Microbiology Flashcards
Give 3 symptoms of influenza
- General malaise
- Myalgia Headache
- Dry cough
- Prostration - extreme fatigue and weakness
- Fever
What are potential causes of classical flu?
- Influenza type A or B viruses
- Influenza type C virus can also cause a form of influenza yet it is less common
How is flu spread?
- Droplets/formites
- Direct contact with respiratory secretions from an infected individual
How can influenza be treated?
Treatment can be:
- Symptomatic - bed rest, maintain fluids etc.
- Curative - antivirals such as oseltamivir and zanamivir
What allows influenza to cause frequent epidemics?
Antigenic drift - minor surface protein changes (usually)
Pandemics are potentially very dangerous when involving influenza - why?
Influenza A viruses only are involved. Antigenic shift occurs in a animal reservoir or mixing vessel This means a “hybrid” virus can be formed that humans will have little if no immunity to
Which laboratory techniques can be used to determine the presence of the flu virus?
- PCR - using nasopharyngeal swabs, throat swabs or other respiratory samples
- Immunofluorescence for antigen detection
- Viral cultures
- Antibody detection
Influenza is prevented though vaccines, what is a “killed vaccine”?
The virus is grown in culture, inactivated and combined with an adjuvant - a substance to enhance immune reaction. This can be given annually to patients at risk of contraction, healthcare workers, the very young/old
Influenza is prevented though vaccines, what is an attenuated vaccine”?
This is a more effective vaccine vs a killed vaccine The real pathogen is used, but with reduced virulence. This vaccine is given to all children aged between 2 and 5
What is the most common cause of community acquired pneumonia?
Streptococcus pneumoniae
What are the three causes of atypical pneumonia?
- Mycoplasma pneumonia
- Legionella pneumonia
- Chlamydophilia pneumoniae
Coxiella burnetii is associated with which two main conditions?
- Q fever
- Pneumonia
A complication, involving Q fever and the heart is likely to be what?
Infective endocarditis
(caused by Coxiella burnetii)
Chlamydophila psittaci causes which condition?
Psittacosis
This is an uncommon sporadic zoonosis (pet birds) and will normally present as pneumonia
What is a sporadic zoonosis?
An infectious disease from animals that can spready to humans
What is bronchiolitis?
A common lower respiratory tract infection causing inflammation of the bronchioles
It normally affects people in the first or second year of life
Grunting will occur - difficulty in breathing, reduced partial pressure of oxygen and sternal indrawing
What is most likely to cause bronchiolitis?
Respiratory synctial virus (RSV)
What is metapneumovirus?
The second most common cause (after RSV) of lower respiratory infection in young children
The virus has highest incidence in winter
How is metapneumovirus diagnosed?
Throat swabs and PCR
What is chlamydia trachomatis?
An STI caused by bacteria
The bacteria can present in one of three ways:
- Genitourinary
- Pulmonary
- Ocular
It can cause pneumonia in infants
Diagnosed by PCR on urine of mother, or pernasal/throat swabs of child
Coxiella burnetii is a becteria mostly spread from what to humans?
Animals such as sheep or goats
When was metapneumovirus discovered?
2001
Name an alpha-haemolytic streptocooci that can cause respiratory tract infection
Strep pnemoniae
Name a beta haemolytic streptococci that can cause respiratory tract infection
Strep pyogenes
Name two key gram negative bacteria that can cause respiratory tract infection
- Haemophilus influenzae
- Moraxella catharalis
What pathogen will cause acute epiglottitis?
Haemophilus influenza type B
What is used to test for the presence of haemophilus influenzae in epiglottitis?
Blood cultures
(not throat swabs)
What is the treatment for epiglottitis?
Ceftriaxone