Infectious Disease Flashcards
Botulism
Clostiridum botulism. Ubiquitous GPR obligate anaerobes in surfaces of vegtables, fruits, seafood, soil/marine sediment
5 Forms – foodborne (25%), infant (73%), wound (3%), adult enteric infectious, inhalational botulism
Acute onset, bilateral cranial neuropathies with symmetric descending weakness within 12-36 hours after ingestion of preformed toxin. Blurred vision, diplopia, nystagmus, pthosis, dysphagia, dysarthria, facial weakness often marks onset of symptomatic illness. Respiratory weakness from diaphragmatic paralysis, upper AW compromise common requiring MV.
Hospitalize immediately, monitor for signs of respiratory failure.
2 Antitoxins – Equine serum heptavalent botulism antitoxin and Botulism Ig
Abx recommended after antitoxin except for infant botulism or GI botulism – Pen G effective; Metronidazole alternative if pcn allergic.
HSV Encephalitis (Diagnosis + Tx)
Defn: Sx: Findings: CSF PCR (gold standard) Mgmt: Note:
We recommend that patients with suspected HSV encephalitis receive empiric therapy, since delays of treatment have led to significant neurologic sequelae (Grade 1B)
- usually infects the temporal lobe à subacute illness with fever, focal neurologic abnormalities, aphasia, mental status changes, and seizures. May have long term sequelae.
- diagnosis: LP with mild lymphocytic pleocytosis <500cells/uL, erythrocytes, xanthochromia, elevated protein, normal glucose, PCR for HSV1 and 2, MRI (hyperintense lesion in the inferior medial temporal lobe, ovten extending into the insula.
- treatment: acyclovir IV 30mg/kg/d x 14 days.
Malignant Otitis Externa
- Diabetes, HTN, atherosclerosis. Less common: Increased ICP, GCA, cavernous sinus mass, sarcoidosis, MS, stroke.
- Paralysis of the facial nerve in association with suppurative parotitis is rare, with only ten previously reported cases.(PubMed).
- History
- Diabetes (90%) or immunosuppression (illness or treatment related)
- Severe, unrelenting, deep-seated otalgia
- Temporal headaches
- Purulent otorrhea
Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
Rhinocerebral mucormycosis
- Rhinocerebral mucormycosis is a rare opportunistic infection of the sinuses, nasal passages, oral cavity, and brain caused by saprophytic fungi. Affects diabetics and immunocompromised patients.
HSV Encephalitis (Clinical Hx)
Focal neurologic findings are usually acute (<1 week in duration) and include altered mentation and level of consciousness, focal cranial nerve deficits, hemiparesis, dysphasia, aphasia, ataxia, or focal seizures. Over 90 percent of patients will have one of the above symptoms plus fever. Other associated neurologic symptoms include urinary and fecal incontinence, aseptic meningitis, localized dermatomal rashes, and Guillain-Barre syndrome. Later in the clinical course, patients may have diminished comprehension, paraphasic spontaneous speech, impaired memory, and loss of emotional control.
HSV encephalitis is often characterized by the rapid onset of fever, headache,
seizures, focal neurologic signs, and impaired consciousness
Meningococcal meningitis (chemoprophylaxis)
Prophylaxis is indicated only for close contacts. Although “close contact” has not been clearly defined, it generally refers to individuals who have had prolonged (>8 hours) contact while in close proximity (<3 ft) to the patient, or who have been directly exposed to the patient’s oral secretions between one week before the onset of the patient’s symptoms until 24 hours after initiation of appropriate antibiotic therapy
Prophylaxis is not indicated if exposure to the index case is brief. This includes the majority of healthcare workers unless there is direct exposure to respiratory secretions (as with suctioning or intubation .
1st line prophylaxis is Ciprofloxacin
Prevention: Post-Exposure Prophylaxis
- Indications: High risk exposures
- Household contacts (up to 800 fold increase in risk)
- Child care centers
- Oral secretion exposure
- Long-distance (>8 hours) travel next to source
- Prophylaxis options (pick one)
-
Rifampin
- Age <1 month: 5 mg/kg PO q12h for 2 days
- Age >1 month: 10 mg/kg (max: 600) PO q12h x2 days
- Adults: 600 mg PO every 12 hours for 2 days
- Ciprofloxacin (adults) 500 mg PO for one dose
-
Ceftriaxone (Rocephin)
- Age <15 years: 125 mg IM for one dose
- Age >15 years: 250 mg IM for one dose
-
Rifampin
CSF Findings (Approach)
Test
Bacterial
Viral
Fungal
Tubercular
Opening pressure
Elevated
Usually normal
Variable
Variable
White blood cell count
≥1,000 per mm3
<100 per mm3
Variable
Variable
Cell differential
Predominance of PMNs*
Predominance of lymphocytes†
Predominance of lymphocytes
Predominance of lymphocytes
Protein
Mild to marked elevation
Normal to elevated
Elevated
Elevated
CSF-to-serum glucose ratio
Normal to marked decrease
Usually normal
Low
Low
Neurocysticercosis
- caused by taenia solium, a tapeworm dz in undercooked meat
- fecal oral transmission
- oncospheres may travel to the brain to create a cystic lesion with a scolex
- treatment is albendazole + steroid
Baird RA evidence-based guidelines treatment of parenchymal neurocysticercosis. Neurology 2013 April 10
listeriosis
- In special populations: immunocompromised
- fever, headache and gastrointestinal illness
- sequelae: brainstem encephalitis (rhombencephalitis) with cranial nerve deficits, cerebellar signs and hemiparesis
- ampicillin
Meningococcal infections
Epidural abscess
- risk factors: alcoholism, diabetes, spinal abnormalities, spinal interventions, local infections, systemic infections
- staph aureus including MRSA
- empiric IV antibiotics: vanco + 3/4th gen cephalosporin
West Nile encephalitis
- neuroinvasive disease involving the interior one cells of the spinal cord
- fever, altered mental status, and flaccid paralysis with areflexia in the absence of sensory findings are typical characteristics of West Nile virus
- CSF typically shows a lymphocytic peel psychosi pleocytosis
Acute Bronchitis
- Self-limited; usually <2wks but cough may last longer; chronic >3mos
- Presents w/ COUGH, coryza, myalgia, fatigue; fever is RARE (PNA, flu)
- Viral: rhino-, RSV, influenza, parainfluenza & adenovirus
- Bacterial: Mycoplasma sp., C. pneumoniae, Streptococcus, Moraxella catarrhalis, and Haemophilus influenzae; Bordetella
- Mimics: upper a/w syndrome, GERD, ACEI, eosinophilic bronchitis
- Dx: resp secretion cx, throat swab, blood cx, ?procalcitonin
- Tx: Supportive (suppressants, inhaler); abx (5d) only for - elderly, AECB, pertussis, comobidities (COPD, CHF, DM), hospitalization in past year
- Augmentin, Azithromycin
- Notes: bullous myringitis (mycoplasma); conjunctivits/adnopathy (adenov)
http://emedicine.medscape.com/article/297108-clinical
2006 ACCP guidelines
El Moussaoui R, Roede BM, Speelman P, Bresser P, Prins JM, Bossuyt PM. Short-course antibiotic treatment in acute exacerbations of chronic bronchitis and COPD: a meta-analysis of double-blind studies.Thorax. 2008 May. 63(5):415-22.
Clinical Predictors of Pneumonia
- Fever (5.5)
- Advanced age (4.6)
- Tachycardia (3.8)
- SOB (2.4)
- focal resp crackles (23.8) / rhonchi (14.6)
Pertussis - Whooping Cough
*
