A new report on the implementation of Indoor Residual Spraying (IRS) by the World Health Organization begins with the following ‘historical’ perspective: “In the 1950s and 1960s the WHO led malaria eradication campaign eliminated the risk of malaria infection for about 700 million people mainly in Europe, Asia and Latin America within a period of about 20 years using IRS as a major tool. In the 1980s, following the global consensus to replace malaria eradication campaign by a long term control program, use of IRS was significantly reduced. In Africa, the intervention was abandoned except in some countries in southern and eastern Africa where IRS remained the corner stone of the malaria control strategy.” The report goes on to expound on the return of IRS and its potential for success throughout Africa.
The above statement makes it sound like the world community just woke up one day and decided, “Let’s stop IRS”, with little reference to problems faced by famed Malaria Eradication Program (MEP). Fortunately Randall Packard has also recently published a book on the history of malaria that helps set the record straight on the MEP.
Technically the MEP was launched in 1955 and came to an official close in 1969, but even before it started, its main technical intervention, IRS with DDT, had already shown signs of mosquito resistance. A number of factors including low levels of economic development, poor health system infrastructure and donor fatigue led to the close of MEP. It truly was a daunting task given the limited tools and difficult environment in many countries.
Today there are more tools, but some are more expensive, e.g. ACT compared to chloroquine. There is also a greater choice of insecticides, though again, cost is a consideration. The new WHO report brushes on some of these challenges, especially the low levels of health system capacity in some of the most endemic countries. But as Packard points out these tools alone are not enough unless programs address the basic underlying social and economic factors that continue to ‘protect’ the persistence of this killer disease.