1. So you think you know what causes malaria ? In 1987 in Rwanda, malaria incidence increased 337 per cent. This increment came associated to a much greater rain precipitation and to a one degree centigrade rise in the average seasonal temperature. This combination of factors resulted in a very significant extension of the areas and regions with environmental ideal conditions for the reproduction of all types of insects, including mosquitoes, the transmitters of Plasmodium vivax, and other plasmodia. As seen in the next slide. Now, the next question is: why did these environmental conditions change so significantly?

2. Factores Físicos y Enfermedad Dr. M. López-Llera M. Paludismo Esquistosomiasis Filariasis Oncocercósis Tripanosomiasis Dengue Fiebre amarilla CALENTAMIENTO GLOBAL POR POLUCION Aumento de 1 Cº en Rwanda = 337% más paludismo (1987) EJEMPLOS 2 millones MUEREN Science. 1995;267:957-8 Trópicos y Sub-trópicos 600 millones enferman Cada Año

3. Interdependencia de Factores Dr. M. López-Llera M. CONTAMINACION AMBIENTAL MULTIPLE A R E A S Y D E V E C T O R E S AUMENTO DE PERSONAS AFECTADAS CONSUMO Y DESPERDICIOS MASIVOS PATRON ECONOMICO CULTURAL V I G E N T E Temp. Cº Factor Físico ? I NCREMENTO DE Sobrecalentamiento MUNDIAL

4. These environmental changes resulted from our present cultural, socio-economic and ethical characteristics that dominate our life-styles, but mostly those of the highly industrialized regions of the World. So, plasmodia transmitted by Anopheles mosquitoes cause Malaria. But between a zero incidence and zero mortality to a very high incidence with two millions deaths per year, many more factors intervene. The bottom line is that in many diseases, the true biological causes are not as relevant as the social, economical, cultural and even physical factors that facilitate its existence and route to mortality. Another typical example is Eclampsia, of course.