Geographies of health and climate change

Interest in mapping the global distribution of malaria is motivated by a need to define populations at risk for appropriate resource allocation and to provide a robust framework for evaluating its global economic impact. Comparison of older and more recent malaria maps shows how the disease has been geographically restricted, but it remains entrenched in poor areas of the world with climates suitable for transmission. Here we provide an empirical approach to estimating the number of clinical events caused by Plasmodium falciparum worldwide, by using a combination of epidemiological, geographical and demographic data. We estimate that there were 515 (range 300-660) million episodes of clinical P. falciparum malaria in 2002. These global estimates are up to 50% higher than those reported by the World Health Organization (WHO) and 200% higher for areas outside Africa, reflecting the WHO's reliance upon passive national reporting for these countries. Without an informed understanding of the cartography of malaria risk, the global extent of clinical disease caused by P. falciparum will continue to be underestimated.

Disasters are traumatic events that may result in a wide range of mental and physical health consequences. Post-traumatic stress disorder (PTSD) is probably the most commonly studied post-disaster psychiatric disorder. This review aimed to systematically assess the evidence about PTSD following exposure to disasters. MethodA systematic search was performed. Eligible studies for this review included reports based on the DSM criteria of PTSD symptoms. The time-frame for inclusion of reports in this review is from 1980 (when PTSD was first introduced in DSM-III) and February 2007 when the literature search for this examination was terminated. We identified 284 reports of PTSD following disasters published in peer-reviewed journals since 1980. We categorized them according to the following classification: (1) human-made disasters (n=90), (2) technological disasters (n=65), and (3) natural disasters (n=116). Since some studies reported on findings from mixed samples (e.g. survivors of flooding and chemical contamination) we grouped these studies together (n=13). The body of research conducted after disasters in the past three decades suggests that the burden of PTSD among persons exposed to disasters is substantial. Post-disaster PTSD is associated with a range of correlates including sociodemographic and background factors, event exposure characteristics, social support factors and personality traits. Relatively few studies have employed longitudinal assessments enabling documentation of the course of PTSD. Methodological limitations and future directions for research in this field are discussed.