Malaria: burden of disease.

Despite more than 100 years since Laveran described plasmodium species and Ross confirmed that they were transmitted by female anopheline mosquitoes, malaria remains a leading cause of morbidity and mortality worldwide. Although the areas where transmission takes place have reduced, and they are by now confined to the inter tropical areas, the number of people living at risk has grown to about 3 billion, and is expected to go on increasing. Not only does malaria cause around 500 million cases every year, and between 1 and 3 million deaths, but it also carries a huge burden that impairs the economic and social development of large parts of the planet. The failed attempt to eradicate malaria gave way to the control policy that was followed by a huge resurgence of malaria during the late 70s and 80s. Together with the emergence and spread of resistance to chloroquine and the weak health infrastructure in many of the endemic countries, particularly in Africa, the malaria situation worsened worldwide. The last decade of the 20th century was witness to the international community becoming increasingly aware of the unacceptable situation that the burden of malaria represented to large parts of the world. Renewed efforts to describe the problem, design and evaluate new control strategies, design and develop new drugs, better understand the biology of the parasite and the immunity it induces in the human host, develop candidate vaccines, together with new financial support constitute renewed hope that may lead to new trends in global health.