2. Countries selection

3–5 years [1–3]. Even though this illness has been present for many years in tropical countries, the main prevention strategy is controlling the vector that carries the infection. Nowadays, vector control and prevention programs are the only strategies in the hands of public officials

In the 1970s, because of the vector control campaign against yellow fever, dengue was close to be eliminated, but then it showed a reinvasion that has been present to this day [4]. The constant presence of the illness (and the mosquitoes) is related with the suboptimal conditions of trash collection, piped water supplies and uncontrolled urban development [5]. Another possible cause is climate change [6]. Warming temperatures have expanded the endemic territories of the A. aegypti and A. albopictus mosquitoes allowing them to be present in larger areas [7], which added to the low efficacy of vector control strategies and create the perfect scenario for the number of dengue cases to rise. Unfortunately, the programs aimed to control the mosquito population have low success rates which are reflected in the consistent high

In recent years, there has been enough interest from the pharmaceutical industry to develop a dengue vaccine that could act as a preventive strategy against the infection [8–10]. Nevertheless, most dengue vaccine strategies are still in their final stages before implementation [11].

Figure 1 shows the evolution of the reported dengue cases in the Americas for the period 2010– 2017, from which it can be observed a drastic decline in the year 2017 after 2 years of high levels of dengue cases. Particularly, 2015 corresponds to the year with the highest number of cases in the region, which suggest it was an epidemic year. Given the cyclic behavior of the

The World Health Organization (WHO) recommends conducting an economic analysis for infectious disease to estimate the cost borne by the society, especially in low- and middleincome countries. These studies provide information to the governments that help them design policies and allocate public resources that achieve a positive impact on public health. The most common and recommended type of analysis is the cost-effectiveness analysis (CEA), which

disease, the year 2017 could be interpreted as an interepidemic year.

Figure 1. Evolution of reported dengue cases in the Americas (2010–2017). Source: PAHO.

to handle and reduce dengue incidence.

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

number of dengue cases in the last decade.

To select the countries reviewed, we consider two main elements. The total number of dengue cases in each country according to Pan American Health Organization (PAHO) reports and the availability of information regarding total and average economic costs (per patient). Additionally,

<sup>1</sup> Although it is challenging to estimate a robust level for underreport, attempts have been made. In Brazil the underreport expansion factor for total dengue cases have been estimated in 1.6, while in Nicaragua this estimation goes as high as 28. Additionally, the estimation for the underreport factor specific for severe dengue cases ranges from 1.4 to 3 [20].

we aimed for having a relevant<sup>2</sup> country for each one of the main territories of the Americas as described by PAHO: Central America and Mexico, Andean, Southern Cone, and the Caribbean<sup>3</sup> (Map 1). Given that dengue cases recorded in North America usually correspond to nonendemic cases, we exclude from this chapter the information related to the USA and Canada.

To obtain robust figures for each country and avoid making a selection based on a particular year, we used the aggregated figures, by adding the total number of reported cases and death for the period 2014–2017. Based on the total number of reported dengue cases and deaths, we

selected Mexico as the representative country of the Central America and Mexico territory (Figure 2). Mexico has the highest number of dengue deaths (149) as well as the highest number of reported dengue cases (564,498). Another benefit of reviewing the Mexican case is the availability of information regarding total and per patient economic cost through a microcosting approach [17]. Similarly, for the Andean territory, we observed that the country with the highest number of reported dengue cases (337,018) and deaths (318) is Colombia (Figure 3). For this country, the cost for patient was calculated using a micro-costing approach that employed the administrative records of the national healthcare system and a household survey

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

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Figure 2. Dengue cases and mortality in Central America and Mexico territory (2014–2017). Source: PAHO. 2017.

In the Southern Cone territory (Figure 4), we observe Brazil as the country with the highest number of dengue cases (3,992,664) and deaths (2,048). The latter is particularly expected since

Figure 3. Dengue cases and mortality in Andean territory (2014–2017). Source: PAHO. 2017.

conducted by the authors [18].

Map 1. Incidence per 100,000 inhabitants in Americas (2014–2017). Source: PAHO. 2017.

<sup>2</sup> We consider a country as relevant based on the burden of the disease in terms of reported dengue cases and dengue related deaths.

<sup>3</sup> As Caribbean territory we considered both Latin Caribbean and Non-Latin Caribbean.

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 25

we aimed for having a relevant<sup>2</sup> country for each one of the main territories of the Americas as described by PAHO: Central America and Mexico, Andean, Southern Cone, and the Caribbean<sup>3</sup> (Map 1). Given that dengue cases recorded in North America usually correspond to nonendemic cases, we exclude from this chapter the information related to the USA and Canada. To obtain robust figures for each country and avoid making a selection based on a particular year, we used the aggregated figures, by adding the total number of reported cases and death for the period 2014–2017. Based on the total number of reported dengue cases and deaths, we

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

Map 1. Incidence per 100,000 inhabitants in Americas (2014–2017). Source: PAHO. 2017.

As Caribbean territory we considered both Latin Caribbean and Non-Latin Caribbean.

We consider a country as relevant based on the burden of the disease in terms of reported dengue cases and dengue

2

3

related deaths.

Figure 2. Dengue cases and mortality in Central America and Mexico territory (2014–2017). Source: PAHO. 2017.

selected Mexico as the representative country of the Central America and Mexico territory (Figure 2). Mexico has the highest number of dengue deaths (149) as well as the highest number of reported dengue cases (564,498). Another benefit of reviewing the Mexican case is the availability of information regarding total and per patient economic cost through a microcosting approach [17]. Similarly, for the Andean territory, we observed that the country with the highest number of reported dengue cases (337,018) and deaths (318) is Colombia (Figure 3). For this country, the cost for patient was calculated using a micro-costing approach that employed the administrative records of the national healthcare system and a household survey conducted by the authors [18].

In the Southern Cone territory (Figure 4), we observe Brazil as the country with the highest number of dengue cases (3,992,664) and deaths (2,048). The latter is particularly expected since

Figure 3. Dengue cases and mortality in Andean territory (2014–2017). Source: PAHO. 2017.

found. Thus, we used the costs per patient estimated by Shepard [20] by extrapolating the results from other countries and considering the differences in purchasing power and income4

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

To assess the economic cost of the disease, we used the results found for Brazil, Colombia, the Dominican Republic, and Mexico. To maintain cost structure homogeneity, we exploited the common methodological framework used in the literature, which is employed in the papers reviewed. There are three main cost categories used to quantify the economic burden of a

Direct medical cost comprises the cost borne by the healthcare unit (professional services, medical inputs, medical drugs, laboratory test). Additionally, direct non-medical cost corresponds to the value expended during a dengue episode and comprises food, lodging and travel expenses. Finally, indirect cost includes the productivity loss5 (by patient and caregivers).

Even though the authors researched a common topic, there are some methodological differences that are worth noting to make a correct comparison between the results. In contrast to Mexico [17], Colombia [18] and Brazil [19] estimate the direct cost per patient grouping the medical and non-medical component in the same category, thus their figures could only be compared to the sum of medical and non-medical direct cost6 from Mexico and Colombia.

Although the three studies present their results in dollars, nominal adjustment<sup>7</sup> was needed<sup>8</sup>

for this we use the GDP deflator calculated by the World Bank for each country. Once the appropriate per patient is defined, the total number of reported dengue cases is required to estimate the total cost in each country; for this, we took the information reported by PAHO for

Productivity loss corresponds to a monetary estimate of the days of work lost by the patient as well as caregivers.

real � <sup>1</sup> <sup>þ</sup> <sup>Δ</sup>%i,j

real � GDPreal,j

nominal � GDPnominal,j

GDPreal,j

Nominal adjustment accounts for price changes due to inflation between years. This adjustment allows for proper

nominal � GDPnominal,j

disease: direct medical cost, direct non-medical cost, and indirect cost.

More details about the methodology employed by the authors can be found in [20].

To nominally adjust the cost figures the GDP deflator was used for two different years ð Þ i; j .

GDPnominal,i <sup>¼</sup> <sup>1</sup> <sup>þ</sup> <sup>Δ</sup>%i,j

nominal <sup>¼</sup> def <sup>i</sup> def <sup>j</sup> � 1

GDPreal,i <sup>¼</sup> <sup>1</sup> <sup>þ</sup> <sup>Δ</sup>%i,j

<sup>¼</sup> <sup>1</sup> <sup>þ</sup> <sup>Δ</sup>%i,j

def <sup>i</sup> <sup>¼</sup> GDPnominal,i GDPreal,i

Direct non-medical costs include out-of-pocket expenses borne by the patient.

¼) GDPnominal,i GDPreal,i

¼)Δ%i,j

comparison between figures from different years.

3. Materials and methods

4

5

6

7

8

.

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,

Figure 4. Dengue cases and mortality in Southern Cone territory (2014–2017). Source: PAHO. 2017.

not only Brazil has the largest population in the region (Southern Cone and Andean territory), but also the other countries in this territory are sub-tropical (Paraguay) and non-tropical (Chile, Argentina and Uruguay). The advantage of reviewing the Brazilian case is the large evidence of total and per patient economics costs which has been estimated using micro-costing, bottomup approach from administrative records, household survey and interviews [19].

Finally, for the Caribbean territory, we found that, based on the information from PAHO, between 2014 and 2017, the country with the highest number of dengue cases (31,326) and deaths (209) is the Dominican Republic (Figure 5). In contrast to Brazil, Colombia and Mexico, no published study, which quantifies the cost of the disease per patient considering the same cost structure framework commonly found in the literature (direct and indirect costs), was

Figure 5. Dengue cases and mortality in the Caribbean territory (2014–2017). Source: PAHO. 2017.

found. Thus, we used the costs per patient estimated by Shepard [20] by extrapolating the results from other countries and considering the differences in purchasing power and income4 .
