4. Results

the year 20159

Eq. (1).

9

10

11

only to ambulatory cases and hospitalized cases.

28 Dengue Fever - a Resilient Threat in the Face of Innovation

hospitalized dengue cases, and PPC per patient cost.

patient and indirect cost per patient.

systems of mandatory notification across the national territories.

hospitalized cases; both figures are used as reported by PAHO.

due to Disability (YLD) for people living with the health condition or its consequence.

. Considering potential lack of homogeneity among countries regarding labora-

tory confirmation practices and policies, we used total reported cases instead of laboratory confirmed cases for our analysis; we allow for this since reported dengue cases also received treatment and PAHO definition for reported cases only includes people "who has a fever or history of fever for 2-7 days duration, two or more symptoms of dengue and one serological test positive or epidemiological nexus with confirmed dengue case 14 days before onset of symptom." Even though using reported dengue cases, we are allowing for a potential overestimation of the economic burden, it is worth noting that by using DALY figures from WHO, we avoid this potential bias in the burden of the disease. It might also be noted that by using this approach, the results we found could be interpreted as an upper bound for the economic burden of the disease. To calculate the total treatment cost, we make the following assumption, and severe cases are considered to receive hospitalized treatment while nonsevere dengue cases<sup>10</sup> are considered to receive ambulatory treatment. From now on, we will refer

Total treatment cost was calculated for both ambulatory and hospitalized cases as presented in

where TC represents total cost, AD number of ambulatory dengue cases, HD number of

PPCi ¼ DMCi þ DnMCi þ ICi,

where DMC represents direct medical cost, DnMC direct non-medical cost and IMC indirect cost. In other words, the total cost of the disease is equal to the number of dengue cases times the cost per patient, for both ambulatory and hospitalized cases. The total treatment cost per patient corresponds to the sum of direct medical cost per patient, direct non-medical cost per

As estimates for the burden of the disease, measured as the number of Disability Adjusted Life Years (DALY)11, we use the figures from the World Health Organization (WHO) for the year

We considered the last published report that includes the information from the whole year. PAHO gathers epidemiological information from official reports made by the countries themselves. Thus, PAHO figures represent the official number of reported dengue cases, death and incidence. This mechanism has been working since 1980 and nowadays counts with

The number of ambulatory dengue cases is equal to the total number of reported cases minus the total number of

According to WHO, one Disability Adjusted Life Years can be thought of as one lost year of "healthy" life. The sum of these DALYs across the population can be thought of as a measurement of the gap between current health status and an ideal health situation where the entire population lives to an advanced age, free of disease and disability and are calculated as the sum of the Years of Life Lost (YLL) due to premature mortality in the population and the Years Lost

TC ¼ AD � PPCambulatory þ HD � PPChospitalized (1)

i∈ f g ambulatory; hospitalized (2)

After nominally adjusting the figures, the cost per patient found by the authors for Brazil, Colombia, the Dominican Republic, and Mexico are shown in Table 1. Since the authors used the same cost structure in their estimation process, we can separate the total cost into their main categories (direct medical and non-medical cost and indirect cost). The figures are presented in 2017 prices, which allows for comparison. Table 1 shows the total cost per patient disaggregated.

In the four countries reviewed, Mexico is the one with the most expensive treatment cost per patient in ambulatory care, even when their indirect cost is the lowest. For ambulatory cases, in contrast to Brazil, Colombia, and the Dominican Republic, the direct medical cost in Mexico is larger than the direct non-medical cost and the indirect cost (even when combined). For hospitalized cases, Mexico keeps having the most expensive treatment cost per patient, with direct costs that more than double the direct costs of the other countries.

The latter shows that Mexico has the most expensive dengue treatment per patient, regardless of the type of care (ambulatory US\$ 501 or hospitalized US\$ 1,475). On the other hand, the less expensive treatment for ambulatory (US\$ 189) and hospitalized (US\$ 488) cases would be in Brazil.

<sup>12</sup>We do not find this assumption to be particularly strong.

<sup>13</sup>Recalling the method used to estimate the total cost of the disease it is noteworthy that the latent risk of overestimation is not present in the estimation of the burden of the disease (DALY), as it is estimated by extrapolating the results of 2005 using the ratio of DALY per reported dengue case.


Source: Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices 2017.

in the country. In terms of burden of the disease, measured as DALY, Brazil keep having the highest figures in absolute terms (49,500 DALYS), followed by Colombia (16,200 DALYS).

Table 3. Total annual treatment cost and DALYs lost per million inhabitants by country (2015). 2017 dollars.

Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard,

Total ambulatory (US Dollars) 310,672,689 31,052,056 3,411,045 107,351,329 Total hospitalized (US Dollars) 766,211 1,096,202 1,637,140 8,060,036 Total cost (US Dollars) 311,438,900 32,148,258 5,048,184 115,411,366 Total DALY 49,500 16,200 9,600 12,100 Population 204,469,667 48,202,951 9,980,185 121,006,250 DALY per million inhabitants 242 336 962 100

The Burden of Dengue Illness and Its Economics Costs in the Americas: A Review on the Most Affected Countries

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31

Having DALY in absolute terms does not allow for a proper comparison, therefore, we adjusted the results by dividing them by the country-specific population. Hence, we could express the burden of the disease as the number of DALY per million inhabitants, which is now perfectly comparable between countries. Now, Brazil is not the country with the highest burden relative to its population size, but the Dominican Republic (336 DALYS per million inhabitants), followed

As well as adjusting the DALY by the population, it is also important to adjust the total treatment cost relative to some economic measure that allows to compare figures between countries in a proper manner. One alternative is to present the results as share of the total Gross Domestic Product (GDP) of each country, but this approach has two disadvantages. First, the resulting figures are too small, which by multiplying them by a factor makes the interpretation more difficult, and second, it does not consider GDP composition. Instead, we have used the total health expenditure estimated by the World Bank (WB) to adjust the total treatment cost. Table 4 exhibits the total health expenditure by country in US billion dollars for

Once adjusted, the total annual cost is very similar among countries. Notably, Colombia and Mexico spend nearly the same proportion (0.18%) of their health expenditure in dengue treatment, and Brazil has a lower share than the latter (0.16%). Given the country selection criteria used, one could assert that the average share of total cost caused by dengue treatment

GDP (US Dollars billions) 2,142 297 67 1,093 Health expenditure (US Dollars billions) 191 18 4 64 Health expenditure (% of GDP) 8.9 6.2 6.2 5.9

Brazil Colombia The Dominican Republic Mexico

by Colombia, which remains in second place (962 DALYS per million inhabitants).

2015 (in 2017 prices).

Source: World Bank. IMF.

Table 4. Total health expenditure (2015). 2017 dollars.

et al. (2011) [20]. Prices 2017.

Table 1. Treatment cost per patient by country (nominally adjusted 2017 dollars).

Since the number of cases presented in Table 2 is not corrected by country-specific population, they cannot be directly compared between themselves; nevertheless, we can observe that more than half the total number of de dengue cases in the Americas in 2015 are located in Brazil (69.1%) and although the population of Brazil is less than twice the population of Mexico, its number of dengue cases exceeds twice the number dengue cases of the latter. This exhibits a concerning situation for the public health in Brazil. Once we controlled for the population of each country, we found that in 2015, the lowest incidence rate corresponds to the Dominican Republic and the highest to Brazil. Although the Dominican Republic has the lowest incidence rate, its mortality rate is much higher than that of the other countries.

Once we have defined the total number of dengue cases for each country and its corresponding treatment cost, it is possible to calculate the total cost following Eqs. (1) and (2). Table 3 exhibits the total treatment cost for the year 2015 (in 2017 prices). In absolute terms, the highest economic cost corresponds to Brazil, which, as was shown before, has the less expensive treatment cost per patient, hence the extent of the total cost is mainly due to the high incidence


Table 2. Number of cases, death and epidemiological by country (2015).

The Burden of Dengue Illness and Its Economics Costs in the Americas: A Review on the Most Affected Countries http://dx.doi.org/10.5772/intechopen.79887 31


Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices 2017.

Table 3. Total annual treatment cost and DALYs lost per million inhabitants by country (2015). 2017 dollars.

in the country. In terms of burden of the disease, measured as DALY, Brazil keep having the highest figures in absolute terms (49,500 DALYS), followed by Colombia (16,200 DALYS).

Having DALY in absolute terms does not allow for a proper comparison, therefore, we adjusted the results by dividing them by the country-specific population. Hence, we could express the burden of the disease as the number of DALY per million inhabitants, which is now perfectly comparable between countries. Now, Brazil is not the country with the highest burden relative to its population size, but the Dominican Republic (336 DALYS per million inhabitants), followed by Colombia, which remains in second place (962 DALYS per million inhabitants).

As well as adjusting the DALY by the population, it is also important to adjust the total treatment cost relative to some economic measure that allows to compare figures between countries in a proper manner. One alternative is to present the results as share of the total Gross Domestic Product (GDP) of each country, but this approach has two disadvantages. First, the resulting figures are too small, which by multiplying them by a factor makes the interpretation more difficult, and second, it does not consider GDP composition. Instead, we have used the total health expenditure estimated by the World Bank (WB) to adjust the total treatment cost. Table 4 exhibits the total health expenditure by country in US billion dollars for 2015 (in 2017 prices).

Once adjusted, the total annual cost is very similar among countries. Notably, Colombia and Mexico spend nearly the same proportion (0.18%) of their health expenditure in dengue treatment, and Brazil has a lower share than the latter (0.16%). Given the country selection criteria used, one could assert that the average share of total cost caused by dengue treatment


Table 4. Total health expenditure (2015). 2017 dollars.

Since the number of cases presented in Table 2 is not corrected by country-specific population, they cannot be directly compared between themselves; nevertheless, we can observe that more than half the total number of de dengue cases in the Americas in 2015 are located in Brazil (69.1%) and although the population of Brazil is less than twice the population of Mexico, its number of dengue cases exceeds twice the number dengue cases of the latter. This exhibits a concerning situation for the public health in Brazil. Once we controlled for the population of each country, we found that in 2015, the lowest incidence rate corresponds to the Dominican Republic and the highest to Brazil. Although the Dominican Republic has the lowest incidence

Direct medical \$70 \$75 \$75 \$281 Direct non-medical \$33 \$14 \$102 Indirect \$119 \$219 \$136 \$118 Total \$189 \$327 \$224 \$501

Direct medical \$258 \$368 \$366 \$1,123 Direct non-medical \$59 \$152 \$193 Indirect \$230 \$345 \$366 \$159 Total \$488 \$771 \$883 \$1,475 Source: Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices

Brazil Colombia The Dominican Republic Mexico

Once we have defined the total number of dengue cases for each country and its corresponding treatment cost, it is possible to calculate the total cost following Eqs. (1) and (2). Table 3 exhibits the total treatment cost for the year 2015 (in 2017 prices). In absolute terms, the highest economic cost corresponds to Brazil, which, as was shown before, has the less expensive treatment cost per patient, hence the extent of the total cost is mainly due to the high incidence

Ambulatory dengue 1,647,439 95,023 15,194 214,129 Hospitalized dengue 1,569 1,421 1,854 5,464 Deaths 863 155 107 42 Incidence per 10.000 inhabitants 80.6 20.0 17.1 18.1 Mortality rate (%) 0.05 0.16 0.63 0.02

Brazil Colombia The Dominican Republic Mexico

rate, its mortality rate is much higher than that of the other countries.

Table 1. Treatment cost per patient by country (nominally adjusted 2017 dollars).

Cost per ambulatory patient

30 Dengue Fever - a Resilient Threat in the Face of Innovation

Cost per hospitalized patient

2017.

Number of cases

Source: PAHO. 2015. Week 52. IMF.

Table 2. Number of cases, death and epidemiological by country (2015).

in health expenditure in an epidemic year is 0.16% for the countries with the highest number of cases (Table 5). Although this result cannot be perfectly extrapolated to all the countries of the Americas, it could be interpreted as an upper bound for the size of the economic burden of dengue in the region.

Figure 6 shows the normalized treatment cost14 and burden for each country. We can observe that while the Dominican Republic is the country with the highest number of DALY adjusted by population, it has the lowest cost per each DALY lost because of the disease. In contrast, Mexico has the highest cost per DALY lost, but the lowest number of DALY adjusted by population.

Finally, Table 6 exhibits the 2015 total economic cost per DALY adjusted for purchasing power parity (PPP). There appears to be high variance in the total treatment cost, with its ranges from \$1,157 in the case of the Dominican Republic to \$17,703 for Mexico. It is noteworthy that Mexico, in relative terms, always presents the highest treatment cost. This result is consistent whether we analyze the total treatment cost per patient, the share of total annual cost over the total health expenditure or the total treatment per DALY adjusted for PPP.

The variance in the results could be explained by the income gap between countries. If we consider the GDP per capital as proxy for the median income of each country, it makes sense that Mexico and Brazil have the highest cost per case and DALY since their GDP (US\$ 9,033 and US\$ 10,476 respectively) is close to 50% higher than the GDP per capita of Colombia and

Total ambulatory (PPP Dollars) \$11,190.5 \$4,385.6 \$782.0 \$16,466.4 Total hospitalized (PPP Dollars) \$27.6 \$154.8 \$375.3 \$1,236.3 Total cost (PPP Dollars) \$11,218.1 \$4,540.4 \$1,157.3 \$17,702.7 Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard,

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According to the review made by Shepard [22], who estimate the burden at a global scale for the year 2013, Latin-American and the Caribbean regions exhibit the highest treatment cost per case. From this perspective, our review presents the burden of the disease for the most affected countries, in terms of reported cases, of the region with the most expensive treatment cost. The latter is particularly relevant if we considered the estimates of the share of total treatment cost over the total health expenditure presented because our results could be interpreted as an

As mentioned before, in this section, we will discuss how the total treatment cost and the burden change in 2017, which we consider to be an inter-epidemic year given the low number

Total ambulatory (US Dollars) 47,458,401 8,494,113 285,339 44,878,911 Total hospitalized (US Dollars) 184,593.94 220,629 77,707 553,169 Total treatment cost (US Dollars) 47,642,995 8,714,742 363,046 45,432,079 Total DALY 7,599 2,481 259 7,554 Population 207,680,999 49,293,878 10,172,243 123,517,856

DALY per 1 million inhabitants 37 50 25 61

Table 7. 2017 Economic and DALY lost per million inhabitants by country (2017 dollars).

Source: PAHO. 2017. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard,

Brazil Colombia The Dominican Republic Mexico

the Dominican Republic (US\$ 6,161 and US\$ 6,713 respectively).

Table 6. 2015 Total economic cost per DALY (2017 PPP dollars).

upper bound for relative economic burden of dengue.

of cases relative to previous years (2010–2017) (Table 7).

5. Discussion

et al. (2011) [20]. Prices 2017.

et al. (2011) [20]. Prices 2017.


Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices 2017.

Table 5. Total annual treatment cost as share of the total health expenditure (2015).

Figure 6. Normalized results. 2015. Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices 2017.

<sup>14</sup>Variable definition: level of current health expenditure expressed as a percentage of GDP. Estimates of current health expenditures include healthcare goods and services consumed during each year. This indicator does not include capital health expenditures such as buildings, machinery, innovation and technology and stocks of vaccines for emergency or outbreaks.

The Burden of Dengue Illness and Its Economics Costs in the Americas: A Review on the Most Affected Countries http://dx.doi.org/10.5772/intechopen.79887 33


Source: PAHO. 2015. Week 52. Martelli, et al. (2015) [19], Castro, et al. (2015) [18], Undurraga, et al. (2014) [17], Shepard, et al. (2011) [20]. Prices 2017.

Table 6. 2015 Total economic cost per DALY (2017 PPP dollars).

The variance in the results could be explained by the income gap between countries. If we consider the GDP per capital as proxy for the median income of each country, it makes sense that Mexico and Brazil have the highest cost per case and DALY since their GDP (US\$ 9,033 and US\$ 10,476 respectively) is close to 50% higher than the GDP per capita of Colombia and the Dominican Republic (US\$ 6,161 and US\$ 6,713 respectively).
