Unit 11 - Upper RTI Flashcards
Anatomy of upper respiratory tract
- Epiglottis
- Larynx
- Nasal cavity
- Pharynx
Anatomy of lower respiratory tract
- Trachea
- Bronchi
- Bronchioles
Why does rhino virus prefer the upper part of respiratory tract?
It thrives in low temperatures
How does pertussis cause a RTI?
stops ciliary action
Lungs are rich in _____
macrophages
The following are all ____ residents of the respiratory tract:
- Oral streptococci
- Neisseria spp. Branhamella
- Candida albicans
- Streptococcus mutans
Common
>50% of normal people
The following are all ____ residents of the respiratory tract:
- Streptococcus pyogenes
- Streptococcus pneumoniae
- Neisseria meningitidis
Occasional
<10% of normal people
The following are all ____ residents of the respiratory tract:
- Corynebacterium diphtheria
- Klebsiella pneumoniae
- Psueodmonas (esp after antibiotics)
- E.coli (esp after antibiotics)
- C. albicans (esp after antibiotics)
Uncommon
<1% of normal people
The following are all ____ residents of the respiratory tract:
- Pneumonocystis jirovecii
- Mycobacterium tuberculosis
- Cytomegalovirus (CMV)
Residents in latent state in tissues (Lung, lymph nodes, etc.)
The following are all ____ residents of the respiratory tract:
- Herpes simplex virus
- Epstein-Barr virus
Sensory neurone/glands connected to mucosae
______ _______ is very common in immunocompromised individuals (such as HIV Pts)
Pneumonocystis jirovecii
What are the two types of RTI’s?
- Restricted to surface
- Spread through body
Examples of RTI’s that are restricted to surface
- common cold virus
- influenza
- streptococci in throat
- chlamydia (conjunctivitis)
- diphtheria
- pertussis
- candida albicans (thrush)
Examples of RTI’s that are spread through the body
- measles, mumps, rubella
- EBV, CMV
- Chlamydophilia psittaci
- Q fever
- Cryptococcosis
What are the two types of Respiratory Invaders?
- Professional invaders
- Secondary invaders
______ invaders = infect healthy respiratory tract
Professional
______ invaders = infect when host defences impaired
Secondary
Professional invaders require what to infect a healthy respiratory tract?
- Adhesion to normal mucosa (in spite of mucocillary system)
- Ability to interfere with cilia
- Ability to resist destruction in alveolar macrophage
- Ability to damage local (mucosal, submucosal) tissues
Secondary invaders require what to infect when host defences impaired?
- Initial infection and damage by respiratory virus (ex. influenza virus)
- Local defences impaired (ex. cystic fibrosis)
- Chronic bronchitis, local foreign body or tumor
- Depressed immune responses (ex. AIDs, neoplastic disease)
- Depressed resistance (ex. elderly, alcoholism, renal or hepatic disease
Rhinitis (common cold) is caused by different types of ____
viruses
> 50% of common colds are due to ??
rhinovirus and coronaviruses
What do common colds induce?
a flow of virus-rich fluid, rhinorrhea
How are common colds transmitted?
- Aerosol
- Virus contaminated hands
Common colds are ??
self-limiting
Is there a vaccine for rhinitis (common cold) ?
No vaccine, antigenically diverse group
Pharyngitis and Tonsillitis can be caused by ____ or _____
viruses or bacteria
viruses make up 70% of cases
What viruses are the most common cause of pharyngitis and tonsillitis?
- Adenovirus
- CMV
- EBV
What is the most common bacteria that causes pharyngitis and tonsillitis?
Streptococus Pyogenes
____ is the largest human herpes virus. Multinucleated cell formation and/or intranuclear inclusions give cells distinct appearance.
Cytomegalovirus (CMV)
Natural host of CMV?
humans
Transmission of CMV?
- saliva
- urine
- blood
- semen
- cervical secretions
Describe pathology of CMV?
Initial infection asymptomatic -> lymphoid tissue -> lymph nodes and spleen (via circulation lymphocytes and monocytes)
Virus localizes in epithelial cells in salivary glands (saliva_, kidney (urine), cervix (secretions), and testes (semen) - shedding for months
CMV has specific __ and ___ response activated but not entirely clear virus
specific Ab and CMI response
CMV infection eventually controlled by ___ mechanisms
CMI
CMV: infected cells remain in body for life and can be source of ________ if CMI impaired
reactivation
CMV is a successful pathogen if it ??
- Evades immune defences
- Poor target for Tc cells
- Interferes with transport of MHC-1 molecules to cell surface
- Induces expression of FC receptors on cell surface
Infants/childs have ___ symptoms with CMV
no
Adults have ____ illnesses with CMV
mild
Describe the spectrum of symptoms of CMV
Adolescents have a glandular fever-type illness:
- fever
- lethargy
- abnormal lymphocytes and mononucleosis
Primary infection during pregnancy:
- spread through placenta to fetus
- reactivation
- 2nd common cause of mental retardation in babies
Vaccines for CMV?
No, but trials are underway
What does CMV cause?
- hearing loss
- poor mental development
Natural host of EBV?
humans
EBV transmitted by the exchange of ____
saliva
-infectious mononucleosis, “kissing disease”
Describe the two peaks of EBV
1-6 years
14-20 years
Describe the clinical features of EBV
Immunologically mediated:
- Virus replicates in epithelial cells and B-lymphocytes (attaches to C3d receptor = CD21)
- Virus shed in saliva from infected epithelial cells
- Spreads to B-lymphocytes in local lymphoid tissues (lymph nodes and spleen)
- T-lymphocytes respond to infected B-cells - CIVIL WAR IN BODY OH NO
EBV: Clinical features of naturally infected infant/young child
no clinical disease
EBV: Clinical features of young adults
- infectious mononucleosis/glandular fever 4-7 weeks after initial infection
- fever, sore throat, petechiae on hard palate, lymphadenopathy, and splenomegaly
- hepatitis
Symptoms of EBV
- cytokine release
- infected B-cells -> polyclonal activation, production of autoantibodies (ex. IgM to erythrocytes)
EBV has ___ recovery, but saliva infectious for months
spontaneous
Treatment for EBV?
No antivirals in immunocompetent patients
Malaria weakens T-cell control of EBV infection and causes ??
Burkitt’s lymphoma
Burkitt’s lymphoma is a problem in ?
parts of Africa and Papua New Guinea
When patients ingest nitrosamines (preserved fish) who have EBV, this results in?
Nasopharyngeal carcinoma (EBV DNA in tumor cells)
Nasopharyngeal carcinoma is a problem in ?
China and SE Asia
What is the most common bacterial cause of pharyngitis and tonsillitis?
Streptococcus pyogenes
Streptococcus pyrogens is the most common cause of bacterial pharyngitis and it is important to treat with ______
penicillin
Symptoms of Bacterial pharyngitis?
- Sore, red throat; difficulty swallowing
- Sudden fever; malaise; and loss of appetite
- Scarlet fever (characterized by a ‘sandpapery’ rash, starts on the neck and chest and spreads all over the body, red strawberry tongue, headache, chills, and muscle ache)
- Rheumatic fever (fever, joint pain, knees, ankles, elbows and wrists, joint swelling, possible cardiac problems, chest pain, shortness of breath)
Streptococcus pyogenes can cause what two things?
- Rheumatic heart disease
- Acute Glomerunephritis
- Anti-Strep Ab -> circulating immune complex -> deposition in glomeruli
- Activation of complement and coagulation systems, inflammation and blood in urine
What is parotitis?
Inflammation of parotid glands (largest of salivary glands)
___ is a type of parotitis
Mumps
How are the Mumps transmitted?
- Airborne droplets
- Close contacts
Recovery of the Mumps within how long?
1 week
Is there a vaccine for mumps?
Yes - MMR
Complications with Mumps?
- Meningitis
- Encephalitis
- Pancreatitis
- Hearing loss
What is Otitis media?
Infection of the middle ear
Otitis media is 50% _____
viral
The other bacterial forms of otitis media are caused by?
- S. pneumoniae
- H. influenzae
- S. pyogenes
- M. catarrhalis
- S. aureus
Otitis media usually happens to ?
preschool-age patients
Early signs of otitis media in children
They are non localized: fever and irritability
Later signs of otitis media in children
ear pain, changes in hearing, purulent discharge (late infection)
Pathogenesis of Otitis Media?
cleansing function by ciliated epithelium
Complications with Otitis media?
damage of the tympanic membrane can lead to hearing loss
What is Otitis Externa?
Infection of the outer ear
*Pathogens are distinct from otitis media
External ear canal has bacterial flora similar to skin: ???
- Staphylococcus aureus
- Candid albicans
- Pseudomonas aeruginosa
How is otitis externa treated?
antibiotic ear drops
Aetiology of acute sinusitis is similar to ___ ____
otitis media
Symptoms of acute sinusitis
- facial pain, local tenderness
- prolonged respiratory tract infection (purulent nasal discharge and pain in the face, fever, maxillary sinusitis - headache, pain in upper teeth)
Complications with acute sinusitis?
- orbital cellulitis
- osteomyelitis
- meningitis
- brain abscess
Epiglottitis: clinical manifestations & pathogenesis?
- edema & inflammation
- airway blockage
- life threatening
Epiglottitis is caused by ?
H. influenzae
