Ebola returns. (Follow-Up).

On 4 December 2001, the World Health Organization (WHO) received reports of seven deaths from an outbreak of suspected viral haemorrhagic fever in Ogooue lvindo province in the northeastern part of the Gabon. Laboratory testing carried out at the Centre International de Recherches Medicales de Franceville (CIRMF) in Gabon confirmed that it was the Ebola virus. This is the fourth outbreak of the disease in that country since 1994 and as of 8 February 2002 the death toll was 54.

WHO is supporting Gabon's Ministry of Health and the national task force in disease containment by coordinating the international response to the outbreak and implementing control measures, including finding cases, tracing and monitoring contacts, and supplying protective equipment. The international aid group Medecins Sans Frontieres (MSF)/Doctors Without Borders is also helping to contain the virus. Gabon's Red Cross Society is carrying out health education activities in the villages.

The first Ebola outbreak in Gabon occurred in December 1994 in the gold mining encampments. Two other epidemics were confirmed, in February 1996 when 13 people became ill after butchering a dead chimpanzee, and then later that year in October. As was documented in Cote d'Ivoire and Gabon, transmission of the virus has occurred by handling ill or dead infected chimpanzees. Although nonhuman primates have been the source of infection for humans, they are not thought to be the reservoir (see box). In Mekambo, bushmeat has been banned since the latest outbreak, and controls on hunting have been reinforced. One of the problems the Government faces is informing people in remote forest villages who do not have access to radios and are not aware of the bushmeat link.

A team of scientists from the WHO Global Outbreak Alert and Response Network went to Gabon to help coordinate the international response to its latest outbreak. "Once we had the original confirmation on 7 December, we were able to start contacting our Network to say we had Ebola and that we were probably going to the field. On the 9th or 10th of December, we received the request for assistance from WHO, and on the 11th the international team arrived in Libreville", says Dr. Mike Ryan, Coordinator of the WHO Response Network in Geneva.

"Ebola is only a tiny fraction of the burden of infectious diseases around the world and as such the sheer numbers don't even put it on the map when it comes to disease. I think the thing for us with Ebola is that if we look at HIV/AIDS in the early 1980s, everyone thought this was a very unusual disease that wasn't very important in public health terms, and I think we know differently now. We are dealing with a highly lethal disease we don't understand very well. We still haven't been able to verify the natural reservoir of the Ebola virus, which seems to reside in the rain forests of Africa and Asia. It is therefore really important that "we snuff out each and every outbreak as quickly as possible", says Dr. Ryan. "Control of Ebola is based on very basic, straightforward public health principles. It does require specific expertise to manage cases, but as the Uganda experience has shown, in controlling an Ebola epidemic, the basic issues of good case management, social mobilization and surveillance can be p ut in place very well by local authorities. But there is a responsibility by developed countries to provide the specialized expertise required on the laboratory side, specialized practical case management and in surveillance methodologies. The unfortunate thing is that these outbreaks happen in very difficult situations and therefore place extra logistic and financial demands on the whole system", he adds.

After the latest initial outbreak in Gabon, four villages were put under quarantine, but not before one infected woman had entered the Republic of the Congo. On 20 December, WHO reported that the outbreak had spread to that country. Fortunately, the affected region is one of the most sparsely populated areas, covered by vast forests with tiny villages. The WHO international team operated on both sides of the border and worked closely in the field with the team from the Congolese Ministry of Health on outbreak control interventions. "The coordination obviously is in a very remote area on both the Gabonese and Congolese sides of the border. It is not an area that suffered big conflict, but certainly the infrastructure is very poor and sparse", Dr. Ryan says.

There are organizations involved, such as CDC (Centers for Disease Control and Prevention in the United States), Epicentre in Paris, as well as Health Canada in Ottawa, Institute Pasteur in Paris, the Public Health Laboratory Services in the United Kingdom and the International Federation of the Red Cross, and particularly MSF in Holland and Belgium, which has been a big part of this response. "So getting that kind of coordination, getting experts from different fields and organizations in the field operating together under one coordinated mechanism is challenging, but technically it works. It has worked a lot better in the last few years and has come together in a more formal network, when we have agreed guided principles and international response and substantive protocols on how we work together in the field", according to Dr. Ryan.

On 8 January, the medical experts were forced to pull out of Mekambo because of threats from local inhabitants. Tensions were running high because the villagers were resentful of being confined to their villages for medical observation and because of the team's efforts to halt the traditional burial rituals that include removing certain body parts and washing the corpses. They were also blaming outsiders for the ban on the sale of bushmeat and crops.

"I think the situation on the ground became quite difficult for the team, and a lot of it is related to misunderstandings among the local population about the cause of the disease. These populations are quite remote and their understanding of the disease can be based on superstitions.

There were elements within the local population who were fomenting some of these ideas and possibly using them for political ends, and this created an intolerable situation in the field. So we withdrew from the Mekambo area for a few days for things to settle down and to allow the Red Cross and others to work more intensely with the local population, as well as to ensure that the Gabonese Government put in place the necessary resources to inform the population of the role of the international team and how Ebola needed to be dealt with", says Dr. Ryan. The team remained fully operational in Libreville, Makokou, and the Republic of the Congo.

Ebola has also become of concern to The Bronx Zoo-based (New York) Wildlife Conservation Society (WCS), which is working to prevent the latest Ebola outbreak from decimating wild populations of gorillas, chimpanzees and other wildlife. WCS is particularly concerned that the outbreak could affect gorilla populations in Odzala National Park in the Republic of the Congo, which is home to tens of thousands of western lowland gorillas. A team that included scientists from WCS, WHO, the Gabonese Center for Medical Research and the European Community-founded conservation programme Ecosystemes Forestiers d'Afrique Centrale (ECOFAC) discovered evidence in dead gorillas, chimpanzees and a forest antelope sometimes eaten by chimpanzees. In response, WCS partners at ECOFAC and the Congolese Government arranged to stop human traffic between the area of the outbreak and the villages surrounding Odzala. Gabonese officials also cordoned off the region to prevent traffic movements on the Gabon side. Doctors of the WCS Field V eterinary Programme suspect that the last Ebola outbreak in the region resulted in the deaths of huge numbers of gorillas and chimpanzees in over thousands of square miles. Since then, WCS has initiated a health programme in the region to reduce risks of the disease among gorillas.

As Dr. Daniel Bausch, a medical epidemiologist at CDC in Atlanta, says in his article in the UN Chronicle (Issue 2, 2001): "When something as dramatic and deadly as Ebola breaks out, a host of resources are mobilized and a United Nations-worth of organizations converge on the epicentre to help put out the fire. They generally do an effective job, but return just a few months later and one usually finds that it's back to business as usual". So until the reservoir of Ebola is identified and a vaccine or cure is discovered, the WHO Response Network, its partners and the affected Ministries of Health will do what they can, as Dr. Ryan says, "to snuff out each and every outbreak as quickly as possible".

RELATED ARTICLE

According to WHO, the natural reservoir of the Ebola virus seems to reside in the rain forests of Africa and Asia, but has not yet been identified. Extensive ecological studies are currently under way.

"The disease is always going to leave the forest; it breaks out of the forest from time to time and affects human populations. There is always the risk of reaching a major capital or outside the country--we have seen that happen in the previous epidemic in Gabon, where a nurse in South Africa was infected by a sick patient who arrived from Gabon. I don't believe that even if that did happen, we would begin with a terrifically worrying situation. Good public health would probably deal with that very quickly. However, there is always that risk, and our job is to try and prevent that. We managed to do that so far, and I believe in Gabon we can do the same", says Dr. Mike Ryan of the WHO Response Network.

The WHO Global Outbreak Alert and Response Network was initiated at a major meeting of 130 experts from 72 institutions and existing networks in April 2000, where a framework for joint action was agreed upon. A working group of partners is guiding the development of the Response Network as a key component of the WHO Strategy on Global Health Security. A WHO operational support team and an Event Management System were established in Geneva and additional regional hubs. The Network's objective is to ensure global health security by combating the international spread of outbreaks, ensuring that appropriate technical assistance reaches affected States rapidly, and evaluating international efforts to contain outbreaks. It focuses on the rapid identification, characterization and containment of epidemic threats and ensures coordinated mechanisms for outbreak alert and response. The Network responded to the largest Ebola outbreak in Uganda in October 2000, which ended four months later, in February 2001, after killi ng 224 persons, including health care workers.