National malaria control programmes have the responsibility
to develop a policy for malaria disease management based on a set
of defined criteria as efficacy, side effects, costs and
compliance. These will fluctuate over time and national
guidelines will require periodic re-assessment and revision.
Changing a drug policy is a major undertaking that can take
several years before being fully operational. The standard
methods on which a decision can be taken are the in vivo
and the in vitro tests. The latter allow a quantitative
measurement of the drug response and the assessment of several
drugs at once. However, in terms of drug policy change its
results might be difficult to interpret although they may be used
as an early warning system for 2nd or 3rd line drugs. The new WHO
14-days in vivo test addresses mainly the problem of
treatment failure and of haematological parameters changes in
sick children. It gives valuable information on whether a drug
still `works'. None of these methods are well suited for
large-scale studies. Molecular methods based on detection of
mutations in parasite molecules targeted by antimalarial drugs
could be attractive tools for surveillance. However, their
relationship with in vivo test results needs to be
established.
