5 Riskiest Nations for Contracting Dengue Fever in Southeast Asia

Dengue fever outbreaks have plagued Southeast Asia for decades, but incidences of the virus over the past year have proven especially troubling. Case rates have doubled for many nations, and deaths from the virus–often children and seniors–are on the rise. Dengue fever, a mosquito-borne viral infection, cannot be cured by treatment. Instead, it must be closely monitored by medical professionals. To help you better navigate risk within the region, we've analysed the case and mortality rates and access to healthcare across SE Asia, identifying the 5 nations with the greatest risk for contracting dengue fever.

Riskiest Nations for Contracting Dengue Fever in SE Asia

1. Philippines

Within the first 48 weeks of 2019 (by 30 November), the Philippines reported 414,532 cases of dengue fever within the country–amongst the highest numbers reported across SE Asian countries. According to the World Health Organization, an estimated 3,000+ people died from dengue in 2016. Even after controlling for population size, this is the highest death rate within the region by far, or 21% higher than the runner-up.

In addition to its high risk of contraction, access to quality healthcare is limited. The Philippines has the lowest hospital bed density in the region at 5 per 10k people. While the physician to patient ratio is moderately competitive (1.3 doctors per 1k people as of 2010), personal spending is almost double what the government spends per individual on healthcare every year. As a result, even if doctors are available, hospitals can quickly become overcrowded and services may not be affordable for some. The high rate of cases and deaths–as well as limits to healthcare accessibility–make the Philippines the riskiest nation in SE Asia for contracting dengue fever.

Philippines Rankings

2. Maldives

While the Maldives only reported 4,793 cases of dengue fever within the 1st 44 weeks of 2019, the nation's population is the smallest amongst the nations surveyed, by over 5.2 million. As a result, the Maldives's density of fever contraction is the highest in the region by a big margin. This also holds true for its death rate, which is moderate-to-high within the region.

Healthcare access and affordability only partially offset the risks associated with contraction. While the Maldives has the highest hospital bed density in SE Asia, with 43 beds per 10k people, its physician rate is quite low at 1 doctor per 1k people (as of 2016). While annual government spending on healthcare is 2.4x higher than citizens' personal spend, the average resident spends more out-of-pocket as a percentage of their salary than those in other nations–including Singapore and Malaysia.

Maldives Rankings

3. Indonesia

A total of 110,921 cases of dengue were reported in Indonesia within the 1st 40 weeks of 2019 (up to November 2019), which is actually moderate-to-low when population size is taken into consideration. Nonetheless, the nation's death rate from dengue is 2nd highest in the region, just below the Philippines. This may be due to poor access to quality healthcare. There were only 0.4 physicians per 1k people as of 2017, and the nation received a Healthcare Access and Quality [HAQ] Index Score of just 44.5 out of 100. This index measures "mortality to incidence ratios from causes that, in the presence of quality healthcare, should not result in death." For reference, Australia scored 95.9 on this index, more than double the score received by Indonesia. Due to poor access to quality medical care, Indonesia ranks amongst the riskiest nations for contracting dengue fever.

Indonesia Rankings

4. Sri Lanka

Sri Lanka reported 104,155 cases of dengue fever in 2019. Given its population size of 21 million, case density is actually quite high. This is also true when considering the estimated 347 dengue-related deaths in 2016; the population-standardised mortality rate is the 4th highest within the region, even above the Maldives. Sri Lanka had 35 hospital beds per 10k people which is reasonably competitive, but only 1 doctor per 1k patients as of 2017, which is quite low. Even still, the nation scored 70.6 on the HAQ Index which is moderately high, suggesting that while risk of contraction is high, access to quality medical treatment in Sri Lanka may be a bit more reliable.

Sri Lanka Rankings

5. Laos

Laos reported 38,753 dengue cases within the 1st 49 weeks (up to December) of 2019. Taking population into consideration, case density ranks 2nd highest in the region, right behind the Maldives. Mortality rates, however, are notably lower than in many other SE Asian nations that might be considered "risky" for contracting dengue. Nonetheless, this isn't reflected in the nation's HAQ Index Score of 36.6–the lowest in the region. Laos had only 15 hospital beds per 10k people as of 2012 and just 0.5 doctors per 1k people in 2014. These statistics suggest that becoming ill in itself may be quite risky in Laos. Given such circumstances, the nation's very low out-of-pocket expenditure rate on health services may not be as impressive. After all, affordable medical care is not as valuable when its quality is greatly lacking.

Laos Rankings

Least Risky SE Asian Countries for Contracting Dengue

New Zealand

New Zealand is perhaps the least risky nation in the region for contracting dengue fever. In fact, cases of dengue are extremely rare within the country. Aedes mosquito carriers themselves are not normally found in New Zealand.

Australia

Dengue fever is also quite rare in Australia, partially as Aedes mosquito carriers are also not commonly found within the country. The virus is typically spread when someone becomes infected overseas. Once they return, a mosquito may bite them and then spread the virus to others. While dengue cannot be spread from person to person, it can in fact be transmitted through mosquitoes that uptake and then spread infected blood.

Thailand

Thailand is currently considered to be in the midst of a dengue fever outbreak. It's lower ranking within this study does not deny the risk of contracting the virus altogether–it simply reflects that neighbouring regions pose an even larger risk. For example, Thailand reported 82,947 cases within the 1st 49 weeks of 2019. After standardising for duration, this number is lower than that reported by the Philippines, Vietnam, India, Indonesia, Malaysia, and Sri Lanka. After controlling for population size, Thailand has the 4th lowest case density out of the 12 nations reviewed. This is also true for mortality rate.

Thailand's access to quality healthcare is not quite as strong. There were only 21 beds per 10k people in 2010, and just 0.8 doctors per 1k people as of 2017. However, the nation's HAQ Index Score is a moderate 69.5 and residents have access to the most affordable medical care in the region. As a result, while the current uptick in dengue cases within Thailand may be considered an outbreak, the country may not be quite as risky as its neighbours.

Singapore

Recently, dengue fever has been in the news quite a lot in Singapore. Case occurrences are on the rise, and rare strains of the virus have shown up on the island. In fact, the government reported 15,142 cases within the 1st 49 weeks of 2019. While this number pales to case numbers reported by the Philippines and Indonesia, Singapore is quite small. After standardising for population size, Singapore's case density is actually higher than in several other nations–including Indonesia.

Death rates are extremely low, nonetheless. This may be, in part, due to Singapore's high quality healthcare system. The nation received a HAQ Index Score of 90.6, second in the region only to Australia (95.9). Singapore also has the 2nd highest physician density score at 2.3 doctors per 1k population as of 2016, and government spend outweighs personal healthcare spend by a notable margin. While dengue fever incidences may be increasing in number, rates are still moderately low within the region, and the national medical system provides substantial, high-quality support.

Methodology & Discussion of Categories

Our analysis drew on a variety of data points to fully capture the risk of contracting–and then successfully recovering from–dengue fever. We identified the 12 nations in SE Asia with the highest number of reported dengue cases, and then ranked each according to the density of cases and mortality rates, access to quality medical care, and medical costs.

Overall Country Rankings

Dengue Case & Death Density

The risks associated with dengue fever are irrelevant if there's no chance of contracting the virus. As a result, our first step was to collect the number of dengue fever cases reported by each nation's government in 2019. Different governments' latest reports had different end dates–for example, some listed cases reported within the 1st 46 weeks of the year, and others reported cases within the 1st 48 weeks. To remedy this discrepancy and standardise occurrence rate, we calculated the average case per week for each nation. As all reports covered 2019 up to November or mid-December, there were no major discrepancies caused by seasonality, allowing us to use this metric as a confident standardised measure.

Next, we paired the number of cases with each nation's population size to determine case density. After all, a larger country is more likely to have a larger number of reported cases than a small country might, even if density of cases reported is much higher in the smaller country. We also drew data from the World Health Organization to compare the number of deaths from dengue in each country as of 2016, and paired this data with 2016 population rates to determine standardised mortality rates. To bring this information together, we applied an intensity factor across subgroup values to accentuate spacing between the values, parse out "ties," and arrive at a final rank value.

Subcategory: Dengue Case & Death Density

Access to Quality Medical Care

Contracting a virus becomes riskier when adequate medical care is not accessible. To integrate this factor into our ranking, we considered several data points. First, we recorded each nation's score on the IHME's 2016 Healthcare Access and Quality [HAQ] Index, which measures "mortality to incidence ratios from causes that, in the presence of quality healthcare, should not result in death." Scores range from 0-100, with 100 approximating ideal conditions. We also recorded each nation's hospital bed density, or number of beds per 10k people, and physician density, or number of doctors per 1k people, from the World Health Organization and World Bank, respectively. To determine an aggregate rank for the category, we applied an intensity factor to subgroup values, parsing out differences by highlighting spacing within the data.

Subcategory: Access to Quality Medical Care

Medical Costs

Finally, the quality of medical care is closely linked with affordability. To determine accessibility of medical treatments, we referred to the Institute for Health Metrics and Evaluation (IHME) for a breakdown of annual health expenditures per individual by country in 2016. We first compared personal spending (prepaid private health spending and out-of-pocket spending) to government spending (domestically financed only). This metric clarifies where the financial burden primarily rests. Next, we compared out-of-pocket medical spending to the average salaries for each country (both standardised to USD). This allowed us to better understand the financial impact of out-of-pocket expenses for each country's residents. Finally, we calculated an aggregate rank by applying an intensity factor, which clarified spacing within the data to parse out potential "ties."

Subcategory: Medical Costs

Bringing the Data Together

Based on the intent of the study, we weighted scoring across each of the 3 main categories to calculate the final, overall ranking. Dengue Case & Death Density received the highest weight (65%), followed by Access to Quality Medical Care (25%), then Medical Costs (10%). We opted for this ranking system as contracting dengue fever would first and foremost be riskiest in areas with high incidences and deaths from the virus. After this consideration, access to medical care does play a meaningful role, as patients are encouraged to go to hospitals for diagnosis and treatment (though it is possible to recover without doing so). Finally, even if quality medical care is available, it may not serve a population well if it's unaffordable. As a result, we included this last metric to control for countries that especially put the financial burden on their citizens.

Study Limitations

This research covers 12 nations in SE Asia, focusing on those that have experienced dengue fever outbreaks within the past several years. We drew from the most up-to-date data available from credible sources, including national government case reports, the World Health Organization, World Bank, and Institute for Health Metrics and Evaluation.

For this study, we did not touch upon government initiatives or programmes for each nation. Instead, this research focuses on the current dynamic within the region. While many governments have developed or implemented preventative programmes, these policies may take several years to effectively spread beyond targeted cities and often heavily depend on the lifestyle choices of individual residents. It may also be hard to measure the effectiveness of such campaigns as climate change and outbreak cycles can disrupt expected trends. As many countries are currently experiencing dengue outbreaks across SE Asia, we've opted to analyse the region to better understand immediate risk.