Achievements, issues and options on strategies for HPAI

control and prevention

Outbreak control responses – overview of country and regional field and programme

operations

Les Sims

Progress so far

• Excellent progress, cause for cautious optimism and praise

• But only first battles in a very long war• Even in countries that have made good

progress in damping down infection (Viet Nam and China) H5N1 HPAI viruses are persisting (as expected)

Why no uniform approach to this disease?

• Not dealing with a single disease situation • There are at least four different scenarios for countries or

parts of countries

Recently infected and rapidly detected, and normally low risk of virus incursion to farms (e.g. EU 2006)

Recently detected, but failure to detect early incursion - disease already widespread before action taken (most countries in SE Asia in 2003-04)

Entrenched infection (multiple widespread cases of disease reported in poultry and/or humans in the previous two years - e.g. Egypt, Nigeria, Mekong region, China, Indonesia, Pakistan?)

High risk of virus incursion (e.g. Hong Kong SAR, large parts of Russia, some countries with entrenched infection)

Why no uniform approach to this disease?

• The approach to control and prevention under each of these scenarios differs

• Standard guidelines promoting early case detection, emergency response and rapid stamping out are most appropriate for the first category (recent infection, early detection)

• This approach failed to eliminate infection in countries with entrenched infection – it will only provide temporary gains unless changes are made to those parts of the industry that allow infection to persist (and won’t detect all cases).

• Focus of presentation will be on countries/regions with ‘entrenched’ infection or in which infection is likely to become entrenched

• Including China, Lower Mekong area, Indonesia, West Africa, Egypt, and possibly Pakistan/Afghanistan and Bangladesh

What to do in places with entrenched infection?

• Get recognition that infection will not be eliminated in the short to medium term

• Strengthen veterinary services, associated legal frameworks and enforcement, and government links to industry (but some issues hard to overcome)

• Contain infection to reduce the risk to poultry and humans (risk reduction) but then consolidate these gains

• The response will not be uniform and depends on many factors (e.g. structure of poultry industry, strength of veterinary services)

What to do in places with entrenched infection?

• Identify high risk production and marketing practices (e.g. sale of commercial broilers through uncontrolled live bird markets)

• Implement feasible modifications (socially, economically, environmentally and technically) to these that minimise these risks and the harm done by the changes (winners and losers)

• Avoid creating new risks – e.g. market closures leading to underground trade (use combination of regulation and market forces to drive change)

Duck farmsGoose farms Chicken farms Other birds

Incl. wild

Duck farms

Chicken ‘Inns’

Chicken farms

Wholesale market

Retail markets

Wholesale market

Quail farms

Mainland China

Hong Kong SAR

1997

Minimal border controls

Risk

Duck farmsGoose farms Chicken farms Other birds

(no wild birds)

Chicken farms

Wholesale market/slaughterhouse

Retail markets

Wholesale market

Quail farms

Mainland China

Hong Kong SAR

2002

Chilled only

Stricter border controls

Risk

Duck farmsGoose farms Chicken farms

Other birds

Chicken farms(less farms)

Retail markets

Wholesale market

Mainland China

Hong Kong SAR

2006

Chilled only

Stricter border controls

Other birds(no wild birds)

Risk

Sl/house

Duck farms incl grazing

Goose farms Chicken farms Other birdsIncl. wild

Duck farms

Chicken holding farms’

Chicken farms

Wholesale market

Retail markets

Wholesale market

Quail farms

2007 elsewhere in Asia

Minimal border controls

Risk

Slaughterhouse

DOC Dealers

What to do in places with entrenched infection?

• If practices can’t be changed then use other measures to contain infection (e.g. vaccination)

• Set key objectives (e.g. no industrial broiler chickens

sold through live poultry markets 5 years from now)

• Develop a ‘road map’ of how to move forward towards achieving objectives

• Get empowered to make these changes

Control Consolidate Eliminate

Emergency activities

Focus on supplying emergency resources

and enhanced preparedness

Continue to dampen down infection

Focus on longer term structural changes(poultry sector and veterinary sector)

Maintain emergencypreparedness

Largely outsidecurrent planning horizons

Some farms and production sectors

will eliminate infectionand demonstrate

freedom but remain at risk

The tipping point – when to move from traditional emergency

approach to longer term approach?

• Requires a thorough assessment of the local situation – examine risk pathways

• Often do not have all the information needed due to limited surveillance capacity …….

….. but now have sufficient experience with this disease to make a crude assessment of the likelihood of early elimination following virus incursion into poultry

Predicting outcomes after incursions

Poor outcomes likely if most of the following apply:

• Millions of poultry flocks• Trade through many middlemen via poorly

regulated large live poultry markets• Large number of domestic ducks• Large populations of game birds• Limited veterinary capacity• Poor governance and little high level support

When to use vaccination?

• Demonstrated high risk of recurrence

• Specific risk high factors identified but can’t alter management (e.g. smallholder scavenging flocks, grazing ducks)

• Affordable and capacity to implement

• Define objectives of the program

• Use of vaccine as a means to reduce levels of infection is acceptable

• Provides time to gradually address the key structural issues and therefore to reduce main risk factors

Stamping out (and why no uniform culling zone)

• Decision on the extent of stamping out extent must be based on the local epidemiological situation

• The objective should be to conduct the least amount of culling compatible with disease control, and the current infection status

• Many examples of success using culling of infected premises only, especially if farms relatively isolated and efficient tracing and movement controls or combined with vaccination

• Ensure culling is an appropriate response (Culling should be subject to the same analysis as other control measures – costs and benefits, especially likelihood of sustained gains from culling)

Farm biosecurity

Movement controls and cleaning and disinfection

Communication

Major achievements• Eradication from many countries• Containment in some others• Excellent support for laboratories • Recognition that this disease will not be

eliminated from many countries in the medium to long term

• Allows a shift to measured, longer term approaches to this disease in places with entrenched infection

• From emergency management and a focus on case detection …..…… to risk detection and reduction.

• Requires political support and commitment from the highest levels of government

• Requires donors to support longer term interventions if gains in these countries are to be sustainable

• Will also lead to reduced risk of other emerging diseases

Guidance for discussion groups this afternoon

• Not about the tools and methods – we know that these work to reduce and sometimes eliminate infection if used appropriately

• Focus on the factors that limit their effective use, including political and financial factors, and ways to overcome these

• Focus on ways to reduce risks• Donors – consider absorptive capacity and

appropriateness of investments and ways to provide long term support

Thank you