Microbiology 2 and 3 - Microbiology of the Resp. tract Flashcards
What are the causes of the classical flu?
Influenza A virusInfluenza B virus
What is the cause of a flu like illness?
Parainfluenza viruses but many other causes
Does haemophilus influenzae cause flu?
Not a primary cause (it is a bacterium) but may be a secondary invader
Complications of flu?
Primary influenzal pneumoniaSecondary bacterial pneumoniaBronchitisOtitis mediaInfluenza during pregnancy may also be associated with perinatal mortality, prematurity, smaller neonatal size and lower birth weight
How is flu treated?
Symptomatic (bed rest, fluids, paracetamol)Antivirals (only if patient is at risk of complications and when flu is circulating and early in disease)
What antivirals are used to treat flu?
OseltamivirZanamivir
What are epidemics of flu associated with?
WinterMinor mutations in the surface proteins of the virus (antigenic drift)
What is the difference between epidemic and pandemic?
An epidemic occurs when a disease affects a greater number people than is usual for the locality or one that spreads to areas not usually associated with the disease. A pandemic is an epidemic of world-wide proportions.
What type of flu can cause pandemics?
Influenza A only
What subtype of influenza A is avian flu?
H5N1
How is influenza confirmed in the lab?
Direct detection of virus:PCR (nasopharyngeal swab, throat swab or other respiratory samples)Other labs/ hospitals may used immunofluorescence, antigen detection (near patient)
Prevention of flu?
Killed vaccine (given to adult/ child (aged 6 months to 2 years) patients at high risk and healthy care workers)Live attenuated vaccine (more effective than killed vaccine in children aged 2-17, given to ALL children aged 2-5 and all primary school children administer intra-nasally)
When are antivirals used as a prophylaxis against flu?
After a contact with fluVery rarely
What are 3 examples of atypical pneumonia?How are these treated?
Mycoplasma pneumoniaeCoxiella and Chlamydohila psittaciTetracycline and macrocodes e.g. clarithromycin
Mortality of atypical pneumonias?
Varies with pathogen by generally lower than classical bacterial pneumonia
How are the atypical pneumonias (mycoplasma, coxiella, psittaci) diagnosed?
By serology (send acute and convalescent bloods to lab)Virus detection (PCR on respiratory swabs/ secretions)
Who tends to get mycoplasma pneumoniae?
Children and young adultsPerson to person spread
What diseases does coxiella burnetti cause?
PneumoniaQ-fever
what is infection with coxiella burnetti associated with?
Sheep and goats
Complications of infection wit coxiella burnetti?
Culture negative endocarditis
What illness does infection with chlamoydophila psittaci cause?How does this usually present?
Psittacosis (parrot fever)Pneumonia
What age do patients present with bronchiolitis?Symptoms
1st or 2nd year of lifeFeverCoryzaCoughWheezeSevere cases can cause grunting, decreased PaO2, intercostal/ sternal indrawing
Complications of bronchiolitis?
Respiratory and cardiac failure(especially if premature or pre-existing conditions)
What is usually the cause of Bronchiolitis?How is this confirmed?
Respiratory Syncytial VirusBy PCR on throat or perusal swab
Therapy for bronchiolitis?
Supportive
What is metapneumovirus?
A respiratory viral pathogen that causes acute respiratory tract infection in childrenMost children have antibody by age 5
What diseases does metapneumovirus cause?
Second only to RSV in bronchiolitis2% of cases pf influenza-like illness Ranges in severity from mild to requiring ventilation
How is metapneumovirus confirmed in the lab?
PCR
what is a cause of infantile pneumonia related to an STI?How is it diagnosed?
Chlamydia trachomatisPCR on urine of mother or perusal/ throat swabs of child
What does chlamoydophila pneumonias cause?
Mostly mild respiratory infecitonPerson to person spread