Control and response measures Dr. Christina Rundi Ministry of Health, Malaysia Foodborne Outbreak...

Control and response measures

Dr. Christina Rundi

Ministry of Health, Malaysia

Foodborne Outbreak Investigation, Hanoi, 1-5 June 2009

Why investigate outbreak?

• To control ongoing public health threats.

• To prevent future outbreaks.• To describe new diseases and learn more

about known diseases.• To evaluate existing prevention strategies,

e.g. vaccines.• Teach (and learn) epidemiology.• To address public concern about the

outbreak.Foodborne Outbreak Investigation,

Hanoi, 1-5 June 2009

Control current outbreak• Timely implementation of control

measures is important and central to outbreak investigation.

• But timing and nature of control measures are difficult.

• Control measures should be guided by the results of outbreak investigations.

• But, this may cause delay in the prevention of further cases.


Control current outbreak

• Lab results may not reveal the responsible organism.

• Reasons:Bacteria which is difficult to identify may

not be detected using current lab methods (same with virus and parasite)

Responsible pathogen reduced in food samples by freezing, temperature abuse or overgrowth of other organisms.

Implicated food no longer exist.Foodborne Outbreak Investigation,

Hanoi, 1-5 June 2009

Epidemiologic TriadEpidemiologic Triad

AgentAgent

HostHost EnvironmentEnvironment

An outbreak comes from a break in the balance between the host, the environment and the agent. Need to understand this breach of balance to propose effective control measures.


Balance between investigation and control measures

Source/ Transmission

Known Unknown

Etiology Known Investigate +Control +++

Investigate +++Control +

Unknown Investigate +++Control +++

Investigate +++Control +


Control of source of outbreak

• Not to eat contaminated food e.g. shellfish during red tide

• Remove implicated foods from the market (food recall, food seizure).

• Close food premises or prohibit the sale or use of foods.

• Modify a food production or preparation process.


Removing implicated foods from the market

• Food recall and/or food seizure

• The objective is to remove implicated foods as rapidly and completely as possible from the market.


Food recall• Food recall – by business responsible

for the manufacture, wholesale distribution or retailing of the suspect food.

• Initiated by the business or requested by authority.

• The longer the time between a food appearing on the market and it being identified as a potential source, the less likely the recovery of that food.


Food Seizure

• Food seizure – removal of food product from the market by an appropriate authority (if the business does not comply with the request to recall).

• Businesses will usually comply to protect themselves from private lawsuits and damaged reputation.


Food Premises Closure

• During site inspections; if there are situations that pose continuous risks to consumers advise closure.

• Voluntary closure vs enforcement • Closed premises should be

monitored by the responsible authorities and remain closed until allowed to reopen.


Prevent further contamination of implicated product

• “Trace back”

• Identify contamination event and/or practice and/or circumstances that allow contamination event.

• “Trace forward”

• Determine where the contaminated food was sent.


Long Term Prevention

• Determine frequency of contamination event.

• Resolve scientific questions related to the outbreaks

• Identify production/processing/handling changes needed to prevent future occurrences. (HACCP, GMP)


Long Term Prevention

• Identify methods of instituting required changes (education, regulation).

• Implement changes.

• Monitor and evaluate effects of changes on food safety.


Issues with control and preventive measures

• Economic and legal consequences – recall food product or closure of food premises

• Implementation of control measures - a balancing act.


PREVENTION OF CASES

CREDIBILITY OF INSTITUTION

Interactions with the Public and Press• Risk communication – very

important.


OUTBREAKOUTBREAK

INVESTIGATION TEAM (OCT)

PUBLIC CONCERN

MEDIA ATTENTION

Information sharing

References• Foodborne Disease Outbreaks: Guidelines for

Investigation and Control. WHO 2008.• Centers for Disease Control and Prevention

(CDC): http://www.cdc.gov• Reingold A.L. Outbreak Investigation – A

Perspective. Perspectives Vol. 4, No. 1, January–March 1998

• Sobel J. et al. Investigation of Multistate Foodborne Disease Outbreaks. Public Health Report. Jan – Feb 2002, Vol. 117


http://www.cdc.gov/

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