MSF-USA: Natural disasters do not necessarily lead to epidemics

January 3, 2005
Natural disasters do not necessarily lead to epidemics

January 3, 2005 - Philippe Guérin is an epidemiologist in charge of epidemiological studies at Epicentre, Doctors Without Borders/ Médecins Sans Frontières’ (MSF) partner organization. In the following interview, he takes stock of the medical consequences of the tsunami and explains that the risk of epidemics is not a result of the disaster itself, but rather the potential consequence of people being displaced from their homes.

In medical terms, what are the consequences of a natural disaster, such as the tidal wave in South Asia last Sunday?

You need to distinguish the direct and indirect consequences. The immediate impact is the huge number of victims of the disaster. The dead, of course, but also the injured, who have to be treated as quickly as possible. People are suffering from cuts and fractures and, if there is no treatment, their wounds quickly become infected in the difficult conditions.

And then, the tidal wave has destroyed houses and infrastructures, in particular drinking water supply systems (wells, pipes etc.). The destruction of homes often means that populations are being displaced and forced to regroup themselves in very makeshift conditions. This the biggest risk in health terms: forced overcrowding, insufficient access to drinking water and medical treatment, and, sometimes, food.

These circumstances can result in diseases and encourage the spread of disease. Sleeping outdoors and in makeshift shelters, people can contract respiratory infections, especially children. After Hurricane Mitch in Central America in 1998, 70 percent of MSF consultations involved respiratory infections, because the homeless caught cold during the night. There is also a risk of diarrhea-related diseases as a result of consumption of contaminated water.

We have heard talk of a major risk of epidemics. What sort of epidemics and should we be worried?

From the current doom-mongering, you would think that the event itself (the tsunami) would lead to a wave of epidemics. That’s quite untrue. Our experience with natural disasters proves that they do not lead to epidemics. I repeat that it is the displacement of populations that encourages epidemics.

The media is focusing on the problem of bodies that have not yet been buried or burnt. But, here again, experience proves that this is far from being the greatest threat. For the survivors, the priority in public health terms is access to drinking water and medical treatment. Of course, bodies have to be collected, but that is more for psychological reasons in these circumstances. In medical terms, some corpses may harbor bacteria that cause diarrhea, but do not have an epidemic potential.

On the other hand, in the case of certain specific pathologies like cholera, dengue, or malaria, they already have to exist in the countries concerned for there to be a risk of an epidemic. In the case of cholera, the cholera vibrio, the bacterium responsible for the disease, must be present in order to spread. The risk of cholera is very small in Thailand, Malaysia and the Maldives and moderate in Sri Lanka, Myanmar (Burma), Indonesia, and India.

The risk is thus limited, but once the risk exists, even if it is limited, we need to be vigilant. In order to detect the start of epidemics, we rapidly need to put in place a system of surveillance specific to this disaster. And, where necessary, we need to be ready to react so that we can treat the sick and endeavor to stop the spread of disease. The biggest problem in this case is to set up a system of surveillance in the most isolated areas.

What is the role of a humanitarian medical organization such as MSF in a catastrophe such as this one?

First of all, assessing the needs on a case-by-case basis. The situations vary significantly from country to country. In Sri Lanka and Indonesia, the health systems are already fragile and have been submerged by the influx of injured, because these countries have been affected so violently. Thailand and Malaysia are less affected and more developed and are, therefore, better equipped to respond. Furthermore, within any country, there are always segments of the population that are neglected by the aid agencies and these are the ones on whom we try to focus our efforts.

We may be asked to intervene in various ways. Sometimes we can help to take care of the injured, where there is a need for this. But caring for the injured is an emergency in the first few days and NGOs often arrive too late for that. So the main part of our action will be to ensure access to treatment, emergency distributions of equipment like plastic tarpaulins for the shelters and blankets, and water supplies for the populations affected by the disaster. In the short term, this should lead to an improvement in their living conditions and limit the mortality rate in the event of the appearance and spread of diseases. Finally, we can participate in the epidemiological surveillance effort. A team from Epicentre is going to the region to support the health authorities and MSF teams.