The dengue menace: Will Sri Lanka ever get this right?

A bizarre conjunction of several events – viz. landslides and floods killing hundreds of people, droughts causing massive damage to crops creating food security issues, the increasing incidence of dengue with more than 250 fatalities already reported and nearly 100,000 infected filling the country’s hospitals, the Uma Oya debacle and of course the provision of protection to Zimbabwean cricketers from wild elephants in Hambantota - were recently reported in Sri Lanka. 

Ever heard of protecting African cricketers from wild elephants? No, not even in Africa, where wild elephants abound but in Sri Lanka we do this. If we destroy pristine wilderness areas including wild elephant habitats by building unnecessary infrastructure, well we have to protect the cricketers from wild elephants. This is inevitable. Sri Lanka is on a war footing now to secure control of the dengue menace which is spiralling out of control. 

Are all these issues divergently different from each other? No, they all emanate from the callous disregard and exploitation of the environment by governments and the people of the country for decades. 

The problems are not new and will continue to worsen over time due to further exploitation of natural resources such as forests, water, rivers and wetlands creating water scarcity, land degradation and air pollution. There is a resurgence of dengue in many countries like Sri Lanka, Malaysia, Thailand and even Singapore which had a good record of dengue control prior to 2000 due to rapid urbanisation and an increase in vector breeding sites especially in urban areas providing a haven for the dengue mosquito. The number of dengue cases increased due to poorly planned globalisation, consumerism, poor solid waste and water management and increasing population movement. 

Climate change is another factor that encouraged vector breeding. India, Indonesia, Myanmar, Sri Lanka and Thailand are among the 30 most dengue endemic countries in the world. This region reported more than 400,000 cases of dengue in 2013.

The Southeast Asian region contributes to more than half of the global dengue cases and about 52% of the world’s population at risk resides in this region. Climate change has increased the growth rate of dengue in South East Asia. The highest growth rate is in the Philippines and next comes Malaysia. Part of the increased incidence in dengue in Sri Lanka may be due to climate change. 

Today over 2.5 billion people, more than 35% of the world’s population, in over 100 countries is at risk of infection from dengue. Long-term sustainable solutions are needed urgently if the costly mistake of the past is to be eliminated.    

    

The dengue menace: need for a multi-disciplinary approach 

 

Despite being present for nearly 40 years, Sri Lanka failed to make any significant dent on the dengue problem. Sri Lankan policymakers failed to conceptualise the centrality of an integrated approach to the dengue problem as an essential element in any long-term solution to the problem. 

Successful long-term sustainable programs and approaches for the problem are imperative but the emphasis is on the short-term measures such as what is happening in Sri Lanka right now where a mad frenzy of activity is observed being carried out by governments and public institutions, the Ministry of Health and allied departments. 

If we were closing in on an election the Government would have redoubled these efforts and many politicians would be seen in places they have never visited before. Long-term solutions are often ignored once some degree of control is achieved and let us see this time next year. I am sure there will be dengue again. 

Dengue is complex and not easy to eradicate and requires a consolidated effort by many. This multidisciplinary nature of the dengue problem failed to sink into the Sri Lankan mind. Doctors alone will never solve the dengue problem in Sri Lanka. Recently the GMOs proposed a model with eight points to solve the dengue problem but this may only reduce the death rate but dengue will continue unabated. 

I also saw recently that three WHO experts, all doctors from some Asian countries, provided a report to the Health Minister on the ways to control dengue in Sri Lanka. This report is partial and not integrated with other disciplines such as social sciences and environmental sciences, agriculture and behavioural sciences which are all germane to the problem. 

The report has suggestions to reduce the incidence of dengue by 50% in three weeks, clearly an indication that the focus is short-term, biased towards medical aspects of dengue only and may lack a viable long-term solution. This short-termism undermines long-term solutions but they are politically acceptable because they help governments to subdue immediate public outrage.  

Biological control of dengue: the Monash Initiative 

The best approach for controlling mosquitoes needs to take advantage of every life stage of a mosquito to achieve control. The recent media reference to a bacteria being imported from Australia to destroy the mosquito and the larvae refers to research done at Monash University, Australia which is developing a natural method using the Wolbachia bacteria to stop the mosquito from being able to transmit the virus which can reduce the incidence of dengue. 

This is in the experimental stage and is not available in a limited way. The research is led by Institute of Vector-Borne Disease at Monash University Director Prof. Scott O’Neill. ‘Eliminate Dengue’ research, transfers the Wolbachia bacteria into Aedes aegypti mosquitoes and when Wolbachia is present in the mosquito it reduces its ability to transmit the dengue virus. 

Some tests have been completed in Townsville in the north of Australia and these have been very successful. Currently this is being used at an experimental level in five other countries including Vietnam and India which are partners in this project. 

In 2013 the Australian Museum awarded the Australian Infectious Diseases Research Centre Eureka Prize for Infectious Diseases Research to Prof, O’Neill and his colleagues. The Wolbachia method will be a game-changer and has the potential to stop the spread of dengue fever at a relatively low cost. Being an academic at Monash University, I am taking a personal interest in this and let us see what happens.   

The absence of any credible research system in Sri Lanka for dengue reflects a clear lack of any long-term vision even now. Past and present governments, and the university system must nurture the hopes of Sri Lankan society but they have failed. Where is the Minister of Higher Education and the universities on the dengue issue? Given adequate financial and other support, the Sri Lankan university system can generate very useful results. Australia allocates nearly a $ 1 billion per year for university research under the Australia Research Council (ARC) system and it has become a global leader in research. Sri Lanka is far behind other countries because of its own misguided priorities.   

Multidisciplinary nature of the dengue problem in Sri Lanka 

The dengue problem is complex and the environmental, social and economic issues involved must be addressed simultaneously. A successful dengue control program requires knowledge from many disciplines such as medicine, science, environment and agriculture, psychology and human behaviour, and engineering and technology. Thus any effort to mitigate the problem in Sri Lanka must be complete, exhaustive and multipronged. 

It is necessary to integrate different disciplinary perspectives into a holistic framework to provide effective dengue control. We cannot examine a multidimensional problem through a uni-dimensional lens but this is what is happening now in Sri Lanka. The GMOA plans to meet the President to discuss measures to combat the dengue problem. This is exactly what should not happen and it is counterproductive for the President to meet such discipline specific groups to find answers to a more complex problem which goes beyond their own disciplinary comfort zones. Multi-disciplinary research demands a complete revolution in the way we organise ourselves and in the way we work.

Sri Lanka must pursue a long-term solution to its dengue problem without constantly resorting to short-term measures - Reuters

Policymakers must facilitate the cross fertilisation of ideas from different disciplines: medicine, science, agriculture, engineering, technology, psychology, etc. to yield sustainable solutions to the dengue problem. 

Dengue control is not the prerogative of any particular discipline and an inter-disciplinary approach is imperative. The Minister of Health must request the GMOA to join other professional associations to form an inter-disciplinary committee for overall dengue control including control and eventual elimination of the mosquitoes so that dengue will never be a problem for the country. 

This is not only a medical problem. We need a more profound understanding of the political, economic, social and ecological complexities of complex social and ecological systems and building trans-disciplinary capacity that recognises the interplay between social and ecological systems. 

The entomologist, epidemiologist, ecologist and anthropologist and the medical fraternity all must work in close collaboration with communities, policymakers and other stakeholders who are relevant to the control efforts. Thus a deeper understanding of the environmental, economic and social interconnectedness of the dengue problem is essential. Academics at universities in Sri Lanka, research institutes, bureaucrats and independent thinkers can provide effective leadership and strong institutional capacity to develop the control strategies.

Such comprehensive long-term sustainable approaches should have been put in place in Sri Lanka maybe 25 years ago and if we had this vision then there would be no dengue problem today. However, if the policymakers opt to ignore these ideas and assert their short-termism looking only at the 2020 General Election, dengue will continue to bite Sri Lanka for the next two decades with enormous costs to the public, Government and health system. 

The health ministers of the Southeast Asia region, at a meeting in September 2014, adopted the Dhaka Declaration on Vector-borne Diseases. The declaration encourages a ‘whole of government’ approach against diseases such as dengue. A multi-sectoral approach to address dengue outbreaks is necessary. This approach must take into account public policies across sectors, seek synergies and avoid harmful health impacts. The medical fraternity is only a part of this story. 

Policy formulation and actions needed  

The outbreak of dengue is influenced by socioeconomic factors that include reduced access to health services, housing, sanitation, water supplies and poverty and also newly-won affluence. Effective and sustainable prevention and control of dengue require interventions that must address these factors. We need to develop linkages between social actors dispersed across various disciplines and institutions which can contribute to an understanding of the complexity of the dengue problem and create effective interventions to achieve long-term control.  

Strengthening community capacity to identify risks and undertake interventions and recognise and adapt to changes in the social-ecological systems is indispensable for a sustainable dengue control program. 

A long-term vision requires the ability to adapt control programs to suit the changing behaviour of mosquitoes, including pesticide resistance and breeding site selection. An understanding of this adaptive response to habitat change or other control measures is necessary to target and modify control strategies accordingly. 

Experiences in other countries can provide useful insight to Sri Lankan policymakers. For example, in Vietnam, the application of copepods (Mesocyclops) to wells, tanks and other domestic containers led to the complete elimination of Aedes aegypti in several northern and central villages. 

Educational initiatives were used to teach householders about Aedes mosquito breeding sites in and around their houses. Schoolchildren were also involved in the implementation of activities with the support of their teachers. 

These national strategies to control dengue in Vietnam are highly relevant to Sri Lanka and at least now should form part of the dengue control package. Vietnam also has experience in the use of the Wolbachia bacteria. 

In 2014, after seven weeks of releasing Wolbachia mosquitoes on Tri Nguyen Island in Vietnam, 62% of local Aedes aegypti mosquitoes were found to carry Wolbachia. These releases will help Wolbachia to establish itself amongst the local mosquito population and dengue transmission on Tri Nguyen Island will reduce.  

We must promote awareness, capacity building and encourage the organisations and the public to actively respond to the dengue problem. Dengue control cannot be achieved without community empowerment and enhanced awareness. Dengue control activities must include integrated vector management and active participation of individuals, families and communities in reducing the sources where mosquitoes breed. 

More importantly, Sri Lanka must pursue a long-term solution to the problem without capitulating to short-term measures. Let us hope that this time sanity will prevail and that the Government will embrace the long-term solution so that the dengue scourge can be completely eliminated. If not, Sri Lanka will continue to suffer from this scourge for another two decades with enormous costs to the nation.  

(The writer can be reached at [email protected]).

The absence of any credible research system in Sri Lanka for dengue reflects a clear lack of any long-term vision even now. Past and present governments and the university system should have nurtured the hopes of Sri Lankan society but they have failed. Where are the Minister of Higher Education and the universities on the dengue issue? Given adequate financial and other support, the Sri Lankan university system can generate very useful results. Australia allocates nearly a $ 1 billion per year for university research under the Australia Research Council (ARC) system and it has become a global leader in research. Sri Lanka is far behind other countries because of its own misguided priorities