Policy and Complex Systems
follows the acute phase , and can last 10 – 30 years or throughout a lifetime ( Prata , 2001 ; Stanaway & Roth , 2015 ). Finally , the chronic phase , which usually follows the indeterminate phase , has symptoms that include heart disease ( i . e ., destruction of target heart cells ), megaesophagus , megacolon , nervous system lesions , and sudden death ( Prata , 2001 ; Rassi et al ., 2010 ; Stanaway & Roth , 2015 ; Teixeira et al ., 2006 ). Heart disease is one of the most common and deadly symptoms ; however , there appears to be heterogeneity in Chagas-related heart disease with three distinct groups ( Rassi et al ., 2006 ). The 10-year mortality rate across all three groups is ~ 27 %, but ranges from ~ 10 % to ~ 84 % ( Rassi et al ., 2006 ). In general , the relative risk ratio of mortality is ~ 1.74 for individuals with Chagas disease compared with similar individuals without the disease ( Cucunubá , Okuwoga , Basáñez , & Nouvellet , 2016 ). In addition to the Chagas-related health effects , there is some evidence that Chagas is a risk factor for high blood pressure ( Vicco , Rodeles , Yódice , & Marcipar , 2014 ), cognitive impairment in older adults ( Lima-Costa et al ., 2008 ), and ischemic stroke ( Lima-Costa et al ., 2008 ).
Currently , there is no preventive medicine for Chagas disease . Nonetheless , there are two anti-trypanosome drugs , nifurtimox , and benznidazole , used to treat Trypanosoma cruzi infections ( González-Ramos et al ., 2016 ; Jannin & Villa , 2007 ; Rassi et al ., 2010 ; Teixeira et al ., 2006 ). Both drugs have a common occurrence of adverse reactions that can prevent infected individuals from completing treatment ( da Silva et al ., 2014 ; Hasslocher-Moreno et al ., 2012 ; Molina et al ., 2015 ; Olivera , Cucunuba , Alvarez , & Nicholls , 2015 ). Studies found that between 13 % and 31 % cannot complete drug treatment ( da Silva et al ., 2014 ; Hasslocher-Moreno et al ., 2012 ; Molina et al ., 2015 ; Olivera et al ., 2015 ).
Benznidazole is the preferred and most effective treatment of Trypanosoma cruzi infections ( González-Ramos et al ., 2016 ; Prata , 2001 ; Rassi et al ., 2010 ). However , adverse reactions in adults include epigastric pain , skin disorders , nausea , abdominal bloating , sleep disturbance , temporary memory loss , headache , loss of appetite , myalgia , eosinophilia , and central and peripheral nervous system disorders ( da Silva et al ., 2014 ; Hasslocher-Moreno et al ., 2012 ; Molina et al ., 2015 ; Olivera et al ., 2015 ). The percentage of adults with at least one of these reactions ranges from 49 % to 80 % ( da Silva et al ., 2014 ; Hasslocher-Moreno et al ., 2012 ; Molina et al ., 2015 ; Olivera et al ., 2015 ). Extreme cases have resulted in intensive care unit treatment with symptoms that included tonic – clonic seizures and in one case , decreased liver function and multiple general organ failure accompanied by 30 % skin detachment in another case ( González-Ramos et al ., 2016 ). Currently , drug treatment is optional for people over 50 , because no proven benefits exist for people in this age cohort ( Rassi et al ., 2010 ). For other age cohorts , treatment efficacy for people with acute Chagas is between 30 % and 83.5 % ( Jannin & Villa , 2007 ; Prata , 2001 ; Teixeira et al ., 2006 ); and for chronic Chagas , the efficacy is much lower ( 5 %– 30 %) ( Jannin & Villa , 2007 ; Teixeira et al ., 2006 ).
Thus , given the lack of preventative medicine , coupled with the adverse drug reactions and low efficacy of drug treatment , the preferred method of combating Chagas disease is by minimizing human contact with the vector . One of the most common tactics for controlling household infestation of T . dimidiata is the use of pyrethroid insecticide ( Acevedo , Godoy , & Schofield , 2000 ; Dumonteil et al ., 2004 ; Hashimoto , Cordon-Rosales , Trampe , & Kawabata , 2006 ; Manne et al ., 2012 ; Nakagawa ,
123