Infectious Disease

Rapid Review

• Background
  • Botulism is a neuro-paralytic disease caused by the ingestion, injection, or inhalation of a pre-formed toxin produced by Clostridium botulinum. 
  • The toxin can be found in incorrectly canned/preserved foods and honey
• Signs/Symptoms
  • Facial paralysis, descending weakness, respiratory arrest
• Diagnosis
  • Clinical diagnosis based on history and physical exam
  • Confirmation of diagnosis requires identification of toxin in serum, stool, vomit, or food sources (may take 1-6 days)
• Treatment
  • Early ventilatory management and wound debridement
  • Heptavalent antitoxin
• Disposition
  • Admission is required for most patients. ICU required if any respiratory involvement.

Pearls

• Early administration of antitoxin (ex. H-Bat) is vital. Although it will not reverse paralysis, it will halt it’s progression. Do not give HBAT for infants < 1 year of age.
• Wound botulism will require thorough wound debridement and parenteral antibiotics (ex. metronidazole or penicillin)

Deep Dive

• Botulism (emDOCs)

Rapid Review

• Background
  • Chlamydia is the most common sexually transmitted infection in the US caused by the baceteria Chlamydia trachomatis. It is a leading cause of infertility.
  • Can affect the cervix, urethra, salpinges, uterus, and epididymis.
• Signs/Symptoms
  • Dysuria, mucopurulent urethral discharge, +/- fever
  • Over 50% of infected individuals are asymptomatic
• Diagnosis
  • NAAT (urine or vaginal swab)
• Treatment
  • Ceftriaxone IM + Azithromycin PO
  • Provide prescription for expedited partner treatment
• Disposition
  • Discharge is appropriate for most patients. Follow up with PCP encouraged for to ensure adequate treatment of infection and for additional STI testing as needed.

Pearls

• Infection can present in other areas as well, such as the rectum or the pharynx. Obtain samples from those areas if they are symptomatic in those regions.
• Have a low threshold for testing for chlamydia/gonorrhea in young women, as they are very often asymptomatic. 

Deep Dive

• Chlamydia (Merck Manual)

Rapid Review

• Background
  • Acute respiratory illness caused by the novel SARS-CoV-2 virus
  • Often causes pulmonary, cardiac, and neurological complications
• Signs/Symptoms
  • Range from mild cold-like symptoms to respiratory failure
  • Most common symptoms include fever, dry cough, fatigue, and SOB. 
  • Associated with cardiac complications and thromboembolic phenomenon. 
• Diagnosis
  • Viral testing (Rapid antigen and/or RT-PCR testing)
• Treatment
  • Pulmonary support (O2, NIPPV, Intubation)
  • Consider Dexamethasone and Remdesivir for moderate-severe infections
• Disposition
  • Most patients can be discharged if healthy, vaccinated, and hemodynamically stable
  • Admission is necessary for patients with tachypnea, hypoxia, or with significant comorbidities.

Pearls

• Paxlovid (nirmatrelvir/ritonavir) is an oral antiviral drug that can be used for mild/moderate COVID-19 infections. However, it cannot be used in patients with severe renal disease (GFR < 30) and it has several drug interactions.
• The current dominant variant (Omicron) is more transmissible and resistant to vaccines/monoclonal therapy than it’s predecessor (Delta), but overall causes less hospitalization and severe disease.

Deep Dive

• REBEL COVID-19 Series (REBEL EM)

Rapid Review

• Background
  • Inflammation of the meninges and subarachnoid space. May be bacterial (most lethal), viral (most common), or in rare cases due to fungal or tuberculosis infection. 
  • Bacterial meningitis is most commonly caused by Streptococcus pneumoniae
• Signs/Symptoms
  • Fever, headache, nuchal rigidity, photophobia
  • (+) Brudzinski sign, (+) Kernig Sign
• Diagnosis
  • Lumbar puncture w/ CSF fluid analysis 
• Treatment
  • Broad-spectrum antibiotics (ex. Ceftriaxone + Vancomycin) and corticosteroids (ex. Dexamethasone)
  • If viral, treat with Acyclovir
• Disposition
  • Admission is required for any known/suspected bacterial infections. ICU is required for any toxic-appearing patients.
  • Discharge with close follow-up is appropriate if the infection is clearly viral and symptoms are controlled.

Pearls

• When in doubt, just do the lumbar puncture! Failure to diagnose meningitis early can be life-threatening  and often results in medicolegal consequences for providers.
• Although a head CT is often performed prior to lumbar puncture, this can cause a significant delay in diagnosis/treatment. Reserve early CT imaging for patients with AMS, neurological deficits, papilledema, or history of CNS disease.

Deep Dive

• Meningitis: Pearls and Pitfalls (emDOCs)

Rapid Review

• Background
  • Infection of the bone with persistent inflammatory destruction. Most commonly caused by bacteria (Staph aureus, pasteurella multocida, pseudomonas aeruginosa), but can also be caused by fungi. 
• Signs/Symptoms
  • Localized bony tenderness w/ warmth, swelling, erythema
  • May experience weight loss, fatigue, and fever.
• Diagnosis
  • X-ray  (will show bony erosions, regional osteopenia, periosteal elevation)
  • Radiography may be normal the first 2-3 weeks of symptoms. CT/MRI will provide earlier detection.
• Treatment
  • Empiric broad-spectrum antibiotics (ex. Vancomycin + Piperacillin/Tazobactam)
  • Obtain bone cultures prior to initiating antibiotics
• Disposition
  • Admission is usually required. 
  • Some cases of chronic or subacute osteomyelitis can be managed outpatient if debridement not needed and home IV antibiotics can be arranged.

Pearls

• The WBC count is often normal, especially in pediatric or subacute/chronic cases.
• Osteomyelitis can be difficult to diagnose in pediatrics (they often present afebrile with no leukocytosis). However,the combination of ESR and CRP elevation has a 98% sensitivity for diagnosing osteomyelitis in the pediatric population.

Deep Dive

• Osteomyelitis (Merck Manual)