La Réunion leads the way in tackling the chikungunya virus

After an outbreak of chikungunya, a mosquito-borne virus which affected 270,000 people on the Indian Ocean island of La Réunion in 2005-06, scientists at L’Institut de recherche pour le développement (IRD) in Marseille have been working hard to come up with a solution so that no one in France’s overseas departments (DOM), or anywhere else, has to experience high fever, headache, rash, and severe joint and muscle pain. These symptoms, although rarely fatal, can last between a few days and several months.

About time too some would say. Indeed, two academic commentators have accused the public health authorities as well as the media in metropolitan France of being far too slow to react to the initial crisis on an island, which lies nearly 6000 of miles southwest of Paris.

In two papers on the chikungunya epidemic in La Réunion, one in 2008 and another in 2009, University of South Australia’s Philip Weinstein and Srilata Ravi claim that the delay in acknowledging the public health risk of the virus reflected “passive denial” by the French metropolitan government, convinced that its mainland European citizens were in no danger, a view which was mirrored in the “residual colonial thinking on the priority placed on reporting on an epidemic in the remote tropical location” by the mainstream media.

It was only towards the end of 2006, observed Weinstein and Ravi, that there was a significant shift in attitude signalled by the use of a “more inclusive language” by government and newspapers, such as Le Figaro and Le Monde, in metropolitan France.

In any event, according to epidemiologists the medical costs of treating around 40 per cent of the population for chikungunya in La Réunion (an island with the healthcare system of a developed country) was around €43.9 million (though note that this figure does not take into account self-medication using over-the-counter medicines, or alternative or complementary remedies).

The chikungunya virus is thought to have originated in urban areas of Africa, and was first isolated from humans and mosquitoes in Tanganyika in 1953. By 1958 the virus had been detected in India and Southeast Asia, affecting over one million people. In December last year, carried by infected global travellers, the virus first appeared in the Caribbean on the French territory of St Martin. The infection quickly spread to other islands, including the Dominican Republic, Guadeloupe, Martinique, Saint Lucia and the US Virgin Islands, as well as French Guiana in the South American mainland.

By 20 June this year there were 183,761 confirmed cases in the region according to the Pan American Health Organisation (PAHO), the local branch of the World Health Organisation (WHO). PAHO expects the numbers contracting the virus to continue to rise because local populations in the Caribbean do not have the life-long immunity bestowed by a previous infection. Not surprisingly, if the chikungunya virus becomes endemic, this is likely to have a significant impact on tourist revenues throughout the Caribbean, as it did in La Réunion which experienced a 60 per cent drop in the number of visitors in the immediate aftermath of the 2005-06 epidemic.

Cases of returning travellers infected with chikungunya are increasing on the US mainland, too. There is concern amongst health authorities that the virus could spread as disease-transmitting mosquito populations multiply rapidly in July and August, especially in the southeast, Great Lakes and mid-Atlantic regions. Outdoor enthusiasts in many US states have already been warned to take suitable precautions, including using insect repellents such as DEET and wearing long pants and long-sleeved shirts. They have also been advised not to use perfumes, colognes or scented soaps as the odours may attract chikungunya-carrying mosquitoes. Concern about the impact of the virus has also been expressed elsewhere, notably by the Australian Department of Health.

Meanwhile in the absence of any effective vaccines or anti-viral therapies for chikungunya, health authorities in La Réunion have attempted to contain mosquito populations by spraying, and educating the public about the importance of eliminating breeding sites, especially in urban areas. But 2015 will see a step-change in strategy: the release of sterile male mosquitoes into the wild, the second phase of the IRD’s Technique de l’insecte sterile (TIS) programme. The hope is that this will drastically reduce the number of breeding females, their longevity and their contact with humans.

However, social and cultural anthropologist Laurence Pourchez of l’Université de La Réunion, an expert on Indian Ocean island communities, who is acting as a consultant to the TIS programme has advised the authorities of the importance of keeping local people informed, especially once the laboratory-sterilised mosquitoes are released into “social” and “natural” spaces. “It is impossible to act without the support of the population,” Dr Pourchez told me.

“Carrying out TIS here in La Réunion could be perceived as scary or frightening as millions of sterile ‘atomic’ mosquitoes will be released into the wild. In the past there have been some mistakes, especially with the recent release of the mouche bleue [bluebottle] used to destroy a plant pest which ended up destroying bees. Consequently the population is not willing to accept anything.” She adds: “Various studies that have been conducted worldwide on sterile insect techniques show that a project is only successful when the population is a partner.”

Dr Pourchez considers that it is especially important to involve working class groups in La Réunion. “In fact, they are the ones who are generally forgotten by the authorities,” she says. “However, working class communities have local knowledge, their understanding of the world, which can sometimes seem at odds with TIS. It’s important not only to listen to people’s knowledge, but also to build on this knowledge to better inform people and make them into partners in the project.”

Eco-anthropologist Dr Sandrine Dupé, who as a PhD student was supervised by Dr Pourchez on the TIS programme, also told me that collaborating with biologists who favour a “technical” approach, juxtaposed with the practices and perceptions of different groups of Réunionese people with their own collective memories, created its own challenges. “We tried to have an interdisciplinary approach, mixing the technical and social aspects of the action-research,” she says. “It was quite hard work for all of us as we had to deconstruct our certainties and paradigms, but we finally found a compromise. In France we are sensitive to the role of the population in development projects. This has been the case since the 1990s. In my opinion, the public interest must be considered above the interests of the programme.”

With the WHO claiming that chikungunya has now been identified in 40 countries in Africa, Asia, Europe and the Americas, it’s clear that a successful programme to eradicate the virus based on trust and partnership between scientists, health authorities and the local population mediated by anthropologists in La Réunion could provide a template for the elimination of other mosquito-borne diseases, such as malaria, dengue fever and yellow fever globally.

A version of this article has appeared at anthropology works

Dr Sean Carey is honorary senior research fellow in the School of Social Sciences, University of Manchester

* Published in print edition on 4 July 2014