomatic carrier

    • Giardiasis of small intestine: symptoms from diarrhea to malabsorption syndrome
    • Incubation period is about 10 days; onset sudden with foul-smelling watery diarrhea, abdominal cramps and flatulence
    • Symptoms persist for 1-2 weeks and chronic disease may develop?

    <p>Giardia duodenalis</p> Signup and view all the answers

    Which organism is described by the following characteristics:

    • Diagnosis: Intestinal giardiasis diagnosed via microscopic detection of trophozoites and cysts in stool; NAATs are available
    • Treatment: Metronidazole or nitazoxanide
    • Prevention: Avoid contaminated water and food; Cysts resistant to chlorine; must boil or filter water?

    <p>Giardia duodenalis</p> Signup and view all the answers

    Which organism has the following descriptions:

    • Structure: Flagellate; 4 flagella
    • Transmission: Exists only as a trophozoite; Person to person transmission through sexual intercourse
    • Pathogenesis: Without treatment, infections persist for months to years
    • Clinical: Vaginitis and urethritis, inflammation of the epithelial lining with associated itching, burning, painful urination, vaginal discharge in women, urethral discharge
    • Geographic: Worldwide?

    <p>Trichomonas vaginalis</p> Signup and view all the answers

    What is the most common parasite responsible for vaginitis?

    <p>Trichomonas vaginalis</p> Signup and view all the answers

    In which form does Trichomonas vaginalis only exist?

    <p>Trophozoite form</p> Signup and view all the answers

    Which organism has the following clinical presentation:

    • Most infected are asymptomatic
    • Vaginitis and urethritis: inflammation of epithelial lining with associated itching, burning, painful urination, vaginal discharge in women, urethral discharge
    • Without treatment infections persist months to years?

    <p>Trichomonas vaginalis</p> Signup and view all the answers

    Which organism has the following diagnostic profile?

    • Detection of parasite by microscopic examination, culture or NAAT of discharge
    • NAAT is the most sensitive test for asymptomatic and symptomatic cases.

    <p>Trichomonas vaginalis</p> Signup and view all the answers

    Which of the following intestinal nematodes lead to infection when the eggs are ingested?

    <p>Toxocara canis</p> Signup and view all the answers

    Which of the following intestinal nematodes do not lead to infection when the larvae penetrate the skin?

    <p>Trichinella spiralis</p> Signup and view all the answers

    Which of the following intestinal nematodes leads to infection via ingestion of larva in meat?

    <p>Trichinella spiralis</p> Signup and view all the answers

    Which of the following intestinal nematodes migrate through the lungs (pneumonitis)?

    <p>Ascaris lumbricoides</p> Signup and view all the answers

    For which intestinal nematode does diagnosis involve finding eggs in the anal folds (tape test)?

    <p>Enterobius vermicularis</p> Signup and view all the answers

    Which intestinal nematode is diagnosed through history, larvae in muscle, and antibodies?

    <p>Trichinella spiralis</p> Signup and view all the answers

    Which intestinal nematodes are diagnosed through eggs in stool? (Select all that apply)

    <p>Ascaris lumbricoides</p> Signup and view all the answers

    Which of the following intestinal nematodes is diagnosed through larvae in the blood?

    <p>Toxocara canis</p> Signup and view all the answers

    Which intestinal nematode has the following characteristics?

    • Structure: Worms 2.5 – 13mm long. Females longer than males. Adult males have blunt end and females have long pointed tail
    • Transmission: Swallowing infective pinworm eggs on fingers, under fingernails, on clothing, bedding or other contaminated objects; can be inhaled (airborne).
    • Pathogenesis: Inflammation with eosinophilia; Allergic response to worm protein is the cause of pruritus (itching, usually anal).
    • Clinical: Itching of anal or vaginal area; Insomnia, irritability, teeth grinding, restlessness; Occasional stomach pain and nausea.
    • Geographic: Worldwide; human only host; Frequently in school or pre-school children and in crowded conditions.

    <p>Enterobius vermicularis</p> Signup and view all the answers

    Which intestinal nematode has the following characteristics:

    • Clinical disease: Enterobiasis characterized by irritation of the anal fold by migrating adult worm when depositing eggs at night, leading to itching and loss of sleep
    • Diagnosis: Eggs or worms at the anus (sticky tape), eggs not found in stool?

    <p>Enterobius vermicularis</p> Signup and view all the answers

    Which of the following intestinal nematodes matches the following descriptions:

    • Structure: Cylindrical body with a cuticle composed of three outer collagen layers; protective function
    • Transmission: Burrowing of larvae through exposed skin
    • Pathogenesis: Larvae penetrate skin, travel to organs including the respiratory tract, lymph nodes, blood, lungs, and intestines; adults in the intestine penetrate blood vessels and suck blood
    • Clinical: Skin irritation due to cutaneous larva migrans; coughing leading to dyspnea; iron deficiency anemia
    • Geographic Distribution: N. americanus - Africa, Asia, Europe, Americas, and Australia; A. duodenale - Africa, Asia, Australia, Americas, Middle East, North Africa, and North India.

    <p>Ancylostoma duodenale</p> Signup and view all the answers

    Which intestinal nematode has the following epidemiology?

    • Filariform larvae in soil penetrates exposed skin
    • Migrates in blood to lungs
    • Penetrates into pulmonary alveoli
    • Ascent to pharynx and are swallowed
    • In the small intestine, larvae mature into adult worm that attaches to intestine wall and produces eggs
    • Eggs passed in stool
    • Contact with soil releases immature larvae (rhabditiform) that mature into infectious form in 2 weeks

    <p>Ancylostoma duodenale</p> Signup and view all the answers

    Which intestinal nematode is associated with the following clinical disease presentation:

    • Asymptomatic infection is most common
    • Migration of larvae to lungs can produce an irritation (pneumonitis) with cough and eosinophilia
    • Hookworm infections can produce symptoms of nausea, vomiting, diarrhea, and anemia from feeding worms
    • Diagnosis: Detection of eggs in stool?

    <p>Ancylostoma duodenale</p> Signup and view all the answers

    Which intestinal nematode has the following characteristics:

    • Structure: Small roundworm, round shape in cross-section, zoonotic
    • Transmission: Infected dogs and cats shed eggs in their feces; Humans accidentally swallow contaminated dirt
    • Pathogenesis: Eggs hatch in the intestine, larvae penetrate the bowel wall and migrate through liver, lungs and CNS, to eyes or other tissues; Tissue damage caused by the parasite and the immune response
    • Clinical: Most asymptomatic; Visceral symptoms include fever, fatigue, coughing, wheezing, or abdominal pain; Can cause eye problems
    • Geographic distribution: Worldwide?

    <p>Toxocara canis</p> Signup and view all the answers

    Which toxocara exhibits the following characteristics:

    • If infected with high numbers – larvae can travel through body: liver, lungs, CNS
    • Fever, coughing, enlarged liver or pneumonia

    <p>Visceral Toxocariasis</p> Signup and view all the answers

    Which Toxocara has the following characteristics: Larvae can travel to the eye and cause inflammation and scarring of the retina – irreversible vision loss?

    <p>Ocular toxocariasis</p> Signup and view all the answers

    Which intestinal nematode has the following characteristics:

    • Structure: Smallest known nematode; Females are larger than males; Slender at the anterior then the posterior end
    • Transmission: Eating raw or undercooked meat that has roundworm larvae; Most commonly found in game meat (bear, fox, wolf, seal, walrus). Less common in pork.
    • Pathogenesis: Once ingested, the larvae exist in the small intestine, penetrate the mucosa and become adults in 6-8 days; New larvae are shed by females
    • Clinical: Headaches, fevers, chills, cough, swelling of face and eyes, aching joints and muscle pain, itchy skin, diarrhea or constipation; If heavy infection may have uncoordinated movement and heart or breathing issues
    • Geographic: Worldwide

    <p>Trichinella spiralis</p> Signup and view all the answers

    Which intestinal nematode has the following clinical presentations: Trichinosis (larvae migrate and embed in muscles), typically infected from wild game meat not properly cooked, with symptoms such as nausea, diarrhea, vomiting, fatigue, fever, and abdominal discomfort?

    <p>Trichinella spiralis</p> Signup and view all the answers

    Which organism has the following description:

    • Flat ribbon-like worms (tapeworms)
    • Head = scolex with suckers and hooks for attachment to intestine wall
    • Long segmented body = proglottids
    • Hermaphroditic
    • Segments close to head are immature and more distal proglottids are gravid (filled with eggs)
    • Gravid proglottids break off and are shed in feces
    • Proglottids and eggs are diagnostic
    • Have at least 2 hosts: primary (adult worms) and secondary (larval forms in intermediate host)
    • Human disease is primarily intestinal?

    <p>Cestodes</p> Signup and view all the answers

    Which of the following are large cestodes?

    <p>Diphyllobothrium latum (fish tape worm)</p> Signup and view all the answers

    Which of the following are small cestodes?

    <p>Dipylidium caninum (dog tapeworm)</p> Signup and view all the answers

    Which of the following cestodes has the following characteristics:

    • Structure: Large worm up to 30 feet long; Fish tapeworm
    • Transmission: Humans eat undercooked fish with larvae; Eggs contaminate fresh water taking 2-4 weeks to develop into free-swimming larvae (coracidium); Coracidium are ingested by crustaceans that are eaten by large fish; Larvae migrate to the flesh of fish and develop into infectious pleroceroid?
    • Pathogenesis: Larvae develop into mature adults in small intestine (10 meters in length); Adults release eggs and passed in feces
    • Clinical: Most asymptomatic; Symptoms can include: epigastric pain, abdominal cramping, nausea, vomiting and weight loss; Vitamin B12 deficiency with anemia and neurologic symptoms
    • Geographic: Worldwide particularly in western Europe, eastern Europe, Asia and the US; Related to international transport of fish; Freezing fish for 7 days or proper cooking kills parasite

    <p>Diphyllobothrium latum</p> Signup and view all the answers

    Which cestode has the following epidemiology:

    -Humans eat undercooked fish with larvae

    • Larvae develop into mature adults in the small intestine (10 meters in length)
    • Adults release eggs that are passed in feces
    • Eggs contaminate fresh water and take 2-4 weeks to develop into free-swimming larvae (coracidium)
    • Coracidium are ingested by crustaceans that are eaten by large fish
    • Larvae migrate to the flesh of fish and develop into infectious plerocercoid larvae?

    <p>Diphyllobothrium latum</p> Signup and view all the answers

    Which of the following cestodes is associated with the following clinical disease presentation:

    • Most asymptomatic
    • Symptoms can include: epigastric pain, abdominal cramping, nausea, vomiting, and weight loss
    • Vitamin B12 deficiency with anemia and neurologic symptoms
    • Diagnosis: Detection of characteristic proglottids or eggs in feces?

    <p>Diphyllobothrium latum</p> Signup and view all the answers

    Which cestode has the following characteristics:

    • Structure: Large worm up to 10 meters long; Beef tapeworm
    • Transmission: Humans eat undercooked meat with cysticerci in muscle; Eggs or gravid proglottids released in feces; Cattle become infected by eating vegetation contaminated by eggs or proglottids; Oncospheres hatch and penetrate intestine wall
    • Pathogenesis: Scolex attaches to intestine; Adults release eggs and proglottids in small intestine
    • Clinical: Taeniasis – mild gastric discomfort, nausea, flatulence, diarrhea, or hunger pains; Cysticercosis disease in cattle
    • Geographic: Worldwide Endemic to eastern Europe, Southeast Asia, Africa, and Latin America?

    <p>Taenia saginata</p> Signup and view all the answers

    Which of the following cestodes corresponds to the following description: Structure: Dwarf tape worm; Transmission: Humans eat embryonated eggs from contaminated food, water, or hands; Insects (beetles and flies) serve as intermediate hosts; Pathogenesis: Eggs or cysticercoids develop into adults in the small intestine; Clinical: Usually asymptomatic or symptoms like weakness, headache, anorexia, and abdominal pain; Geographic: Warm climates, especially in children in countries with inadequate hygiene and sanitation?

    <p>Hymenolepis nana</p> Signup and view all the answers

    Which cestode has the following characteristics:

    • Structure: Dog tapeworm
    • Transmission: Cats and dogs are definitive hosts; humans are incidental hosts; Transmission by ingesting infected flea adults in the small intestine. Gravid proglottids are passed in feces. In the environment, they develop into egg packets that are eaten by flea larvae; in fleas, they develop into cysticercoids – infection form.
    • Pathogenesis: Cysticercoids develop into adult worms in the small intestine in about 20 days.
    • Clinical: Asymptomatic; mild gastrointestinal disturbances can occur; passage of proglottids in stool.
    • Geographic: Ubiquitous and common among pet dogs and cats; human infection is rare.

    <p>Dipylidium caninum</p> Signup and view all the answers

    Which of the following schistosomes has the following characteristics?

    • Snails are an important intermediate host
    • Free swimming cercariae are released from snails and penetrate human skin
    • Disease is related to where adults establish residence in the circulatory system and release eggs
    • Most widespread schistosome, endemic in South and sub-Saharan Africa, Nile River Valley, South America, Caribbean, West Indies
    • Found in waters of great lakes and rivers where host snails are present and sanitation is poor
    • Reservoir hosts are primates, marsupials, and rodents
    • Associated with swimming in waters contaminated with free-swimming cercariae.

    <p>Schistosoma mansoni</p> Signup and view all the answers

    Which organism has the following etiology?

    • Migrates to portal blood in liver and matures into adults
    • Paired adult male and female worms migrate to the inferior mesenteric vein near the lower colon and lay eggs
    • Eggs are shed in stool

    <p>Schistosoma mansoni</p> Signup and view all the answers

    Which organism has the following clinical disease presentation:

    -Penetration through skin results in itching, allergic reaction and dermatitis

    • Migration through lungs and liver results in cough and hepatitis
    • Egg laying adult produces fever, malaise, abdominal pain and liver tenderness, diarrhea and bloody stool
    • Chronic infection with hepatosplenomegaly?

    <p>Schistosoma mansoni</p> Signup and view all the answers

    Which organism is diagnosed via detection of eggs in stool, and treated with Praziquantel?

    <p>Schistosoma mansoni</p> Signup and view all the answers

    Study Notes

    Viruses and Their Characteristics

    • DNA Virus Not Replicating in Nucleus: Poxvirus
    • Tropism: The preference of a virus to infect specific cell types, tissues, or hosts.
    • Tropism Link: Linked to the presence and compatibility of viral receptors on host cells.

    Examples of Viruses

    • Non-enveloped, DNA Virus: Adenovirus
    • Non-enveloped, RNA Virus: Picornavirus
    • Enveloped RNA Virus: Retrovirus (e.g., HIV)
    • Enveloped DNA Virus: Herpesvirus

    Virus Particle Components

    • Required Component of Infectious Virus Particle: Nucleic acid (RNA or DNA)
    • Not Required Component: Lipid envelope

    Virus Examples and Diseases

    • Example of Adenovirus: Adenovirus 7
    • Papillomaviruses: Can cause cervical cancer and warts.
    • Polyomaviruses: Can cause diseases like progressive multifocal leukoencephalopathy (PML).
    • Hepadnaviruses: Associated with hepatitis B virus (HBV), causing liver disease.
    • Herpes Viruses: Cause conditions such as cold sores, chickenpox, and genital herpes.
    • Poxviruses: Can cause smallpox and molluscum contagiosum.

    Virus Types

    • Not Naked dsDNA Virus: Herpesvirus
    • ssDNA Naked Virus: Parvovirus
    • Disease from Picornaviruses: Poliomyelitis

    RNA Virus Characteristics

    • Not ssRNA Positive Naked Virus: Coronavirus
    • ssRNA Positive Enveloped Virus for Hep C: Hepatitis C virus
    • Not Positive-Sense ssRNA Enveloped Virus: Arenavirus
    • Disease from Bunyaviruses: Hantavirus pulmonary syndrome

    Virus Life Cycle

    • Cytopathic Effect: The observable cellular damage caused by viral infection.
    • Initial Virus Life Cycle Step: Attachment to host cells.
    • Mediators for DNA Virus Entry: Endocytosis
    • Second Step in Virus Life Cycle: Uncoating
    • Third Step: Replication of viral genome
    • Fourth Step: Assembly of viral particles and budding

    Unique Virus Lifecycle

    • Special Lifecycle Example: Retrovirus

    Additional Virus Concepts

    • Inclusion Bodies: Aggregates of viral particles or proteins within host cells.
    • Syncytia: Multinucleated giant cells formed by the fusion of infected cells.

    Transmission Types

    • Vertical Transmission: Transmission from mother to child during pregnancy or delivery.
    • Horizontal Transmission: Transmission through direct or indirect contact between individuals.

    Immune Evasion by Viruses

    • Virus Evading Immune Defenses: HIV, by varying its surface antigens.
    • Restricting Expression of Antigens: Some herpesviruses.
    • Preventing Binding of Neutralizing Antibodies: Some mimicking or altering host proteins.
    • Prions in Cattle: Bovine spongiform encephalopathy
    • Prions in Sheep: Scrapie
    • Prions in Humans: Creutzfeldt-Jakob disease
    • Typical Length of a Prion: Approximately 30-50 amino acids
    • Giemsa Stain Utilization: Used for identifying certain parasites, including Plasmodium spp.

    Plasmodium spp. and Disease Transmission

    • Pathogenesis: Involves rapid proliferation in RBCs leading to anemia.
    • Most Severe Symptoms Species: Plasmodium falciparum
    • Species with Dormant Liver Phase: Plasmodium vivax
    • Sexual Reproduction Initiated in: Anopheles mosquitoes
    • Structure of Plasmodium spp.: Flatted, oval shape as tachyzoites.

    Miscellaneous Concepts

    • Dissemination: Spread of virus throughout the body.
    • Viremia: Presence of viruses in the blood.
    • Blood-Borne Virus Example: Hepatitis B virus.
    • Negri Bodies: Found in rabies virus infections.
    • Owl's Eye Inclusions: Associated with Cytomegalovirus infections.

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    Description

    Test your knowledge on DNA viruses, particularly those that replicate outside the nucleus. This quiz will cover key characteristics, examples, and mechanisms of these unique viruses. Dive into molecular biology and enhance your understanding of viral replication.

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