Diseases Flashcards
1
Q
Staphylococcus aureus signs and symptoms
A
- Pus filled wound, redness, swelling, pain, nausea, diarrhea, dehydration, hypotension
- Increased neutrophils in CBC
2
Q
Staphylococcus aureus morphology and lab tests
A
- Gram positive bacteria, cocci, clusters
- Positive gram stain, purple cocci clusters
- Yellow colony growth on BAP with beta hemolysis
- Coagulase positive
3
Q
Where is Staphylococcus aureus found
A
resident flora on our bodies, mainly in nose
4
Q
Most commonly known Staphylococcus aureus strain
A
Methicillin resistant Staphylococcus Aureus
5
Q
Infection or diseases caused by Staphylococcus aureus
A
- Toxic Shock Syndrome
- Food poisoning
- PNA
- Meningitis
- Osteomyelitis
- Endocarditis
- Bacteremia
- Sepsis
6
Q
Length of Staphylococcus aureus infection and treatment
A
- 10-20 days
- Drainage of abscess
- For severe infections only, 7-10 antibiotic treatment.
- Penicillin or Vancomycin
7
Q
What is the causative agent of typhoid fever
A
Salmonella enterica
8
Q
What type of bacteria Salmonella enterica
A
Rod-Shaped, Flagellate, Facultative Aerobic, Gram Negative, family of Enterobacteriaceae
9
Q
Where is Salmonella enterica normally found
A
Lives in the intestines of people and animals using the body as a reservoir
10
Q
Most common bacterial food borne pathogen
A
Salmonella enterica
11
Q
Transmission & Pathogenesis of Salmonella enterica
A
- If survives gastric juices able to produce toxins and invade the epithelial cells in the intestines
- Creates a proinflammatory cytokines which ignites an acute inflammatory reaction
- potential to travel from the intestines and cause systemic diseases
12
Q
Salmonella enterica signs and symptoms, incubation, prodromal period, illness length
A
-Diarrhea
-Incubation period depends on the dose of the bacteria
-Prodromal phase is about 6-72 hours
-Nausea, vomiting, abdominal cramps, fever, chills, headache,
-Most important characteristic is blood in the stool
Illness stage lasts about 2 days to a week
13
Q
Diagnosis of Salmonella enterica
A
Lab test that detects the bacteria in a person’s stool, tissue, or fluids
14
Q
Salmonella enterica complications
A
- Can occur if the diarrhea persists
- Bacteremia, Enteric fever, Reactive arthritis
- Severe dehydration; Decreased urine output, Dry mouth, Sunken eyes
15
Q
Salmonella enterica treatment
A
- Hydration
2. Antibiotics; chloramphenicol, ciprofloxacin or ofloxacin, Azithromycin
16
Q
What infections does Neisseria meningitides cause
A
Meningococcal septicemia, Meningococcemia, Meningitis,
Pneumonia, Arthritis, Otitis media
17
Q
Neisseria meningitides morphology
A
aerobes, gram negative diplococci (coffee bean shaped), fastidious, encapsulated, nonendospore forming, nonmotile, possess pili
18
Q
What areas of the body are affected by a serious Meningococcal disease
A
blood, brain, spine
19
Q
Symptoms of Meningococcal disease
A
sudden onset of fever, headache, stiff neck, can rapidly progress to death
20
Q
Is there a vaccine for Meningococcal disease
A
Yes, recommended for 11 to 12 year old kids
21
Q
Long term effects of Meningococcal disease
A
Infection can enter blood stream, damage blood vessels, cause blood clots, gangrene infection and loss of extremities, can enter spinal fluid and brain and cause damage to nervous system
22
Q
Meningococcal disease incubation period
A
5-10 days after breaking BBB, lethal in 24 hours
23
Q
Signs and symptoms of Meningococcal disease
A
Sudden onset of intense headache, vomiting, stiff neck, inactivity, drowsiness, sensitivity to light, confusion, petechia, high fever, rash
24
Q
Treatment for Meningococcal disease
A
PCN, Sulfa, Ceftriaxone
25
Can meningococcemia be prevented
Yes, with bactericidal antibodies in serum
26
What are severe complications of Meningococcal disease
seizures, can progress in to coma within few hours, hemorrhagic fever, disseminated intravascular coagulation coagulation and circulatory collapse
27
Diagnoses of Meningococcal disease
1. Blood culture, NP swab, LP, skin scrapings
| 2. Oxidase positive, maltose fermenter
28
Meningococcal disease colonize the
nasopharynx
29
How does Meningococcal disease enter the bloodstream
It can get into your bloodstream from your sinuses, ears, or throat. The bacteria travel through your bloodstream to your brain
30
E. coli morphology
facultative anaerobe, Gram negative straight rods, singles or in pairs, non-spore forming
31
E. coli biochemical tests
nitrate postive, indole positive, MR positive, lactose fermenter
32
E. coli agar culture results
1. MAC: bright pink lactose fermenter colonies
| 2. EMB: purple, black green hue, lactose fermenter colonies
33
What are the 3 most common infections caused by E. coli
1. Sepsis/meningitis
2. UTI
3. Diarrheagenic E. coli
34
E. coli sepsis/meningitis
Mostly affects premature neonates, occurs during delivery or HAI
35
E. coli UTI (cystitis) signs, symptoms and treatment
1. dysuria, urinary urgency
2. u/a >100CFU/ml and +WBC esterase test
3. Treatment: Antibiotics
36
What happens if untreated E. coli UTI, symptoms, diagnoses, and treatment
1. pyelonephritis: fever, flank pain, back pain
2. Can lead to bacteremia
3. Scar tissue in kidneys, impaired kidney function (dx blood cx, gram stain, u/a)
4. treatment: 2nd and 3rd generation antibiotics
37
What are the 2 types of Diarrheagenic E. coli
1. Shiga toxin-producing E. coli (STEC)
| 2. Enterohemoryhagic E. coli (EHEC)
38
How is Diarrheagenic E. coli transmitted
contaminated food or water, under cooked meat ,unpasteurized milk or juices or from human to human
39
What is Shiga toxin-producing E. coli virulence factor
Most outbreaks consist of serotype O157:H7, cell lysis occurs, releasing toxin, if antibiotic therapy is started, the infection worsens
40
Diarrheagenic E. coli symptoms, incubation, and duration
1. mild uncomplicated diarrhea
2. Incubation period 1-5 days
3. duration 5-10 days
41
What are complications of Diarrheagenic E
1. hemorrhagic colitis: Inflammation of colon, excessive bleeding
2. hemolytic uremic syndrome: blood in urine, thrombocytopenia, hemolytic anemia, often leading to kidney injury
42
Helicobacter pylori morphology
Gram Negative Helically-Shaped, Microaerophilic Bacteria with Terminal Flagella
43
Helicobacter pylori incubation, prodrome, illness
1. Incubation: Unknown Incubation Period, no visible signs
2. Prodrome: Asymptomatic until Ulcers Form or Cancers Form
3. Decline: Stays with Host until Death
44
Helicobacter pylori transmission and target site of infection
1. Unknown, possibly fecal-oral, gastric-oral, oral-oral, contaminated food
2. Stomach and duodenum
45
Helicobacter pylori symptoms and duration
Chronic asymptomatic gastritis, less than 20% never develop symptoms, but it can result in ulcers and stomach cancer, remains in body for life without treatment, although most will not realize they have it
46
Long term effects of Helicobacter pylori
1. 15% ulcers, 2% develop cancer
2. 3 types of cancer:
a. MALT Lymphomas
b. Large B-Cell Lymphomas
c Adenocarcinomas.
47
Helicobacter pylori diagnoses
Urea Breath Test, Fecal Antigen Assay, or Biopsy.
48
Helicobacter pylori treatment
1. A Proton Pump Inhibitor (Omeprazole)
2. Antibiotics (Amoxicillin, Clarithromycin, and Metronidazole)
3. Most people that are infected never receive treatment because they are unaware that they have it.
49
What are virulence factors of Helicobacter pylori
1. Urease neutralize gastric acid
2. Lipopolysaccharides adhere to host cells causing inflammation--> reduces cellular adhesion
3. Effectors cause actin remodeling, host cell growth, and apoptosis inhibition
4. Secretory enzymes and exotoxins cause gastric mucosal injury
50
What is the causative agent of Toxoplasmosis
Toxoplasma gondii
51
What is Toxoplasma gondii
1. parasitic protozoan that infects most warm-blooded animals by forming cysts on muscle and nerve tissue
2. usually in brain and eyes
52
What are the symptoms of Toxoplasma gondii
mostly asymptomatic for immunocompetent individuals
53
Who are most at risk of Toxoplasma gondii
Pregnant women are most at risk as vertical transmission is possible
54
How does infections of Toxoplasma gondi occur
1. Contamination of food or water with oocysts; consumption
2. Host eats the infected intermediate
3. Infection between intermediates can also occur by the consumption of tissue cysts or inoculation of tachyzoites
55
What is the primary reservoir of Toxoplasma gondi? intermediates?
1. Members of Felidae family (house cats). T. gondii can form oocysts in cat intestine.
2. Intermediate hosts consist of most warm blooded animals
56
Symptoms of Toxoplasma gondi
1. Prodromal stages are flu-like and consist of body aches
2. Infection in the eyes can cause eye irritation, uveitis, and blindness
3. Primary infection in pregnant women can cause stillbirth, disability, and/or blindness
4. links between toxoplasmosis and impaired thinking in rats as well as schizophrenia in humans
57
How is Toxoplasmosis diagnosed
Toxoplasmosis is diagnosed through serologic tests
58
Treatment of Toxoplasmosis
1. usually isn’t necessary
2. Acute infection may need treatment by a combination of an antiparasitic, antibiotic and chemotherapy drugs that reduce toxicity of the antiparasitic infection
59
Long term effects of Toxoplasmosis
if not treated immediately, is usually beyond infection and aims more at development of disabled organs if possible
60
How long does Herpes Simplex Virus last
1. Latent infection: Alternates between a latent stage
| 2. Dormancy period in which there are few symptoms — and an outbreak stage
61
Herpes Simplex Virus morphology
Enveloped, double-stranded, linear DNA virus, Icosahedral capsid
62
What infections does HSV cause
1. HSV type 1: Can cause rarer conditions, for example, keratitis and other ocular sequelae, and encephalitis
2. HSV type 2: Might be unrecognized or cause painful genital ulcers, increases the risk of acquiring HIV
3. Symptomatic and asymptomatic viral shedding are normal for both types
63
Herpes Simplex Virus signs and symptoms
1. Symptoms typically appear as a blister or as multiple blisters on or around affected areas: mouth, genitals, or rectum
2. Blisters break, leaving tender sores
64
Herpes Simplex Virus diagnoses
1. Appearance is typical, no testing is needed to confirm the diagnosis
2. If health care provider is uncertain,
Can be diagnosed with lab tests: DNA or PCR tests and virus cultures
65
Where is the location of latency for HSV
1. It gets into the nerve roots and distributes itself to the sensory nerve ganglia
2. For genital region: ganglia are directly adjacent to the spinal rope in the lower back
3. For oral herpes: ganglia are situated behind the cheek bone
4. It can remain dormant in the bundle of nerves at the spine base.
5. When it reactivates it moves through the nerve paths to the surface of the skin, sometimes causing outbreak
66
Hepatitis B morphology
1. An envelope composed of viral-encoded proteins and host-derived lipid components
2. A core particle made up of the
Nucleocapsid protein (hepatitis B core antigen)
3. Viral DNA genome (double stranded circular DNA)
4. Polymerase (virally encoded)
67
What organ does Hepatitis B affect
1. It affects the function of the liver
2. Virus invades hepatocytes; liver cells
3. An immune response is triggered and the immune system attacks infected liver cells which injure the liver
68
Signs and symptoms of Acute Hepatitis B
1. Individuals immune system may be able to fight off on its own
2. Early symptoms: loss of appetite, fever, joint pain, nausea, vomiting, stomach pain, light colored stools, dark colored urine
69
Signs and symptoms of chronic Hepatitis B
1. Lasts longer than 6 months
2. Infection lingers in immune system, unable to be fight off severe symptoms
3. Indicates liver in distress:
Severe vomiting, yellowing of the eyes and skin (jaundice), bloated stomach
70
Hepatitis B treatment
1. No specific cure, acute stage clears on its own in 90% of cases
2. Symptoms can be treated such as anti-nausea meds for vomiting
3. Chronic HBV can be treated with antiviral meds; stops the replicating and prevents it from developing into liver CA or liver disease.
4. If liver CA developed in can become fatal, die within months
71
Why does the hepatitis B vaccine not require a booster?
Hepatitis B virus evolves very slowly compared to an RNA viruses such as HIV and influenza and therefore the immunity from the series of vaccines is lifelong
72
Marburg Virus Morphology
Zoonotic RNA virus
73
Marburg Virus transmission
1. Unknown how initial infection to human occurred
2. May be do to unprotected exposure to infected fruit bat fluids such as feces or other fluids
3. Person to person, direct contact blood, body fluids, or infected tissues
74
Marburg Virus incubation period
2-21 days
75
Marburg Virus Initial symptoms
Symptoms are sudden: Hemorrhaging fever, chills, headache, myalgia
76
Marburg Virus symptoms at about 5th day
1. Maculopapular rash (most prominent on trunk)
| 2. Nausea, vomiting, chest pain, sore throat, abdominal pain, diarrhea
77
Severe symptoms of Marburg Virus symptoms
Jaundice, inflammation of the pancreas, severe weight loss, delirium, shock, liver failure, massive hemorrhaging, multiple organ dysfunction
78
Marburg Virus diagnoses
Antibody enzyme-linked immunosorbent assay (ELISA), Antigen detection test, Serum neutralization tests, Reverse-transcriptase polymerase chain reaction (RT-PCR) assay,
Virus isolation by cell culture
79
Marburg Virus treatment
1. No specific treatment for the virus
2. Hospital care is recommended
3. Watch fluids and blood pressure
80
Severe Acute Respiratory Syndrome Coronavirus 2 morphology
It is an enveloped, positive-sense, single-stranded RNA virus
81
Severe Acute Respiratory Syndrome Coronavirus 2 signs and symptoms
1. Coughing, fever, SOB, loss of taste/smell (occurs in some “asymptomatic” pts), GI symptoms, fatigue, confusion, CP
2. Kidney failure, decreased WBC
3. No visible symptoms – about 80% of all cases
82
What organs does COVID-19 affect
Can infect the lungs, heart, kidney, small intestines, testes, and neurons.
83
COVID-19 incubation period
Incubation period is 2-27 days (usually no more than 14 days
84
COVID-19 duration
Usual duration of infection is 2-3 weeks. Patients can remain infected for up to 37 days (contagious the whole time)
85
COVID-19 diagnosis
1. Antibody tests (usually cannot distinguish active infections)
2. Reverse-transcriptase PCR tests (determines if there is an active infection)
86
COVID-19 complications
Cytokine storm, Pediatric Multisystem, Inflammatory Syndrome (PMIS)
occurs in some children, widespread microclotting, HA, strokes, heart ruptures, PNA, organ failures, SARS
87
What is the causative agent of Lyme disease
Borrelia burgdorferi
88
Borrelia burgdorferi morphology
1. A gram-negative, corkscrew-shaped bacterium aka spirochete
2. Instead of a LPS outer membrane, it has immunoreactive glycolipids
89
Borrelia burgdorferi reservoir
blacklegged deer ticks which have feasted on small mammals, birds, and lizards
90
Borrelia burgdorferi transmission
1. vector-borne from infected black-legged tick biting a human/animal
2. Tick has a blood meal on animal infected by Borrelia burgdorferi
3. Tick transmits bacteria into host after it bites
4. Not contagious person to person
91
What virulence factors does the outer membrane immunoreactive glycolipids have
It activates suppressor T cells to a maximum, allowing the bacteria to have greater virulence because the immune system is compromised
92
Osp A
1. Ticks saliva transmits bacteria into host, this protein is responsible for attachment into host
2. It keeps the bacteria in the midgut of the tick, allowing it to colonize there
93
OspC
1. facilitate the bacteria moving from gut wall and migrate through the hemolymph to the salivary gland.
2. Interacts with the tick’s salivary proteins, giving it better infectiveness into a new host
94
What is are 2 common characteristic of Lyme disease? What are they?
1. Borrelia burgdorferi’s ability to cause specific immune response
2. Adhesin proteins and other molecules invoke immune response, causing lesions on host and developing disease
3. Arthritic pain: Lipoproteins interact w/host receptors to set off pro-inflammatory cytokines, metalloproteinases, and chemokine: Sx of pain, swelling of joints and muscles.
95
Signs and symptoms of Lyme disease
1. Fever, chills, headaches, muscle aches, fatigue and swollen lymph nodes
2. At about day 3-30: Most get a red circular, "bullseye," rash around site of infection called an Erythema Migrans Rash (characteristic lesion)
96
Severe complications from Lyme's disease
1. Bacteria in NS causing Inflammation of organs of NS: arthritic pain, facial palsy, numbness in the feet and hands,
2. Heart palpitations
3. Erythema Migrans rashes appear on other areas of body
97
Stages of lyme disease
1. Incubation: between day 1 and day 3
2. Prodromal: between day 3 and 30
3. Illness : varies, dependent on if Tx received, when they received it
4. Decline: varies, dependent on the factors above
98
Diagnoses of Lyme disease
1. Assess symptoms
2. Likelihood of being in tick infested area
3. Blood tests searching for antibodies for Borrelia Burgdorferi
a. ELISA (risk for false positive)
b. Western blot test to confirm antibodies specific for the surface proteins on the bacterium
99
Treatment
Antibiotics: doxycycline, amoxicillin, or cefuroxime axetil
100
What is the causative agent of measles
rubeola virus: Morbillivirus
101
Morphology of measles
1. Virus is spherical & enclosed in a lipid-containing envelope
2. Single-stranded, negative-sense RNA
102
Measles transmission
Can be spread through the air from respiratory droplets & small aerosol particles (from coughing, sneezing)
103
How does measles enter the body
upper respiratory system
104
What is pathogenesis of measles
1. Infects macrophages in lungs
2. Infected cells migrate to lymph nodes where they
3. Virus transferred to B and T cells
4. CD150 on WBC is point of entry
5. Infected B & T cells migrate t/o body releasing virus particles into blood
105
What is the destination of measles virus
The destinations for the virus are the spleen, lymph nodes, liver, thymus, skin & lungs
106
In rare conditions, measles can cause
It can cross the BBB and cause swelling of the brain
107
Measles symptoms
Fever, dry cough, runny nose, sore throat, inflamed eyes,
| white spots w/bluish-white centers red background inside mouth, and flat, large, blotchy rash
108
Measles incubation period
10-12 days
109
After incubation period what symptoms do measles infected patients have
1. the symptoms appear beginning with symptoms resembling those of the common cold
2. Shortly, the macular rash appears beginning on the face & spreading to the trunk & extremities
3. Lesions in the oral cavity are called Koplik’s spots
110
Why are measles extremely dangerous to elderly and infants
Because of their weakened immune systems, they can be complicated by a secondary bacterial infection (ex: middle ear infections, pneumonia)
111
What are complications associated with Measles
Dehydration, conjunctivitis, liver infection, bronchitis, pneumonia, encephalitis, death
112
How is Measles diagnosed
1. Based on the characteristic rash
2. PCR testing (polymerase chain reaction) swab from throat or NP
3. Blood test: detect for IgM antibodies in serum, must collect few days afte rash onset: will show recent infection (not to be confused with IgG: vac)
113
Measles treatment
1. No treatment
| 2. supportive care: for fever, rest, plenty of fluids
114
Why does measles cause a rash
1. It is due to inflammation in the skin. The virus travels in the blood, it infects capillaries in the skin.
2. Immune cells release chemicals such as NO and histamines: destroy the viral invaders and call other immune cells
3. These chemicals cause swelling and damage to cells, resulting in itchy skin rash.
115
What does Mycobacterium tuberculosis cause
tuberculosis (TB) in humans
116
Mycobacterium tuberculosis morphology
1. Acid-fast, obligate aerobe, slender, slightly curved to straight bacillus arranged in ropelike structures or clumps
2. Outer layer is made up of glycolipids and mycolic acids covering thin peptidoglycan
3. Slow growing
117
Pathogenesis of Mycobacterium tuberculosis
1. After inhalation TB cells arrive at alveoli sacs, activate immune response
2. Unique cell wall of TB will allow some to evade phagocytosis
3. Tb multiply inside macrophages
4. Macrophages cause a chemotactic response, try to isolate tb, release cytokines, cause damage, macros die
5. Tubercle will enlarge and symptoms will worsen, disease can become latent
6. tubercles will form calcifications If tubercle not latent, will continue to enlarge until rupturing
7. Tubercle bacilli can distribute into bronchioles, then lymphatic system and circulatory system
118
Latent TB
10% of people exposed will develop active TB.Those with latent TB have +PPDR. They do not display symptoms and they are not contagious. The greatest risk of reactivation is within the first 2 years after infection.
119
TB treatment
1. Shorter tx: 1-2 drugs x 3-6 months
2. Drugs used are isoniazid, rifapentine and/or rifampin
3. Can become active if the immune system becomes weakened
120
Where does Mycobacterium tuberculosis hide in the body with latent TB?
1. They can hide inset cells in bone marrow, inaccessible to immune cells and can't be reached by drug molecules
2. When immune systems weakens can move to other parts of body or lungs
121
Pulmonary tuberculosis
Persistent cough, fatigue, hemoptysis, fever, pain w/respiration, chills, appetite loss, CP
122
TB incubation
~2-12 weeks
123
Tb Prodroma
~2-4 weeks
124
Period of illness of TB
can last up to 2 months
125
Period of decline
can last up to 6 months
126
Streptococcus pyogenes morphology, reservoir
1. (GAS), G +, aerotolerant, non-motile and non-sporing cocci
2.Visual- small , unpigmented colonies, beta hemolysis
smooth or moist surface and clear margins
3. Humans are primary but cattle as well
127
Streptococcus pyogenes virulence factor
1. M protein- is found on the cell wall on a fuzzy layer of fibrils
2. prevent activation of complement
3. Evade phagocytosis and killing by neutrophil
4. adhere and colonize mucous membranes
5. Hyaluronic acid- found on their capsule; resembles human connective tissue, few antibodies against the capsule produced
6. Exotoxin A: produced by M proteins, act as a superantigen, immune system to contribute to the damage
128
Streptococcus pyogenes transmission
Direct contact, airborne droplets from cough or sneeze, sharing eating utensils,and sharing drinks
129
Streptococcus pyogenes signs and symptoms
quick onset of sore throat, pain w/swallowing, red and swollen tonsils, swollen lymph nodes, fever, HA, rash, vomiting
130
Diagnosis of Streptococcus pyogenes
1. Throat culture
2: First Rapid Strep test
3. Second test checks for enzymes or acid extract parts of S.pyogenes, called antigens
4. Imaging- rare, to evaluate serious complications
131
Treatment of Streptococcus pyogenes
1. Antibiotics- Penicillin
| 2. Over the counter medicine- Tylenol and Advil
132
What does Streptococcus pyogenes cause
Group A streptococcus (GAS), causes numerous infections in humans including pharyngitis, tonsillitis, scarlet fever, cellulitis, erysipelas, rheumatic fever, post-streptococcal glomerulonephritis, necrotizing fasciitis
133
How is Streptococcus pyogenes superantigenicity make it more virulent
Superantigen is a class of antigen that has the ability to cause an excessive activation of the immune system. It causes the non-specific activation of T-cells that will lead to polyclonal T cell activation and massive cytokine release.
134
Human Papilloma Virus
| morphology
Non enveloped, icosahedral capsids, double stranded and circular DNA
135
What is HPV
1. Most common STD
2. low risk Infects skin, causes genital warts
3. High risk infects mucous membranes, oncogenic HPV, overtime develops into cancer
136
Pathogenesis of HPV
1. Infects cells of skin and mucous membranes
2. Infection occurs in the basal cell layer of squamous epithelial cells
3. HPV favors stages of growth and cell division in host
137
How is HPV transmitted
1. Skin to skin contact
2. Sexual contact
3. Asymptomatic individuals c
138
Symptoms of HPV
1. Usually shows no symptoms
2. Some develop into papillomas (benign tumors)
- Genital Warts
- Common Warts
- Plantar Warts
- Flat Warts
3. Others develop into precancerous lesions or cancer
139
HPV incubation period
Low risks infections: incubation period from HPV to genital warts takes 2wks to 8 months
140
If treatment is started how long does HPV take yo clear up
Once treatment has started, takes 6 months to clear
141
What HPV cases get CA
Those who cannot clear the warts will progress to cancer, interval between infection and cancer is 10-20 yrs.
142
HPV treatment
1. No treatment for virus itself
2. Treatment for warts include anti tumor topical cremes
3. If patient is not responding to cremes, other options for removal
143
HPV tests
Vinegar Acetic Acid
HPV DNA Tests
Pap smears
144
What is the scientific name of Rabies Virus
Lyssavirus rabies
145
Rabies Virus morphology
Bullet-shaped, enveloped RNA virus
146
How is Rabies Virus reservoir
1. zoonosis
2. Reservoirs: wildlife and canine
3. Non-reservoirs: rodents, domesticated animals, livestock
4. To humans
147
How is rabies virus transmitted
1. Direct contact with saliva or brain/nervous system tissue
| 2. Rare, through corneal and organ transplants
148
What is affected by rabies virus
1. Replicates in muscle near bite and enters neuron of PNS
2. Moves from PNS to CNS
3. Ascends spinal cord
4. Reaches brain and causes encephalitis
5. Enters salivary glands and other organs
149
Stages of rabies virus disease
1. Incubation: 10-90 days
2. Prodrome: 2-10 days, virus moves to CNS & multiplies rapidly
3. Illness: 2-7 days
4. Decline: 10 days after onset of symptoms
5. There are 3 stages
150
Prodrome signs and symptoms of rabies virus
Discomfort at the site of the bite, anxiety, agitation, insomnia, flu-like illness
(stage 1)
151
Illness signs and symptoms of Rabies virus
1. Hallucinations, aggression, seizures, “dumb” rabies – no signs of overactivity
2. Other stage 2 symptoms: photosensitivity, cramps, fear
3. Death may occur
152
Decline symptoms of Rabies virus
1. Stage 3 symptoms: paralysis of eyes and limbs, salivation from mouth, hydrophobia
2. Patient slips into coma and dies of paralysis of breathing muscles or heart failure
153
Rabies testing
1. Saliva
2. Serum and CSF
3. Skin biopsy, from base of hair follicle
154
Treatment of Rabies virus
No specific treatment once symptoms have started
155
What is Zika virus
a virus that is transmitted mainly to humans through the bite of an infected mosquito species.
156
How is Zika virus transmitted
1. Through the bites of mosquitos
2. From an infected pregnant woman to her fetus
3. Through unprotected sex
4. Blood transfusion, organ transplant
157
Zika virus morphology
Single stranded RNA virus within icosahedral capsid, lipid membrane within envelope
158
What is scientific name of Zika virus
Flavivirus
159
Most common transmission of Zika virus
infection during a viremic blood meal and injection of infectious saliva during blood feeding (horizontal transmission).
160
Signs & Symptoms of Zika virus
1. Most people will not show symptoms or will have mild ones
2. Most common Sx: fever, rash, HA, joint pain, red eyes, muscle pain
3. Death is rare
161
How long do signs & symptoms last
They can last from several days up to a week.
162
Can someone become reinfected with Zika virus
No, once infected, they will develop immunity
163
How is Zika diagnosed
1. blood test
| 2. urine test
164
How are intrauterine pregnancies affected by Zika virus
1. It can pass from the mother to fetus during pregnancy or delivery.
2. Risks to baby are: microcephaly, damage to the brain, Congenital Zika Syndrome, SAB, stillbirth
165
What is Congenital Zika Syndrome
5 types of birth defects not commonly seen
1. Severe microcephaly
2. Decreased brain tissue/damage
3. Damage to the back of the eye with specific scarring and increased pigment
4. Limited range of motion
5. Too much muscle tone restricting body movement
166
Treatment of Zika virus
no treatment, not life threatening, people generally recover without any problems
167
Ebola virus genus and morphology
1. Ebolavirus
| 2. lipid-enveloped, single-stranded, negative-sense RNA virus
168
How doe Ebola virus trasmission occur
1. mucous membranes and/or broken skin
2. contaminated objects with body fluids such dead body, medical instruments, infected fruit or bushmeat
3. Virus cannot spread until symptoms develop
169
What organs does Ebola virus affect
1. Immune system
2. Spleen, kidneys, lungs
3. It kills cells that help regulate fluid and chemical balance
4. Produce proteins that clot in the blood.
5. Vital functions are shut down, causing blood vessels to leak fluid into surrounding tissues.
170
What is one of the strongest indicators of the severity of Ebola
The extent of Lymphopenia: Decreased WBC/T cell count
171
Signs and symptoms of Ebola virus
1. Initial symptoms:*fever, *fatigue, muscle pain, HA, sore throat
2. Followed by: *vomiting, *diarrhea, rash, impaired kidney and liver function
172
Lab indicators of Ebola virus
Low WBC counts, Low platelet counts, Elevated LFTs
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Incubation Period of Ebla virus
2-21 days
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How long does Prodromal Stage of Ebola last
Up to 10 days
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Treatment of Ebola virus
1. Fluids therapy via IV
2. O2 if needed
3. Meds for BP
4. Reduce vomiting and diarrhea
5. Manage fever/pain
6. Treat other infections
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What does Varicella-Zoster virus cause
Chicken pox, shingles
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Varicella-Zoster virus genus and species
1. Varicellovirus
| 2. Human herpesvirus
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Varicella-Zoster virus morphology
Double stranded DNA virus
| Enveloped virus w/polyhedral capsid
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Varicella virus signs and symptoms
1. Pruritic rash t/o body(scalp, face or trunk)
2. Rash progression into macules, papules and vesicular lesions, crusting then scabs
3. Fever, fatigue, HA, flu-like Sx,
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What is considered primary and secondary infection of Varicella-Zoster virus
1. Varicella is considered the primary infection.
| 2. Herpes zoster is considered the secondary infection.
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Varicella virus stages
1. Incubation: 14 - 16 days
2. Prodrome: 1 - 2 days
3. Illness: 2 – 3 days
4. Decline: day 5 -6
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Herpes Zoster virus signs and symptoms
1. Pruritic rash clusters restricted to dermatomal distribution (upper trunk)
2. Rash progression: 3-5 days w/new cluster formation then crusting and scabs
3. Pain, paresthesia, severe burning, HA, photophobia, malaise
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Herpes Zoster virus stages
1. Incubation: 10 – 21 days
2. Prodrome: 1 - 2 days
3. Illness: 4 -7 days
4. Decline: day 8 - 9
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Complications of Varicella
1. Bacterial infections of skin, soft tissue, bones, or joints
2. Sepsis, bacterial pna, meningitis, encephalitis, toxic shock syndrome
3. Dehydration
4. Reye’s syndrome in patients that take aspirin during outbreak
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Complication of Herpes Zoster
1. Bacterial superinfection
2. Cranial and peripheral nerve damage, meningoencephalitis
Hepatitis, vision impairment or loss, Post-herpetic neuralgia (most common) can last up to 90 days after rash onset.
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Varicella-Zoster virus transmission
1. Highly Contagious t/o infection
2. Droplet: coughing, sneezing
3. Direct contact with skin and/or lesions
4. Indirect: touching freshly soiled contaminated items.
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How long is someone contagious for Varicella-Zoster virus
Patients are usually contagious from a few days before onset of the rash until the rash has crusted over.
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How long after exposure does someone develop symptoms
10-21 days to develop post-exposure
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Varicella-Zoster virus virulence
1. It evades human immune response, can remain latent in dorsal root ganglion for many years.
2. Humoral antibodies unable to penetrate nerve cells, no viral antigens expressed on surface of nerve cells, cytotoxic T cells are not activated
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Treatment of Varicella-Zoster virus
1. Topicals for itching
2. Pain relief: ibuprofen and acetaminophen
3. Antivirals
4. Treatments for complications: lidocaine patches, Gabapentin,
anticonvulsants
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Cholera is caused by
1. Vibrio Cholerae
| 2. Extracellular bacterial infection of the small intestine
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What is a characteristic sign of Cholera? Why does it happen
1. Acute “Rice Water” diarrhea due to rapid severe dehydration and electrolyte imbalance
2. Peristalsis response to rid the body of toxins and microbes.
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How long does Cholera last
1. Onset is 12 hours to 5 days.
| 2. Total duration up to 3 days to 7 days.
194
Can cholera spread if someone is asymptomatic
Can be spread for 2 weeks without symptoms. Can possibly be long term carriers
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Who is the most vulnerable to Cholera
Children and others especially vulnerable.
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What are does Cholera affect
1. Grow in small intestine mucus.
| 2. Fecal-oral route.
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Why are certain strains of Cholera more virulent
Toxin production from Bacteriophage.
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What effect doe cholera toxin have on the intestines
1. Chemical feedback to regulate fluid loss is lost
| 2. Chloride is lost
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How much fluid loss occurs with Cholera
Up to 3 to 5 gallons a day.
200
What gives rice water appearance
Mucus and epithelial cells
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What effect does fluid loss during Cholera infection have on the circulatory system
1. Viscous blood
2. Low blood pressure
3. Shock and organ failure
4. Death
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What are the effects of electrolyte loss as a result of Cholera
1. Loss of muscle function, including heart rhythm.
2. Seizures and coma.
3. Difficulty breathing and increased vomiting due to acidosis
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Treatment of Cholera
1. **Rehydration: oral, sucrose and table salt drink, IV isotonic solution for severe
2. Potassium and bicarbonate.
3. Antibiotics: tetracycline.
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What is the source of infection of Cholera
1. Contaminated water
| 2. Improperly cooked shellfish
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HIV morphology
1. Genus: Lentivirus
2. Species: HIV-1, HIV-2
3. Clades: M
4. Envelope, spikes, 2 identical and single stranded RNA molecules, reverse transcriptase, integrase, and protease.
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What are vital coreceptors that enable attachment of HIV
CCR5 and CXCR4
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Signs and symptoms of HIV
| Phase 1
Initial acute infection
1. Increased viral load and decrease in CD4+ T cells
2. Sx: fever, enlarged lymph nodes, sore throat, headache, rash
3. CD4+ T cell return to normal and viral load decreases
Asymptomatic/Latent period
1. Can last 7 to 10 years
2. No major symptoms of disease
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Signs and symptoms of HIV
| Phase 2
1. HIV is actively infecting new cells at a slow, steady rate
2. Slow decline of CD4+ T cells, but maintained at normal level of above 300 cells/mm3
3. Opportunistic infections develop
4. Sx: fever, persistent diarrhea, white patches in the mouth or genital area
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Signs and symptoms of HIV
| Phase 3
1. Increased viral load
2. Decrease of CD4+ T cells below 200 cell/mm3
3. HIV progresses into AIDS
