Infectious Disease Part 3 Flashcards by Alexis B

Q

Causes:
Sinusitis, mastoiditis, and otitis media, abscesses, emboli from congenital heart disease, AVM, pulmonary infection, skin infection, endocarditis, abdominal and pelvic infections

A

Brain abscess

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Q

Anaerobic cocci & gram-negative and gram-positive anaerobic bacilli

A

Common organisms for brain abscess

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Q

Staphylococcus aureus, Enterobacter, Streptococcus species

A

Anaerobic cocci & gram-negative and gram-positive anaerobic bacilli for brain abscess

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Q

In order of occurrence:
Headache-> mental status changes-> focal neurologic deficits-> fever-> seizures-> nausea and vomiting -> nuchal rigidity-> papilledema

A

Brain abscess

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Q

Facial weakness, headache, fever, vomiting, dysphagia, and hemiparesis

A

Brainstem lesion

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Q

Diagnostic evaluation for brain abscess

A

MRI/CT of the head
CBC with diff, blood culture, ESR, CRP, specific serology
Surgical aspiration or stereotactic CT for culture

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Q

Brain abscess treatment

A

Vancomycin, cefotaxime, metronidazole
Control of ICP
Surgical resection, aspiration, or drainage (esp if more than one area is involved)
Consult with neurosurgeon and ID specialists

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Q

Inflammation of membranes lining the brain and spinal cord

A

Meningitis

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Q

When is the peak incidence for meningitis?

A

3-12 months

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Q

When is the peak season for meningitis?

A

Late fall and early winter

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Q

Males > Females
Urban areas, crowded living conditions, poverty
Underlying chronic illness/immunosuppression, asplenia
Routes of CNS invasion
Congenital or acquired defects in skull or spinal cord

A

Risk factors for meningitis

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Q

Age-associated pathogens for meningitis

<1 mo

A

Group B streptococcus
E. coli
Listeria monocytogemes
Klebisella species

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Q

Age-associated pathogens for meningitis

1-2 mo

A

Group B strep
E. coli
Strep. pneumoniae
H. infleunzae type B
N. meningitidis

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Q

Age-associated pathogens for meningitis

2 mo - 5 yr

A

Strep. pneumoniae
H. influenza type B
N. meningitidis

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Q

Age-associated pathogens for meningitis

5 yr and up

A

N. meningitis

Strep. pneumoniae

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Q

WBC in CSF will be _____ for bacterial meningitis

Increased or Decreased or Normal

A

Increased

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Q

Protein in CSF will be _____ for bacterial meningitis

Increased or Decreased or Normal

A

Increased

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Q

Glucose in CSF will be _____ for bacterial meningitis

Increased or Decreased or Normal

A

Decreased

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Q

Pressure in CSF will be _____ for bacterial meningitis

Increased or Decreased or Normal

A

Increased

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Q

Lactate in CSF will be _____ for bacterial meningitis

Increased or Decreased or Normal

A

Increased

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Q

Fever/chills, anorexia/poor feeding, myalgias/arthralgias, URI symptoms, tachycardia/hypotension, petechiae, purpura, erythematous macular rash

Severe throbbing headache, photophobia
Nuchal rigidity
Kernig sign
Brudzinski sign

A

Bacterial Meningitis

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Q

Passive extension of the knee in supine position causing back pain and resistance

A

Kernig sign

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Q

Passive flexion of the neck resulting in involuntary flexion of knees and hips

A

Brudzinski sign

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Q

When there is a traumatic/bloody spinal tap, how do you calculate the predicted WBC count?

A

CSF RBC x (serum WBC/serum RBC)

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What is the safest interpretation of traumatic spinal tap for WBC?

Count the total number of WBCs and disregard RBC count | If there are more than normal WBC for age, then treat

If a child is too unstable for lumbar puncture, should antibiotics be on hold or started prior to obtaining LP cultures?

Start DO NOT WAIT TO OBTAIN CULTURES PRIOR TO STARTING ANTIBIOTIC THERAPY IF CHILD IS UNSTABLE

Treatment for basilar skull fracture antimicrobials

Vancomycin + 3rd generation cephalosporin (cefdinir, cefixime, cefotaxime, ceftazidime)

Antimicrobials for recent neurosurgery or ventricular shunt infection

Vancomycin + Cefepime Vancomycin + Ceftazidime Vancomycin + Meropenem

What is the mortality rate for bacterial meningitis?

5-15%

Long-term neurodevelopmental sequelae of bacterial meningitis

Hearing loss, neurologic impairment, seizures, visual impairment, delay in language acquisition, chronic residual hydrocephalus

Most common cause of meningitis in children

Viral meningitis

When is the peak incidence of viral meningitis?

Late summer/early fall

Glucose in CSF will be _____ for viral meningitis Increased, Decreased, Normal

Normal or Slightly Decreased

Protein in CSF will be _____ for viral meningitis Increased, Decreased, or Normal

Slightly Increased

WBC in CSF will be _____ for viral meningitis Increased, Decreased, or Normal

Mildly increased with neutrophil predominance (early) and lymphocyte (later)

What is the gold standard for HSV meningitis diagnosis?

CSF PCR for HSV

``` Acute-onset fever/lethargy/irritability Increased ICP, autoregulation Anorexia/vomiting Hyper/hyporeflexia Bulging fontanel, increased ICP Seizures Skin rash (varicella, enteroviruses) Diarrhea (enteroviruses) URI (enteroviruses) Not as "toxic" appearing ```

Viral Meningitis

Treatment for viral meningitis

Usually self-limiting and resolves in 7-10 days Control of seizures Specific antiviral therapy if HSV suspected

Ataxia, focal neurologic signs, acute encephalopathy

High suspicion for viral meningitis

If HSV meningitis is suspected, which medication should be promptly initiated?

Acyclovir IV

Inflammatory process of brain parenchyma which usually is caused by infectious process or hyperimmune reaction

Encephalitis

Can occur with bacterial meningitis with organisms, such as Borrelia burgdorferi, Bartonella, and Treponema pallidum

Encephalitis

Caused by cryptococcus and others; concern for immunocompromised children

Fungal encephalitis

Rabies virus, herpes simplex virus, and other etiologies can trigger this

Viral encephalitis

Fever, altered consciousness, seizures, focal neurologic signs Neonates/infants present with shock, lethargy, irritability, poor feeding, seizures, apnea

Encephalitis

CSF is usually ___ and ____ for LP of encephalitis

Clear and colorless

Opening pressures may be ____ or ______ for LP for encephalitis

Normal or elevated

What is the typical mononuclear pleocytosis in LP for encephalitis?

>5 WBC/uL

Protein and Glucose are ____ in LP for encephalitis Increased, Decreased, or Normal

Normal

What is a normal protein in a normal CSF?

15-45 mg/dL CSF

What is normal blood/RBC in normal CSF?

NONE

What is normal glucose in a normal CSF?

50-75 mg/dl CSF

What is normal WBC for neonates in normal CSF?

0-30 cells/uL

What is normal WBC for 1-5-year-old in normal CSF?

0-20 cells/uL

What is normal WBC in 6-18 year old in normal CSF?

0-10 cells/uL

What is normal WBC in an adult in normal CSF?

0-5 cells/uL

Temporary placement of a needle in the subarachnoid space of spinal column to obtain CSF

Lumbar Puncture

What does cloudy CSF appearance indicate?

Increased WBC or protein

What does red-tinged CSF appearance indicate?

Presence of blood

What do neutrophils mean in CSF?

Bacterial meningitis/cerebral abscess

What do mononuclear lymphocytes mean in CSF?

Viral meningitis/encepahlitis

What causes protein to be present in CSF?

meningitis, encephalitis, and myelitis

When does glucose decrease in CSF?

When bacteria, inflammatory, or tumor cells are present

If CSF blood glucose level is less than 60% of blood glucose level, what does that indicate?

Neoplasm or meningitis

What are contraindications for LP?

Increased ICP (herniation) Patient receiving anticoagulation (epidural hematoma) Patients with an infection near LP site

Mild: Fever; headache; muscle aches; eye pain; itchy rash on neck, body, arms, or legs; lymphadenopathy, weakness, anorexia, nausea and vomiting

West Nile Virus

Severe: High fever, body and muscle weakness; itchy rash on neck, body, arms, and legs; GI upset; CNS symptoms

West Nile Virus

IgM antibody capture enzyme-linked immunosorbent assay (MAC_ELISA) of serum or CSF within 8 days of onset

West Nile Virus diagnosis

West Nile Virus Prevention

Stay indoors during most active times (between dust and dawn) Apply insect repellant Remove standing water Use screens on doors and windows Report dead birds to local health department

Borrelia bugdorferi spirochete organism causes what?

Lyme Disease

Where is the prevalence highest for Lyme disease?

Northeast, mid-Atlantic, Wisconsin, Minnesota, Northern California

ELISA from blood sample | IgG and IgM Western blot if symptoms > 30 days

Lyme disease

What is treatment for uncomplicated lyme disease?

Doxycycline

What is the treatment for complicated lyme disease?

IV ceftriaxone or penicillin

Rickettsia rickettsii (obligate intracellular gram-negative) caused what?

Rocky Mountain Spotted Fever

Where is the prevalence for rocky mountain spotted fever?

Everywhere but Maine/Vermont

Fever, severe headache, myalgia, characteristic rash (starts on wrists, ankles, palms, and soles and then progresses to trunk), thrombocytopenia

rocky mountain spotted fever

RMSF serologic assay

diagnosis of rocky mountain spotted fever

Treatment for rocky mountain spotted fever

Doxycycline until afebrile for 72 hours

Should treatment be delayed for serologic testing for rocky mountain spotted fever?

NO

Where is dengue fever typically present?

Tropics and subtropics | Puerto Rico, Virgin Islands, and American Samoa

Acute phase--nonspecific febrile phase, retro-orbital headache pain, myalgias, maculopapular rash Critical phase--defervescence within 2 to 7 days after onset; some progress to severe case (vomiting, mucosal bleeding, leukopenia, thrombocytopenia, elevated hematocrit, difficulty breathing, shock, DIC, pleural effusion, and ascites)

Dengue Fever

Leukopenia with thrombocytopenia and elevated hematocrit

Dengue Fever

ELSIA for anti-dengue IgM and IgG antibodies

Dengue Fever

What medications do patients with dengue fever avoid>

Aspiring and NSAIDs

Where is typhoid most common?

Tropics, subcontinental India, Southeast Asia, and southern Africa

How is typhoid fever acquired?

Ingestion

Fever, headache, lethargy, malaise, abdominal pain with diarrhea or constipation, hepatosplenomegaly, stupor, rose spots (blanching erythematous macules), confusion, delirium, convulsion, obtundation

Typhoid Fever

What is the most life-threatening complication of thyroid fever?

Intestinal perforation

What is the best source for culture for typhoid?

Bone marrow

Blood culture in large volumes (1-15 mL) | Normal-to-low WBC count, elevated LFTs

Typhoid

Treatment for typhoid

Ceftriaxone or ciprofloxacin | Ampicillin

How long can fevers persist with appropriate therapies with typhoid?

up to 7 days

Vi capsular polysaccharide (Typhim Vi) vaccine can be given to what age groups? How soon should be given prior to exposure?

Older than 2 years | At least 2 weeks prior to possible exposure

Ty21a (Vivotif) vaccine is what kind of vaccine?

Live-attenuated oral vaccine

How old can you be to receive Ty21a?

Older than 6 years

How many doses of ty21a?

4 doses; taken every other day

Where is Japanese encephalitis present?

Eastern Asia, subcontinental India, and western Pacific

Leading cause of vaccine-preventable encephalitis

Japanese encephalitis

Vast majority are asymptomatic Incubation period of 5-15 days headache, vomiting, fever, altered mental status, weakness, parkinsonism, seizures progressing to paralysis mild leukocytosis, mild anemia, hyponatremia

Japanese encephalitis

Normal glucose, elevated protein, leukocytosis with lymphocyte predominance

CSF Japanese encephalitis

Anti-JEV IgM antibodies

Japanese encephalitis

Mosquito-transmitted Plasmodium parasitic infection

Malaria

What are the high-risk travel places?

Sub-Saharan Africa, Vanuatu, Papua New Guinea, Solomon Islands, Indian subcontinent

Paroxysmal fever, due to synchronicity of reproductive cycles, is characteristic sign Chills, headache, malaise, cough Anemia with thrombocytopenia Proteinuria and hemoglobinuria in times of fever or presence of rapid hemolysis

Malaria

Hypotension, renal dysfunction, metabolic acidosis, hypoglycemia

Severe Malaria

Artesunate monotherapy or quinidine in combination with doxycycline, tetracycline, or clindamycin

Severe Malaria

Chloroquine or hydroxychloroquine

Mild Malaria

Avoid doxycycline and tetracycline in those ___ years of age

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