Containment of artemisinin resistance at the Cambodia-Thailand border

Sylvia Meek, Technical Director, Malaria Consortium, CMWG Meeting 8 July 2009

Drug Resistance in Southeast Asia

• Asia fought resistance to one drug after another from 1970s to 90s

• Often first found in the same area on Thailand / Cambodia border

• Moved from cheap and simple to costly and complex treatments

• After years of research and debate most countries now use Artemisinin-based Combination Therapies (ACTs)– Debates on choice of drug overrode efforts to improve

delivery and access– Now these are being addressed– Results look good

• Progress towards elimination could be threatened if resistance to artemisinin derivatives appears

The Greater Mekong Subregion

Artemisinin derivative resistance has been detected in Thailand and

Cambodia• Research over last two years has confirmed

increased time for parasites to be cleared• Biggest problem is knowing how far it has spread• In the meantime we cannot wait so a special

containment programme is underway in the areas where there is evidence

Distribution of confirmed malaria cases in the Greater Mekong Subregion, 2007*

Viet Nam, 14,581

Myanmar, 200,679

Thailand, 33,178

China-Yunnan, 6,085

Cambodia, 42,518

Lao PDR, 19,037

Source: National Malaria Control Programmes & WHO*2006 data for Myanmar

The containment strategy

Remove selection pressure

Reduce and ultimately eliminate falciparum malaria

Three Phases of the Response

Phase 3 - the medium-term strategy

Re-defining the goal – Continue containment of artemisinin resistance– Commence elimination of malaria parasites countrywide

during this time period pre-elimination status for Plasmodium vivax is unlikely to be completed but strategy will begin the process

Expanding activities from current containment zones to other malaria areas of the country

Testing, implementing and scaling up innovative “packages” of activities– Several of these will be piloted and refined during Phase

2 supported by WHO, BMGF, USAID and others, so evidence for key decisions is expected in 2010

ObjectivesObjective 1: To detect all malaria cases

(including among mobile/migrant populations) and ensure effective treatment and Pf gametocyte clearance (through single dose primaquine).

Objective 2: To decrease drug pressure for selection of artemisinin resistant malaria parasites by improving access to appropriate treatment and preventing use of monotherapy and substandard drugs in both public and private sectors

Objectives (2)Objective 3: To prevent transmission of artemisinin

resistant malaria parasites among target populations (including mobile/migrant populations) by mosquito control and personal protection

Objective 4: To support containment of artemisinin resistant parasites through comprehensive behavior change communication (BCC), community mobilization, and advocacy

Objective 5: To provide effective management (including information systems and surveillance) and coordination to enable rapid and high quality implementation of the strategy

Key areas of focus• Mobile and migrant populations

– How to reach, what about new economic migrants?

• Surveillance and information systems• Suppression of using monotherapies

– Private sector issues– Understanding patient behaviour

• Joint action by Thailand and Cambodia• Planning for sustainability

Female migrant workers in Komrieng District, Battambang Province. The plastic sheet at the back is used as shelter for

sleeping at night and for keeping their belongings and in case of rain. (source: Kim Sedara, MC/CDC)

Challenges• Need extraordinary efforts to control malaria even where it is

less common– Link between resource allocation and disease burden is

less clear• There are beneficial side-effects

– improving surveillance – improving private sector strategies– Learning to work with mobile populations– Learning for elimination

• Are we missing the main target?– How to determine routes of spread– How to support malaria control in Myanmar/Burma

Challenges (2)• We cannot be complacent and rely on current tools

lasting for ever– Investment in R&D is essential– How much to invest in protecting drugs versus

deploying them and moving on to next ones• We shall continue to lose good tools if we do not take

systems strengthening and regulation seriously– Re-emphasise quality, delivery, diagnosis

• Deciding when to act then raising support is a challenge– If we saw the same amount of evidence in Nigeria

or Ethiopia, what scale of response could we mount?

Priority Partnership Activities

• Gain consensus on strategy components• Plan for contingencies – response scenarios for

different regions• Communicate issues realistically• Review relevant experiences

• Multidisciplinary task force proposed