modes of transmission and distribution factors - various scenarios 
 should be considered when trying to understand the transmission dynamics of t. 
 cruzi . the emergence of transmission of t. cruzi and the 
 maintenance cycle of chagas disease involve a diversity of elements . there is diversity 
 in vector species , their behaviours and biotopes ( fig . 
 1 ) 2012 ) , diversity in its wild and human hosts , in 
 their potential susceptibility to infection and in their response and there is also 
 diversity in the behaviours of the people infected and their social environment , 
 generating a variety of risk or protection scenarios for the various forms of 
 transmission . 
 fig . this map was provided by dr r salvatella , pan american 
 health organization , uruguay . the conjunction of this diversity creates some specific scenarios that must be taken 
 into account when making a diagnosis of the situation and designing control strategies 
 to prevent transmission or mitigate the existing damage . regarding the determinants related to the vector and its behaviour , we could consider 
 scenarios where the main vector is exclusively domestic and introduced , as in the case 
 of rhodnius prolixus in costa rica , which could be eliminated ( hashimoto & schofield 2012 ) . scenarios in which 
 the main vector is essentially domestic , but not exclusively ( as it can be found in wild 
 niches close to homes ) , with the consequent risk of the reintroduction of this and other 
 species , as in the case of triatoma infestans in the phytogeographic 
 region of south america s gran chaco ( constituted by geographical areas of argentina , 
 bolivia and paraguay ) ( ceballos et al . scenarios where the main vector is exclusively peridomestic in peridomestic and wild 
 environments , as in the case of triatoma dimidiata in mexico , with the 
 consequent difficulty of intervening to control its reproduction niche ( pacheco - tucuch et al . a different context is that of vector and oral transmission , which is mainly associated 
 with the presence of infected vectors that can contaminate food ( shikanai - yasuda & carvalho 2012 ) . the conditions for food contamination with infected vectors in the amazon region to 
 become a risk of oral transmission of t. cruzi are partly the jungle 
 environment where the infected triatomines reproduce and survive and which forms the 
 domestic landscape in which the inhabitants of that region prepare and consume their 
 food ( ops 2009b ) . t. cruzi is genetically diverse and understanding the population 
 structure of this parasite is critical due to its association with transmission and 
 disease cycles . currently , t. cruzi is divided into six discrete typing 
 units ( dtus ) , tci - tcvi , with different prevalence according to the geographic region . dtus tci are prevalent in domestic settings , which have a higher risk for vector 
 transmission , in northern south america and central america , while dtus tcii , v and vi 
 are prevalent in southern south america ( zingales et al . the authors that made this description concluded that major advances in 
 the understanding of the pathogenicity and epidemiologic characteristics of these 
 parasites can be expected in the next decade from the comparative analysis of the 
 genomes of several dtu strains ( zingales et al . 2012 ) . however , potential differences with respect to the performance of 
 diagnostic methods and therapeutic responses must be considered . to all the above , we must add the prominent role played by social factors , which 
 determine the behaviour of the people and their living conditions . unfavourable 
 geographical and political phenomena that prevent people from living under decent 
 conditions play a fundamental role in determining the risk of vector infestation in 
 human habitats and the consequent risk of becoming infected through these routes . for example , a study 
 conducted in 1984 in south america s gran chaco region ( termas de ro hondo , santiago 
 del estero , argentina ) , in which there was no vector control or recent insecticide 
 treatments at the time of the study , analysed the factors associated with the presence 
 of infection in children . the combination of the presence of hiding places for vectors 
 within the houses ( cracked walls and thatched roofs ) , having more than two dogs or cats , 
 animals sleeping in the bedrooms and peridomestic structures ( sheds , pens etc . ) close to 
 the bedrooms were associated with an infection rate in children between five-14 years of 
 age of 36.4% , while families in the same area where these same factors were absent had 
 infection rates in children of the same age of 7.7% . given that no vector control with 
 insecticides was a factor in both cases , the presence of environmental and behavioural 
 factors posed a significant risk for acquiring the infection through vector transmission 
 ( chuit et al . the routes of transmission by blood are not conditioned by environmental factors , as in 
 the case of vector and oral transmission , but almost exclusively by sociodemographic 
 determinants associated with the migration of people . the risk of transmission by blood 
 exists where there are infected persons , the main factor to consider when planning 
 public health interventions being the amount of infected people in a locality , whether 
 or not the area suffers from triatomine infestation and vector transmission . thus , in 
 areas where no conditions exist for vector transmission ( absence of vectors ) , but where 
 there is intense immigration of people from an area with vector transmission , there may 
 be a risk of transmission by blood that requires the implementation of measures to 
 control transmission through these routes , such as screening of blood and organ donors 
 and monitoring of pregnant women and newborns from women infected with t. 
 cruzi ( mallimaci et al . control strategies must combine two general courses of action including prevention of 
 transmission to prevent the occurrence of new cases ( these measures are cost effective ) 
 ( vazquez - prokopec et al . 2009 ) , as well as 
 opportune diagnosis and treatment of infected individuals in order to allow them to 
 recuperate their health , when possible , to provide comfort to the patient and to their 
 family and community and to break the chain of transmission by blood by reducing the 
 amount of parasites in donors and mothers ( sosa - estani 
 et al . it must be noted that reducing the burden of the disease on 
 society would lead to a consequent reduction in health - care spending ( lee et al . evolution of intervention strategies for control - intervention 
 strategies for the control of insect vectors were designed and implemented in the 50s 
 and 60s and for the control of transmission by transfusion in the 60s and 70s , 
 respectively . the pioneers in implementing these strategies were venezuela , brazil and 
 argentina ( ops 2002 ) . strategies for control of 
 congenital transmission began to be implemented in the 80s ; while it still can not be 
 prevented , it can be controlled by early diagnosis and timely treatment of children with 
 congenital infection ( blanco et al . 2000 ) . the chronology described above occurred in several countries in the americas , with 
 different times of implementation and different levels of efficacy . there also countries 
 without formally established programs for controlling the transmission of t. 
 cruzi . since the end of the 90s , other regions such as north america , europe 
 and australia have launched research projects and some countries have implemented 
 programs for controlling a specific route of transmission ( the only one in the area ) , 
 such as universal screening of blood donors in the usa , or , as in spain , of donors 
 coming from regions of endemic vector transmission ( who 
 2002 ) . the practices for taking care of people infected with this disease have evolved from the 
 time when carlos chagas first described it ; they currently include health team 
 interventions and care guides ( ms 2012a ) , which have been implemented in very different 
 ways in different endemic countries . only in the mid-90s some countries started to 
 implement the practice of detecting infected children and providing them with 
 etiological treatment as part of a number of strategic actions for controlling the 
 disease ( ops 2002 ) . this is now part of the 
 protocol used by endemic countries , which have institutional control programs through 
 which they certify the interruption of vector transmission by demonstrating the absence 
 of infection in children less than five years of age . a certification of the 
 interruption of transmission is complemented by the absence of the vector , low domestic 
 infestation ( < 1% ) and no reported cases of acute vector chagas , among other 
 indicators . the status reached of interruption is characterised by a sustained 
 surveillance after intensive activities of control of vectors ( ops 2002 ) . a review conclude that the combination of spray 
 activities for control of focus of infestation and the community participation should 
 become a strategic component of chagas disease surveillance ( abad - franch et al . the activities to prevent transmission of t. cruzi by transfusion are 
 based on the implementation of blood bank control . these strategies started in 70s by 
 2005 did not reached an adequate rate of implementation in latin america ( schmunis & cruz 2005 ) , but it was improved 
 during last decade and more recently these programs were implemented in nonendemic 
 countries ( requena - mndez et al . 2 shows the progress of the interruption of 
 vector transmission in the countries of the americas . only recently has emphasis been 
 placed on the comprehensive care of infected people in any stage of the infection ( ms 
 2012b ) as essential to the goal of eliminating chagas disease as a public health problem 
 ( sosa - estani 2012 , sosa - estani et al . 2012 ) . source : pan american 
 health organization 
 ( paho.org/hq/index.php?option=com_topics&view=article&id=10&itemid=40743 ) . 
 
 achieved effect - the sum of the measures for prevention of 
 transmission have had different a different effect depending on the possibility of 
 implementing interventions . the factors on which this depends include : ( i ) the political 
 and technical decision to implement the strategies with sufficient evidence of efficacy 
 [ some examples that demonstrate the feasibility of the various factors described in ( i ) 
 are the success in interrupting vector and blood transmission , with total or partial 
 geographic coverage in some countries , such as argentina , brazil , chile , uruguay and 
 some others in central america ( fig . 2 ) ] , ( ii ) the 
 complexity of the scenario in which the intervention takes place [ examples of ( ii ) could 
 correspond to specific sub - regions , such as the complexity of determinants in the amazon 
 region that cause outbreaks of oral transmission ] and ( iii ) the lack of tools or 
 strategies or insufficient evidence of efficacy [ examples of ( iii ) could be special 
 situations such as the occurrence of pockets of triatomines resistant to insecticides 
 approved for vector control ] ( germano et al . the measures implemented in recent decades have had an effect , as confirmed by the world 
 health organization ( who ) when describing that the number of infected people decreased 
 from 30 million in 1990 to 15 million in march 2006 ( ops 
 2006 ) . however , these estimates may have methodological shortcomings in their 
 calculations and may not allow us to make an accurate assessment due to their high 
 potential margin of error . it is also clear that the various control measures that have 
 been systematically carried out since the formal establishment of control programs for 
 chagas in endemic countries at the start of the 60s have served to prevent new cases in 
 many countries in the americas . however , the diversity of socioepidemiological scenarios 
 and implementation status of control programs has meant that while the main routes of 
 transmission of public health interest ( vector and blood ) have been successfully 
 interrupted in some regions , new cases involving these routes of transmission are still 
 occurring in other regions . the control of vector and blood transmission of t. cruzi clearly 
 improved the transmission profile in latin america . some specific examples of these 
 progress in different geographical dimension are the control in the state of so paulo , 
 brazil , which started by 70s with continuous surveillance and high impact avoiding new 
 cases by vector transmission for several decades ( carvalho et al . 2011 ) . on the other hand in central america ( guatemala , el 
 salvador , honduras and nicaragua ) an example of interaction between international 
 cooperation by the japan international cooperation agency , japan , official control 
 programs of the countries involved and community organised this model highlighted for the success : the knowledge for what 
 actions should be taken to control the disease , the competence to obtain resources and 
 capacity to implement control actions , the channels for the institutional network and 
 infrastructure and the control of the technical and administrative management ( hanada & hashimoto 2014 ) . a very important issue to warranty the success of the chagas disease programs is to 
 implement evaluations programs of each activity , control quality , to monitoring its 
 efficacy . these aspects were recently reviewed by a paho / who group of experts and in 
 addition were discussed that subjects involving sustainability , coverage , financing and 
 quality of the program must be taken into account in each evaluation . also it is necessary to offer process such as social , administrative and political 
 issues involving an official declaration of disease elimination , considering the 
 possible positive and negative points that can arise from this declaration taking into 
 account gaps and needs for this goal . some examples of the new scenario and the role of 
 different actors are the recent constitution of the federation of people affected for 
 chagas disease ( findechagas.com/ ) , the coalitions of nongovernmental organisations 
 ( ngos ) 
 ( web.mundosano.org/novedades/mundo-sano-hoy/lanzan-una-coalicion-global-para-luchar-contra-la-enfermedad-de-chagas/ ) 
 in same case with the industry ( unitingtocombatntds.org/resource/london-declaration ) , 
 forum for research 
 ( dndial.org/es/doencas-negligenciadas/enfermedad-de-chagas/plataformachagas.html ) , the 
 constitution or revision of a national plan with political support and international 
 declaration of who assembly . beyond the measurement of progress , several questions still remain , which can only be 
 answered by further scientific research . at present , there is the need of designing and 
 implementing a quality control system for the supply of domestic insecticides and for 
 making accurate estimates of the effect of control measures on the incidence of new 
 infections . considering the response of health systems to the reemergence of another infection 
 caused by insects , dengue , it is surprising how fast they reacted , despite the fact that 
 several programs for control of vector - borne diseases have started to be dissolved . in 
 some regions of latin america , this fast response was made possible by the strong 
 influence of the control initiatives carried out by the paho of the who . although we 
 can not quantify this influence , it can be said that it is a cultural influence generated 
 by the initiatives . the case of the reemergence of the dengue virus and that of the 
 emergence of the chikungunya virus , both transmitted by the aedes 
 genus , calls into question whether it is not time to strengthen the control programs and 
 the scientific and technical training of the members of those programs in order to make 
 them more effective and less costly in the context of the current challenges . having achieved the desired effect of interrupting the transmission of a disease , a 
 major challenge is to achieve sustainable control measures to prevent a reestablishment 
 of transmission , as happened with dengue and malaria in the americas ( dick et al . some of the current strategies 
 aimed to achieve sustainability involve empowering local governments and promoting 
 community mobilisation and participation through organised communities and ngos . the establishment of integrated programs constructed collectively allows proposing 
 strategies that address as many determinants as possible for the control of chagas 
 disease . as an example , the recently revised national program for control of chagas 
 disease in argentina , implemented between 2010 - 2016 , consists of five strategic lines : 
 ( i ) strategies for the prevention and control of vector transmission ( vector control and 
 surveillance , resistance monitoring , improvement of the environment - domestic and 
 peridomestic ) , ( ii ) strategies for the prevention and control of nonvector transmission , 
 particularly of transmission by blood , ( iii ) strategies for the control of congenital 
 infection , ( iv ) strategies for the control of acute and chronic infection in carriers of 
 t. cruzi and ( v ) general and transversal strategies for the whole 
 program including strengthening of the political dimension , strengthening of the 
 resources of the national and local programs for chagas , social communication and 
 community participation , assessment and monitoring of the program ( ms 2012b ) . these nationwide programs should consider particular situations , mainly related to 
 vulnerable communities , such as care in indigenous communities where the perception and 
 acceptability of the strategies should be approached with particular caution . this based 
 on the evidence of the failure of interventions in these communities due to several 
 factors , one of them being the use of standard procedures which in these populations may 
 cause a kind of culture shock ( sosa - estani et al . 
 2009a , dellarciprete et al . 2014 ) . in 2010 , the who estimated the existence of seven - eight million people infected with 
 t. cruzi distributed throughout the world . the region of the 
 americas , particularly latin america , where those with the highest proportion of 
 infected people , being endemic areas for vector transmission the most efficient type of 
 transmission . however , the phenomenon of human migration has created scenarios in need 
 of attention in other regions of the world such as europe , japan and australia , mainly 
 with respect to the diagnosis and treatment of infected people to prevent and control 
 congenital transmission and transmission by contaminated blood ( who 2013 ) . there is limited information about the effect of health care activities in infected 
 people on the overall activities of prevention and control . however , two fundamental 
 concepts must be taken into account , either with evidence or when suggesting a 
 hypothesis . the first is the direct effect that timely cares with early interventions 
 have on the quality of life of the patients , with the consequent reduction of the burden 
 of the disease by preventing or stopping its progression ( secondary and tertiary 
 prevention ) ( sosa - estani et al . the second 
 concept is that indicating a trypanocidal treatment , which has proven effective in 
 eliminating or reducing the parasitic infection , modifies the population parasitaemia , 
 with consequential benefits . these benefits may include changing the natural history of 
 the disease by producing less severe clinical chronic forms and/or decreasing the 
 influence of parasitaemia ( sosa - estani et al . 2009b ) as a determining factor in the occurrence of congenital transmission 
 ( bua et al . there are guidelines advising regarding management and care of people infected with 
 t. cruzi . a precocious and adequate clinical management is required 
 to all acute or chronic cases . a timely and adequate clinical , pharmacological and 
 chirurgical management if necessary is essential . the specific treatment has to be 
 considered currently among other therapies ( who 
 2002 ) . for instance , timely management of initial arrhythmia , heart failure or 
 megaesophagus is fundamental to avoid or delay the appearance of severe and irreversible 
 situations , according several longitudinal studies have demonstrated ( viotti et al . a challenge to each health system is how to implement the activities to provide an 
 adequate care of people infected . there is a diversity of system , but all of them must 
 to warrant a care with quality . there is a consensus that most of patients can to be 
 care in the primary health care level and to be included into the schedule of national 
 control programs . the role of etiological treatment for t. cruzi infection on several levels of 
 prevention in public health - the etiological treatment allows for actions 
 on several levels of public health prevention . previous studies provide evidences useful 
 for applying health care strategies in control programs in several countries . when a 
 high number of people can get diagnosis , treatment and cure , it generates a new scenario 
 for the future reduction of the burden of the disease . primary prevention level - if the goal is to prevent the occurrence of 
 new infections , etiological treatment could have an indirect effect when applied to 
 children and young people . curing children and women in reproductive age would prevent 
 future events of congenital t. cruzi transmission ( sosa - estani et al . in addition , blood and organ donors would 
 increase if infected people are treated . unfortunately , the effectiveness of the 
 etiological treatment with respect to these primary prevention indications remains 
 unknown , although it can be assumed to be at least equal to the seronegativisation rates 
 observed in some studies . another strategy would be to obtain a feasible treatment for 
 pregnant women , such as that used for human immunodeficiency virus ( hiv ) infection , to 
 prevent congenital transmission during pregnancy . however , safe drugs are necessary for 
 this strategy . etiological treatment in cases of accidents with material contaminated with parasites or 
 with blood samples of patients infected with t. cruzi could also be 
 considered as an indication for primary prevention . in fact , the treatment is not 
 strictly prophylactic , as it is not possible to prevent infections , but the infection 
 can be aborted immediately after the accident with a timely treatment and an appropriate 
 concentration of specific drugs ( herwaldt 2001 ) . recent results show the benefit , in terms of primary prevention , of treating girls and 
 women of childbearing age before pregnancy , preventing the congenital transmission of 
 t. cruzi to children born afterwards ( sosa - estani et al . secondary prevention level - if prevention activities can not prevent 
 infection in children , curing infected children is still possible by prescribing 
 etiological treatment ( cerisola 1977 , moya et al . in this regard , 
 etiological treatment should be indicated when damages from cardiac or digestive disease 
 are not strongly present in children . this is the best opportunity to get 
 seronegativisation and avoid disease , thus preserving social , mental and physical health 
 into adulthood ( de oliveira jr et al . national control programs have been implemented in more and more latin - american 
 countries since 1994 . they consist of the screening of children populations as a regular 
 strategy providing early diagnosis and treatment ( silveira 2002 ) . the positive effect of curing infected children detected by 
 serological screening must be assessed by taking into account the number of infected 
 people , the transmission , evolution and burden of chagas disease , so that it becomes 
 possible to analyse the usefulness of serology as an indicator of action against the 
 vector . another indication for etiological treatment in secondary prevention is to prevent the 
 reactivation of a chronic infection . 2007 ) or 
 hiv / acquired immune deficiency syndrome ( cordova et al . even though the effectiveness of etiological treatment for the clinical control of 
 reactivation episodes has been demonstrated , it is necessary to gather evidence as to 
 whether preventive treatment is effective in patients with no signs of clinical 
 reactivation and with abnormal immunological parameters ( nishioka 2000 ) . in this regard , some protocols recommend treating organ 
 donors infected with t. cruzi to reduce the risk of transmission by 
 transplant ( altclas et al . tertiary prevention level - the use of etiological treatment against 
 t. cruzi infection in order to reduce the negative effect of 
 established disease is being evaluated using two randomised clinical trials for 
 assessing its efficacy in patients with ongoing cardiac disease ( reyes & vallejo 2005 , riarte et 
 al . these trials are appraising the efficacy of benznidazole for preventing the progression 
 of cardiac disease . several observational studies have been published showing the effects of etiological 
 treatment on patients infected with t. cruzi with respect to preventing 
 the progression of chronic chagasic cardiomyopathy ( sosa - estani et al . these studies achieved quality of evidence type ii 
 and strength of recommendation b and c. the prognosis of patients with heart failure or 
 advanced stages of chagasic cardiomyopathy is poor ( rassi jr et al . 2006 ) , but similar to that of other patients who develop 
 heart failure . since the disease is chronic and heart damage develops over decades , it 
 is very important to recognise the factors that determine the progression of the disease 
 in the early stages ( viotti et al . the 
 evolution of knowledges addressed to the current scenario with a new paradigm regarding 
 benefit of trypanocide treatment ( viotti et al . 
 2014 ) . the etiological treatment should be considered as a protective factor 
 in the model of the physiopathology of chagasic cardiomyopathy . as mentioned above , the effectiveness of etiological treatment in the control of 
 reactivation episodes has been proved , showing recovery from severe manifestations of 
 reactivation such as meningoencephalitis , myocarditis , panniculitis etc . ( diez et al . 2007 , cordova et al . 2008 ) . based on our current understanding of the disease , there is a consensus that every 
 patient infected with t. cruzi must ( children ) or should be treated 
 ( adults ) . treatment can cure infection and reduce or prevent the progression of 
 chagas - related heart disease / cardiomyopathy . the current evidence of the benefits and 
 limitations of etiological treatment based on clinical and implementation research help 
 prioritise primary health care strategies , focusing on completing the course of 
 treatment , rather than demonstrating serological negativisation . incorporating etiological treatment as a public health strategy useful at the primary , 
 secondary and tertiary prevention levels is essential to reduce the burden of the 
 disease and to eliminate chagas disease as a public health issue . there are guidelines advising regarding management and care of people infected with 
 t. cruzi . a precocious and adequate clinical management is required 
 to all acute or chronic cases . a timely and adequate clinical , pharmacological and 
 chirurgical management if necessary is essential . the specific treatment has to be 
 considered currently among other therapies ( who 
 2002 ) . for instance , timely management of initial arrhythmia , heart failure or 
 megaesophagus is fundamental to avoid or delay the appearance of severe and irreversible 
 situations , according several longitudinal studies have demonstrated ( viotti et al . the medical care all over latin america have different systems with subsystems and it 
 must to have into account to resolve access to diagnosis and treatment , coverage , 
 referential system , medical expertise , among others considerations . this is a new goal 
 for an integrated chagas disease control programs , including the care of people infected 
 as formal objective and activities . control models and their effect - based on the above , we can graph 
 three intervention models and their expected effect on the evolution of the number of 
 infected people . 3 defines three scenarios according to 
 the intervention models and three times ( baseline , medium and long term regarding time 
 lapsed ) . these three scenarios are described just as a concept and not defined through a 
 mathematical model . the first scenario where no intervention against the vector is 
 carried out and vector transmission continues unabated generates an increase in the 
 number of infected people . the second scenario is where only primary prevention actions 
 are implemented , such as vector control and control of blood and organ donors . these 
 actions achieve a progressive reduction of the number of infected people , but without 
 care for infected people they remain infected for the rest of their lives ; due to the 
 phenomenon of population parasitaemia and migration , the risk of transmission by blood 
 would increase . finally , the third scenario considers primary prevention actions in 
 conjunction with care of infected people , including etiological treatment . this 
 combination can reduce the number of people infected with t. cruzi in a 
 shorter time . 
 fig . 3:combined effect of prevention and care for people in the control of chagas 
 disease . the implementation of actions with sufficient evidence of efficacy carried out in an 
 integrated manner throughout the country is a challenge of political and technical 
 decision - making . the proof of success in some communities should be a 
 stimulus / incitation for communities with similar scenarios where these actions have not 
 been implemented . the field of research is oriented towards finding alternatives when the tools / strategies 
 used stopped working or are unavailable . thus , the research priorities for the present 
 situation have been defined different in discussion forums , trying to find the best way 
 of achieving an efficient implementation of control actions for the prevention of new 
 cases and for taking care of those already infected ( dujardin et al . chagas disease can not be eradicated due to the multiple scenarios that contribute to the 
 occurrence of new cases and mainly because of the demonstrated existence of infected 
 wild triatomines in permanent contact with domestic cycles . however , it is possible to 
 interrupt the transmission of t. cruzi in a large territory , we have 
 discussed before the complexity of dynamic of vector transmission to avoid new cases and 
 having expectance to eradicate or eliminate this disease . measures available of 
 prevention of chagas disease can reach high level of control due to total interruption 
 of transmission by transfusion , total interruption of vector transmission in large areas 
 and partial interruption or control in areas like amazon region and adequate level of 
 coverage of timely diagnoses and treatment of people infected . the hypothesis is that in 
 the future always will remain just few new cases , but the conjunction of the previous 
 goal described will allow to eliminate chagas disease as a public health problem . in 
 this sense a cut - off point of magnitude of prevalence or incidences of people infected 
 and its burden disease to decide when chagas disease is not a public health problem has 
 to be developed .
chagas disease or american trypanosomiasis is , together with geohelminths , the 
 neglected disease that causes more loss of years of healthy life due to disability in 
 latin america . 
 chagas disease , as determined by the factors and determinants , shows 
 that different contexts require different actions , preventing new cases or reducing 
 the burden of disease . 
 control strategies must combine two general courses of action 
 including prevention of transmission to prevent the occurrence of new cases ( these 
 measures are cost effective ) , as well as opportune diagnosis and treatment of 
 infected individuals in order to prevent the clinical evolution of the disease and to 
 allow them to recuperate their health . all actions should be implemented as fully as 
 possible and with an integrated way , to maximise the impact . 
 chagas disease can not be 
 eradicated due because of the demonstrated existence of infected wild triatomines in 
 permanent contact with domestic cycles and it contributes to the occurrence of at 
 least few new cases . 
 however , it is possible to interrupt the transmission of 
 trypanosoma cruzi in a large territory and to eliminate chagas 
 disease as a public health problem with a dramatic reduction of burden of the 
 disease .