Experimental infection and protection against ... - TI Pharma

10 Chapter 1
generally milder disease that is rarely fatal, but, in the case of vivax and ovale
malaria, that may remain in a dormant form for years.
Malaria control receives high priority from the international community, which
has been established in the United Nation's Millennium Development Goal 6
aiming at the reduction of the incidence of malaria and other major diseases by
2015. Malaria control is also central to Millennium Development Goal 4,
targeting a two-third reduction in the mortality rate among children under the
age of five [5].
Current control strategies are based on early diagnosis and treatment of malaria
infections combined with preventive measures aimed at mosquito control. The
development of widespread resistance to the anti-malarial drugs chloroquine
and sulfadoxine-pyrimethamine has re-directed treatment strategies to
artemisinine-based combination therapies, such as artemether plus
lumefantrine, artesunate plus amodiaquine, artesunate plus mefloquine or
artesunate plus sulfadoxine-pyrimethamine, which are now the WHOrecommended
treatment regimens. Unfortunately, Pf resistance has been
observed to many of the currently used antimalarial drugs (amodiaquine,
chloroquine, mefloquine, quinine and sulfadoxine-pyrimethamine) and, more
recently, also to artemisinine derivatives [6]. To date, there are no new
medicines in advanced stages of development to replace the artimisinins [7].
Vector control is the primary intervention for reducing malaria transmission at
the community level. When universal vector control coverage is achieved by
impregnating bednets and spraying indoor surfaces of houses with insecticides,
transmission can be reduced to close to zero. However, the increasing resistance
of mosquitoes to insecticides including dichlorodiphenyltrichloroethane (DDT)
and pyrethroids, particularly in Africa, poses challenges to current prevention
policies [8].
The current control strategies permitted the interruption of malaria
transmission in low transmission countries, particularly in those with a robust
institutional infrastructure and well-functioning health systems, and in those
neighbouring malaria-free areas [8]. However, the lack of new effective antimalarial
drugs and insecticides places malaria control and elimination efforts at
considerable risk. In order to reach the ultimate goal of malaria eradication,
much greater gains could be achieved with currently available tools, including
elimination from a number of countries and regions, but even with maximal
effort we will fall short of elimination in many areas and of global eradication