Transcript Dr. Caroline Lynch

Synthesis of current evidence on the multiple causes of
malaria drug resistance
Caroline Lynch & Jim Tulloch
June 2014
Overview
1.
Why do drugs stop working?
2.
What actions are potentially accelerating antimalarial
resistance?
3.
Update on artemisinin resistance.
4.
Policy options.
1. Why do drugs stop working?
Accidents during
reproduction
Susceptible parasite
Parasite with mutations
Mutations
Hinders parasite
No effect
Helps parasite
Susceptible and resistant parasites
•
If parasites have a mutation which
protects them from treatment they will
survive.
•
Susceptible parasites are eliminated the drug has ‘selected’ resistant
parasites.
•
Resistant parasites will produce
gametocytes which can be transmitted to
mosquito.
Treatment
Drug selection for resistant parasites
Imagine a malaria-endemic village
Antimalarial treatment
Susceptible parasite
Resistant parasite
Drug pressure
What could contribute to drug pressure?
A high proportion of the population with variable amounts of
antimalarials in their bloodstream – how?
o
High malaria transmission
o
Too much treatment (overtreatment)
o
Too little treatment (undertreatment/ partial treatment).
2. What actions are potentially
accelerating antimalarial resistance?
Why too much treatment?
Supply side
• Treatment without diagnosis
Demand side
• Patients seek treatment
without diagnosis
Why too little treatment?
Supply side
• Availability of monotherapy
(direct selection) and
substandard antimalarials
• Partial treatment provided to
patients
Demand side
• Patients take partial treatment
Demographic factors
Migration
Chloroquine resistance
Previously resistance emerged
in GMS and spread.
• High mobility in GMS
• Increased ties with Africa
• High potential for spread of
AR
Sulfadoxine-Pyrimethamine resistance
3. Update on artemisinin resistance
• Artemisinin resistance has been detected in all GMS countries.
• GPARC and regional containment strategies in place.
• In 2013;
o
Emergency Response to Artemisinin Resistance (ERAR).
o
Funds for artemisinin resistance containment.
o
Molecular marker (Kelch 13) identified.
4. Policy options
Develop strong regional mechanisms for rapid
response
• Ban monotherapy and eliminate substandard antimalarials
o Part of broader recommendation to improve regulatory
capacity
• Facilitate cross-border surveillance & multisectoral
collaboration.
• Establish agile and aggressive field team to support ERAR.
• Ensure immediate implementation of primaquine policy.
• Create flexible fund for specific, answerable questions
around interim antimalarial dosing and treatment
o Part of broader recommendation on funding for Operational
Research
Ensure accountability & transparency
• Track and respond to artemisinin resistance
Track : Immediately begin monitoring 1-2 artemisinin resistance
indicators updated monthly by secretariat.
Respond: Where countries are not on track – taskforce identify
bottlenecks and provide immediate support to countries to find
solutions.
High level collective advocacy
• Advocate to the DG/WHO for AR to be reviewed - Public Health
Emergency of International Health.

All avenues of advocacy
• Continue advocacy at regional level to ensure political support for
technical frameworks for artemisinin resistance elimination
o Part of broader recommendation for ongoing advocacy in support
of malaria elimination
“A regional public health disaster
which could have severe global
consequences”
(WHO, 2014)
There is a window of opportunity if
we act now