Drug-Resistant Malaria - libdoc.who.int - World Health Organization

RESEARCH FOR CONTROL / 81
and Phase 1 and 2 clinical trials, enters the ultimate phases
which are (ref. TRS.529):
Phase 3: Pilot field trials in partially immune subjects
Phase 4: Treatment of hospital patients
Phase 5: Extended field trials
Phase 6: Observations on mass drug administration
While dose range-finding studies, and tolerability studies m
different ethnic groups are essentially part of Phases 3 and 4,
and the responsibility of specialized clinical workers, field
research in drug development will be required with the release of
a new preparation for Phase 5. Detai led protocols must be drawn
up in close collaboration with investigators who have been
responsible for the earlier phases of development, and, in the
context of the present meeting, with the Secretariat of CHEMAL.
PRIORITY TOPICS
The following research topics
priate for field or laboratory
priority consideration.
were
based
selected as being approresearch
and deserving
Effect of Gametocyt3cidal Drugs
The effect of single doses of gametocytocidal drugs (e.g.
primaquine) on the transmission of P. falciparum, including
drug-resistant P.falciparum, as a complementary measure to vector
control needs to~evaiuated.
The place of gametocytocidal treatment in malaria control
should be assessed 1n various epidemiological situations. This
could be done in circumscribed populations which are sufficiently
stable and accessible to allow adequate evaluation.
When second-line drugs are being used (quinine or sulfadoxine/
pyrimethamine or mefloquine) for the treatment of chloroquineresistant
(or sulfadoxine/pyrimethamine-resistant) malaria, it
becomes necessary to investigate whether the spread of these
resistant strains will be restricted by the addition of primaquine
to this regimen. Furthermore, it would be indicated to study the
impact of the periodic (e.g. weekly) administration of primaquine
on the spread of drug-resistant strains.
Comparative Vector Competence for Resistant and
Sensitive Parasite Strain~-----
With regard to vector competence it has been suggested in the
past that the transmission of chloroquine-resistant P.falciparum
has been associated preferentially with one or more species of
Anopheles. While there seems to be only questionable evidence to