Reducing disease risks and improving food safety in smallholder pig value chains in Vietnam: Risk assessment component

Reducing disease risks and improving food safety in smallholder pig value chains in Vietnam

Risk assessment component: planned activitiesNguyen Viet Hung (Hanoi School of Public Health) - PresenterHoang Van Minh (Hanoi Medical University) Hoang Thi Thu Ha (National Institute for Disease and Epidemiology)Kohei Makita (Rakuno Gakuen University) Fred Unger (International Livestock Research Institute) Lucy Lapar (International Livestock Research Institute) Delia Grace (International Livestock Research Institute)

Objectives

• 1. To assess impacts of pork-borne diseases on human health and the livestock sector and identify critical points/opportunities for risk management

• 2. To develop and test incentive-based innovations to improve management of human and animal health risks in smallholder pig value chains.

• 3. To sustainably improve capacity to assess and manage risks in smallholder pig value chains by engaging stakeholders and co-generating evidence.

• 1. To assess impacts of pork-borne diseases on human health and the livestock sector and identify critical points/opportunities for risk management

Project framework

Risk profiling

Risk assessment

Microbial Risk Assessment

Chemical Risk Assessment

Economics (eg health, CBA)

Value chain

Rapid assessment

Economic assessment

Animal Health Risk Assessment

…

….

Interventions

Action research 1

Action research 2

Action research 3

…………………

Engaging stakeholders and co-generating evidence, Advocacy, Communication, OM

1

2 3

4

Incentive-based interventionsRandomized Control Trials (RCT)

Risk assessment

Risk analysis• Risk analysis describes how risks are dealt within the society, including 3 components

• Risk communication: Communication of risks to managers, stakeholders, public officials, and the public.

• Risk management: how to reduce risk

• Risk assessment (RA): is there a problem? How adverse the problem is?

Source: Codex (1999)

Risk Assessment

Risk Management

Risk Communication

Hazard vs. Risk

3.Exposure Assessment Size & nature of the population, route, amount and

duration of the exposure

1.Hazard IdentificationDescribe environment, pathogens, Health effects

2.Dose-response Analysis Relationships between exposure (dose) & frequency of infection/illness (response)

4.Risk Characterization Integrate the information from 3 and 4 to express public health outcomes, taking into account the

variability and uncertainty of the estimations.

Q M R A

Risk management

Quantitative Microbial Risk Assessment (QMRA) within Risk Analysis framework

Co

mm

un

icat

ion

wit

h s

take

ho

lder

s

Dat

a ac

qu

isit

ion

, ve

rifi

cati

on

, m

on

ito

rin

g

Quantitative Risk assessmentFood safety risk analysis: Codex vs. informal

marketing system

Participatory methods

Risk Assessment

Risk Management

Risk Communication

Concept of participatory risk analysisBonfoh B. (2010) Revue Africaine de Santé et de Productions Animales.

Adapting quantitative risk assessment to the context of food safety in informal markets: incorporation of information collected using participatory methods; engagement of stakeholders; use of “appropriately imprecise” data (that is, collected at least cost for the purpose).

3.Exposure Assessment Size & nature of the population, route, amount and

duration of the exposure

1.Hazard IdentificationDescribe environment, pathogens, Health effects

2.Dose-response Analysis Relationships between exposure (dose) & frequency of infection/illness (response)

4.Risk Characterization Integrate the information from 3 and 4 to express public health outcomes, taking into account the

variability and uncertainty of the estimations.

Q M R A

Risk management

Where is participatory used in the conventional RA

Co

mm

un

icat

ion

wit

h s

take

ho

lder

s

Dat

a ac

qu

isit

ion

, ve

rifi

cati

on

, m

on

ito

rin

g

Participatory methodsfit well

Activities

•Risk profiling and priority hazard identification

•Risk assessment

•Economic assessment of disease burden on humans and CBA

1. Risk Profiling and priority hazard identification

• Broad and qualitative summary of relevant information on a specific food safety issue or animal disease.

• Hazard, impact on human and/or animal health, population affected, incidence and prevalence, epidemiology of transmission, stakeholder concerns, relative importance of the hazard, and options for management, etc.

• Recommendations whether or not to further address the problem and the recommendation to whether or not to commission risk assessments. This needs to be done in collaboration with national stakeholders to reflect priorities.

• Rough analysis (sample collection and analysis)

• Design: desk study based on systematic literature review + sampling

Food-borne disease Diseases of pigParasiticCysticercus cellulosaeTrichinella spiralisToxoplasma gondiiFasciola spp

BacterialBacillus cereusBrucella suisCampylobacter spp.Salmonella enetericaStaphylococcus aruesShiga toxin producing E. coliYersinia enterocolitica

ChemicalAntibiotic residuesAflatoxinsSteroids/growth promoters

EctoparasitesEndoparasites (gut, lung, liver)Respiratory (bacterial, viral)Gastrointestinal (bacterial viral)ReproductiveSkeletalFoot-and-mouth disease Classical swine feverPorcine reproductive and respiratory syndrome

Non-food borne zoonosesJapanese encephalitisErysipeloidStreptococcus suisLeptospira spp

Farm to fork (Microbiological Risk Assessment Series No2-2002, No7-2008)

Nf Np Nr

Pathogen concentration (N)

Pf Pp Pr

Infection risk (P)

FarmMarketSlaughter

houseCon-

sumption

Exposure assessment

Exposure assessment

Exposure assessment

Exposure assessment

Risk

Risk

Piglets source -sow-feed-contamination

FARM & TRANSPORT

Weaners source -new pig in batch-feed-contamination

Finishers source-new pigs in batch-feed-contamination

Transport & lairage-mixing of pigs-contamination of transport

Slaughter-Scalding-Dehairing-Singeing-Polishing-Evisceration-Trimming-Chilling

Randomly sampling

PROCESSING:(different pig meat products)

PREPARATION & CONSUMPTION(Different end-products)

-transmission-cross-contamination

-transmission-cross-contamination

-transmission-cross-contamination

-transmission-cross-contamination-inactivation

-transmission-cross-contamination-inactivation-growth

An overview of the modules within the farm-to-consumption for risk assessment

Understanding a value chain

Quantifying a value chain

Quantifying contamination and growth

Quantifying risk mitigation in a value chain

Building into risk characterization model

Understanding a logic of exposureFault tree

Participatory &interviews

A survey,literature

Participatory &interviews

Participatory &interviews

Modeling process in exposure assessment

Dose-response modelLiterature

Day 2-1

Chemical risk assessment

• Heavy metals (lead, mercury, arsenic, cadmium …)• Polychlorinated dibenzo-p-dioxins (PCDDs), • Polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated

biphenyls (DL-PCBs), hexachlorobenzene (HCB), polychlorinated naphthalenes (PCNs),

• Polycyclic aromatic hydrocarbons (PAHs), polychlorinated diphenyl ethers (PCDEs), polybrominated diphenyl ethers (PBDEs), 16 polycyclic aromatic hydrocarbons (PAHs) (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-c,h]pyrene), antibiotics, etc.

• February 2012, officials in Vietnam found beta-Agonists, a banned lean meat enhancing drug in some pig-rearing households in Dong Nai.

• Environmental health risk assessment framework.

Sampling (1)

• At farm: environmental impact• Slaughter house• Market• Consumption • Predictive microbiology (microbial growth)• Combined assessment on consumption, market,

SH etc.. with interview of the value chain actors…• Modeling

Sampling (2)

• Pork foodstuffs, way of preparation, and eating habits identified by the survey.

• Raw and cooled, in the case of (iv), prepared pork meat samples will be collected at four points for testing: i) Small scale slaughterhouse, ii) Market (wet market and supermarket), iii) Consumer handling (undercooking and cross-contamination) and iv) Consumption (exposure to pathogens).

• Environmental samples (farm, water, soil)

• Variability, seasonal bias amples will be collected in two different seasons on a distribution of 8 months.

Challenges

• Difficulties to follow farm to folk: do we need to trace pork from farm to fork?

• Chemical risk assessment: what will be the key hazard (technique for hazard ranking?)

• Risk factor vs. Phylogeny study to identify etiology of diseases

• Uncertainty