PA-1 Bacterial infections 1 Flashcards
Pathogenesis
Ability of a micro-organism to cause disease
The ability of a pathogen to cause disease
Pathogenicity
Virulence
intensity of disease/ degree of harm caused
Bacteremia
Bacteria present in the blood - small number not problematic
opportunistic
caused by organisms that don’t normally infect healthy hosts
primary infection
initial infection within a patient
localised infection
infection that remains at one body site or organ
systemic infection
infection that has spread to multiple organs/sited ,or spread to the blood stream
septicemia
life threating condition arising from pathogens in the blood
sepsis
host response to high levels of infection in the blood
septic shock
sepsis accompanied by low blood pressure
what are the common site by bacterial infection
Respiratory tract
Upper Respiratory tract
(nose and throat/ Ear/ Conjunctiva)
Lower Respiratory tract
(Trachea and lungs)
Urinary Tract
Lower/ upper and Ascending/ descending
Sexually Transmitted Infections
Gastrointestinal Tract
Central Nervous System
Skin, bone and soft tissue
Blood and heart
HAI
what are the common infected places in URT ( nose and mouth)
Common infections=Pharyngitis and tonsillitis
Urt - Upper respiratory tract infections – Nose and throat
70 percent are viral infections so most cant be treated successfully with antibiotics
Streptococcus sp.
Gram positive cocci- There are lots of different species
Divided into groups –Identified by different microbiology tests
what are the groups Streptococcus sp.
Group A Streptococcus (GAS)
- Example: Streptococcus pyogenes
- Infections: Throat, skin, invasive infections (IGAS), toxic shock syndrome, necrotizing fasciitis.
Group B Streptococcus (GBS)
- Example: Streptococcus agalactiae
- Location: Gut, urinary tract, vagina.
- Infections: Serious newborn infections (e.g., meningitis), UTIs, skin, bloodstream, pneumonia, soft-tissue, bone, and joint infections.
- Screening: Pregnant women are tested for GBS in the vagina.
Group C, F, and G Streptococci
less common - still a potential to cause infcetions found in animals
Upper respiratory tract infections (URT): Pharyngitis and tonsillitis
Main symptoms and complications
Inflamed tonsils, Difficulty swallowing,
Fever, headache
Opportunistic Pathogen/ Spread by Respiratory droplets
Complications:
Tonsillar abscesses (quinsy), otitis media, sinusitis, bacteraemia.
Viral * (70%) Most common
Bacterial: Group A Streptococcus (GAS)
Streptococcus pyogenes
Usually mild treatable –’Strep throat’
what are the less common symptoms of Bacterial: Group A Streptococcus (GAS)
Less common symptoms
Scarlet fever- Strep throat symptoms + a body rash which spreads. (bright red/ raised pin head rash)
Often occurs in spring - school children.
Can trigger Autoimmune effect- Rheumatic fever, glomerulonephritis (Kidney)
Invasive infection (iGAS) –
Occasionally GAS infection will breach barriers to infection and become a life threatening- Systemic infection
(necrotising fasciitis and Streptococcal toxic shock syndrome)
Acute otitis media
Viral* (50%) * Most common
Bacteria
Streptococcus pneumoniae
Haemophilus influenzae
Symptoms: (ACUTE)
Rapid onset, pain in ear, hearing loss,
Dizziness (balance),
fever, vomiting, diarrhoea
Ear infections are very common in young children
Chronic otitis media
Viral* (50%)
Streptococcus pneumoniae
Haemophilus influenzae
Chronic infection can cause:
Tissues surrounding the Eustachian tube swell up.
Blocks Eustachian tube.
The air in the middle ear is absorbed into the surrounding tissues.
A vacuum forms in the middle ear.
Fluid accumulates.
Leads to Glue ear/ recurrent infections
what do children get fitted to equal out the pressure in there ear due to Chronic Otitis Media
grommets
Conjunctivitis symptoms, treatment
Symptoms:
Redness in the white of the eye / inner eyelid
Increased amount of tears
Thick yellow discharge that crusts over
theeyelashes especially aftersleep
Green or white discharge from the eye
Burning, itchyeyes
Blurred vision
Increased sensitivity to light
treatment
topical chloramphenicol
