Editorial: Unfortunate, but Timely

When I proposed “Epidemiologic Approaches to Disasters” as the theme for the 2005 issue of Epidemiologic Reviews, Jon Samet, Chair of the Department of Epidemiology at the Johns Hopkins Bloomberg School of Public Health, remarked that the topic is unfortunate, but timely. We had reviewed most of the submitted and invited papers for the issue and had begun to assemble those that had passed peer review when, on December 26, 2004, the world learned of a disaster of monumental proportions. I remembered Jon's comment: disasters are always unfortunate, but devoting an issue to this topic is indeed timely.

Tsunami is a Japanese word, which the Oxford English Dictionary defines as a “long, high, sea wave caused by [an] underwater earthquake.” Time magazine attributed the cause of the disaster to “a massive earthquake off the coast of Indonesia, where two plates of the earth's crust grind against each other. … About 750 miles of the edge of the Burma plate snapped, forcing a massive displacement of water in the Indian Ocean. … The waves spread in all directions, moving as fast as 500 m.p.h. … The retreat of a tsunami from land can be quick—and just as dangerous as its approach” (1, p. 32). Floods and earthquakes have been with us for centuries. The New York Times recently listed the 10 worst floods in recent history (between 1911 and 1954), in which millions died, and the 10 worst earthquakes (between 1920 and 1976), in which thousands died (2). Most of these flood- and earthquake-related deaths were in China; other countries affected by both disasters were Japan, the Soviet Union, Italy, Peru, Pakistan, Iran, Guatemala, Venezuela, and Bangladesh.

Like cyclones and floods (3), the recent tsunami caused many deaths and injuries, but it was several times more severe than the “average” disaster. Some sources reported 214,000 dead, 142,000 missing, and 34,000 injured (4). Most of the deaths were caused by drowning, and many of the dead were children and the elderly; the injuries were mostly aspiration and trauma related. Although it was anticipated that disease outbreaks would follow as a result of contaminated drinking water, poor sanitation, spread of mosquitoes, and overcrowding in makeshift tents, such outbreaks did not materialize to the degree expected. However, investigation of some consequences of disasters often leads to unanticipated benefits: a young girl was diagnosed with measles, which helped to launch “a massive strategy for identifying, treating, and immunizing every child in her camp and in every camp and home she had visited. This strategy bore secondary fruit, as we found severe dehydration, diarrhea, and skin infections in people lining up for vaccinations” (5, p. 965).

As evidenced in this issue, epidemiology has an important role to play in the study of characteristics of populations affected by disasters and the deaths and injuries that follow. A seminal article, published in the Lancet almost 35 years ago and republished in this issue, shows epidemiologic approaches to disaster assessment at their best (6). Two population-based surveys were carried out 2 months apart to determine the magnitude of the disaster, the characteristics of the populations affected, and the subsequent mortality and morbidity. It was shown that the East Bengal cyclone of November 1970 resulted in the highest death rates among children and the elderly and that women fared worse than men in all except the youngest age groups. Furthermore, the study used a control area and found that postcyclone mortality, morbidity, and nutritional status in the affected areas compared favorably with those in the control area. When epidemiologic studies of the tsunami disaster are completed, a picture not unlike that reported in the East Bengal study might emerge.

It is well known that disasters and ill health are usually more prevalent in the developing world and among those who are economically deprived. It is interesting to note that tsunamis and similar disasters have some features in common with human immunodeficiency virus/acquired immunodeficiency syndrome: both have the greatest effect and worst consequences in the developing world and in the poorest segments of the population. The tsunami destroyed roads, seaports, and the infrastructure necessary for relief missions to reach and help the victims. Likewise, the human immunodeficiency virus/acquired immunodeficiency syndrome epidemic destroys the immune system that defends the body against this disease (although vaccines are currently being developed to help its sufferers and to prevent further spread).

As presented in several papers in this issue, epidemiologic methods and public health strategies are important in assessing and containing disasters. Some basic epidemiologic measures such as counting the dead and injured and computing incidence and prevalence by time, place, and person factors are helpful in characterizing the nature and magnitude of the disaster. The time-honored public health prevention and control measures come into play: supplying clean water and sanitary waste disposal to prevent cholera and dysentery, vaccinating high-risk groups against infectious diseases, and eradicating breeding sites and using screens to control mosquitoes. Disasters are unequaled in creating a situation in which epidemiologists' and public health workers' tools and skills need to be applied in full force to alleviate further pain and suffering.

The papers in this issue demonstrate that, in epidemiologic terms, a lot remains to be done. For example, evidence for long-term consequences, both physical and emotional, through the use of cohort studies with sufficient follow-up time is somewhat lacking. Collecting and sharing standardized information and using rigorous research methods across regions and nations are clearly inadequate. In addition, proper evaluation of interventions will help in devising appropriate and timely relief missions that undoubtedly will be required in the future.

Now more than ever, public health preparedness has become a high priority of governments that must have the ability to predict, prevent, and control disasters and their consequences. Adequate funds and political will are crucial to achieve this purpose, but epidemiologic know-how also has a role to play.

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