Dengue control:

The Cuban way and the Sri Lankan way

Jayatilleke DE SILVA

Cuba is a country that has successfully combated dengue epidemics. Its expertise is sought by many countries to combat dengue. Now two Cuban epidemiologists are in Sri Lanka to assist her in combating the epidemic.

How did Cuba achieve success? What was its approach to the problem? The Cubans followed three basic principles in working out their approach. First, they relied on scientific data that determined how to confront and eliminate the epidemic. Second was political will or government support. Third was mass participation of the public in the anti-dengue campaign.

Their methodology of working was sequential. They first established a national surveillance system with suitable technical facilities to cover the entire population. Then the surveillance system identified the presence and spread of the pathogen. Subsequently the government and the public health system was alerted.

Further, the media was fully involved in creating an awareness of the problem and their role in combating it. Such a strategy requires coordination across all sectors and pooling of resources. Professor and Associate Researcher at the Higher Institute of Medical Sciences, Havana and Director of Health Tendencies Analysis Unit (UATS) Daniel Rodriguez Milord says the Cuban Surveillance model “is based on integration, cooperation and participation between all disciplines and institutions in the function of public health and there is no public health without political will on the part of the government”. For example the Cuban system relies on even the expertise of geographers, meteorologists and ecologists in surveying, analysing and evaluating health risks.

Hence it is wrong to assume that the Cuban system relies merely on the application of bio-larvicides for mosquito control. The use of bio-larvicides, however, yielded quick and lasting results. Cuba produces and uses two types of bio-larvicides.

They are Griselesf and Bactivec. While Bactivec has been used in Cuba since 1980, Griselesf has been in use since 1990.Both of them are recognized by public health institutions in Bactivec is registered in nine countries and Griselesf in 13 countries. Geographically these countries are in Central and South America, Africa and Asia. China has already started a factory to produce them locally.

Both products have been validated by several WHO collaborating research centres. They are highly effective in the control of larvae of different types of mosquitoes under most varied climates and application conditions. They do not cause any harmful effects on animals and plantlife. As they are bio-degradable, they are environment friendly. Bactivec has proved to be effective in small doses against the larvae of the Aedes aegypti mosquito. Griselesf is used in the case of large water bodies.

What has been the Sri Lankan way? While Cuba has developed an integrated coordinated system for surveillance and control ours has been a disjointed system with various institutions in the healthcare system itself being at loggerheads with one another. Nor has there been sufficient public awareness and participation in dengue control. The media too has taken sides, unfortunately on political allegiances of journalists and publishing houses.

Sri Lanka is yet to set up a unified command for dengue control with the participation of all sectors and institutions. Cuban experience also tells us the necessity of constant surveillance and the need to use scientific methodology and technology for the purpose.

The authorities should realize that even one death is too many. There is also the danger of people contacting the disease for second and third time with the risk of fatality increasing. Unfortunately there seems to be a strong lobby that for commercial and other reasons are opposed to the introduction of Cuban BTI to the country. They have been raising various unfounded concerns about its environmental impact even without bothering to find out the properties of the bio-larvicides. There was also an attempt to cast doubts on their suitability by claiming that they have not been certified by the WHO.

This is untrue as they are validated by the WHO and several other UN agencies. The viscious nature of the anti-Cuban BTI lobby could be seen from the humorous media stories about “Missing Cuban epidemiologists” when their arrival was delayed due to changed flight schedules.