Foodborne Dz Flashcards
Is all food borne illness zoonotic?
- no
- but food does represent an important vehicle for zoonotic pathogens
> salmonella
> campylobacter
> e. Coli
> listeria
What is the extent of total disease burden of zoonotic food borne disease
Unknown - not seeing doctor, unreported, esp developing countries
- > aetiology often unknown too
- > difficult to implement risk based management
What are the 2 groups of food borne illness according to CDC?
> known food borne pathogen s
unspecified agents
- agents with insufficient data to estimate agent specific burn den
- known Agents not yet identified as causing food borne illness
- microbes, chemicals or other substances known to be in food whose ability to cause illness is unknown
- agents not ID
How do foodborne outbreaks differ in EU to US?
Majority Unknown as for US (80%)
- measured as food borne outbreaks rather than individual cases as for US
- salmonella, viruses eg novovirus, bacterial toxins, campylobacter main known agents
Most common causative agents for foodborne illness in the EU
salmonella, viruses eg novovirus, bacterial toxins, campylobacter main known agents
> but majority of cases still unknown cause
How have the trends for the most common cases of foodborne illness changed over the last 6 years
> salmonella decreasing
- assoc with decrease prevalence of salmonella + flocks
- most commonly via egg products consumed in the home kitchen
viruses eratic
bacterial toxins increasing
campylobacter eratic
How many outbreak cases of foodborne illness occoured in the 2013
84
- high morb, low mort
- not massive numbers
- but always present
Revise notes year 3 on pre-harvest food risks
Define case, outbreak and epidemic
- outbreak : cases clustered in time and space at a higher level than expected
- epidemic : occourence of more cases than expected in the a given area or specific group of people over a particular period of time
> outbreaks may not be recorded as such! Need good monitoring surveillance
Steps in investigating foodborne outbreaks according to CDC
- detect possible outbreak
- find cases
- generate hypothesis through interviews
- test hypothesis through analytic studies and lab tests
- solve point of contamination and original source of outbreak vehicle
- control through recalls, facility improvements and industry collaboration
- decid when outbreak ends
WHO steps during a n outbreak
- prelim assessment of the situation
- communication
- descriptive epidemiology
- food and environmental investigations
- analysis and interpretation
- control measures
- further studies
WHO objectives in controlling an outbreak j
- Reduce number primary cases by prompt recognition identification and control of the source of infection or contamination (tracing back)
- Reduce number secondary cases by id cases and taking appropriate action to prevent subsequent spread (tracing forward)
- Prevent further episodes by id continuing hazards and eliminating or minimising risks they pose
What are epidemic curves? How should they be constructed?
> show time course of outbreak
- time of onset of each case (or date of report, death etc.)
- set time interval max 1/3 or less of incubation period
- include time period before and after (2 incubation period)
- if dz Unknown draw several epidemic curves with different units and select one that best represents data
How do epidemic curves look with foodborne disease outbreaks ? Person to person spread? Continuous exposure? Intermittent common source exposure?
- sharp incline and sharp decline with no tail = point source
- tail or multiple continuous curves suggestive person to person transmission
- sharp incline and decline fluctuating = intermittent common source
- sharp incline and continued high levels = continuous common source
How are foodborne disease outbreaks in the UK inbestigated?
= incidence control team, a multi-disciplinary team
> local authorities (LA)
- informs FSA on outbreaks
- statutory responsibility to control outbreaks and powers of control
> food standards agency (FSA)
- protectionof public health in relation to food
- will assist in investigationof implicated foods
> public health England
- coordinates surveillance
> local health protection units
- support LAs in investigation and management of outbreaks
> animal and plant health agency
- assist in outbreak investigation where animal source is implicated
> primary care trusts
- influence primary care resources
> department of health
- NHS
