Progress Report as of March 2002

Climate Variability and Human Health Impacts in Venezuela

The two areas selected demonstrate contrasting patterns in climate and epidemiological behavior of malaria, which is a requisite to meet the objectives of the study.

Bolivar state is located in southern Venezuela on the border with Guyana and Brazil. In this state, the team selected the Municipality of Sifontes for detailed study. Sifontes has a population of 51,827 and its main economic activities are mining and logging. Malaria transmission occurs all year round. Preliminary analysis for the period 1993-2001 shows no correlation between monthly rainfall, maximum and mean temperature and malaria prevalence. Significant correlation exists between malaria prevalence and minimum temperature and mean relative humidity. That is, malaria prevalence decreases when minimum temperature and mean relative humidity decrease.

Sucre state is located in northeastern coastal Venezuela. The team selected the Municipality of Cajigal for detailed study. Cajigal showed the highest prevalence of malaria in the state during 2000. So far the data for analysis are available only at the state level. Preliminary data show that after a major drop of malaria prevalence between 1992-1994 there has been a continuous increase. Mean monthly malaria cases in Sucre for the period 1988-2001 showed a peak of transmission between January and March during the dry season when the relative humidity and temperatures were at their lowest values. Mean monthly malaria cases decreased at the beginning of the rainy season but then increased, reaching a plateau during August at the peak of the rains.