**2. Epidemiology**

CD is endemic in 21 countries in Latin America, from Mexico to the south of Argentina and Chile. Nevertheless, due to migrations and climate change, the disease has spread alarmingly to other parts of the world [6]. The World Health Organization (WHO) classifies this parasitic disease as a VBD (Vector-Borne Disease) that is among the unattended tropical diseases associated to extreme poverty in rural areas where the vectors are distributed, which favors their transmission route [7]. VBDs can be caused by bacteria, virus, and parasites, are usually transmitted by bloodsucker arthropods, represent 17% of all infectious diseases, and are prevalent in tropical and subtropical regions [8]. During the past three decades, the epidemiological overview of this disease has experienced important changes due to the implementation of vector control measures such as the use of pesticides and housing improvements [9]. In this respect, there has been a clear descent in the number of people infected by *T. cruzi*, going from 30 million in 1990 to 6–7 million currently infected. The incidence has also decreased from 700,000 estimated cases in 1990 to 30,000 cases per year in 2018. Furthermore, the mortality has gone down from 45,000 to 12,000 deaths in the same years [10, 11]. Despite all these efforts, CD continues to be an important health problem. Migration of asymptomatic people in chronic stage, who are unaware of their infection, has led to the spread of the disease to urban areas and nonendemic regions, increasing the frequency of cases in countries such as the United States, Japan, Australia, Spain, Italy, the United Kingdom, and other European countries where it is considered an emerging disease [6, 12]. In Latin America, Argentina (1,535,235), Brazil (1, 156, 821), and Mexico (876, 458) are the countries with the highest number of cases, followed by Bolivia with 607, 186 cases, making it the

*Modulation of Host Cell Apoptosis by* Trypanosoma cruzi*: Repercussions in the Development… DOI: http://dx.doi.org/10.5772/intechopen.103740*

country with the highest prevalence, with an estimate between 6.8 and 18% of the population seropositive for *T. cruzi* [13]. Recent estimations suggest that there could be 300,000 infected people with *T. cruzi* in the United States [14]. A study performed in Los Angeles reported a seroprevalence of 5.2% among Latin American migrants who also presented cardiac abnormalities [15]. Outside of America, Spain is the most affected country. It is estimated that only in this country there could be more than 50,000 infected individuals, most of them South American immigrants [16].
