- Alphavirus - Transmitted by Aedes mosquitos (during the day) - Endemic to West Africa ★

Infections Flashcards by Sydney DeArmond

Zika Virus description?

This virus is carried by
?

How is this virus transmitted?

-Flavivirus(flavus latin for yellow due to its propensity to cause jaundice)

-Aedes Mosquito (lives in tropical locations)
○ day time and twilight feeders

The virus is transmitted via

infected mosquito
maternal-fetal
sex
blood transfusions
organ transplants
lab exposure

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Clinical Manifestations of Zika Virus

-acute: disease is usually mild
• low-grade fever(100.4-101.3 F),
• maculopapular pruritic rash
• arthralgia (usually small joints hands and feet)
• conjunctivitis (non-purulent)
★ clinical diagnosis if 2 or more symptoms are present

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Incubation period between bite and clinical manifestations is usually ?
Symptoms resolves in ….?
Clinical manifestations occur in how many people who become infected with zika?

-Incubation period between bite and clinical manifestations is usually ?
○ 2-14 days
-Symptoms resolves in ….?
○ 2-7 days
-Clinical manifestations occur in how many people who become infected with zika?
20-25%

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Complications of Zika ?

fetal loss
microcephaly of fetus(abnormal small size head)
Guillian- Barre Syndrome
Brain ischemia
Myelitis
Meningoencephalitis

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Management and Prevention of Zika

■ Management: No specific management 
-Supportive-rest, hydrate, acetaminophen 
-NSAIDS avoided until Dengue ruled out 
-ASA avoided in children due to risk of Reye syndrome  
■Prevention:
-no vaccine yet 
-limit travel
-remove standing water 
-mosquito repellant 
-long sleeves and pants 
-protected intercourse

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Describe Chikungunya

Alphavirus
Transmitted by Aedes mosquitos (during the day)
Endemic to West Africa ★

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Clinical Manifestations of Chikungunya

begin abruptly with fever, joint pain, and malaise (starts 3-7 days from bite)
acute phase usually lasts 7-10

Progress stage:
-High grade fever 104F (last 3-5 days)
-Polyarthralgia ★ begins 2-5 days after fever onset (commonly involves multiple joints-bilateral &amp; symmetrical)
→ hands 50-76%
→ wrists 29-81%
→ ankles 64-3%
(Pain is usually intense and disabling)

Rash in 40-75% of pts (macular or macularpapular-start on limbs and trunk)
Pruritus 25-50%
Death in pt’s older than 65 with comorbidities
respiratory, renal and heart failure
Some pts have persistent or relapsing of disease (18mo-3yrs)

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Diagnostic Studies?

Most common lab findings with Chikungunya are?

D.S.:
-Sereolgy:
→ 1-7 days PCR for
Chikungunya virus RNA
→ >8 days Elisa IgM anti-Chikungunya virus antibodies
→ IgM presents following 5 days onset of symptoms and up to 3 months
→ IgG appear after 2 weeks and persist for years

Most common non-specific lab findings with Chikungunya are?

Lymphopenia
Thrombocytopenia

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Management of Chikungunya

NSAIDS
Supportive care
Steroids
Methotrexate
Immune modulating agents
No Vaccine thus far

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Dengue Virus Description and Transmission

Single-stranded RNA virus

4 stereotypes -DENV 1-4: all cause full disease
Mosquito borne(evidence of maternal-fetal transmission)

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Dengue Virus Affects what areas the most

tropics and subtropics -rare occurrence in the U.S.

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Severe and Mild Symptoms of Dengue ?

Mild:

n/v
rash
headache, eye pain
muscle ache, joint pain

Severe:

abdominal pain and tendernesss
persistent vomiting
clinical fluid accumulation
mucosal bleeding
lethargy or restlessness

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Phases of infection of Dengue

Febrile:

sudden onset high fever >101.3 (last 3-7 days)
accompanied by headache, rash, vomiting , myalgia, arthralgia
On PE see conjuctival injection, pharyngeal erythema, LAD, hepatomegaly, facial puffiness, petechiae
Leukopenia, thrombocytopenia, and ↑ LFT’s
after which patients recover w/o complications

Critical:

Systemic vascular leak syndrome, -plasma leak, bleeding , shock , organ failure
Days 3-7 and last 24-48 hours
US for fluid
Moderate to severe thrombocytopenia

Convalescent Phase:(starting to recover)

plasma leakage and hemorrhage resolve, vital signs stabilize (2-4 days)
additional rash may appear
profound fatigue
retinal vasculitis is common

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Diagnostic Studies for Dengue

Nucleic acid amplification test (NAAT)

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Management and Prevention of Dengue

Management:

supportive
fever mangement (Acetaminophen- NO NSAIDS)
bleeding management (blood replacement)
Plasma leakage (volume replacement )
Shock treatment

Prevention
-Vaccination-Dengvaxis ★

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EEE Transmission ?

End Result after contraction of EEE?

Transmitted through mosquitoes (4-10 day incubation period)
30% die and many survivors have ongoing neurological problems

Clinical Manifestations of EEE

Sudden onset
Fever
Headache
N/V
2% of adults and 6% children develop encephalitis
Once neuro sx begin condition deteriorates rapidly → 90% of patients becoming comatose ★
Seizures, focal neurologic signs, including nerve palsies develop in 1/2

Diagnostic Studies and Findings of EEE

Studies:

Serum of CSF
IgM antibody capture ELISA
Fatal cases→ histopathology, autopsy tissues

Diagnostic Findings:

Leukocytosis
Hyponatremia
CSF- pleocytosis (↑ WBC) elevated protein
MRI/CT abnormalities

Management of EEE

Supportive

no vaccine for humans just horses

Ebola virus Tranmission

direct contact with infected body fluids (vomit, feces, & blood) or meat
those that provide hands on medical care or prepare bodies for burial are most at risk
less infectious in early stages
virus can live on surfaces from hours to days

What are the five species of Ebola virus

zaire (worst)
Sudan (50% case fatality)
Tai forest-irony coast(only one identifiable case)
Bundibugyo(case fatality 30%)
Reston(maintain animal reservoir only)

Clinical Manifestations of Ebola virus

hemorrhage is less common( could have some bleeding in stool)
Fever chills malaise
Maculopapular Rash (may develop day 5-7)
volume loss from vomiting and diarrhea contribute more to severe illness ★
symptoms come on suddenly
incubation period is 6-12 days post exposure
produces a systemic inflammatory response

When do you recover from Ebola virus?

Recovery days (7-12) but up to 2 years of prolonged ex’s of arthralgia, weakness, fatigue, insomnia, uveitis

Diagnostic Studies and Lab findings of Ebola virus

DS-
→ PCR viral RNA in serum
→ ReEbov deters virus antigen used in field

Lab Findings:

↓ WBC’s
↓ platelets
↑ ALTs and ASTs due to liver damage
Coagulation abnormalities→ can lead to DIC in severe cases
Proteinuria
↓ sodium and calcium

Ebola Management and Prevention

-Supportive care and aggressive fluid and electrolyte resuscitation with caution PreventionL - proper use of PPE - rVSV-ZEBOV (recombinant vesicular stomatitis virus-zaire Ebola virus (effective when used in ring vaccination) - Merck Vaccine

Ebola virus is considered category A?

bioterrorism

Etiology of Bacteremia

- may result from dental work or vigorous tooth brushing - from infections like pneumonia, UTI, ENT(tract) - colonization of indewelling devices - Gram neg bacteria→ GU, GI, or decubitus ulcers, immunocompromised, or chronically ill - Staphylococcal bacteremia- IV drug users, IV catheters SSTI - Bacteriodes bacteria -infections of abdomen and pelvis - gram pos bactermia- infections above the diaphragm respiratory - sepsis develops in 25-40% of patients

Clinical Manifestations of Bacteremia

- asymptomatic - mild or persistent fever/chills - MS changes - hypotension - tachypnea - focal symptoms

How do you diagnosis /manage

Diagnose: -pos blood cultures → up to 50% of pos BC can be contaminated w/ coagulase neg staph, corynebacterium, viridian's Manage: - appropriate antibiotics - prophylaxis (when going to the dentist after total knee replacement

What causes sepsis? What people are the most at risk for sepsis?

What causes sepsis? -Caused by dysregulated inflammatory response to infection (don't need bacterium to cause sepsis) What people are the most at risk for sepsis? •lowest doses vaspressor 5% •older, chronic illness, renal dysfunction 13% •inflammation and pulmonary dysfunction 24% •liver dysfunction and septic shock 40%

Pathophysiology of Sepsis

Infection → bacteremia (can skip this step) → sepsis → septic shock( circulatory collapse, cellular and metabolic abnormalities) → MODS → death -gram pos bacteria most frequently identified (approx 50% cases organism is not identified )

Systemic inflammatory response syndrome is clinically recognized by the presence of two or more of the following... don't use clinically anymore but medicate and medicaid still do

temp: less than 38C or greater than 36C HR: >90bpm Resp rate: > 20 breaths/min or Pa CO2 < 32mmHg WBC: - > 12,000 - <40000 - 10% immature band forms

Risk factors for sepsis

- ICU admission - Bacteremia - Advanced age - Immunosuppression - Obesity - Diabetes and cancer - Community acquired pneumonia - Previous hospitalization

Clinical Manifestations of Sepsis

``` Hypotension SBP<90 Tachycardia Tachypnea >22 Fever >100.9 Altered MS Oliguria Cough ```

Lab Findings for Sepsis

- Leukocytosis >12 or Leukopenia<4 - Hyperglycemia >140 - Elevated CRP - Elevated Cr - Coag abnormalities - Thrombocytopenia<100 - ★ elevated serum lactate(what your cells put off when they are dying (used to monitor progression of sepsis) - Elevated procalcitionin - Decreased PaO2(BBG and ABG)

Septic Shock Tx? Si/Sx's?

Circulatory collapse -vasodilatory shock → circulatory, cellular and metabolic abnormalities with greater risk for mortality than just sepsis Tx: requires vasopressors Si/sx: - cool skin - cyanosis - oligouria - altered metabolism - elevated lactate

MODS: | si/sx and management

Si/sx: -progressive organ dysfunction management: - supplemental oxygen - aggressive IVF - peripheral and central access - empiric broad spectrum abs w/n 1 hr tailored to patient ★ - vasopressors PRN