Preventing Infectious Diseases Flashcards
1
Q
Risk Factors for Infectious Disease - Developing Countries
A
- Underweight
- Unsafe sex
- Unsafe water, sanitation and hygeine
- Indoor smoke from solid fuels
- Zinc deficiency
- Vitamin A deficiency
- Tobacco
2
Q
Risk Factors for Infectious Disease - Developed Countries
A
- Tobacco
- Illicit drugs
- Unsafe sex
3
Q
Foodborne Illness
A
- Caused by the consumption of food contaminated with organisms or their toxins. • •The ‘big five’ bacteria:
- Salmonella
- Campylobacter
- E coli 0157
- Listeria monocytogenes
- Clostridium perfringens
- Important because they cause a lot of cases of intestinal illness or because they cause severe disease, or both
- Factors that may influence spread of infection from food chain to humans include:
- Intensive farming
- Global distribution
- Mass production
- New microbes
- Antibiotic residues
4
Q
Hospital Acquired Infections
A
- Neither present or incubating when patient enters hospital but develop during hospital or are present/incuvating when discharged
- Affects 8% of hospital admissions
- Caused by:
- Breaches in normal body defences:
- Surgery
- Invasive devices
- Underlying illness increasing vulnerability
- Impaired immune response
- Diabetic ulcers
- Exposure to micro-organisms
- Endogenous human flora
- Environmental contamination/colonisation
- Breaches in normal body defences:
5
Q
Hospital Acquired Infections - Mechanisms of Spread
A
- Hands and contaminated equipment
- MRSA and Group A Streptococcus
- Faecal/oral spread and contaminated environment
- Viral gastroenteritis and C.difficile
- Airborne/droplet
- Viral gastroenteritis and Group A Streptococcus
6
Q
Hospital Acquired Infections - Sites
A
- Urinary tract (23%)
- Minor severity
- Risk factors:
- Urinary catheter use
- Prevention:
- Correct management of catheters
- Lower respiratory tract (23%)
- Severe
- Risk factors:
- Ventilation
- Post-surgery
- NG feeding
- Prevention:
- Physiotherapy
- Tracheostomy care
- NG care
- Bloodstream
- Severe
- Risk factors:
- Intravascular devices - ITU/renal/haematology
- Prevention:
- Correct management of lines
7
Q
Hospital Acquired Infection - Prevention
A
- Clean environment
- Clean reusable equipment between use
- Hand washing (staff and patient)
- Source and protective isolation
- Meticulous aseptic technique during invasive procedures
- Meticulous care of invasive devices and prompt removal
- Ward closure during outbreak
- Antimicrobial stewardship
- Surveillance
8
Q
Hospital Acquired Infection - Surveillance
A
- Mandatory:
- MRSA
- C. difficile
- Glycopeptide resistant enterococci (GRE)
- E.coli
- Surgical Site infections
- Voluntary:
- Methicillin-sensitive Staphlococcus aureus (MSSA)
- Pseudomonas/Acinetobacter/Stenotrophomonas
9
Q
Antibiotic Prophlaxis - Surgical
A
- Peri-operative antibiotics may be given to prevent Surgical Site Infection (SSI)
- Responsible for up to 20% of HAI
- Risk depend on type of surgery and patient:
- Clean vs. dirty surgery
- Proceedure complexity
- Foreign material
- Injury to wound tissues
- Severity of illness
- Host immunocompromise
- Diagnosis based on clinical signs not lab results
10
Q
Antibiotic Prophlaxis - Surgical - Grading
A
- Clean:
- Non-traumatic
- No inflammation
- No break in technique
- No breach of respiratory, alimentary or genito-urinary tracts
- No prophylaxis needed (unless metalwork or spinal surgery)
- Clean-contaminated:
- Non-traumatic
- Break in technique or breach of respiratory, alimentary or genito-urinary tracts
- No significant spillage
- One dose of antibiotics
- Contaminated:
- Major break in technique
- Gross spillage from a viscus that may contain non-purulent material
- Dirty traumatic wounds
- Faecal contamination
- De-vitalised viscus
- Pus encountered from any source during surgery
- Antibiotics for 5-7 days
11
Q
Antibiotic Prophlyaxis - Susceptible Populations
A
- Infective endocarditis - NICE guidance does not recommend antibiotic prophylaxis solely to prevent IE in at-risk patients undergoing dental and non-dental proceedures
- Prevention of invasive pneumococcal disease post-splenectomy
- Decrease the incidence of urinary tract infections
- Prevention of opportunistic infections post solid organ and bone marrow transplants
12
Q
Antibiotic Prophylaxis - Eradicating Carriage
A
- Aim is to prevent secondary cases in contacts of people with serious invasive diseases:
- Meningococcal disease
- H.influenzae type B
- Tuberculosis
- Group A Streptococcus
- Contacts identified through contact tracing by CCDC/HPU
13
Q
Antibiotic Prophylaxis - Pre/Peri/Post Exposure
A
- Aim is prevent acquisition and development of an infection in relation to a defined exposure or period of exposure:
- Influenza
- HIV
- Malaria
- Hepatitis B
- Perinatal vertical infections:
- HIV
- Beta-haemolytic Streptococcus B
14
Q
Treatment As Prevention
A
- Important in developing countries
- Aim to decrease burden of disease and protect whole population:
- Decreased spread
- Decreased environmental contamination
- Examples:
- TB (respiratory droplet spread, 10% contacts of cases of open TB develop active disease)
- Trachoma (worldwide major preventable cause of blindness caused by Chlamydia trachomatis)
- Gut helminths eg. Ascaris (faeces/soil)
15
Q
Vaccination
A
- Vaccines induce active immunity and provide immunological memory
- Enables the immune system to recognise and respond rapidly to exposure to natural infection at a later date ==> prevention or modification of disease course
- Vaccines can be made from:
- Attenuated live organisms
- Inactivated (killed organisms)
- Important antigens:
- Inactivated toxoids
- Surface proteins
- Capsular polysaccharide
19
Q
Vaccinations For At Risk Groups
A
