We show how normal climatic conditions are associated to diverse malaria transmission indices troughout Colombia. Hydrological and climatic variability at interannual timescales in tropical South America is strongly associated to El Niņo/Southern Oscillation (ENSO). Most of the region, including Colombia experiences prolonged dry periods and above normal air temperatures during El Niņo, and generally opposite conditions during La Niņa. Through correlation analysis we show that during El Niņo events there are outbreaks of malaria and dengue fever in Colombia. These outbreaks could be explained in terms of precipitation decrease and air temperature increase, both factors favoring the ecological, biological and entomological components of these diseases.
We illustrate the prediction capability of malaria cases in Colombia by using an epidemiological model, based on the concept of vectorial
capacity (Martens et al., 1997). This epidemiological model is driven with surface air temperatures derived from an atmospheric general circulation model (ECHAM3 model, Max Planck Institute for Meteorology) with a spatial resolution of about 300 km. The malarial model produces peaks in P. Vivax vectorial capacity during El Niņo years and an upward trend with time, in agreement with the Colombian malarial historical record.
These statistical correlations and modeling results may be used for developing Health Early Warning Systems of climate conditions conducive to outbreaks, that may facilitate early public health interventions to control and mitigate the incidence of these vector-borne diseases.
Results of an undergoing field experiment to relate climate variability with malaria incidence in Colombia are shown. Simultaneous climatic and malarial records have been gathered at two locations with different climatic behavior in Colombia, during El Niņo 1997-1998. Results are used to test the existing hypotheses to explain the climate-malaria linkages in Colombia