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34 Cards in this Set
- Front
- Back
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Acute Respiratory Illnesses:
Most common of human diseases accounting for >50% of all acute illnesses -Two-thirds to three-fourths of cases caused by ... More than 200 different ... responsible Vast majority involve the ... respiratory tract -Disease in ... respiratory tract usually seen in younger age groups, the elderly and in certain epidemiological settings |
viruses
viruses upper lower |
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What are the 4 components of the upper respiratory tract?
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Nasal cavity
pharynx larynx upper trachea |
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What composes the lower respiratory tract?
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lower trachea
lungs (bronchi, bronchiole, alveoli) |
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clinical presentation:
... -Inflammation of the nasal mucosa ... or ... -Inflammation of the nares and paranasal sinuses ... (common cold) -Inflammation of the nares, pharynx, uvula and tonsils ... (sore throat) -Inflammation of the pharynx, uvula and tonsils |
Rhinitis
Rhinosinusitis or sinusitis Nasopharyngitis Pharyngitis |
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Clinical presentation continued:
... -Inflammation of the larynx/trachea and/or throat -MC seen in very young children ... -Inflammation of the trachea and the large and small bronchi ... -Inflammation of the bronchioles ... -Lung parenchyma/aveolar inflammation -Fluid-filled alveoli -involves most of the lower tract |
Laryngotracheobronchitis (Croup)
Acute bronchitis Acute bronchiolitis Viral pneumonia |
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look at slide 7
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ok
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What are the 2 common viruses associated w/ the common cold?
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rhinoviruses and coronaviruses
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What are the viruses commonly associated w/ influenza?
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influenza viruses
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what are the viruses commonly associated w/ croup?
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parainfluenza viruses
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What are the viruses commonly associated w/ bronchiolitis?
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HRSV
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what are the 3 viruses that are commonly associated w/ pneumonia?
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influenza viruses, HRSV, adenoviruses
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look at slide 8
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ok
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...:
Major cause of the common cold Nonenveloped, single-stranded, negative RNA Greater than 100 different serotypes -Multiple serotypes circulate simultaneously -No one serotype is more prevalent than the others -Majority of serotypes infect cells by binding ..., a few via the LDL receptor Grows preferentially at 33°C (temperature of the ...) (... respiratory tract) |
Rhinovirus
ICAM-1 (intercellular adhesion molecule-1) nares upper |
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Clinical manifestations of rhinoviruses:
-Rhinorrhea and ... accompanied by nasal congestion, throat sore -Mild or absent malaise and headache, fever unusual -Reports of bronchitis, bronchiolitis and bronchopneumonia in children, although not a major cause of LRT disease in children -Exacerbate ... and chronic pulmonary disease in ... -Complications related to obstruction of eustachian tubes or sinus ostia leading to otitis media or acute sinusitis (sneezing spreads it) -Illness generally lasts for 4-9 days, resolving spontaneously without sequelae |
sneezing
asthma adults |
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Pathogenesis of rhinovirus:
-Nasal mucous is edematous, often hyperemic -Mild infiltrate with ... cells (neutrophils, lymphocytes, plasma cells and eosinophils) -Mucus-secreting glands hyperactive, nasal turbinate engorge potentially leading to obstruction -Inflammatory mediators linked to the signs and symptoms (bradykinin and histamine) -Virus ... coincides with the onset of illness or begins shortly after symptoms appear |
inflammatory
shedding |
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Epidemiology of rhinoviruses:
Detected in 50% of common cold-like illnesses by ... and ... Infection rates higher among infants and young children -Rate ... with increasing age -Infections occur throughout the year with seasonal peak in ... and ... in temperate climates Spread through direct contact with infected secretions By adulthood, all individuals have neutralizing antibodies to multiple serotypes Peak incidence during ... and ... months |
PCR and tissue culture
decreases early fall and spring summer and fall |
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...:
-Large, enveloped, positive-stranded RNA viruses -Named derived from its crown-like appearance produced distinctive, long, petal-shaped spikes -Second most common cause of the common cold (10-35% of cases) -There are three confirmed human isolates: ..., ..., and ... |
Coronavirus
HCoV-229E, HCoV-OC43 and SARS-CoV |
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Coronavirus continued:
Infect ciliated epithelial cells in the ...; damage of cialiated cells, induction of chemokines/cytokines -Aminopetidase N receptor (metalloprotease on intestinal, lung and kidney cells) -Sialic acid receptor Clinical features of common cold are similar to illness caused by rhinoviruses -Incubation period ... -Duration of illness ... -... nasal discharge Infections prevalent in ..., ..., and ... |
nasopharynx
longer shorter More late fall, winter and early spring |
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...:
Nonenveloped, linear double-stranded DNA virus 51 serotypes classified into six subgroups(A-F) Common disorders include respiratory tract infection, conjunctivitis and gastroenteritis -Infect mouth, nasopharynx or ocular conjunctiva -Serotypes causing respiratory disease initially replicate in ... respiratory epithelium Transmitted by aerosol, close contact or fecal-oral route; establishment of ... infection (in most cases) |
adenovirus
non-ciliated pharyngeal |
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Adenovirus: febrile URT illness:
Accounts for 5% of URT infection in children younger than 5 Symptoms include nasal congestion, coryza and cough, sometimes tonsillitis -Respiratory symptoms accompanied by malaise, fever, chills, myalgia and headache Common serotypes ... and ... Occurs primarily in the ... and ... months ... fever when conjunctivitis accompanies above symptoms -Bilateral conjunctivitis caused by serotypes ..., ..., and ... |
Ad1-3 and Ad5-7
spring and winter Pharyngoconjunctival Ad3, 4 and 7 |
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Adenovirus:
Known to cause ... infections in children -10% of childhood pneumonias Tracheobronchitis, bronchiolitis and pneumonia may mimic an HRSV or influenza infection |
LRT
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adenovirus: ...
Most frequently seen in recently assembled military recruits Febrile respiratory illness -Symptoms include sore throat, coryza and regional ... (usually cervical area) -Serotypes ... and ... most prevalent (vaccine available) 70% of recruits became infected in the prevaccine era Spread rapidly under the conditions of fatigue and crowding |
acute respiratory disease
lymphadenopathy Ad4 and Ad7 |
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Adenovirus vaccine:
use in military only Oral enteric-coated vaccine -live, unattenuated ... and ... -Enteric coating allows the ... epithelium to be bypassed; only replicates in the ... -Asymptomatic infection -Good neutralizing antibody response Supply exhausted in the late 1990s Since 1999 10-12% of military recruits have become infected |
Ad4 and Ad7
respiratory intestine |
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...
Leading cause of lower respiratory tract (LRT) infection in infants and younger children Most common cause of ... and ... in children under 1 year of age -Between 25% and 40% of children have signs or symptoms of bronchiolitis or pneumonia during first infection -0.5%-2% require hospitalization (125,000/year) Seasonal epidemics, ... through ... |
Human respiratory syncytial virus (HRSV)
bronchiolitis and pneumonia late fall through spring |
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General structure of HSRV:
Enveloped, ss(-)RNA virus Infection via two envelope proteins: -... attaches virus to respiratory epithelium -... fuses virus to cell membrane Name derived from the ability of HRSV to form ... -... allows the host cell membrane to fuse with neighboring cells (giant multinucleated cells) |
G protein
F protein syncytia F protein |
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HRSV pathogenesis:
Viral replication begins in ... -Replication primarily in the superficial layer of epithelium, virus shed from apical surface into lumen Spread from ... to ... -1-3 days after onset of rhinorrhea -Likely due to aspiration of secretions -Transmission by cell-cell ... (tissue culture phenomenon) |
nasopharynx
URT to LRT fusion |
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Clinical features of HRSV:
... Infection -Rhinitis, Pharyngitis, Low-grade fever -Disease normally limited to URT in persons older than ... years LRT Infection (... and ...) -Cough -Poor feeding, lethargy -Hypoxemia -Respiratory distress (Tachypnea, Rales, Retractions) -Apnea |
URT
3 bronchiolitis and pneumonia |
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Pathology of HRSV: Bronchiolitis and pneumonia
-Mucosal edema -Increased mucus secretion -Cell ... in mucosa; sloughing of destroyed ... cells -Influx of ... cells and lymphocytic infiltrates -... of bronchioles and aveoli by cell debris and inflammatory cells -Small diameter of bronchioles in young infants contribute to severe LRT disease; prone to obstruction |
necrosis
epithelial polymorphonuclear Obstruction |
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... (think croup)
Important cause of viral LRT disease in young children: ... (croup), bronchiolitis and pneumonia Like HRSV, commonly reinfects older children and adults to produce URT disease Four HPIV types 1-4 -Types ... a major cause of croup -Seasonality of croup mirrors seasonality of ... Seasonality -HPIV1-every 2 years in ... of ... numbered years -HPIV2-annually in ... -HPIV3 infections in ... and ... |
Human Parainfluenza virus (HPIV)
laryngotracheobronchitis 1-3 HPIV1 autumn odd fall spring and summer |
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General structure of HPIV:
Enveloped, single-stranded, negative RNA virus HN and F glycoprotein -... activity mediates attachment by binding to host cell sialic acid -... activity in progeny virions cleave sialic acid to facilitate release -... mediates the fusion between the viral envelope and host cell plasma membrane |
Hemagglutination
Neuramidase F protein |
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HPIV Pathogenesis:
Viral replication in the ... of respiratory tract Early infection involves mucosa of ... and ... -Fever above 100°F -Sinusitis and otitis media Extensive infection (croup) -Involvement of ... and ... -Can spread to lower trachea and bronchi |
epithelium
nose and throat larynx and upper trachea |
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Croup – Acute Laryngotracheobronchitis:
Progressive symptoms of rhinitis, pharyngitis, fever and cough Cough worsens after several days -Brassy, seal-like or barking -Stridor Most children recover in ...-... hours Those who do not recover may develop air hunger (get to ER!) -Cyanosis -Sternal and intercostal ... -Progressive airway obstruction HPIV Transmission -Direct person-to-person contact -Contact with infected secretions |
48-72
retractions |
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Role of immunity in HPIV infection:
Deficient in ... and ... -Immunologic immaturity (first 6 months) -Suppression of humoral response -Poor neutralizing local antibodies and poor serum response ... occurs frequently during early childhood ... and ... control and clear infections Short-lived protection from reinfection by CTLs and secretory antibodies Long-term resistance by ... |
infants and young children
Reinfection Antibodies and CTLs serum neutralizing antibodies |
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look at slide 32
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