The World Health Organization (WHO) has ranked dengue as the fastest spreading mosquito-borne viral disease in the world, as seen through a 30-fold increase in global incidence over the past 50 years.
Dengue has spread at an alarming speed, with a jump from only nine countries affected in 1970 to now being endemic in more than 100 nations across WHO regions. Though the full global burden of the disease is still uncertain, the patterns are alarming for both human health and the global or emerging-market economy.
While dengue is a global concern, the surge in dengue incidence is significant in Asia, which accounts for 75 percent of the global population, or approximately 1.8 billion individuals, living at risk for dengue. These figures translate into the less visible, but perhaps more long-term, impactful effect of dengue—namely its economic burden on emerging economies in Southeast Asia.
Dengue is a serious and complex disease that can affect anyone regardless of age, gender, health or socioeconomic status. As governments seek to contain the disease, related healthcare costs rise accordingly. The current annual economic burden of dengue in Southeast Asia alone is estimated to be nearly $1 billion, or about $1.65 per capita, according to a research conducted from 2001 to 2010. The current burden of the disease this part of the world averages 2.9 million dengue cases and 5,906 deaths annually across 12 Southeast Asian countries. These numbers may be understated because of unreported and undiagnosed cases and, in fact, WHO is constantly revising its dengue burden of disease, citing recent improvements in reporting.
Costs stem from direct and indirect repercussions of dengue
The cost of dengue can be attributed to both the direct consequence, which includes high medical bills due mainly to dengue hospitalizations, as well as indirect consequences such as loss of work productivity among dengue victims.
At a national level, the most immediate economic impact of dengue is the strain on local and national health-care systems, which encompasses both hospitalizations and physician consultations that spike uncontrollably during outbreak situations.
The reported economic costs of dengue in the Philippines are significant. An estimated $8.2 billion is lost due to illness resulting from dengue every year.
The average cost of diagnosis per patient is $113. This costs more than the average therapeutic management for dengue, which costs about $98. The total direct medical cost of a treated hospitalized case averaged $772.46 in private hospitals and $387.84 in public hospitals. The average cost of a dengue case treated only in an ambulatory setting was $79.43 in the public sector and $168.31 in the private sector.
For instance, 70 percent to 80 percent of 14,000 dengue sufferers were hospitalized during the 2005 dengue outbreak in Singapore, accounting for about 10 percent of hospital beds. The rising number of cases, particularly during outbreaks, represents a huge burden to the health-care delivery system in the region.
Cost of dengue to individual families
At level of an impacted family’s economy, hospitalizations and medical bills were a major problem, especially among the poorer populations of the region. Nearly 50 percent of families in Vietnam, with a child having Dengue Hemorrhagic Fever (DHF), had to borrow money for treatment, and, after six months, 79 percent of them are still in the bed. Thailand also saw a financial loss of $61 in each of the affected families, an amount higher than the average monthly income in the country
In addition to the abovementioned costs, indirect consequences can worsen the situation. One indirect consequence that is often overlooked is the loss of productivity among dengue patients. Symptoms of dengue are often sufficient to confine patients to their bed for seven to 10 days as they suffer from dengue symptoms of prolonged fever, severe joint and muscle pain, and fatigue. This results in absenteeism from work or school as an immediate consequence. However, signs of lethargy may continue to plague victims for up to six months after recovery, reducing the productivity of affected individuals. During times of severe dengue outbreak, this impact is worsened due to the collective infection of workers, resulting in a major cumulative blow to workplace productivity and national economy.
An average of 10,000 dengue cases are reported annually in Malaysia, costing the country $135 million and each hospitalized case costs about $1,739. Dengue is, therefore, economically devastating for individuals and the governments.
Apart from tangible costs incurred from treatment and lost productivity, opportunity costs of time also adds to the staggering economic impact of dengue. Of the $1 billion incurred, 52 percent was attributed to lost productivity, suggesting that dengue outbreaks pose a major threat to a country’s gross domestic product (GDP).
Such costs prompt the need for immediate disease control, which, at this point, is limited to vector control policies. As of 2007, Singapore’s annual vector-control budget stands at $70 million, while Malaysia expended the same amount during an outbreak in 2008. To maximize preventive outcomes, WHO encourages an integrated approach to vector management, and sustained control measures at all levels.
Effect of dengue on tourism
The economic burden of dengue extends to an international level due to its impact on travel, both from within the country, as well as from tourists visiting regions that rely heavily on this industry. It is recognized that tourism is affected by the perception of health risks. More specifically, fear of contagion, amplified by mass-media coverage during epidemics, may deter tourists and travel to endemic regions. This could greatly impact regions that rely on tourism to drive the local economy.
Putting things into perspective, a 4-percent decline in tourists from nonendemic countries could cause a loss of $65 million for Malaysia and $363 million for Thailand. This figure is particularly pressing for Thailand as tourism accounts for 7 percent of its national GDP.
Foreign direct investments (FDI) could also take a backseat in hyper-endemic countries due to the negative publicity these countries receive in light of the dengue outbreaks.
Changes in public policy
Public policy-makers across Asia are being forced to consider the economic burden of dengue in terms of aggregate cost of treatment (borne by the patients, families and health-care systems), as well as in terms of lost productivity to businesses. Large urban areas that house manufacturing, logistics and financial centers in Southeast Asia are particularly impacted by dengue outbreaks as spread of dengue can rapidly impact business.
An example of this is the impact on businesses in Singapore’s Orchard Road area that became a dengue hotspot in the summer of 2013. The prime shopping belt saw more than 90 cases in a week at the height of the outbreak, posing significant threats to businesses in the area.
Drivers of dengue incidence and geographical spread
The rapid urbanization in Asia has resulted in millions of susceptible people moving to the cities. The insufficient housing and basic facilities, such as water supply, sewer and waste management, provides an ideal conditions for dengue transmission. Urbanization also creates millions of solid waste. The Asian Development Bank estimates that the waste quantities generated by Indian cities will increase from 46 million tones in 2001, to 65 million tones in 2010. Accumulation of solid waste also creates breeding sites of vectors.
Asia is currently home to over half of the world’s megacities and 53 percent of the world’s urban population. As Asia is expected to continuously being urbanized, the region’s megacities will suffer from further shortage of living space, which may eventually magnify the breeding of vectors.
Another significant factor in the increased economic burden of dengue in Asia is climate change. Global changes in temperature and rainfall patterns have brought with it corresponding geographical and seasonal expansion of dengue. As the Aedes mosquito vector of dengue is also highly sensitive to climate conditions, studies suggest that climate change could expose an additional 2 billion people to dengue transmission by the 2080s. Curbing dengue in response to climate change would be challenging given that there is currently no specific treatment for dengue.
Vaccine to reduce economic burden
By properly evaluating and recognizing the full economic burden of dengue outbreaks, policymakers and public health officials can make better informed decisions on the value of national dengue control programs, including the future utilization of vaccine.
Having been the first in the world to demonstrate efficacy in Phase 3 clinical studies, the Sanofi Pasteur candidate dengue vaccine is the most clinically advanced candidate in development. While vaccination is expected to alleviate the disease burden and be cost effective, a combined approach including vector control and vaccination will allow for a greater reduction of dengue burden and a better control of outbreaks.
The dengue vaccine has been recognized as a breakthrough in dengue fever management and one of the top science stories of 2014. This represents the most significant asset in securing long-term control and eventual eradication of the disease, as governments start to look at possible introduction of the vaccine into their market. Along with further efforts in raising awareness on vector control, the Asian region will be on the path to reducing the economic burden of dengue outbreaks shared by businesses, communities and governments, and on the path to meeting the goals of reducing dengue mortality by 50 percent and morbidity by 25 percent by WHO.