Bordetella pertussis: Difference between revisions
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Bordetella pertussis
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+ | ==Background== |
||
− | = Bordatella pertussis = |
||
− | == |
+ | ===Microbiology=== |
− | * |
+ | *Small, Gram-negative coccobacillus |
− | * |
+ | *Fastidious, slow-growing, and strictly aerobic |
− | * |
+ | *Catalase positive non-fermentative |
− | * |
+ | *Pertussis toxin helps it to evade the host defenses |
− | === |
+ | ===Pathophysiology=== |
+ | *Four steps to infection: attachment, evasion of host defenses, local damage, and systemic manifestations |
||
− | * ''B. pertussis'', ''B. parapertussis'', and ''B. holmesii'' are the most common species to cause disease in humans |
||
+ | *Virulence determined by filamentous hemagglutinin (FHA) and fimbriae (FIM) adhesins |
||
− | * ''B. bronchiseptica'' causes kenel cough in dogs and cats, with rare human infections in immunocompromised hosts |
||
+ | **Required for tracheal colonization |
||
− | * Ovine-adapted ''B. parapertussis'' causes respiratory infections in sheep |
||
+ | **Pertussis toxin (PT) also plays a role |
||
− | * ''B. avium'' causes disease in poultry |
||
+ | *Adenylate cyclase toxin (ACT) and PT allow it to evade host defenses |
||
− | * ''B. hinzii'' causes disease in poultry and rarely in immunocompromised hosts |
||
+ | **ACT inhibits macrophages by catalysing ATP to cAMP |
||
− | * ''B. trematum'' has been found in wounds and otitis media |
||
+ | **PT delays neutrophil recruitment by suppressing G protein signaling pathways |
||
− | * ''B. petrii'' causes rare infections in immunocompromised hosts |
||
+ | *Tracheal cytotoxin (TCT) produces NO and damages the tracheal epitheleal cells |
||
− | * ''B. ansorpii'' was isolated from an epidermal cyst and an immunocompromised host |
||
+ | *Few systemic manifestations because it doesn't enter circulation |
||
+ | ==Clinical Manifestations== |
||
− | == Pathophysiology == |
||
+ | *Presents with cough lasting 14 days or more, with paroxysms of coughing, an inspiratory whoop, and post-tussive vomiting |
||
− | * Four steps to infection: attachment, evasion of host defenses, local damage, and systemic manifestations |
||
+ | *Incubation period of [[Usual incubation period::7 to 10 days]] on average (range [[Incubation period range::5 to 21 days]]) |
||
− | * Virulence determined by filamentous hemagglutinin (FHA) and fimbriae (FIM) adhesins |
||
− | ** Required for tracheal colonization |
||
− | ** Pertussis toxin (PT) also plays a role |
||
− | * Adenylate cyclase toxin (ACT) and PT allow it to evade host defenses |
||
− | ** ACT inhibits macrophages by catalysing ATP to cAMP |
||
− | ** PT delays neutrophil recruitment by suppressing G protein signaling pathways |
||
− | * Tracheal cytotoxin (TCT) produces NO and damages the tracheal epitheleal cells |
||
− | * Few systemic manifestations because it doesn't enter circulation |
||
− | == |
+ | ===Young Children=== |
+ | *Three stages: |
||
− | === Presentation === |
||
+ | *#'''Catarrhal stage''', with rhinorrhea, nonpurulent conjuctivitis, occasional cough, and a low-grade fever; lasts 1 to 2 weeks. |
||
+ | *#'''Paroxysmal stage''', with fits of coughing and an inspiratory whoop; lasts 1 to 6 weeks. May have post-tussive emesis. Occasionally associated with hyperinsulinemia and hypoglycemia in infants. |
||
+ | *#'''Convalescent stage''', with the cough slowly resolving over 1 to 6 weeks, occasionally up to 8 weeks. |
||
+ | ===Adults=== |
||
− | * Presents with cough lasting 14 days or more, with paroxysms of coughing, an inspiratory whoop, and post-tussive vomiting |
||
− | * Incubation period or 7 to 10 days on average (range 5 to 21 days) |
||
+ | *Can present atypically, with less whooping and less post-tussive vomiting |
||
− | ==== Young Children ==== |
||
+ | *Coughing is seen in most patients, lasting longer than 21 days |
||
+ | **Mean duration 36 to 48 days |
||
+ | *Post-tussive vomiting is suggestive of pertussis |
||
+ | ===Carrier State=== |
||
− | * Three stages: |
||
− | *# '''Catarrhal stage''', with rhinorrhea, nonpurulent conjuctivitis, occasional cough, and a low-grade fever; lasts 1 to 2 weeks. |
||
− | *# '''Paroxysmal stage''', with fits of coughing and an inspiratory whoop; lasts 1 to 6 weeks. Occasionally associated with hyperinsulinemia and hypoglycemia in infants. |
||
− | *# '''Convalescent stage''', with the cough slowly resolving over 1 to 6 weeks, occasionally up to 8 weeks. |
||
+ | *Transient nasopharyngeal carriage in immunized children |
||
− | ==== Adults ==== |
||
+ | ===Complications=== |
||
− | * Can present atypically, with less whooping and less post-tussive vomiting |
||
− | * Coughing is seen in most patients, lasting longer than 21 days |
||
− | ** Mean duration 36 to 48 days |
||
− | * Post-tussive vomiting is suggestive of pertussis |
||
+ | *Case-fatality rate of 1% in children under 6 months |
||
− | === Diagnosis === |
||
+ | *Pnuemonia is the most common complication, either caused by the disease itself for by coinfection (especially RSV) |
||
+ | *Encephalopathy is a rare complication, usually in unimmunized children |
||
+ | **Begins weeks 2 to 4 after cough, with seizures and focal neurologic deficits |
||
+ | *Pulmonary hypertension |
||
+ | *Pneumonia and urinary incontinence are common in older patients |
||
+ | *The paroxysms of coughing can also cause subconjunctival hemorrhages, syncope, and rib fractures |
||
+ | ==Diagnosis== |
||
− | * Nasopharyngeal swab/aspirate culture |
||
− | ** Sensitivity 15 to 80% |
||
− | * PCR |
||
− | * Serology |
||
− | ** Antibodies (IgG and IgA) against GHA, agglutinogen, or PT |
||
− | *** IgG rises 2 to 3 weeks after infection or immunization (1 week after booster) |
||
− | *** Look for a two-fold increase in IgG to diagnose acute infection |
||
− | ** Antigens including PT |
||
+ | *Nasopharyngeal swab/aspirate culture |
||
− | === Management === |
||
+ | **Sensitivity 15 to 80% |
||
+ | *PCR |
||
+ | *Serology |
||
+ | **Antibodies (IgG and IgA) against GHA, agglutinogen, or PT |
||
+ | ***IgG rises 2 to 3 weeks after infection or immunization (1 week after booster) |
||
+ | ***Look for a two-fold increase in IgG to diagnose acute infection |
||
+ | **Antigens including PT |
||
+ | ==Management== |
||
− | * Treat within 21 days of symptom onset (except if <1 mo. old, just treat) |
||
− | * In children |
||
− | ** Azithromycin 10 mg/kg on day 1 followed by 5 mg/kg/d for 4 days |
||
− | ** Erythomycin 40-50 mg/kg/d divided qid for 7-14 days |
||
− | ** Clarithromycin 15 mg/kg/d divided bid for 7 days |
||
− | ** Azithromycin for children <1 year |
||
− | * In infants <1 mo, azithromycin 10 mg/kg/d for 5 days |
||
− | * In adults |
||
− | ** Azithromycin 500mg followed by 250 mg daily for 4 more days |
||
− | ** Erythomycin 500 mg qid for 7-14 days |
||
− | ** Clarithromycin 500 mg bid for 7 days |
||
− | * Consider prophylaxis of close contacts, third-trimester pregnancy, infants, and healthcare workers |
||
− | ** Azithromycin 500 mg for one day followed by 250 mg for 4 more days |
||
− | ** Erythromycin 500 mg qid for 7 to 14 days |
||
− | ** Clarithromycin 500 mg bid for 7 days |
||
+ | *Treat within 21 days of symptom onset (except if <1 mo. old, treat regardless of duration) |
||
− | === Complications === |
||
+ | *In children |
||
+ | **[[Azithromycin]] 10 mg/kg on day 1 followed by 5 mg/kg/d for 4 days |
||
+ | **[[Erythomycin]] 40-50 mg/kg/d divided qid for 7-14 days |
||
+ | **[[Clarithromycin]] 15 mg/kg/d divided bid for 7 days |
||
+ | **[[Azithromycin]] for children <1 year |
||
+ | *In infants <1 mo, [[azithromycin]] 10 mg/kg/d for 5 days |
||
+ | *In adults |
||
+ | **[[Azithromycin]] 500mg followed by 250 mg daily for 4 more days |
||
+ | **[[Erythomycin]] 500 mg qid for 7-14 days |
||
+ | **[[Clarithromycin]] 500 mg bid for 7 days |
||
+ | ==Prevention== |
||
− | * Case-fatality rate of 1% in children under 6 months |
||
− | * Pnuemonia is the most common complication, either caused by the disease itself for by coinfection (especially RSV) |
||
− | * Encephalopathy is a rare complication, usually in unimmunized children |
||
− | ** Begins weeks 2 to 4 after cough, with seizures and focal neurologic deficits |
||
− | * Pulmonary hypertension |
||
− | * Pneumonia and urinary incontinence are common in older patients |
||
− | * The paroxysms of coughing can also cause subconjunctival hemorrhages, syncope, and rib fractures |
||
− | === |
+ | ===Infection Control=== |
− | * |
+ | *Droplet precautions |
+ | *Duration |
||
+ | **Treated: after 5 days of effective treatment |
||
+ | **Untreated: after 3 weeks from onset of paroxysms |
||
+ | *Communicable from onset of catarrhal stage to 3 weeks after onset of coughing or paroxysms |
||
+ | ===Post-Exposure Prophylaxis=== |
||
− | == Carrier State == |
||
+ | *Consider prophylaxis of close contacts (face-to-face within 3 feet), third-trimester pregnancy, infants, and healthcare workers |
||
− | * Transient nasopharyngeal carriage in immunized children |
||
+ | *Should be considered up to 21 days following last contact |
||
+ | *Options include: |
||
+ | **[[Azithromycin]] 500 mg for one day followed by 250 mg for 4 more days |
||
+ | **[[Erythromycin]] 500 mg qid for 7 to 14 days |
||
+ | **[[Clarithromycin]] 500 mg bid for 7 days |
||
− | == |
+ | ===Immunization=== |
− | * |
+ | *Options include whole-cell (DTP) and acellular (DTaP or Tdap) |
− | ** |
+ | **Acellular removed lipopolysaccharide so is less reactive, but is as or more effective than whole cell |
− | *** |
+ | ***There was a fear of encephalopathy and SIDS with DTP |
− | *** |
+ | ***Acellular has PT, the two hemagluttinins, and protectin |
− | ** |
+ | **DTaP (diphtheria toxoid, tetanus toxoid, and acellular pertussis, pediatric formula) |
− | *** |
+ | ***Given at 2, 4, 6, and 18 months, with booster at 4-6 years |
− | ** |
+ | **Tdap booster once in adulthood, and with every pregnancy for women (third trimester) |
− | * |
+ | *None of the vaccines carry life-long immunity; even the immunity from the acellular pertussis vaccine wanes after 4-5 years |
+ | |||
+ | {{DISPLAYTITLE:''Bordetella pertussis''}} |
||
+ | [[Category:Gram-negative coccobacilli]] |
||
+ | [[Category:Respiratory infections]] |
||
+ | [[Category:Pediatrics]] |
Latest revision as of 12:40, 25 January 2022
Background
Microbiology
- Small, Gram-negative coccobacillus
- Fastidious, slow-growing, and strictly aerobic
- Catalase positive non-fermentative
- Pertussis toxin helps it to evade the host defenses
Pathophysiology
- Four steps to infection: attachment, evasion of host defenses, local damage, and systemic manifestations
- Virulence determined by filamentous hemagglutinin (FHA) and fimbriae (FIM) adhesins
- Required for tracheal colonization
- Pertussis toxin (PT) also plays a role
- Adenylate cyclase toxin (ACT) and PT allow it to evade host defenses
- ACT inhibits macrophages by catalysing ATP to cAMP
- PT delays neutrophil recruitment by suppressing G protein signaling pathways
- Tracheal cytotoxin (TCT) produces NO and damages the tracheal epitheleal cells
- Few systemic manifestations because it doesn't enter circulation
Clinical Manifestations
- Presents with cough lasting 14 days or more, with paroxysms of coughing, an inspiratory whoop, and post-tussive vomiting
- Incubation period of 7 to 10 days on average (range 5 to 21 days)
Young Children
- Three stages:
- Catarrhal stage, with rhinorrhea, nonpurulent conjuctivitis, occasional cough, and a low-grade fever; lasts 1 to 2 weeks.
- Paroxysmal stage, with fits of coughing and an inspiratory whoop; lasts 1 to 6 weeks. May have post-tussive emesis. Occasionally associated with hyperinsulinemia and hypoglycemia in infants.
- Convalescent stage, with the cough slowly resolving over 1 to 6 weeks, occasionally up to 8 weeks.
Adults
- Can present atypically, with less whooping and less post-tussive vomiting
- Coughing is seen in most patients, lasting longer than 21 days
- Mean duration 36 to 48 days
- Post-tussive vomiting is suggestive of pertussis
Carrier State
- Transient nasopharyngeal carriage in immunized children
Complications
- Case-fatality rate of 1% in children under 6 months
- Pnuemonia is the most common complication, either caused by the disease itself for by coinfection (especially RSV)
- Encephalopathy is a rare complication, usually in unimmunized children
- Begins weeks 2 to 4 after cough, with seizures and focal neurologic deficits
- Pulmonary hypertension
- Pneumonia and urinary incontinence are common in older patients
- The paroxysms of coughing can also cause subconjunctival hemorrhages, syncope, and rib fractures
Diagnosis
- Nasopharyngeal swab/aspirate culture
- Sensitivity 15 to 80%
- PCR
- Serology
- Antibodies (IgG and IgA) against GHA, agglutinogen, or PT
- IgG rises 2 to 3 weeks after infection or immunization (1 week after booster)
- Look for a two-fold increase in IgG to diagnose acute infection
- Antigens including PT
- Antibodies (IgG and IgA) against GHA, agglutinogen, or PT
Management
- Treat within 21 days of symptom onset (except if <1 mo. old, treat regardless of duration)
- In children
- Azithromycin 10 mg/kg on day 1 followed by 5 mg/kg/d for 4 days
- Erythomycin 40-50 mg/kg/d divided qid for 7-14 days
- Clarithromycin 15 mg/kg/d divided bid for 7 days
- Azithromycin for children <1 year
- In infants <1 mo, azithromycin 10 mg/kg/d for 5 days
- In adults
- Azithromycin 500mg followed by 250 mg daily for 4 more days
- Erythomycin 500 mg qid for 7-14 days
- Clarithromycin 500 mg bid for 7 days
Prevention
Infection Control
- Droplet precautions
- Duration
- Treated: after 5 days of effective treatment
- Untreated: after 3 weeks from onset of paroxysms
- Communicable from onset of catarrhal stage to 3 weeks after onset of coughing or paroxysms
Post-Exposure Prophylaxis
- Consider prophylaxis of close contacts (face-to-face within 3 feet), third-trimester pregnancy, infants, and healthcare workers
- Should be considered up to 21 days following last contact
- Options include:
- Azithromycin 500 mg for one day followed by 250 mg for 4 more days
- Erythromycin 500 mg qid for 7 to 14 days
- Clarithromycin 500 mg bid for 7 days
Immunization
- Options include whole-cell (DTP) and acellular (DTaP or Tdap)
- Acellular removed lipopolysaccharide so is less reactive, but is as or more effective than whole cell
- There was a fear of encephalopathy and SIDS with DTP
- Acellular has PT, the two hemagluttinins, and protectin
- DTaP (diphtheria toxoid, tetanus toxoid, and acellular pertussis, pediatric formula)
- Given at 2, 4, 6, and 18 months, with booster at 4-6 years
- Tdap booster once in adulthood, and with every pregnancy for women (third trimester)
- Acellular removed lipopolysaccharide so is less reactive, but is as or more effective than whole cell
- None of the vaccines carry life-long immunity; even the immunity from the acellular pertussis vaccine wanes after 4-5 years