Bordetella Pertussis and Influenza Flashcards
Agent that causes pertussis
Bordetella pertussis
Gram negative
Mode of transmission and incubation period of pertussis
Transmission by respiratory droplets (5ft)
Humans are the only reservoir
Incubation 1-3 weeks
Method of infection by pertussis
Organism is inhaled, adheres to ciliated epithelium in nasopharynx
Disseminated through lower respiratory airways, but does not go into alveoli
Does not invade farther than epithelium
Epidemiology
MC in developing countries
In US, mostly affects infants
Adults/adolescents important reservoir
Increasing since 2001–increased diagnosis, waning immunity, increased circulation
Phases of pertussis
catarrhal
paroxysmal
convalescent
Catarrhal Phase
Indistinguishable from viral URI
Rhinorrhea, lacrimination, conjunctival injection, malaise, low grade fever, mild cough
First 7-10 days
Paroxysmal phase
1-6 weeks, up to 10 weeks
Cough becomes more severe, plateauing at week 2-3, decreases gradually
Paroxysms of cough (bursts of numerous coughs in one inspiration) followed by a long inspiratory gap with high pitched whoop
May have posttussive emesis and exhaustion
Sputum may be purulent or non-purulent
Convalescent phase
paroxysms less common
cough resolves over 2-3 weeks
Clinical Presentation and Complications in Children
Typially have prolonged respiratory illness with paroxysmx of cough followed by whoop
atypical presentation frequent in young infants and children who have been vaccinated
Complications:
- MC and deadly: secondary bacterial pneumonia
- Post tussive vomitting and hypoxia–>seizure
Clinical Presentation and Complications in Adults
Frequently only have prolonged, persistent paroxysms of cough 36-48 days
Post tussive vomiting MC than whoop.
More likely to have atypical presentation because of previous immunization or previous infection
Complications: uncommon
- Rib fracture
- hernia
- back pain
- pneumothorax
- atypical pneumonia
Hopitalization in pertussis
Admit if have signs of respiratory distress, signs of pneumonia, inability to feed, cyanosis or apnea, seizures
Provide supportive care. Close monitoring of respiratory and nutritional status
DDx of Pertussis
Viral- influenza, adenovirus, rhinovirus, etc
Bacterial - M. pneumonia, C. pneumonia, TB
NonInfectious - asthma, foreign body, GERD, PND, malignancy
Diagnostics for Pertussis
Increased WBC
CXR- r/o pneumonia
Clinical Case Definition
**Bacterial culture **
- Gold standard
- Nasopharyngeal swab
- Most sensitive early on
PCR
- MC used for pertussis
- Retains specificity and sensitivity through 3-4weeks
Serology
- Used late in illness
- Not practical in clinic
<2 weeks: culture+ PCR
>2 weeks: PCR+ serology
>4 weeks: only serology
Pertussis must be reported to the department of health within how many days?
1 day
When is it best to treat pertussis?
During the catarrhal phase to decrease transmission and severity.
Antibiotics
Post exposure prophylaxis is recommended for who?
For close contacts
Especially if at risk for severe complications: if around kids
Isolation for pertussis
Isolate until 5 days of tx or 21 days of sxs
MDH will help
Principles of Immunization
DIsease prevention: form of primary prevention
Immunization: cause an immune response without causing disease
Vaccine safety: Adverse reactions are rare and are reportable
Types of vaccinations
Live attenuated
- Weakened whole cell organism
- MMR, varicella, influenza, zoster
Inactivated
- Inactivated whole cell organism - polio
- Inactivated toxin - tetanus
Acellular
- Subunit - Fragment of microorganism – pertussis influenza
- Recombinant – genetic engineering – HBV, HPV
- Conjugate – carrier protein - pneumococcus
Common adverse reactions to vaccines
fever
injection site sensitivity
rash
injection site edema
vasodilation
Pertussis Vaccination
Acellular toxin
Lasts 5-10 years
DTaP: series for children
Tdap: booster for adults
Influenza virus classified by
core proteins A, B, or C
subtypes of A are classified by glycoproteins
H: hemagluttinin binds to respiratory epithelium
N: neuraminidase involved with propogation of new virus
species of origin
geographic location
Influenza A
Seasonal outbreaks during winter months
Morbidity and mortality most affect those at high risk
Influenza can reassort at high rates because of what characteristic?
segmented genome
