Transcript Active Immunization

Core Tutorial in Pediatric
Infectious Diseases for Third
Year Medical Students
Infectious Disease
Emergencies
How would you evaluate this patient?
A sixteen-year-old girl presents with fever
and lower abdominal pain but denies
urinary urgency or frequency. She is
sexually active and uses condoms
infrequently.
How would you evaluate this patient?
A sixteen-month-old presents with a history
of nasal discharge for the past week
presents with a swollen, red eye and fevers
to 1030 F.
Learning Objectives
• Be able to recognize an infectious disease
emergency
• Understand the age-appropriate approach to
diagnosis and initial management of
infectious disease emergencies
• Be familiar with various agents with
bioterrorism potential
Bacteremia and Sepsis
• Bacteremia = Presence of pathogenic bacteria in the blood of mildly
or moderately ill child
– Incidence peak at age 6 to 18 months
– See “Fever” tutorial for complete discussion of work-up and
management
• Sepsis = Bacteremia with serious systemic illness
– Pathogens
• birth to 2 months: Group B Streptococcus, E. coli
• older infants: Strep. pneumoniae, N. meningitidis, Group A
Streptococcus, S. aureus, Salmonella
– Risk factors
• neoplasia, immunodeficiency syndromes, immunosuppressive
therapy, asplenia, sickle cell disease
Sepsis
• Signs and Symptoms
– fever, tachycardia, tachypnea, hypotension, metabolic acidosis,
thrombocytopenia, leukocytosis (leukopenia with overwhelming
infection)
• Work-up
– CBC
– blood culture
– coagulation studies, electrolytes, LFT’s, BUN and creatinine
• Treatment
– fluids, vasopressors; close monitoring in ICU
– age < 2 months: ampicillin and gentamicin or cefotaxime
– age > 2 months ceftriaxone or cefotaxime +/- vancomycin
Meningococcemia
• Neisseria meningitidis
• Peak incidence is first year of life, 40% in age < 5 yrs
• Risk factors include overcrowding, poverty, cigarette
smoke exposure, prior respiratory infection, congenital
impairment of phagocytosis
• Transmission by respiratory droplets, close direct contact
• Endotoxin (lipopolysaccharide) causes endothelial damage,
systemic inflammatory response
• Can progress from asymptomatic to death within hours
Meningococcemia, con’t
• Signs and symptoms
– Fever, headache, myalgias
– Altered mental status , high fever or hypothermia, tachypnea,
hypotension
– Petechial rash progressing to purpura may begin as macules,
maculopapules, or urticaria
• Case fatality rate > 40%
• Work-up
– Culture blood, CSF, skin lesions
– CSF antigen testing (latex agglutination)
Meningococcemia, con’t
• Treatment
– Penicillin G if susceptible (most are but start with third generation
cephalosporin until sensitivities are known)
– Supportive care
• Prevention
– chemoprophylaxis of contacts
• rifampin, ceftriaxone, ciprofloxacin
– vaccine
• A/C/Y/W135
Meningitis
• Incidence peak at age 6 to 24 months
• Cerebrospinal fluid normal values vary with age
• Meningeal signs (neck stiffness, Kernig’s sign and
Brudzinski’s sign) may be absent in young infants
• Most common bacterial pathogens vary with age:
– Neonate: Group B Strep, E. coli, L. monocytogenes
– Older infants and children: S. pneumoniae, N.
meningitidis, H. influenzae
Meningitis, con’t
• Colonization (nasopharynx) resulting in bacteremia can
lead to hematogenous seeding of meninges; also can have
direct extension from a parameningeal focus (i.e., sinusitis)
• Work-up
– CBC, electrolytes, BUN, creatinine, glucose, coagulation studies
– blood culture
– CSF analysis: cell counts, protein, glucose, gram stain and culture,
• Management
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ABC’s, monitoring
supportive care
age < 1 month: ampicillin and cefotaxime
age > 1 month; vancomycin and ceftriaxone or cefotaxime
Other CNS Infections
• Encephalitis
– viral, bacterial, post-infectious, non-infectious
– treatment depends on etiology
• Subdural empyema
– immediate surgical drainage
• Brain abscess
– antibiotics, steroids
– management of elevated intracranial pressure
– frequently requires surgical drainage
• Orbital cellulitis
– I.V. antibiotics and frequent evaluation by ophthalmologist with
consideration of surgical drainage
Epiglottitis
• Common etiology was H. influenzae type b prior to the
introduction of vaccine
• Other etiologies: Strep. pneumoniae, Strep. pyogenes,
Staph. aureus
• Incidence was highest in age 3 to 6 years but with vaccine
incidence has declined dramatically
• Presentation is toxic-appearing child with fever, drooling,
stridor, tachycardia, tachypnea, and a preference for sitting
up leaning forward
• This is a true emergency and can progress rapidly to
complete airway obstruction especially if the child is
disturbed
• If epiglottitis is suspected priority is control of the airway
before any other intervention or diagnostic evaluation
Epiglottitis, con’t
• Infection leads to edema of epiglottis, spreads to
aryepiglottic folds, arytenoids, and entire supraglottic
larynx
• Work-up and treatment after securing airway
• Work-up
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WBC (leukocytosis with left shift)
blood culture
epiglottis culture
lateral neck film (“thumb sign”)
• Treatment
– ceftriaxone or cefotaxime
– close observation in ICU
Bacterial Tracheitis
• Bacterial complication of viral laryngotracheobronchitis
• Pathogens: Staph aureus, Strep pyogenes, H. influenzae,
Strep pneumoniae; rarely M. catarrhalis, anaerobes
• As viral infection wanes, abrupt worsening of symptoms
with new fever and stridor
• Toxic-appearing, agitated
• Priority is establishment of an artificial airway
• Work-up and management: see Epiglottitis
Retropharyngeal Abscess
• Potential space between anterior border of cervical
vertebrae and posterior wall of esophagus
• Group A Strep, anaerobes, Staph. aureus
• Age < 4 years more common
• Fever, toxic-appearance, stridor, drooling, meningismus
• Lateral neck film or CT
• Risk of airway obstruction
• Treatment: Clindamycin or penicillin and cefazolin;
drainage
Septic Arthritis
• Presentation is systemic illness with fever and refusal to
use joint
• Exam reveals warmth, swelling, tenderness, and limited
passive range of motion
• Usual etiology is hematogenous seeding of synovial tissue
• May also result from extension of osteomyelitis
• Most are monoarticular
• Boys more commonly affected than girls
• Bacterial etiologies: Staph. aureus, Strep. pneumoniae,
Strep. pyogenes, H. influenzae (also Group B Strep and
gram-negatives in neonates; N. gonorrheae in adolescents)
Septic Arthritis, con’t
• Work-up
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CBC (leukocytosis with left shift)
ESR
joint fluid analysis (WBC, glucose, culture)
blood culture
• Treatment
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hip: immediate surgical drainage
age birth to 2 months: oxacillin and gentamicin
2 months to 3 years: cefotaxime, ampicillin/clavulanate
3 to 12 years: oxacillin
adolescents: ceftriaxone
Toxic Shock Syndrome
• Staphylococcus aureus of phage group I that produces
epidermal toxin, toxic shock syndrome toxin-I (TSST-I)
• Also toxin-producing Streptococcus pyogenes
• Presenting signs/symptoms: fever, hypotension,
erythrodermatous sunburnlike rash with subsequent
desquamation of palms and soles, multiorgan system
involvement (diarrhea, vomiting, myalgias, azotemia,
hepatitis, thrombocytopenia, change in mental status)
• Treatment includes fluid resuscitation, vasopessors,
intensive care monitoring, antibiotics
• Mortality due to cardiac arrhythmias, respiratory failure,
bleeding
Appendicitis
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Most common pediatric abdominal surgical emergency
Polymicrobial with enteric flora
Age > 5 years (peak 10 - 19 years)
Perforation in one-third of cases; more common in age < 6
years
Mid-abdominal pain initially, then RLQ pain
Fever, anorexia, nausea, vomiting, rebound tenderness
Psoas and obturator signs
Elevated WBC
Imaging modalities most helpful U/S and CT scan
Appendicitis, con’t
• IV antibiotics directed against gram negatives and
anaerobes
• Antibiotics prior to surgery
• Complications: peritonitis, abscess, wound infection,
multiorgan failure, hernia, adhesions, death
Biological Terrorism
• Features of a potential bioterrorism event
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multiple patients with same symptoms
severe illness among young, previously healthy
unusual organisms
unusual antibiotic resistance patterns
atypical presentations
unusual patterns of disease (geographic clustering)
intelligence information
sick or dead animals or plants
» adapted from Annals of Emergency Medicine 1999;34:183-90
Biological Terrorism, con’t
• Biological agents (highest priority per CDC)
– Smallpox
– Bacillus anthracis (anthrax)
– Yersinia pestis (plague)
– Clostridium botulinum toxin (botulism)
– Francisella tularensis (tularemia)
– Filoviruses
• Ebola and Marburg hemorrhagic fevers
– Arenaviruses
• Lassa (Lassa fever), Junin (Argentine hemorrhagic fever)
Biological Terrorism
Click to link to the CDC web site
on biological terrorism
www.bt.cdc.gov
References
• Fleisher GR and Ludwig S, eds. Textbook of Pediatric
Emergency Medicine, Fourth Edition. Lippincott Williams
and Wilkins, 2000.
• Reece RM, ed. Manual of Emergency Pediatrics, Fourth
Edition. W. B. Saunders Company, 1992.
• Centers for Disease Control and Prevention. Biological
and chemical terrorism: strategic plan for preparedness and
response. Morbidity and Mortality Weekly Report
2000;49(RR-4).
• Richards CF, et al. Emergency physicians and biological
terrorism. Annals of Emergency Medicine 1999;34:183-90.
1 of 8
Questions for Discussion
A sixteen-year-old girl presents with fever
and lower abdominal pain but denies
urinary urgency or frequency. She is
sexually active and uses condoms
infrequently.
How would you evaluate this patient?
2 of 8
Questions, con’t
A sixteen-month-old presents with a history
of nasal discharge for the past week
presents with a swollen, red eye and fevers
to 1030 F.
What are you most concerned about?
How would you evaluate this patient?
3 of 8
Questions, con’t
A fourteen-year-old male presents with six
hours of severe abdominal pain that is now
more right sided. He has had no diarrhea.
How would you evaluate this patient?
How would your approach differ if the
patient were a girl?
4 of 8
Questions, con’t
A 14-month-old girl presents with the
sudden onset of fever and refusal to walk.
Discuss your differential diagnosis and
evaluation of this child.
5 of 8
Questions, con’t
A five-year-old presents with a swollen, red
knee.
Discuss your differential diagnosis and
evaluation of this child.
6 of 8
Questions, con’t
A three-year-old child presents to the
Emergency Department with acute onset of
stridor and tachypnea.
Discuss your approach to this patient,
including important aspects of the history
and physical exam, the differential
diagnosis, and management principles.
7 of 8
Questions, con’t
A four-month-old baby presents to the
Emergency Department with a fever of 1040
F and petechiae.
What is your differential diagnosis?
How would you evaluate and manage this
patient?
Questions, con’t
8 of 8
A previously healthy 14-month-old presents to
the Emergency Department following 2-3
minutes of generalized, symmetric tonic-clonic
movements.
Discuss your approach to the following scenarios:
(a) The child was sleepy initially but is
now awake, alert and easily consoled by her parents.
Her temperature is 104 F.
(b) The child remains somnolent and appears to have
nuchal rigidity.