Microbiology > #55-68 > Flashcards

#55-68 Flashcards

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1
Q

What is Hepatitis B (Serum Hepatitis)?

A

Viral infection of the liver causing inflammation, jaundice, possible chronic liver disease

Caused by the Hepatitis B virus (HBV).

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2
Q

What is the target organ for Hepatitis B?

A

Liver (hepatocytes)

The virus replicates in the nucleus and cytoplasm of hepatocytes.

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3
Q

What are the early (prodromal) symptoms of Hepatitis B?

A
  • Fatigue
  • Malaise
  • Loss of appetite
  • Low-grade fever
  • Nausea
  • Vomiting

These symptoms occur during the incubation period of 1-6 months.

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4
Q

What are the acute phase symptoms of Hepatitis B?

A
  • Jaundice
  • Dark urine
  • Pale stools
  • Right upper quadrant pain
  • Hepatomegaly

Jaundice is characterized by yellowing of skin and eyes.

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5
Q

What are the potential complications of Hepatitis B?

A
  • Fulminant hepatitis
  • Chronic hepatitis
  • Cirrhosis
  • Liver failure
  • Hepatocellular carcinoma (HCC)

Chronic infection may lead to serious liver conditions.

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6
Q

What is the incubation period for Hepatitis B?

A

1-6 months

Symptoms may not appear until after this period.

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7
Q

What is the reservoir/source for Hepatitis B?

A

Human reservoir only

Infected blood, semen, vaginal fluids, and other bodily fluids are sources of transmission.

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8
Q

What are the modes of transmission for Hepatitis B?

A
  • Parenteral route (bloodborne)
  • Sexual contact
  • Perinatal (mother-to-child)
  • Occupational (healthcare workers)

Not spread by casual contact, food, or water.

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9
Q

What are the serological markers for diagnosing Hepatitis B?

A
  • HBsAg: active infection
  • Anti-HBs: recovery or immunity
  • Anti-HBc IgM: acute infection
  • Anti-HBc IgG: past or chronic infection
  • HBeAg: active replication
  • Anti-HBe: reduced infectivity

PCR tests can detect viral DNA load.

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10
Q

What is the treatment for acute Hepatitis B infection?

A

Usually self-limiting; supportive care

Chronic infections may require antiviral drugs.

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11
Q

What is the prevention method for Hepatitis B?

A
  • Vaccination: Recombinant HBV vaccine
  • Post-exposure prophylaxis (PEP)
  • Safe sex practices
  • No sharing needles
  • Screening of blood donors

Vaccination is given at birth, then at 1 and 6 months.

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12
Q

True or false: Hepatitis B can be spread through casual contact.

A

FALSE

It is primarily transmitted through blood and bodily fluids.

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13
Q

What is the Dane particle in relation to Hepatitis B?

A

Complete infectious viral particle

It is a key component of the Hepatitis B virus.

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14
Q

What is the role of reverse transcriptase in Hepatitis B?

A

Used in viral DNA replication

This is unusual for a DNA virus.

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15
Q

What is the chronic carrier state in Hepatitis B?

A

Patient continues to produce HBsAg and spread infection

This can lead to lifelong persistence of the virus.

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16
Q

What happens when Hepatitis B co-infects with Hepatitis D virus?

A

Causes more severe disease

Hepatitis D requires HBV to replicate.

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17
Q

VF hepatitis b serum hepatitis

A

HBsAg helps virus enter hepatocytes indicates activate infection
HBcAg found in infected hepatocytes
HBeAg secreted antigen indicating active replication and high infectivity
Reverse transcriptase

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18
Q

What is the virus family associated with Genital Warts?

A

Papillomaviridae

The specific virus responsible for genital warts is Monas popilomevius (HPV).

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19
Q

What type of genome does HPV have?

A

Double stranded & circular DNA

HPV is classified as a non-enveloped (naked capsid) virus.

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20
Q

What is the incubation period for HPV?

A

2 weeks to 3 months

This period varies among individuals before symptoms appear.

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21
Q

Which HPV types are responsible for approximately 90% of genital warts cases?

A
  • HPV types 6
  • HPV types 11

These are classified as low-risk HPV types.

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22
Q

What are common symptoms of genital warts?

A
  • Itching or burning in genital area
  • Pain during sexual intercourse
  • Vaginal discharge with unusual odor
  • Bleeding during urination or sexual activity
  • Visible warts: small, raised bumps or clusters of bumps

Warts may resemble cauliflower and can be skin-colored, pink, or gray.

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23
Q

What is the primary mode of transmission for HPV?

A

Primarily sexual contact

Other modes include skin-to-skin contact and autoinoculation.

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24
Q

True or false: HPV can cause oncogenesis.

A

TRUE

HPV can insert into the genome and lead to malignant transformations.

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25
What are the **high-risk HPV types** associated with cancer?
* HPV types 16 * HPV types 18 ## Footnote These types are responsible for most HPV-related cancers.
26
What is the recommended age for **HPV vaccination**?
11/12 years old ## Footnote Vaccination is recommended for both females and males prior to becoming sexually active.
27
What are some **treatment options** for genital warts?
* Imiquimod (Zyclara) * Podophyllin (Podocon-25) * Podofilox (Condylox) * Trichloroacetic acid * Sinecatechins (Veregen) * Surgery (cryotherapy, electrocutery, surgical excision, laser treatments) ## Footnote Treatments aim to remove warts rather than cure the virus itself.
28
What are potential **cancers** linked to HPV?
* Cervical cancer * Vulvar cancer * Anal cancer * Penile cancer * Oral cancer ## Footnote Certain types of HPV are closely linked with these cancers.
29
What are the **psychological impacts** of genital warts?
* Psychological distress * Damaged sexual life ## Footnote These impacts can arise from the stigma and physical appearance of warts.
30
Fill in the blank: HPV can enter the body through ______ during sexual contact.
microabrasions ## Footnote This entry point is crucial for the viral infection process.
31
What is the **role of E6 and E7 proteins** in high-risk HPV types?
* E6 inhibits apoptosis * E7 interferes with tumor suppressors ## Footnote These proteins are crucial for the malignant transformation process.
32
System genitalia warts
Reproductive
33
VF genitalia warts
Insert in genome & cause oncogenesis Enter skin mucous membrane Cellular replication
34
Diagnosis genitalwarts
Physical exam Pap test Pelvic exam Acetowhite test Hpv test Biopsy Dna probes PCR
35
Prev genitalia warts
Hpv vaccine
36
What is the **virus family** of the influenza virus?
Orthomyxoviridae ## Footnote The influenza virus is classified under the family Orthomyxoviridae.
37
How many types of influenza viruses are there, and what are they?
* A * B * C * D ## Footnote Types A and B cause annual human epidemics, type C causes mild illness, and type D affects cattle.
38
Which type of influenza is the only one to cause **pandemics**?
Type A ## Footnote Type A is known for its potential to cause pandemics due to its ability to undergo antigenic shift.
39
What is the **shape** of the influenza virus?
Spherical/Elliptical ## Footnote The influenza virus has a spherical or elliptical shape.
40
What type of nucleic acid does the influenza virus have?
Single-stranded, negative-sense RNA (SSRNA) ## Footnote The genome structure is segmented, with 7-8 segments for types A and B.
41
What are the primary **systems/tissues** affected by the influenza virus?
* Respiratory system * Cardiovascular system * Gastrointestinal system * Nervous system * Immune system ## Footnote The virus primarily affects epithelial cells, vascular endothelium, and immune cells.
42
List common **symptoms** of influenza.
* Fever (above 100°F/37.8°C) * Cough (dry/productive) * Sore throat * Runny/stuffy nose * Body aches & pains * Headache * Fatigue * Vomiting & diarrhea (more common in children) ## Footnote Severe cases may lead to seizures or confusion.
43
What are the roles of **hemagglutinin (HA)** and **neuraminidase (NA)** spikes in the influenza virus?
* HA spikes: Pathogen attachment & cell entry * NA spikes: Enzyme for cell exit & spreading new virus particles ## Footnote These spikes are crucial for the virus's ability to infect and spread.
44
What is **antigenic drift**?
Minor, gradual mutation in genes for HA & NA ## Footnote This allows the virus to reinfect people whose immune systems remember previous strains.
45
What is **antigenic shift**?
Major, abrupt change resulting in new combination of HA & NA proteins ## Footnote This can lead to pandemics due to lack of pre-existing immunity.
46
What are the **core components** of the viral machinery for influenza?
* PB2 * PB1 * PA ## Footnote These components are essential for replicating the viral genome and transcribing viral genes.
47
What is the role of **non-structural protein 1 (NS1)** in the influenza virus?
Major antagonist of the host's innate immune system ## Footnote NS1 helps the virus evade the host's immune response.
48
What are the primary **hosts** for the different types of influenza?
* Type A: Primarily wild aquatic birds, poultry, swine, humans * Type B: Primarily humans * Type C: Primarily humans * Type D: Primarily cattle, pigs, sheep, horses ## Footnote Each type has different primary hosts.
49
How is influenza primarily **transmitted**?
* Respiratory droplets (cough, sneeze, talking) * Airborne transmission (aerosols) * Indirect contact (contaminated surfaces) * Animal-to-human * Person-to-person ## Footnote The virus can enter through the respiratory tract or eyes.
50
What are the **diagnostic methods** for influenza?
* Symptoms & signs * Rapid molecular tests (PCR, NAAT) * Rapid antigen tests * Serological tests * Viral culture * Chest X-ray ## Footnote These methods help confirm influenza and rule out other conditions.
51
What are some **preventive measures** against influenza?
* Annual flu vaccination * Good hygiene practices * Avoid contact with sick individuals * Cover coughs & sneezes * Clean & disinfect surfaces * Stay home when sick * Don't share food/eating utensils ## Footnote Vaccination is crucial for prevention.
52
What are common **treatments** for influenza?
* Rest * Hydration * Over-the-counter medications (acetaminophen, ibuprofen) * Antiviral medicines (zanamivir, oseltamivir, peramivir, baloxavir marboxil) ## Footnote Antiviral medications can reduce the duration of symptoms.
53
What are some **complications** of influenza?
* Acute respiratory distress syndrome (ARDS) * Myositis * Myocarditis * Encephalitis * Multi-organ failure * Sepsis * Pneumonia * Sinus & ear infections * Bronchitis * Meningitis * Death ## Footnote Rare complications include Reye's syndrome and Guillain-Barré syndrome.
54
What are the **risk factors** for severe influenza?
* Young children (2 years and younger) * Adults older than 65 years * Weakened immune system * Chronic illnesses * Living in facilities with many people * Pregnancy (2nd & 3rd trimesters) * Obesity (BMI of 40 or higher) * Race/ethnicity (Native American, Alaska Native, Black, Latino) ## Footnote These factors increase the likelihood of needing hospitalization.
55
Influenza occurs seasonally in temperate regions during _______.
Autumn & winter ## Footnote In tropical regions, influenza can occur year-round.
56
Influenza predisposes patients to secondary bacterial infections, such as pneumonia caused by _______ and _______.
* Streptococcus pneumoniae * Staphylococcus aureus ## Footnote These bacteria can cause severe complications following influenza infection.
57
Res flu
Human, swine, birds
58
What virus causes **Bronchiolitis**?
Respiratory Syncytial virus (RSV) ## Footnote RSV belongs to the virus family **Paramyxoviridae**.
59
What type of virus is **RSV**?
* RNA virus * Enveloped * Pleomorphic (variable) * Negative-sense * Single-stranded RNA genome ## Footnote These characteristics define the structure and classification of RSV.
60
Which systems or tissues are primarily affected by **RSV**?
* Respiratory system (lower RT: bronchioles) * Epithelial cells * Mucus * Airways * Cardiovascular system * Immune system * Severe cases: alveoli ## Footnote RSV primarily targets the respiratory system but can affect other systems in severe cases.
61
List some **symptoms** of RSV infection.
* Runny nose * Stuffy nose * Cough * Sometimes a slight fever * Severe: bluish skin color, struggling to breathe, wheezing, appears slow-moving/weak, refuses to drink/eat, breathing very fast, irritability ## Footnote Symptoms can vary from mild to severe, especially in infants.
62
What role does the **VES G protein** play in RSV?
Promotes attachment to airway epithelial cells ## Footnote This protein is crucial for the virus's ability to infect host cells.
63
What is the function of the **F protein** in RSV?
* Facilitates cell fusion * Promotes mucus hypersecretion * Inhibits the production of antiviral interferons ## Footnote The F protein is essential for the virus's pathogenicity.
64
How does the **M protein** affect the host's immune response?
Down-regulates the synthesis of antiviral interferons ## Footnote This action helps the virus evade the host's immune defenses.
65
What are the **transmission methods** of RSV?
* Respiratory droplets * Person to person * Indirect contact by contaminated surfaces/objects ## Footnote RSV spreads easily, especially in crowded environments.
66
What are the **exit routes** for RSV from an infected person?
* Respiratory secretions (saliva) * Mucus from cough/sneezing * Nasal discharge ## Footnote These secretions are the primary means by which RSV is transmitted to others.
67
What are some **diagnostic methods** for RSV?
* Signs & Symptoms (S&S) * Viral testing * Chest X-ray * Blood tests * PCR * Rapid antigen test ## Footnote These methods help confirm an RSV infection.
68
What are some **preventive measures** against RSV?
* Good hygiene * Avoid contact/crowds * Stay home when sick * Clean & disinfect surfaces * Vaccination ## Footnote Preventive measures are crucial, especially for high-risk populations.
69
What is the **Abrysvo vaccine** used for?
Vaccination in infants and pregnant individuals ## Footnote This vaccine helps protect against RSV infection in vulnerable populations.
70
What supportive care is recommended for RSV infections?
* Rest * Fluids * Over-the-counter medication (acetaminophen, ibuprofen) ## Footnote Most cases of RSV require supportive care rather than antibiotics.
71
What severe treatments may be necessary for RSV?
* Hospital care * IV fluids * Humidified oxygen * Mechanical ventilation ## Footnote Severe cases of RSV may require intensive medical intervention.
72
What are some **complications** associated with RSV?
* Pneumonia * Bronchiolitis * Bronchitis * Dyspnea * Middle ear infection (otitis media) ## Footnote These complications can arise, particularly in infants and older adults.
73
What are the **long-term effects** of RSV in children?
* Asthma * Recurrent wheezing ## Footnote RSV can have lasting impacts on respiratory health in children.
74
What are the **risk factors** for developing severe RSV infection?
* Infants under 2 years (especially under 6 months) * Prematurity * Low birth weight * Weakened immune system * Exposure to secondhand smoke * Boys are slightly more likely to develop bronchiolitis than girls * Nursing home residents ## Footnote These factors increase the likelihood of severe RSV outcomes.
75
True or false: RSV is the most common cause of **pneumonia** in infants.
TRUE ## Footnote RSV is a leading cause of respiratory infections in young children.
76
Is RSV considered a **chronic** infection?
No, it is chronic with no latency ## Footnote RSV infections do not have a latent phase but can lead to chronic respiratory issues.
77
What is the **virus** responsible for COVID-19?
SARS-CoV-2 ## Footnote SARS-CoV-2 is an enveloped, positive-sense single-stranded RNA virus belonging to the family Coronaviridae.
78
What is the **size** range of SARS-CoV-2?
60-140 nm ## Footnote The virus has a spherical shape and features crown-like spike glycoproteins on its surface.
79
Which **systems/tissues** are primarily affected by COVID-19?
* Respiratory system * Cardiovascular system * Gastrointestinal system * Renal system * Nervous system ## Footnote The virus infects epithelial cells expressing ACE2 receptors.
80
List the **common symptoms** of COVID-19.
* Fever * Dry cough * Fatigue * Sore throat * Headache * Myalgia * Loss of taste or smell (anosmia) * Shortness of breath * Diarrhea ## Footnote Severe cases can lead to viral pneumonia and ARDS.
81
What are the **severe complications** associated with COVID-19?
* Viral pneumonia * ARDS * Septic shock * Multi-organ failure * Thrombosis * Myocarditis * Renal injury ## Footnote These complications can arise in severe cases of the disease.
82
What is the role of the **Spike (S) protein** in SARS-CoV-2?
Mediates attachment and fusion via ACE receptor ## Footnote It is key for host entry and immune evasion.
83
What is the **natural reservoir** for SARS-CoV-2?
Bats ## Footnote Intermediate hosts may include pangolins or other wild mammals.
84
How is COVID-19 primarily **transmitted**?
* Respiratory droplets * Aerosols from coughing, sneezing, or speaking * Direct contact with contaminated surfaces ## Footnote Fecal-oral route is rare; vertical transmission is possible but uncommon.
85
What are the **diagnostic methods** for COVID-19?
* RT-PCR (viral RNA detection) * Antigen tests * Antibody tests * Chest imaging (ground-glass opacities) ## Footnote These methods help confirm the presence of the virus.
86
What are the **preventive measures** against COVID-19?
* Vaccination (mRNA, vector-based, or protein subunit vaccines) * Mask use * Hand hygiene * Social distancing * Isolation/quarantine ## Footnote Supportive therapy includes rest, fluids, and oxygen.
87
What is **Long COVID**?
Persistent symptoms lasting weeks to months after recovery ## Footnote Symptoms include fatigue, dyspnea, chest pain, brain fog, and loss of smell/taste.
88
When was COVID-19 first identified and when was the pandemic declared?
First identified in late 2019; pandemic declared in March 2020 ## Footnote The rapid global spread led to significant health and social impacts.
89
Name some **variants** of SARS-CoV-2.
* Alpha * Delta * Omicron ## Footnote These variants differ in transmissibility and immune escape potential.
90
What virus causes **Red Measles (Rubeola)**?
Morbillivirus ## Footnote It belongs to the virus family Paramyxovirus and has a negative-sense single stranded RNA genome.
91
What systems or tissues are affected by **Red Measles**?
* Respiratory tract!!!! * Lymph nodes * Oral mucosa (Koplik spots) * Skin (rash) * Sometimes the brain ## Footnote These areas are primarily impacted by the measles virus.
92
List the **signs and symptoms** (S&S) of Red Measles.
* Fever * Sore throat * Dry cough * Runny nose * Headache * Koplik spots * Conjunctivitis * Rash * General malaise and fatigue ## Footnote The rash is red and maculopapular, starting at the head and spreading downward.
93
What is the **viral effect (VE)** of the measles virus?
* Syncytia formation * Immune suppression * Highly contagious respiratory transmission ## Footnote Syncytia formation helps the virus spread cell-to-cell while avoiding antibodies.
94
How does the **measles virus** primarily spread?
Airborne spread through coughing, sneezing, and breathing ## Footnote It is extremely contagious with one of the highest Ro values of any virus.
95
What are the **diagnostic methods** for Red Measles?
* Recognition of Koplik spots * Characteristic red maculopapular rash * Detection of measles-specific IgM antibodies in blood * RT-PCR to identify measles RNA from throat or nasal swabs ## Footnote These methods help confirm a measles infection.
96
What is the **MMR vaccine** used for?
Measles, mumps, rubella ## Footnote It is highly effective in preventing measles.
97
What is critical for preventing the spread of **measles**?
Population immunity (herd immunity) ## Footnote Measles is extremely contagious, making herd immunity essential.
98
What supportive care is recommended for **measles**?
* Reduce fever * Maintain hydration * Treat secondary infections * Vitamin A supplements recommended ## Footnote These measures help reduce severity and complications, especially in children.
99
List some **complications** associated with Red Measles.
* Pneumonia * Ear infections * Encephalitis * Severe diarrhea * Subacute sclerosing panencephalitis (SSPE) ## Footnote Long-term immune suppression and malnutrition/weight loss can also occur.
100
Who is at **risk** for Red Measles?
* Unvaccinated individuals * Infants * Immunocompromised persons * Pregnant women * Malnourished children (especially vitamin A deficient) ## Footnote These groups are particularly vulnerable to measles infection.
101
How long does the **measles virus** survive in the air or on surfaces?
Approximately 2 hours ## Footnote The virus is fragile and is destroyed by heat, light, drying, and disinfectants.
102
What is the **virus** responsible for Rubella?
Rubella virus (family Matonaviridae, genus Rubivirus) ## Footnote Rubella is also known as German or 'Three-Day' Measles.
103
Describe the **type** of virus that causes Rubella.
Enveloped, single-stranded positive-sense RNA virus ## Footnote It has one antigenic type and is small and spherical.
104
What is the typical **incubation period** for Rubella?
14-21 days ## Footnote The onset is usually sudden but mild.
105
List the **systems/tissues** affected by Rubella. German measles
* Skin * integumentary!!!! * Respiratory tract * Heart (in congenital cases) * Eyes (in congenital cases) * Ears (in congenital cases) * Brain (in congenital cases) * Liver (in congenital cases) * Spleen (in congenital cases) ## Footnote Congenital cases can lead to severe complications.
106
What are the common **signs and symptoms** of Rubella?
* Mild or asymptomatic infection * Low-grade fever * Sore throat * Swollen glands (especially behind ears) * Fine pink rash starting on face and spreading downward (lasting about 3 days) ## Footnote In adult women, joint pain or arthritis may occur.
107
What serious complications can occur during **pregnancy** due to Rubella?
* Miscarriage * Stillbirth * Congenital rubella syndrome (CRS) - heart defects, cataracts, deafness, developmental delays ## Footnote Congenital infection interferes with fetal cell division and growth.
108
How is Rubella primarily **transmitted**?
* Respiratory droplets * Direct contact * Transplacental (for congenital cases) ## Footnote The virus replicates in the nasopharynx and lymph nodes.
109
What is the **diagnosis** method for Rubella?
* Serology for rubella-specific IgM and IgG * RT-PCR testing ## Footnote These tests help confirm the presence of the virus.
110
What is the **preventive measure** for Rubella?
MMR vaccination (two doses, lifelong immunity) ## Footnote No specific antiviral treatment exists; supportive care is provided.
111
What are some **complications** associated with Rubella?
* Congenital rubella syndrome * Encephalitis * Thrombocytopenic purpura * Arthritis ## Footnote These complications can arise from both congenital and non-congenital infections.
112
True or false: Rubella has been eliminated in the U.S. but remains endemic in other regions.
TRUE ## Footnote Many infections are silent, allowing unnoticed spread.
113
VF rubella German measles
Virus replicates in nasal pharynx and lymph nodes allow spread to skin and placenta and congenital infection interferes with the fetal cell division and growth
114
115
What virus causes **Acquired Immunodeficiency Syndrome (AIDS)**?
Human Immunodeficiency Virus (HIV-1 & HIV-2) ## Footnote HIV is an enveloped virus from the family Retroviridae, genus Lentivirus.
116
What is the size range of the **HIV virus**?
~ 100-120 nm ## Footnote The virus has a spherical shape and an icosahedral capsid.
117
What are the primary systems affected by **HIV**?
* Immune system (CDA-T-helper cells) * CNS * Lymphatic tissues * GI tract * Bone marrow * Skin * Reproductive organs ## Footnote These systems are primarily affected during the course of the infection.
118
What are the **early/acute stage symptoms** of HIV?
* Flu-like illness * Fever * Sore throat * Rash * Lymphadenopathy ## Footnote These symptoms typically occur shortly after infection.
119
What characterizes the **asymptomatic latency** stage of HIV?
No symptoms for years, gradual CD4 decline ## Footnote This stage can last for a significant period before progressing to AIDS.
120
What are some **AIDS stage symptoms**?
* Weight loss * Fatigue * Persistent fever * Night sweats * Diarrhea * Oral thrush * Skin rashes * Opportunistic infections ## Footnote These symptoms indicate a progression to AIDS.
121
What are the **viral factors** of HIV?
* gp120 and gp41 spikes: bind CD4 and co-receptors (CCR5/CXCR4) * Reverse transcriptase: converts RNA → DNA → integrates into host genome * High mutation rate: frequent antigenic variation ## Footnote These factors contribute to immune evasion and drug resistance.
122
How is **HIV transmitted**?
* Sexual contact * Blood-to-blood (needles, transfusion, organ transplant) * Vertical (from mother to child) ## Footnote Understanding transmission routes is crucial for prevention.
123
What is the **diagnostic method** for HIV screening?
ELISA (detects antibodies to HIV) ## Footnote Confirmation can be done using Western blot or PCR.
124
What is the **CD4 count** threshold for diagnosing AIDS?
< 200 cells/mm³ ## Footnote This count indicates severe immune system compromise.
125
What are the components of **Antiretroviral Therapy (ART)**?
* NRTIs: Zidovudine (AZT), Tenofovir, Lamivudine * NNRTIs: Efavirenz, Nevirapine * Protease inhibitors: Ritonavir, Lopinavir * Integrase inhibitors: Raltegravir, Dolutegravir * Entry/Fusion inhibitors: Enfuvirtide, Maraviroc ## Footnote ART aims to maintain CD4+ > 500/mm³ and undetectable viral load.
126
What are some **AIDS-defining illnesses**?
* Kaposi's sarcoma * Lymphoma * Pneumocystis jirovecii pneumonia * Toxoplasma gondii encephalitis * CMV retinitis * TB * Chronic candidiasis ## Footnote These illnesses indicate the progression to AIDS.
127
True or false: There is a **cure** for HIV.
FALSE ## Footnote HIV infection is chronic and currently has no cure; it persists in the body.
128
What are the **risk groups** for HIV infection?
* Unprotected sexual contact * IV drug users * Infants of infected mothers * Blood transfusion recipients ## Footnote These groups are at higher risk for contracting HIV.
129
What is the **family** and **genus** of the poliovirus?
Family: Picarnaviridae Genus: Enterovirus ## Footnote Poliovirus includes Types 1, 2, and 3.
130
Describe the **structure** of the poliovirus.
* Non-enveloped * Single-stranded positive-sense RNA * Icosahedral capsid (~30 nm) * Acid-stable * Resistant to many disinfectants ## Footnote These characteristics contribute to the virus's stability and transmission.
131
What is the **incubation period** for poliovirus infection?
7-14 days ## Footnote This period precedes the onset of symptoms.
132
List the **systems/tissues** affected by poliovirus.
* Central nervous system (motor neurons of spinal cord and brain stem) ## Footnote These systems are critical for the virus's replication and impact.
133
What are the **symptoms** of mild poliovirus infection?
* Fever * Fatigue * Headache * Vomiting * Stiff neck * Sore throat ## Footnote These symptoms typically last for 2-5 days.
134
What percentage of poliovirus infections develop into **paralytic disease**?
Less than 1% ## Footnote This severe form can lead to sudden flaccid paralysis and respiratory difficulties.
135
How does the poliovirus enter the **central nervous system**?
By replicating in the intestine, entering the bloodstream, and crossing into the CNS ## Footnote This process destroys anterior horn cells, leading to paralysis.
136
What is the primary **transmission route** for poliovirus?
Fecal-oral route ## Footnote Contaminated water/food and occasionally oral-oral via droplets.
137
What are the **exit routes** for poliovirus?
* Feces * Throat secretions ## Footnote These routes facilitate the spread of the virus.
138
What are the **diagnostic methods** for poliovirus?
* Stool or throat swab culture * PCR for poliovirus RNA * Serology * Clinical evaluation of acute flaccid paralysis ## Footnote These methods help confirm the presence of the virus.
139
What are the **preventive measures** against poliovirus?
* IPV (inactivated polio vaccine) * OPV (oral, live-attenuated vaccine) ## Footnote Vaccination is crucial for prevention; there is no cure for the disease.
140
What are the **complications** associated with poliovirus infection?
* Permanent paralysis * Respiratory failure * Death * Post-polio syndrome (late muscle weakness and pain) ## Footnote These complications can arise during or after the acute infection.
141
What is the **goal** of the global polio eradication effort?
Ongoing eradication goal ## Footnote Global cases have dropped over 99% since 1988 due to vaccination efforts.
142
What is the **Hepatitis A Virus (HAV)** classified as?
Non-enveloped, small (27-32 nm), spherical virus with an icosahedral capsid ## Footnote Family = Picornaviridae, Genus = Hepatovirus.
143
What type of infection does **Hepatitis A** cause?
Acute, self-limiting ## Footnote No chronic or latent stage.
144
What is the **incubation period** for Hepatitis A?
15-50 days (average 28 days) ## Footnote Contagious ~2 weeks before to 1 week after onset of jaundice.
145
What are the **primary systems/tissues** affected by Hepatitis A?
* Liver (hepatocytes; Kupffer cells) * Bile ducts * GI tract ## Footnote Secondary effects on bile ducts and GI tract.
146
List some **symptoms and signs** of Hepatitis A.
* Fever * Malaise * Nausea * Vomiting * Loss of appetite * Right-upper-quadrant abdominal discomfort * Dark urine * Pale stools * Jaundice * Fatigue * Hepatomegaly ## Footnote Usually mild in children; more severe in adults.
147
What is the **mode of transmission** for Hepatitis A?
Fecal-oral route - contaminated food, water, or hands ## Footnote Entry: ingestion → intestinal mucosa → blood → liver; Exit: feces.
148
What are the **diagnostic methods** for Hepatitis A?
* Symptoms and signs * Elevated liver enzymes (ALT > AST) * Detection of anti-HAV IgM (acute infection) or anti-HAV IgG (past infection or vaccination) * PCR or antigen assays in stool ## Footnote Elevated liver enzymes are indicative of liver damage.
149
What are the **preventive measures** for Hepatitis A?
* Good hygiene * Sanitation * Proper sewage disposal * Safe food handling * HAV vaccine (inactivated virus) * Immune globulin for post-exposure prophylaxis ## Footnote Prevention is crucial in controlling outbreaks.
150
What is the **treatment** for Hepatitis A?
Supportive care (rest, fluids, nutrition); no antiviral therapy needed ## Footnote Complete recovery is expected.
151
What are the **complications** associated with Hepatitis A?
Rare: fulminant hepatitis in elderly or those with preexisting liver disease ## Footnote Most cases resolve without complications.
152
What is the **immunity status** after a Hepatitis A infection?
Lifelong immunity after infection; no chronic state or carrier state ## Footnote Hepatitis A does not have a latency period.
153
What are some **risk factors** for contracting Hepatitis A?
* Poor sanitation * Travel to endemic areas * Close contact with infected person * Consuming contaminated food or water ## Footnote Hepatitis A is not chronic and not zoonotic.
154
VF hepatitis a
Acid & bile resistance survives stomach and intestines Survives on hands, food, and surfaces High fecal shedding
155
What type of virus is the **Hepatitis C virus (HCV)**?
Enveloped, single stranded positive-sense RNA virus ## Footnote Belongs to the family Flaviviridae and genus Hepacivirus.
156
What is a significant characteristic of the **HCV genome**?
Highly variable due to error-prone RNA polymerase ## Footnote This leads to multiple genotypes and quasispecies.
157
Which cells does **HCV** primarily infect?
Liver hepatocytes and mononuclear cells ## Footnote Persistent infection can lead to chronic inflammation and liver damage.
158
What are common **symptoms** of Hepatitis C when present?
* Fatigue * Malaise * Anorexia * Nausea * Abdominal pain * Jaundice * Dark urine * Hepatomegaly ## Footnote Often asymptomatic for years, referred to as the 'silent epidemic'.
159
What are signs of **liver failure** in the chronic stage of Hepatitis C?
* Ascites * Jaundice * Spider angiomas ## Footnote These symptoms indicate severe liver dysfunction.
160
What is the **virulence factor** of HCV related to its genetic variability?
High genetic variability (antigenic drift) ## Footnote This allows for immune evasion, aided by envelope glycoproteins El and E2.
161
What is the primary **transmission route** for Hepatitis C?
Bloodborne ## Footnote Transmission can occur through transfusions, IV drug use, tattooing, and sexual contact.
162
What diagnostic tests are used for **Hepatitis C**?
* Elevated ALT/AST * Anti-HCV antibodies (ELISA) * HCV RNA detection (PCR) ## Footnote Genotyping helps guide treatment decisions.
163
What are the **preventive measures** for Hepatitis C?
* No vaccine available * Screen blood products * Avoid needle sharing * Safe sex practices * Infection control in healthcare settings ## Footnote Prevention is crucial due to the lack of a vaccine.
164
What is the treatment for Hepatitis C?
Direct-acting antivirals (DAAs) ## Footnote Examples include sofosbuvir, ledipasvir, and glecaprevir/pibrentasvir, with a cure rate >95%.
165
What are the **complications** associated with chronic Hepatitis C?
* Chronic hepatitis (70-85% cases) * Cirrhosis * Hepatocellular carcinoma * Liver failure * Mixed cryoglobulinemia * Glomerulonephritis ## Footnote Chronic carrier state can last decades and is a major cause of liver transplants.
166
What are the **risk factors** for contracting Hepatitis C?
* IV drug use * Unsterile needles * Transfusions before 1992 * Multiple sex partners * Hemodialysis ## Footnote These factors increase the likelihood of infection.
167
What is the **incubation period** for Hepatitis C?
2-26 weeks ## Footnote This period varies among individuals before symptoms may appear.
168
What is **West Nile Fever** caused by?
West Nile virus (WNV) ## Footnote It is an arboviral infection that can progress to meningitis or encephalitis.
169
What are the **primary targets** of West Nile virus?
* Central nervous system (CNS) * Reticuloendothelial system ## Footnote Tissues affected include the brain, spinal cord, meninges, and vascular endothelium.
170
What is the **incubation period** for West Nile virus?
2-14 days ## Footnote It can be longer in immunocompromised individuals.
171
What are the symptoms of **Mild/West Nile Fever**?
* Low grade fever * Headache * Body aches * Fatigue * Rash (maculopapular) * Lymphadenopathy ## Footnote 80% of cases are asymptomatic.
172
What are the symptoms of **Severe/Neuroinvasive Disease**?
* High fever * Neck stiffness * Confusion * Tremors * Seizures * Muscle weakness * Paralysis * Coma * Possible death ## Footnote Particularly affects the elderly and immunocompromised.
173
What is the role of the **Envelope (E) glycoprotein** in West Nile virus?
Facilitates viral attachment and cell entry ## Footnote NS proteins inhibit interferon-mediated antiviral responses.
174
What are the **natural reservoirs** for West Nile virus?
* Wild birds (especially crows, jays, sparrows) * Amplifying host: Birds * Incidental/Dead-end hosts: Humans and horses ## Footnote Humans and horses do not develop sufficient viremia to spread the infection.
175
What is the **vector** for West Nile virus transmission?
Culex mosquitoes (primarily Culex pipiens in the U.S.) ## Footnote The transmission cycle is mosquito -> bird -> mosquito -> human or horse.
176
What are some **rare routes** of West Nile virus transmission?
* Blood transfusions * Organ transplants * Transplacental (mother to fetus) * Breastfeeding * Laboratory exposure ## Footnote These routes are not the primary means of transmission.
177
What is the **diagnostic method** for detecting West Nile virus?
* Serology (ELISA) * PCR or RT-PCR * MRI brain * Culture (rare) ## Footnote Serology detects IgM antibodies, while PCR detects viral RNA.
178
What is the **supportive care** for West Nile virus infection?
* IV fluids * Pain and fever management * Airway protection for severe cases * Hospitalization for encephalitis or meningitis ## Footnote There is no specific antiviral therapy.
179
What are some **preventive measures** against West Nile virus?
* Mosquito control * Eliminate standing water * Use insect repellents * Wear long sleeves * Use window screens and bed nets * Avoid outdoor activity at dusk/dawn ## Footnote A vaccine is available for horses but not yet approved for humans.
180
What are some **long-term effects** of West Nile virus infection?
* Chronic fatigue * Memory loss * Depression * Long term muscle weakness or paralysis ## Footnote Neurological symptoms can persist for months to years.
181
Where was West Nile virus **first identified**?
West Nile District, Uganda (1937) ## Footnote The virus was introduced to the U.S. in 1999 during a New York outbreak.
182
VF West Nile fever
Envelope glycoprotein: facilitates viral attachment and cell entry NS protein: inhibit interferon mediated antiviral responses Ability to cross blood brain barrier and infect neuron
183
What is another name for **Noroviral Gastroenteritis**?
stomach flu ## Footnote Norovirus is a common cause of acute viral gastroenteritis.
184
What is the target **system** affected by Norovirus?
Gastrointestinal tract (GI tract) ## Footnote Specifically, it affects the small intestinal epithelium, especially villous enterocytes.
185
What are the **typical symptoms** of Noroviral Gastroenteritis?
* Sudden onset of vomiting * Watery diarrhea * Abdominal cramps and pain * Nausea * Low-grade fever * Headache * Muscle aches * Dehydration ## Footnote Symptoms usually appear 12-48 hours after exposure.
186
What is the **duration** of Noroviral Gastroenteritis?
1-3 days ## Footnote The illness is typically self-limiting.
187
What is the **capsid protein** of Norovirus that aids in attachment and entry?
VP1 ## Footnote It binds to histo-blood group antigens on intestinal cells.
188
What is the **infectious dose** of Norovirus?
10-100 viral particles ## Footnote This low infectious dose contributes to its high transmissibility.
189
What are the **reservoirs/sources** of Norovirus?
* Human GI tract (infected individuals) * No known animal reservoirs ## Footnote The virus is shed in large quantities in vomit and feces.
190
What is the most common **transmission route** for Norovirus?
Fecal-oral route ## Footnote Other routes include contaminated food or water and person-to-person contact.
191
What are common **settings** for Norovirus outbreaks?
* Nursing homes * Cruise ships * Schools * Daycares ## Footnote The virus is highly contagious and outbreaks are common in crowded areas.
192
What is the **diagnosis** method for Noroviral Gastroenteritis?
* Clinical diagnosis based on symptoms and outbreak pattern * Lab tests: RT-PCR for Norovirus RNA in stool, antigen detection, electron microscopy ## Footnote Clinical diagnosis is often sufficient during outbreaks.
193
What is the **treatment** for Noroviral Gastroenteritis?
* Supportive care only * Oral rehydration to prevent dehydration * IV fluids in severe cases * Antimetics for nausea/vomiting ## Footnote There is no specific antiviral treatment available.
194
What are key **prevention** measures for Norovirus?
* Hand hygiene * Disinfection with bleach-based cleaners * Proper food handling and cooking * Isolation of infected individuals during outbreaks ## Footnote No vaccine is available for Norovirus.
195
True or false: **Norovirus** is named after Norwalk, Ohio.
TRUE ## Footnote It is more common in winter months.
196
Res noroviral gastroenteritis
Human gi tract No animal
197
What are **Transmissible Spongiform Encephalopathies (TSEs)**?
* Creutzfeldt-Jakob Disease (CJD) * Variant CJD (VCJD) * Bovine Spongiform Encephalopathy (BSE) ## Footnote TSEs are diseases caused by abnormal misfolded proteins known as prions.
198
What is the **type** of prion responsible for TSEs?
Non-living infectious protein (no DNA/RNA) ## Footnote Prions are extremely resistant and do not elicit an immune response.
199
What systems or tissues are primarily affected by **TSEs**?
Central Nervous System (CNS) - brain and spinal cord ## Footnote TSEs cause gray matter degeneration leading to a spongiform appearance.
200
List the **signs/symptoms** of **Creutzfeldt-Jakob Disease (CJD)**.
* Rapidly progressive dementia * Memory loss * Confusion * Behavioral/personality changes * Myoclonus * Ataxia * Visual disturbances * Coma → Death (within 6-12 months) ## Footnote CJD symptoms progress rapidly and lead to death within a year.
201
What are the **early symptoms** of **Variant CJD (VCJD)**?
* Early psychiatric symptoms (depression, anxiety, pain) * Slower progression than CJD * Affects younger adults (20s-30s) ## Footnote VCJD later leads to neurological decline and muscle stiffness.
202
What behavioral changes are associated with **Bovine Spongiform Encephalopathy (BSE)**?
* 'Mad' behavior * Aggression * Nervousness * Loss of coordination * Difficulty standing * Paralysis ## Footnote BSE is fatal within months in cattle.
203
What is the **virulence factor** of prions in TSEs?
Popse (prion protein) ## Footnote It catalyzes the conversion of normal PrP to PrPsc in an autocatalytic process.
204
What is the **latency** period for TSEs?
Extremely long incubation period (years to decades) ## Footnote There is no immune response as the host immune system does not recognize prions as foreign.
205
How is **CJD** transmitted?
* Sporadic * Inherited (PRNP mutation) * Surgical contamination ## Footnote CJD can occur due to genetic factors or contamination during medical procedures.
206
How is **vCJD** transmitted?
* Ingestion of BSE-contaminated beef ## Footnote vCJD is linked to consuming infected cattle products.
207
What is the **portal of entry** for **vCJD** and **BSE**?
* Oral (vCJD, BSE) * Surgical exposure (CJD) ## Footnote The portal of exit for prions is neural tissue postmortem.
208
What are the **diagnostic methods** for TSEs?
* Clinical presentation * MRI or EEG * CSF detection of 14-3-3 protein * RT-QuIC assay or Western blot for PrPsc * Brain biopsy showing spongiform changes ## Footnote No culture or staining is possible as prions are non-cellular.
209
What is the **prevention/treatment** for TSEs?
* No cure or vaccine * Strict sterilization of neurosurgical instruments * Banning animal-derived protein feed for cattle * Avoiding consumption of high-risk tissues ## Footnote Supportive care is the only option available for affected individuals.
210
What is the **complication** associated with TSEs?
Always fatal: severe neurodegeneration leading to coma and death ## Footnote The sequence includes a long incubation period followed by rapid neurological deterioration.
211
True or false: There is a **chronic carrier** state for TSEs.
FALSE ## Footnote There is no chronic carrier; the latent phase involves asymptomatic accumulation of prions.
Microbiology
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