MultiSystem Final Lectures Flashcards
0
Q
Pasteurella multocida
A
Carried in nasopharynx of 50-90% cats Avg incubation 15 hrs Local cellulitis, low grade fevers Range of infectious complications Sensitive to B lactams, azithromycin (augmentin) AVOID eyrthomycin, clindamycin
1
Q
Capnocytophaga canimorsus
A
Normal flora in dogs and cats Severe infection in immunocompromised Wide spectrum (fevers, myalgias rash GI complaints -> sepsis) Bacteremia/sepsis very rare! Resistant to TMX/SMX and aminoglycosides Augmentin is drug of choice
2
Q
CA-MRSA
A
Colonization in domestic animals
S intermedius > S. Aureus
Outbreaks in vet hospitals
Dermatitis, pustular disease, perineal cellulitis
3
Q
Management of Animal Bite Wounds
A
Irrigation: sterile saline, debridement if necrotic tissue
Surgical evaluation
Leave wound open except for complex facial wounds
Elevation
Antibiotics
Gram Stain! Esp if there is abscess, cellulitis etc…
Imaging (rule out foreign body)
4
Q
Antibiotic Prophylaxis Indications
A
- Deep puncture wounds (esp. cat bites)
- Mod-severe wounds with associated crush injury
- Wounds in areas of venous/lymphatic compromise
- Wounds on hands or close to joint/bone
- Wounds that require surgical repair
- Wounds in immunocompromised
5
Q
Oral Antibiotics for Dog/Cat bites
A
•Drug of Choice:
–Amoxicillin-clavulanate 875/125mg BID
•Alternate Empiric Regimens:
–Doxycycline/TMP-SMX/Penicillin VK/Cefuroxime/Moxifloxacin
plus
–metronidazole/clindamycin
•AVOID: cephalexin, dicloxacillin, erythromycin
6
Q
IV antibiotics for the dog/cat patient who is admitted
A
•Monotherapy with B-lactam/B-lactamase inhibitors:
–Ampicillin-sulbactam 3gm q6hrs
–Piperacillin-tazobactam 4.5gm q8hrs
•Ceftriaxone plus metronidazole
•Alternative IV regimens:
–Fluoroquinolone plus metronidazole
–Monotherapy with carbapenems:
7
Q
What organism causes Cat Scratch Disease?
A
•Caused by Bartonella henselae •Bites or scratches from felines –Kittens, strays •Most cases in fall/winter –Infected fleas? •Most common in children < 15 years old
8
Q
Cat Scratch Disease Symptoms
A
Papule or Pustule at inoculation site
Fever
Enlarged, tender lymph nodes that develop…
9
Q
Cat Scratch Disease Diagnosis
A
–Clinical
–Serology
–PCR or culture
•Pus, lymph node aspirates
10
Q
Cat Scratch Disease Treatment
A
–Most cases resolve spontaneously
–Azithromycin (Z-pak) for disseminated or severe disease
11
Q
Human Bites Pathogens
A
–Staphylococcus and Streptococcus species
–Anaerobes:
•Eikenella, Fusobacterium, Peptostreptococcus, Prevotella, Porphyromonas spp.
•Most often polymicrobial
•Viral pathogens:
–Hepatitis B/C, HIV, HSV
12
Q
Boar/Pig Bite Organisms
A
•Polymicrobial infections
–Streptococcus and Staphylococcus spp., P. multocida, anaerobes
–Actinobacillus suis
13
Q
Rat Bite Fever Organisms
A
Streptobacillus moniliformis
Spirillum minus
14
Q
Seal Finger
A
Mycoplasma species
Papular lesion -> pain, swelling, joint involvement
Treatment: tetracyclines
15
Q
What infection are you most concerned with monkey bites?
A
Herpes B Virus
Persists in sensory ganglia for lifetime
Incubation 5-21 days
16
Q
Bacteria cultured in war wounds, from one study from a fresh wound
A
Coagulase-negative Staphylococcus - common
17
Q
War wound organism 5 days after the initial injury
A
Acinetobacter - war wound
Soldiers started on Gram + coverage antibiotics, so after a few days patients start developing gram - rod infections
18
Q
VHF properties
A
all enveloped RNA viruses
Survival is dependent on an animal or insect host
geographically restricted to areas where host species live
human outbreaks of VHF occur sporadically and irregularly
no cure
19
Q
Viral Families Containing VHF agents
A
Arenaviruses
Bunyaviruses
Flaviviruses
Filoviruses
20
Q
Key clue in history for patient that is exhibiting VHF
A
Foreign travel to endemic or epidemic area
21
Q
VHF treatment
A
Supportive Care
Ribavirin possibly effective for:
Arenaviruses, Bunyaviridae (CCHF, Hantavirus, RVF)
22
Q
Vaccines for VHF
A
Candid #1: Argentine hemorrhagic fever (Junin virus)
Yellow fever 17D: Yellow fever virus
23
Q
Crimean-Congo hemorrhagic Fever (CCHF) transmission
A
Ticks
24
CCHF viral family
Bunyavirus
25
Arenaviruses, how do humans get infected?
Contact with rodent excreta - ingestion of contaminated food, direct contact with broken skin, inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission)
26
Lassa Fever
Hemorrhagic illness caused by arenavirus Lassa
| Endemic in areas of West Africa
27
Who is affected by Lassa Fever the worst?
pregnant women
28
Most common complication of Lassa Fever?
Hearing loss
29
Lassa Fever Virus Protection
Rotent control
30
What differentiates small pox from chicken pox?
In smallpox:
vesicles are in the same stage of disease
•Denser on face, arms, hands, legs, and feet than on body
•Involvement of palms & soles
31
Organism causing Lumpy Jaw
Actinomycosis caused by Actinomyces
32
Infections of Prosthetic Devices Organism
Propionibacterium
33
Anaerobes are concentrated where in our body?
Oral Cavity and Large Intestine
34
Unique characteristics of anaerobes
crepitation - gas formers/ferment
bad odors
brownish serous fluid - digest tissues
35
Anaerobic infections above the waist are almost always related to what?
Dentition.
36
What anaerobic infections (above or below the waist) are sensitive to antibiotics?
Above
37
Free radical ozone (O3).
| What is it composed of? What are they affects on lungs?
Nitrogen Oxides + volatile organic compounds + UV
| Free radical damage of lung epithelial and Type I alveolar cells -> increases SOB in asthma or emphysema
38
People who are most likely susceptible to having complications from pollutants
Asthmatic Individuals
39
Name 5 outdoor air pollutants
Ozone, nitrogen dioxide, sulfur dioxide, acid aerosols, particulates
40
Indoor Pollution
Tobacco Smoke, CO, Nitrogen oxide (component of smog could also affect indoors), asbestos, radon, formaldehyde
41
Definition of Toxicology
science of poisons.
| distribution, effects and MOA of toxic agents affecting our metabolism
42
What is the most preventable cause of death?
Smoking
43
60+ substances in tobacco are a/w carcinogenesis. Name a few of those constituents.
Tar, benzopyrene, nitrosamine, polycyclic aromatic hydrocarbons (carcinogenesis)
Nicotine, phenol (tumor promotion)
CO (impaired oxygen transport and utilization)
Formaldehyde (toxicity to cilia)
44
Complications from smoking
```
Cancer of oral cavity, larynx, esophagus, lung, pancreas, bladder
Chronic bronchitis, emphysema
MI
Systemic atherosclerosis
Peptic Ulcer
```
45
Legally drunk
>= 80 mg/dL
46
Alcohol consumption is responsible for how many deaths annually?
100,000
| 50% are MVA, homicide or suicide
47
Metabolism of alcohol
Ethanol is absorbed unaltered in the stomach and Small intestine, then distributed to all tissues and fluids of the body in direct proportion to the blood level. Less than 10% is excreted unchanged in the urine, sweat, and breath. Most of the alcohol in the blood is biotransformed to acetaldehyde in the liver by three enzyme systems consisting of alcohol DH, microsomal ethanol-oxidizing system (MEOS) and catalase.
48
T/F The rate of metabolism affects the blood alcohol level
True.
Chronic alcoholics can tolerate up to 700 mg/dL, partially explained by accelerated ethanol metabolism caused by 5-10-fold induction of liver CYPs.
49
What is the main enzyme system involved in alcohol metabolism? Where is it located
```
alcohol dehydrogenase (ADH)
cytosol of hepatocytes.
```
50
At high blood alcohol levels, besides ADH what other system comes into play for metabolism of alcohol?
MEOS
51
Three enzyme systems involved in alcohol metabolism.
| What is the end product of these three systems?
Alcohol DH, MEOS, Catalase
Acetaldehyde
52
Acetaldehyde is converted to ______ by _______, which is then utilized in the mitochondrial respiratory chain
```
acetate
acetaldehyde DH (ALDH)
```
53
The microsomal oxidation system involves CYPs, particularly which one?
CYP2E1 located in smooth ER
54
Why do alcoholics have an accumulation of fat within the liver?
Ethanol conversion to acetaldehyde by ADH converts NAD+ to NADH. NAD+ is needed for fatty acid oxidation in the liver.
55
Why are some Asians unable to tolerate alcohol?
50% of Asians have very low ALDH activity, due to substitution of lysine for glutamine at residue 487. The mutant allele has dominant-negative activity, such that even 1 copy of the allele reduces ALDH activity significantly. individuals homozygous are completely unable to oxidize acetaldehyde and cannot tolerate alcohol, experiencing nausea, flushing, tachycardia, and hyperventilation after its ingestion.
56
Chronic Alcoholism affects many different systems and contributes to significant morbidity. Name some of the systems affected and common consequences.
Liver: fatty change, alcoholic hepatitis, cirrhosis
GI: massive bleeding from gastritis, peptic ulcer, esophageal varices
CNS: vit B1 def, cerebral atrophy, cerebellar degeneration
CVS: dilated CHF, HTN
Endo: Acute and chronic pancreatitis
OB: fetal alcohol syndrome
Increased risk of cancer
57
Principle lesions resulting from Thiamine deficiency that is common in chronic alcoholics.
Peripheral neuropathies
| Wernicke-Korsakoff syndrome
58
What are moderate amounts of alcohol (20-30 g daily intake) shown to increase?
HDL levels and inhibit platelet aggregation, protecting against coronary heart disease
59
What does fetal-alcohol syndrome consist of?
microcephaly, growth retardation, facial abnormalities in the newborn, reduction in mental functions as child grows older
60
What is considered to be the main agent associated with alcohol induced laryngeal and esophageal cancer
acetaldehyde
61
What does red wine contain that may be protective against obesity and cardiovascular disease?
resveratrol
62
What are four heavy metals most commonly associated with harmful effects in humans?
lead, mercury, arsenic, cadmium
63
Morphology of lead poisoning
punctuate basophilic stippling of the red cells.
64
Metabolite seen in serum that would tell you that a person has cocaine in their system.
Benzoylecgonine (BE)
65
Metabolites found in blood when individual is taking heroin
6-monoacetylmorphine (6-MAM) and morphine
66
Classification of Blunt Force Injury
Abrasion
Contusion
Laceration
Fractures
67
Abrasion Definition
Scraping and removal of the superficial surface of the skin
68
Types of abrasions
Road Rash
Pattern Abrasion
Impact
69
Contusion Definition
Area of bleeding(hemorrhage) into the skin or soft tissue as a result of rupture of blood vessels due to blunt force injury or pressure
contusion = bruise
70
Hematoma
focal collection of blood
71
Is aging bruises a reliable system?
No! Do not worry about color just identify contusion
72
Laceration Definition
Tearing of the skin or tissue due to stretching, crushing, shearing, or avulsing due to a blunt force.
Soft tissue bridging of blood vessels from blunt force
NOT A CUT, STAB, SHARP FORCE INJURY
73
Three types of sharp force injuries
Stab/puncture: depth greater than width
Incised/cut
Chop wounds
THESE ARE NOT LACERATIONS
74
Double edged knife
Both margins with a V-shaped margin
75
Length greater than depth?
Incised/cutting wounds
76
Most common cause of death in sharp force injury
Hemorrhage
77
Gunshot wound
Range of fire:
| contact, intermediate, distant
78
perforation
entrance AND exit
79
penetration
Entrance but NO exit
80
Reasons for death due to malaria in U.S.
1. failure to take chemoprophylaxis
2. not promptly seeking medical care
3. low suspicion of disease/late diagnosis
4. improper therapy
81
What type of pathogen is malaria and what type of cells does it infect?
Protozoa parasite
| Single cell eukaryotic pathogen affecting RBC and hepatocytes
82
In non-immune patients, falciparum malaria is a medical emergency!!
...
83
Risk factors for severe malaria
Nonimmune individuals
children less than 5 yo
pregnant women
asplenic patients
84
Species of Malaria
Plasmodium falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi
85
Vector for Malaria
anophelene mosquitoes
| non-human reservoir
86
What is the infected form of the parasite of malaria
Sporozoites
| come from mosquito, travel to liver, infect hepatocytes (liver schizont)
87
Merozoites infect RBCs where they form ring-stage what?
trophozoites.
| these mature into schizonts which rupture and release merozoites, which infect more RBCs
88
•Dormant liver stage in P. vivax and P. ovale
Hypnozoite
| Release blood stage parasites weeks to months after primary infection
89
How long after infection does one develop symptoms?
Pf 8-11 days
Po 10-17 days
Pv 10-17 days
Pm 18-40 days
90
Onset of symptoms of malaria usually coincides with what?
the start of the erythrocytic cycle.
91
Malaria classical presentation
```
Fever
Chills
Headache
.... remember to ask HISTORY OF TRAVEL
about 1/5 of cases, patients have abdominal pain
```
92
Malaria Lab Values
Not specific
Only about a quarter of people have anemia
more people will have a low platelet count (avg. 148K)
93
Malaria Clinical Types
Uncomplicated malaria
| Severe Malaria
94
Uncomplicated (mild) malaria occurs with what species?
| Classic paroxysms
ALL plasmodium species.
Classic paroxysms
sudden episodes of:
1. cold stage with shaking
2. hot stage with high temperature (>104°F)
3. sweating stage with resolution of fever
95
How does severe malaria kill people?
-cerebral malaria, respiratory distress, severe anemia (children of endemic countries.
Adults more often get multi-organ failure.
96
Complications of severe anemia are usually caused by which Plasmodium species?
These complications primarily occur with
| Plasmodium falciparum, usually when parasitemia >2%.
97
Why are P. falciparum infections the most severe?
No limit on the degree of parasitemia. (slide)
98
What is a major cause of tissue hypoxia and lactic acidosis in Pf?
SEQUESTRATION!
Erythrocytes containing mature P. falcip. parasites develop “knobs” and express adhesion molecules that bind to endothelial cells of capillaries and post-capillary venules.
Additionally, there is decreased deformability of infected AND non-infected RBCs, contributing to sludging, rosetting, aggregation, and eventual blockage of blood vessels.
This causes tissue hypoxia and organ failure.
99
What is cerebral malaria?
•acute encephalopathy not attributable to other causes in a patient with malaria
-->obstruction of vessels is heterogenous
(some blocked, some not)
-->the brain is swollen because of mass effect of all the
sequestered RBCs, not because of cerebral edema
•mortality: 100% without Rx, 20% with Rx
•gross neurologic sequelae in 10% of survivors
100
```
Severe malaria manifestations mechanism?
lactic acidosis?
Hypoglycemia?
Renal Failure?
Anemia?
Pulmonary Edema?
```
lactic acidosis hypoperfusion from sequestration
hypoglycemia ↑ demand and ↓ consumption
renal failure filtration of hemolysis products
anemia hemolysis, sequestration, splenic removal
pulmonary edema unknown
101
How do you diagnose Malaria?
* blood smear (thick and thin)
* antigen testing
* PCR
102
When could you get a false negative test with the Binax Now malaria card test?
Very low levels of parasitemia... Just wait 12 hrs and do the test again.
103
Schuffner's Dots and enlarged infected cells -> which species of Plasmodium?
P vivax or ovale
104
P vivax vs P ovale... distinguish?
Mature schizont ... merozoites
| P vivax has more merozoites
105
p. falciparum
Multiple ring forms trophozoites
| banana shaped gametocyte
106
P. malariae
- band form
- Owl eye trophozoite
- smaller infected cells
- yellow/brown pigment
107
Malaria Prevention
```
•Personal protection measures
•Chemotherapy
–doxycycline
–atovaquone/proguanil
–mefloquine
–Primaquine
–Chloroquine (in chloroquine-sensitive areas)
```
108
Most important risk factor for developing malaria in the U.S.?
Immigrant families visiting friends and relatives most important risk factor
109
Anti-malarial treatment (4 categories to consider)
•quinoline derivatives
(incl. quinine, chloroquine, mefloquine, and primaquine)
•artemesin compounds
•antifolates (incl. proguanil and pyrimethamine/sulfadoxine)
•other (incl. tetracycline, atovaquone/proguanil)
110
Which anti-malarial drug do you need to make sure to test for G6PD deficiency?
Primaquine
111
Atovaquone:
| MOA
- Inhibits parasite mitochondrial electron transport
| - Effect potentiated when paired with proguanil
112
What type of virus is measles?
Paramyxovirus:
Enveloped
SS-linear Nonsegmented
Helical
113
Characteristic findings of Measles (rubeola) virus
Koplik spots
| descending maculopapular rash
114
3 C's of measles:
Cough
Coryza
Conjunctivitis
115
Spirochetes (General Info)
Spirochetes are spiral-shaped organisms that exhibit corkscrew motility,
don't Gram stain, grow slowly in vitro or not at all
116
Spirochetes include which organisms?
BLT. B is Big
Borrelia (big size)
Leptospira
Treponema
117
Which organism causes Lyme Disease?
Borrelia burgdorferi
118
How is Borrelia burgdorferi transmitted?
Tick borne- most common arthropod-borne infection in US
| in Northeast and Midwest = Ixodes scapularis (also called Ixodes dammini.
119
Which stage in the lifecycle of ticks is primarily responsible for transmission of the Borrelia burgdorferi infection? When are they most active?
nymphal stage
| Late spring and early summer
120
Describe the 3 stages of Lyme Disease.
Stage 1 localized infection: erythema chronicum migrans, flulike symptoms
Stage 2 disseminated infection: neurologic (Bell's palsy) and cardiac manifestations (AV nodal block)
Stage 3: chronic monoarthritis and migratory polyarthritis
121
Describe erythema chronicum migrans
Expanding "bull's eye" red rash with central clearing.
122
Which animal is important to the tick life cycle that transmits Borrelia burgdorferi?
deer and mice
123
Treatment for Lyme Disease:
Usually can be treated with oral antibiotics (doxycycline)
| Patients with arthritis or neurological abnormalities may require IV antibiotics treatment
124
Is there a vaccine for Lyme Disease?
No, it was taken off of the market.
Had to be given every year, and thought that it might make arthritis worse. It was expensive.
They have talked about trying to reintroduce it.
125
Relapsing Fever: which organism causes it?
Borrelia sp. and characterized by recurrent episode of fever separated by asymptomatic intervals.
126
Leptospira interrogans
Question mark-shaped bacteria found in water contaminated with animal urine
127
Leptospirosis
Flulike symptoms
Conjunctival suffusion: reddening of the conjunctiva (the front surface of the eye) caused by increased blood flow.
Jaundice
Photophobia with conjunctivitis!
128
Who gets leptospirosis?
military
surfers
veterinarians
people in the tropics
129
What is Weil's Disease?
icterohemorrhagic leptospirosis
| severe form with jaundice and azotemia from liver and kidney dysfunction; fever, hemorrhage, anemia
130
Spirochetes are sensitive to penicillins, so why are these diseases treated with doxycycline?
Doxycycline can cross the CNS more readily than penicillins. The CNS manifestations are the most traumatic and want to be readily avoided... so prophylaxis in adults.
Remember you do not treat doxycycline in pregnant women and children!
131
STARI
| Southern Tick Associated lllness
similar primary illness to Lyme Diseas but NOT caused by B. burgdorferi
A rash similar to the rash of Lyme disease has been described in humans residing in southeastern and south-central states and is associated with the bite of the lone star tick, Amblyomma americanum. This Lyme disease-like rash has been named Southern tick-associated rash illness (STARI).
132
Borrelia recurrentis: epidemic relapsing fever-lice
..
133
Borrelia hermsii:
Endemic relapsing fever
| Ticks
134
Rabbit fever AKA Tularemia AKA Glandular Fever: Which organism causes this?
Francisella tularensis
135
Francisella:
Gram Stain
Morphology
Gram Negative
| Rod (bacillus)
136
What are the Facultative intracellular organisms?
```
Some Nasty Bugs May Live FacultativeLY
Salmonella
Neisseria
Brucella
Mycobacterium
Listeria
Francisella
Legionella
Yersinia pestis
```
137
Transmission and source of Francisella tularensis?
Ticks, RABBITS, deer fly
138
Tularemia Spectrum of Infections:
| 4 types
•Ulceroglandular
Follows primary infection of the skin
75-85% of cases; 5% fatality rate
```
• Oculoglandular
Contaminate eye (conjunctiva) with infected material
0-5% of cases
```
• Pneumonic
Transmission via aerosol or via 2° spread to the lung
30% fatality rate
• Typhoidal
Ingestion of the organism; symptoms similar to typhoid fever
139
What causes Brucellosis/undulant fever?
Brucella spp.
140
Major transmission route to humans of Brucella sp.?
Infected milk, milk products
Direct contact with infected animals
"Unpasteurized Dairy"
NO INSECT vector
141
Chronic Brucellosis (Undulant Fever):
Incubation Period
Clinical Presentation
Incubation period: 2- 8 weeks
Fever, night sweats, headaches, chills, myalagia, weight loss
Organs of the RES often NOT enlarged
```
Complications:
hepatic lesions
arthritis
meningitis
endocarditis
```
DIFFICULT TO DIAGNOSE!
142
Occupational Recreational Risks for Brucellosis
slaughterhouse workers, meat packing employees, veterinarians, lab workers, hunters
143
Is there a Brucella vaccine?
Yes, Live-attenuated brucella vaccine given to cattle... prevents them from getting active infection or shedding into their milk.
This is why there are a lot less cases of Brucellosis in the U.S.
BUT bison, buffalo still have the infection
144
What organism causes Cat scratch Disease? What is the transmission and source of this organism?
Bartonella henselae
Cat scratch (duh) ; cats are reservoir, humans are incidental host
vector is a flea
145
Carrion's disease: what are the two phases? What organism causes it? What is the reservoir host?
1st: Oroya fever (hemolytic anemia)
2nd: Verruga peruana
Bartonella bacilliformis
human reservoir; Sand fly vector
146
What sorts of things should you consider for toxic history?
Trauma,
size matters (how many pills, mgs, co ingestions?)
medical and psych history
147
Why do acutely poisoned/intoxicated patients die?
TRAUMA!
Intentional (suicide- usually pills, and "roofies")
Accidental (heroin, alcohol, etc., children, elderly)
envenomations
bioterrorism
148
What is a toxidrome? What are some key features?
Toxic physical exam:
Exclude trauma!
Key features: vital signs, pupils, skin (wet or dry), bowel sounds, mental status
149
Which drug is not clinically detectable with an overdose?
Acetaminophen!
acetyl cysteine is the antidote which is very successful so it is unfortunate that we cannot clinically tell an acetaminophen overdose.
150
Pinpoint pupils is characteristic of what drug overdose?
opiates
151
Wet or dry skin in cocaine overdose?
wet
152
Treatment principles for poisoning
Decontamination
-clothes/washing, dialysis, supportive care works
Lots of treatment that do not work well or only in very specific situations: lavage,whole bowel irrigation, Emetics, charcoal
153
How do you treat compartment syndrome?
Fasciotomy
154
Rickettsiaeceae
```
Obligate Intracellular Bacteria
Transmitted by arthropods
Fastidious
Gram Negative coccobacilli
Visible with Giemsa stain
Require host cell for many functions (synthesis of nucleotides and amino acids)
```
155
Classification of Rickettsiaeceae
Classification: Based on clinical features, epidemiologic aspects, and immunologic characteristics
156
Major groups of Rickettsiaeceae
Typhus
| Spotted Fever
157
Genera of Rickettsiaeceae
Rickettsia
| Orientia
158
How does Rickettsia spread?
Cell-to-Cell involves actin polymerization
| similar to Listeria and Shigella
159
General disease features with spotted fever and typhus?
* The pathogenesis of both spotted fever and typhus organisms is vasculitis caused by proliferation of the organisms in the endothelial lining of small arteries, veins, capillaries. Vascular lesions are prominent in the skin.
* Clinical manifestations: Skin rash, fever, severe headache, malaise, prostration, and enlargement of the spleen and liver.
160
Which organism is naturally occurring that is on the East Coast of the United States that causes Rocky Mountain Spotted Fever?
Rickettsia rickettsii
| Tick-Borne -> adult dog tick bites you -> it's big so you may remember.
161
New competent (carry and transmit) vector for RMSF? Who is the primary host?
Brown dog tick (Rhipicephalus sanguineus)
* Recently identified as a reservoir of R. rickettsii, causing Rocky Mountain spotted fever, in the southwestern U.S. and along the U.S-Mexico border.
* Found throughout the U.S. and the world. Dogs are the primary host.
162
Most common vector tick species to carry RMSF?
Dermacentor
163
How do you treat RMSF?
Doxycycline
164
Difference between measles and RMSF rash?
RMSF has rash on palms and soles (the only other disease that could do that is secondary syphilis)
165
What does Rickettsia akara cause?
Cause of rickettsial pox;
mite-borne (rodent -> mite -> human)
Cosmopolitan in distribution; occurs in USA
166
What does mite borne mean?
Rodent -> mite -> human
167
What does the rash of Rickettsia akara look like?
Rash more like that of chicken pox (papulovesicular). Eschar at site of mite bite.
168
Rickettsia prowazekii
prototype, cause of epidemic typhus (WWI and WWII)Body louse, not in USA; in places of war (Somalia)
169
Orientia tsutsugamsushi causes what?
Vector? Reservoir?
Does it occur in the US?
Cause of scrub typhus
mite (chiggers, red mites)-borne; reservoir is mite (transovarial passage) or rodent population infected by mites; does not occur naturally in US but was of military importance in Vietnam.
170
Rickettsia typhi causes what?
| Vector?
Cause of endemic or murine typhus; disease occurs worldwide to include USA (about 50-100 cases/year mostly in Gulf Coast area); flea-borne; rodent vectors
171
Murine typhus is also called what?
Fleaborne or Endemic Typhus...
Murine typhus, also called fleaborne or endemic typhus, is caused by the organism Rickettsia typhi. Another organism, R. felis, may also play a role in causing murine typhus. Most of the murine typhus cases in Texas occur in South Texas from Nueces County southward to the Rio Grande Valley..
172
Ehrlichia & Anaplasma what type of cells do they survive in?
obligate intracellular bacteria that survive in cytoplasmic vacuoles of mammalian hematopoetic cells (in contrast to Rickettsia and Orientia that live in endothelial cells)
173
Distinguishing feature of Ehrlichia Chaffeensis on HME stain?
morula
174
Primary tick vector species for the most common type of ehrlichiosis (Ehrlichia chaffeenis)?
```
Amblyomma americanum (Lone Star Tick)
Southeast in the US
```
175
Anaplasma phagocytophilum.
Primarily infects what type of cell?
What species transmits it? What does this species also transmit?
Anaplasma phagocytophilum
primarily infects granulocytes (neutrophils and rarely eosinophils). The pathogen is often referred to as the agent of HGE. Transmitted by Ixodes scapularis -can co-transmit the agent of Lyme disease, Borrellia burgdorferi
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Ixodes scapularis, common name?
Deer Tick
| Black legs distinguishing factor
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Coxiella burnetii
How are humans infected?
What does this cause?
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Coxiella burnetii (Q fever), humans infected through contact with cattle, goats, sheep (aerosol route)
ticks probably important in animal to animal transmission; atypical pneumonia; rarely endocarditis
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Best known species of chigger in Northern America?
Hard-biting Trombicula alfreddugesi of SE United States and humid mid-west and Mexico
After crawling into their host, they inject disgestive enzymes into skin that break down cells.
Form a hole in the skin called a stylostome, chew up tiny parts of inner skin, causing severe irritation and swelling.
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Tick-borne bacterial infections
Lyme disease, HGE (human granulocytic ehrlichiosis), HME, STARI, endemic relapsing fever, RMSF and sometimes tularemia and Q fever
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Mites-borne bacterial infections
Scrub typhus
| Rickettsialpox
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Lice-borne bacterial infections
Trench Fever (WWI)
Epidemic typhus
epidemic relapsing fever
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Flea-borne bacterial infections
endemic typhus (=murine typhus)
murine typhus like
bubonic plague
cat scratch fever
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Poxviruses:
DNA or RNA?
Where does is replicate?
Common diseases?
BIGGEST VIRUS, DNA virus that replicates in the cytoplasm, resistant to inactivation
Diseases: Smallpox; Molluscum contagiosum
Vaccine for smallpox
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Smallpox
SMALLPOX
•Disfiguring disease with high mortality
•Spread by secretions from mouth & nose and by material from pocks or scabs
•Thus, transmission requires close contact with patients or their clothing or bedding
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Molluscum contagiosum.
Clinical presentation of disease?
How is it spread?
Molluscum contagiosum –
Wart-like, 2-5 mm papular lesions on the face, back, and buttocks, mainly in children.
Spread via towels in swimming pools and gymnasiums, by direct contact, possibly through minor skin lesions, and sexually in young adults.
Self limiting after 4 to 6 months, but second attacks are common.
If you are immunocompromised -> can go systemic.
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Orf lesion is caused by what?
Poxvirus of sheep or goats, cowpox and vaccinia can cause this type of lesion as well.
Does not go systemic
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Monkeypox
Disease can be serious but is very rare with a few hundred total cases limited to West and Central Africa.
Does go systemic, can lead to scarring.
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Rabies
Viral family? Envelope? RNA or DNA?
What clinical manifestation doe it cause?
"Key words"
Rhabdovirus
Raccoon main reservoir in the US
Enveloped, negative-sense ss-RNA, bullet shaped
causes an acute encephalitis in all warm-blooded hosts, including humans.
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Bullet shaped, negri bodies
Uniformly fatal (untreated)
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Treatment post exposure for rabies?
For persons who have NEVER BEEN VACCINATED against rabies, post-exposure anti-rabies vaccination include passive antibody (HRIG) and vaccine (killed)
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Coronaviruses cause what infections?
common cold
| SARS
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Coronavirus
Envelope?
RNA/DNA?
Capsid symmetry?
Enveloped
SS-linear RNA
Helical
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MERS
Coronavirus that looks like SARS
| Saudi Arabia, London
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Influenza virus contains which two antigens on the outside?
Hemagglutinin (promotes viral entry)
| Neuramidinase (promotes progeny virion release)
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How do humans get infected with rodent-borne viral illnesses such as CMV and Hantavirus?
Contact with rodent excreta - ingestion of contaminated food, direct contact with broken skin, inhalation of tiny particles soiled with rodent urine or saliva (aerosol transmission)
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Lassa Fever encephalitis is caused by what viral family?
Arenavirus
Enveloped SS-circular with 2 segments
Genome contains 2 strands of ambisense RNA (+ and - strands together, S and L
Rodent-borne diseases; each virus usually is associated with a particular rodent host.
The virions are enveloped, and have a grainy appearance caused by ribosomes from their host cells (name is derived from Latin "arena," which means "sandy.“)
Their genome contains 2 strands of ‘ambisense’ RNA i.e. + and – strands together, S and L.
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Lassa Fever
Found where?
Reservoir?
How is infection spread?
Found predominantly in West Africa, in particular Nigeria, Sierra Leone and Liberia.
The natural reservoir is the multimammate rat (Mastomys)
Infections are through contact with infected urine and feces.
Human to human transmission can occur through infected body fluids.
Well documented nosocomial outbreaks
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Reassortment, which virus should come to mind?
FLU
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LCMV (Lymphocytic choriomeningitis virus)
Viral family
Clinical Presentation
How is it spread?
Arenavirus
Presents as aseptic meningitis or encephalitis: asympt. infection or mild febrile illness.
Biphasic febrile illness: initial phase (week) fever, malaise, anorexia, muscle aches, headache. few days of remission then...
second phase: meningitis, or encephalitis
Spread by common house mouse, mus musculus
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Hantavirus:
Viral family?
How is it transmitted?
Bunyavirus
Enveloped, SS- circular, 3 negative segments (L, M, S)
>Unlike other bunyaviridae, its transmission is by inhalation of infected rodent excrement or by direct contact through skin (not an insect)
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Hantavirus pulmonary syndrome (HPS)
| Clinical presentation
Bunyavirus!
damage to the capillaries occurs predominantly in the lungs rather than the kidney (compared to HFRS)
majority of HPS cases caused by the Sin Nombre virus
"Four Corners" area of New Mexico
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Common Features of Hantavirus
Headaches, back/abdominal pain, fever, chills, nausea, blurred vision
Then... HFRS vs HPS
Think of patient history! (Southwest US)
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Hemorrhagic Fever with Renal Syndrome (HFRS)
Hantavirus
Fever headache hemorrhage and acute renal failure
Systemic
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Arbovirus means what?
transmitted by arthropods (mosquitos or ticks)
| The vector is insect, reservoir is usually an animal (zoonosis) and humans are dead-end host
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NEED to know arboviruses! (all in first aid)
West Nile virus, St. Louis Encephalitis, Yellow Fever, Dengue- Flavivirus
EEE, WEE - Togavirus
California serogroup (most common cause mosquito borne encephalitis) , La Crosse (peds in midwest) - Bunyavirus
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What are some distinguishing features of reoviruses?
NOT enveloped
| DOUBLE STRANDED RNA virus
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How many segments do bunyaviridae have?
3 segments
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How do you diagnose arbovirus infection?
Serology- acute titer and convalescent weeks later
| Direct Detection Tests - assays for detection of antigen or nucleic acids (PCR)
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Yellow Fever
Viral family
Where is it?
Flavivirus
| Now mainly in West Africa and South America
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Yellow Fever, how many forms?
Occurs in two major forms (urban and jungle)
Jungle YF is the natural reservoir of the disease in a cycle involving non-human primates and forest mosquitoes. Humans may become incidentally infected upon venturing into jungle.
Urban YF is transmitted between humans by the Aedes aegypti mosquito.
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Symptoms of Yellow Fever
Symptoms: Classically yellow fever presents with chills, fever, and headache, generalized myalgias and GI complaints (N+V).
GI haemorrhage leads to “black vomit” and liver involvement causes jaundice (hence, "Yellow fever). 50% of patients with frank YF will die.
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How is diagnosis made for Yellow Fever?
Is there an antiviral treatment?
Is there a vaccine?
Diagnosis: Usually made by serology.
There is no specific antiviral treatment
An effective live attenuated vaccine (17D) is available and is used for persons living in or travelling to endemic areas.
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Dengue
Viral Family?
Where is it found?
Flavivirus, 4 serotypes.
Biggest arbovirus problem in the world today! Over 2 million cases per year.
Found in SE Asia, Afica, and Caribbean and S America
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Is there a vaccine for Dengue?
NO, there are 4 serotypes of Dengue. If you are infected with 1 serotype youll feel crappy, 2nd infection youll feel even worse... etc. If you vaccinate your population, you need a vaccination that has all 4 serotypes in the vaccine. If only 1 or 2 work in the vaccine, if the patient gets the other strains, you are priming them for a severe infection the first time they are exposed.
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Symptoms of Dengue?
Classically, high fever, lymphadenopathy, myalgia, bone and joint pains, headache, and a maculopapular rash.
Severe cases may present with hemorraghic fever and shock with a mortality of 5-10% (Dengue HF or Dengue shock syndrome). Seen most often in patients previously infected with a different serotype, suggesting a immunopathogenic mechanism
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Flaviviruses
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HCV
Yellow Fever
Dengue
St. Louis Encephalitis
West Nile Virus
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Toga (alpha) viruses transmitted by what?
insects, mosquito borne
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Togaviruses?
Rubella
Eastern equine encephalitis
Western equine encephalitis
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Most important cause of pediatric arbovirus encephalitis in US?
La Crosse Virus
Bunyavirus
Localized in Midwest states
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Colorado tick fever Virus
Viral family?
Tranmission?
Disease?
Reovirus
Wood tick transmission high in the colorado mountains!
Disease: generally mild or subclinical. Symptoms of acute disease resembles those of dengue. Incubation period 3 to 6 days, then fever, chills, headache, myalgia, athralgia, photophobia, lethargy.
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First line of treatment for Q fever?
Doxycycline, adults and children with severe illness. If patient does not respond, they may not have Q fever.
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What organism causes Q fever?
Coxiella Burnetti
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Leptospirosis caued by what organism?
Leptospira interrogans
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Question mark-shaped bacteria found in water contaminated with animal urine
Leptospira interrogans
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What are the symptoms of Leptospirosis
Flulike symptoms, jaundice, photophobia with conjunctivitis.
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Most prevalent infection among surfers and in the tropics
Leptospira interrogans
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What is Weil's Disease?
Icterohemorrhagic leptospirosis
| Severe form of jaundice and azotemia from liver and kidney dysfunction; fever hemorrhage and anemia
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How do you have to examine Leptospira organisms?
Best visualized by dark-field microscope
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RABBIT. What disease?
Tularemia
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What organism causes Tularemia?
zoonotic infection caused by Francisella tularensis, fastidious gram negative bacteria
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Tularemia: what is the most common presentation?
Ulceroglandular
Most common form of tularemia, occurs following a tick or deer fly bite or after handling of an infected animal.
Skin ulcer: at the site where the organism entered the body. Ulcer accompanied by swelling of regional lymph glands, usually in the axillae or groin.
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Tularemia Treatment
Streptomycin
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Conjugate vaccines are good for what age group?
children
T independent antigens, like polysaccharides, are not recognized by children less than 2.
When polysaccharide is conjugated to protein, all ages recognize it and respond with T cell help, and then IgG and memory cells can come too. Allow young children to make anti-polysaccharide responses.
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DTaP vaccine
Tetanus, diptheria, acellular pertussis
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Whooping cough organism
Bordetella pertussis.
Gram negative, short coccobacilli, pleomorphic, encapsulated when virulent.
Acute infectious disease of tracheobronchial tree with characteristic clinical picture
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Bordetella Pertussis growth requirements
Bordet-Gengou agar
or, preferred, Regan Lowe (RL) charcoal medium supplemented with horse blood
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Two toxins associated with Bordetella pertussis
Pertussis toxin -> ADP is on -> increased cAMP -> increased fluid -> increased secretions. Also systemic effect.
Adenylate cyclase toxin resembling anthran edema toxin effect -> inc. cAMP increased fluid secretion in URT
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Adhesive factors of the Bordetella pertussis
Filamentous hemagglutinin and pertactin are the adhesive factors.
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Does Bordetella pertussis get in the blood stream?
No!
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What is the organism that causes Diphtheria
Corynebacterium diphtheriae
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"chinese letters" with bacteria
Corynebacterium diphtheriae
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Corynebacterium diphtheriae toxin
Potent exotoxin inhibits protein synthesis via ADP ribosylation of EF-2. Exotoxin encoded by Beta-prophage
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Diphtheria clinical symptoms
Pseudomembranous pharyngitis (grayish-white membrane) with lymphadenopathy
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Corynebacterium diphtheriae ABCDEFG
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ADP ribosylation
Beta-prophage
Corynebacterium
Diphtheria
Elongation Factor-2
Granules
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Macularpapular rashes
Measles
Rubella
Parvovirus P19
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Vesicular/papular
Varicella
Smallpox
Coxsackievirus Group A members (HFMD)
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Any RNA virus that is negative sense has to go to positive sense RNA... how does it do this?
RNA-dependent RNA polymerase
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Paramyxoviruses
Parainfluenza - croup
RSV - bronchiolitis in babies
Rubeola (Measles) Mumps
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What is the MOST important cause of lower respiratory tract disease in young children
RSV
Will infect virtually all infants by age 2
Symptoms resemble common cold
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Common cold virus
Rhinovirus
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Mumps virus POM
Parotitis
Orchitis
Meningitis
Flu like symptoms.
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Does infection or vaccine cause life long immunity?
Yes!
| Infection confers lifelong immunity because there is one serotype worldwide and infection is systemic.
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Two systemic paramyxoviruses
Measles
| Mumps
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Rubeola common name
Measles
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With measles virus, patients with reduced cell-mediated immunity (CMI) do not develop a rash. What will they develop instead?
Measles giant cell pneumonia
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MMR vaccine
Measles Mumps Rubella
| Live attenuated virus
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What viral family does Rubella belong to?
Togavirus
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German Measles
Rubella
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Clinically apparent rubella
Clinically apparent rubella: any combination of symptoms that include maculopapular rash (Rubelliform) lymphadenopathy, low-grade fever, conjunctivitis, sore throat, and arthralgia.
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The Rubella vaccine is primarily a benefit to whom?
The benefit of the unborn to inhibit a congenital infection (toRches)
An infection in the young will almost always just lead to a rash and thats it
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Parvovirus B19 nickname
Slap cheek syndrome!
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Human Disease associated with B19
Erythema infectiosum (EI, 5th disease)
Apastic crisis in people with chronic hemolytic anemia (sickle cell anemia)
Hydrops fatalis (anemia & congestive heart failure)
Polyarthritis
