The global burden of dengue is three times what the World Health Organization (WHO) has estimated, says a study published in the journal Nature on April 7, 2013.
In a map of the world that demonstrates the spread of the disease, researchers indicate India as having contributed more than one-third of the burden in the year 2010. The same study claims, “Asia bore 70 per cent of the burden and is characterised by large swathes of densely populated regions coinciding with very high suitability for disease transmission.”
The researchers estimate that around 390 million dengue infections take place across the world every year. According to the study, the total number of infections is more than triple WHO’s most recent estimate of 50-100 million infections per year. The researchers say that the risk maps and burden estimates would help predict the future burden of the disease.
The investigators collected the known records of dengue occurrence worldwide and used a modelling framework to map the global distribution of dengue risk. They then correlated this to a database of 8,309 occurrence records for the period 1960 to 2012 from a combination of published literature and online resources. Simon Hay, a Wellcome Trust Senior Research Fellow at the University of Oxford who was part of the team, explained, “We found that climate and population spread were important factors for predicting the current risk of dengue around the world. With globalisation and the constant march of urbanisation, we anticipate that there could be dramatic shifts in the distribution of the disease in the future: the virus may be introduced to areas that previously were not at risk, and those that are currently affected may experience increases in the number of infections.”
Dengue is a viral infection that is transmitted between humans by mosquitoes. In some people, it causes life-threatening illness. In another article published in British Medical Journal last December, a senior public health specialist of the Public Health Foundation of India, Manish Kakkar, claimed that large number of dengue cases go unreported in the country every year. He wrote, “As of November 26, 2012, 37,070 cases of dengue fever had been reported in India. But a substantially bigger population is at risk, and India reported only an average of 4.2 per cent of the total number of cases reported in the World Health Organization South East Asia region between 2000 and 2010.”