Epidemic crisis: dengue fever in Singapore, 1986 – present

In the early 1980s, scientists and public health officials from around the world hailed Singapore as a model for the control of dengue fever. Between 1965 and 1985, health authorities dramatically reduced the incidence of dengue by suppressing Aedes aegypti mosquitoes through cleaning campaigns and environmental modification. However, after 1985, annual epidemics of dengue swept through the country despite low mosquito densities, leaving authorities scrambling for answers.

This talk analyses contemporary explanations given for the return of dengue fever using documents from the Ministry of the Environment, journal publications, and newspaper articles. Although different explanations were offered at the time, including a fall in population immunity, changes in mosquito behaviour, and public apathy, they were united by the idea that success at controlling dengue only increased vulnerability to future epidemics and thus required constant vigilance. For instance, health authorities asserted that because dengue had been controlled so well in the past, the population had lost its immunity to the disease, allowing for quicker epidemic spread in the present. But because this motivated even stricter mosquito control, this generated more vulnerability, creating a vicious cycle.

This link between success and vulnerability drew on, and contributed to, a wider “crisis mentality” in Singaporean politics that was used to justify heavy government intervention in the lives of citizens, even as it deflected responsibility for failures away from the state.

Drawing on the literature on the use of crisis in politics and in science, I suggest that the Singaporean dengue control program is a revealing example of what it means to think of public health in terms of the constant risk of failure and resurgence.