present context, displacement due to war can contribute significantly to the emergence and spread of infectious diseases (Kalipeni and Oppong, 1998; Murray et al., 2002). In most of these emergencies, three out of four deaths are attributable to communicable diseases. Refugee camps are usually crowded and dirty, with little or no access to medical care or protection from vectors, and full of people from many different geographic areas (and thus probably carrying a broad range of infectious agents). For example, in 1994 more than a million Rwandan refugees were sheltered in Goma, Democratic Republic of the Congo, formerly known as Zaire, when cholera and dysentery swept through the camps, killing 12,000 people in just 3 weeks. In the post-conflict phase, malaria accounted for over one-third of the total mortality among displaced populations in Central Africa in the aftermath of the Great Lakes crisis of 1994, and TB was estimated to have caused one-fourth of all deaths among refugees in Somalia in the 1990s (Connolly, 2002).
While related in some instances to large-scale environmental patterns, famine is highly correlated with factors other than the weather. Rather, it is highly correlated with social, economic, and political forces, including land tenure, deforestation, and rapid demographic change. According to one theory, a root cause of famine is ultimately a deficiency in food “entitlement,” owing to political disenfranchisement (Sen, 1981); an exclusive focus on issues of food production that ignores this root condition is deeply counterproductive (Sen, 1999). During the Rwandan genocide, to take one extreme example, famine conditions in the vicinity of the refugee camps were thought to have been greatly exacerbated by the toll on household industry exacted by the shigellosis epidemic (Paquet and van Soest, 1994).
As with war, the causal chain between famine and disease is bidirectional (Topouzis and Hemrich, 2000). Emerging epidemics can severely disrupt food production, especially through high mortality and morbidity among workers in agricultural areas and the depletion of family savings to care for those stricken. The social epidemiology of HIV in sub-Saharan Africa testifies to this bidirectional phenomenon; countries that are more dependent on agriculture are affected more by HIV/AIDS (Topouzis and du Guerny, 1999). Clearly, HIV is a recipe for a catastrophic decline in food supplies; preliminary data suggest that such a decline has in fact taken place. In Zimbabwe, according to a recent report cited by FAO, communal agricultural output has declined by half over the past 5 years, almost entirely as a result of HIV/AIDS.