Epidemiology Chagas disease

chagas disease in latin america (endemic zones).

chagas disease affects 8 10 million people living in endemic latin american countries, additional 300,000–400,000 living in nonendemic countries, including spain , united states. estimated 41,200 new cases occur annually in endemic countries, , 14,400 infants born congenital chagas disease annually. in 2010 resulted in approximately 10,300 deaths 9,300 in 1990.

the disease present in 18 countries on american continents, ranging southern united states northern argentina. chagas exists in 2 different ecological zones. in southern cone region, main vector lives in , around human homes. in central america , mexico, main vector species lives both inside dwellings , in uninhabited areas. in both zones, chagas occurs exclusively in rural areas, triatomines breed , feed on more 150 species 24 families of domestic , wild mammals, humans, natural reservoirs of t. cruzi.

although triatominae bugs feed on them, birds appear immune infection , therefore not considered t. cruzi reservoir. when colonies of insects eradicated house , surrounding domestic animal shelters, can re-emerge plants or animals part of ancient, sylvatic (referring wild animals) infection cycle. in zones mixed open savannah, clumps of trees interspersed human habitation.

the primary wildlife reservoirs trypanosoma cruzi in united states include opossums, raccoons, armadillos, squirrels, woodrats, , mice. opossums particularly important reservoirs, because parasite can complete life cycle in anal glands of animal without having re-enter insect vector. recorded prevalence of disease in opossums in u.s. ranges 8.3% 37.5%.

studies on raccoons in southeast have yielded infection rates ranging 47% low 15.5%. armadillo prevalence studies have been described in louisiana, , range low of 1.1% 28.8%. additionally, small rodents, including squirrels, mice, , rats, important in sylvatic transmission cycle because of importance bloodmeal sources insect vectors. texas study revealed 17.3% percent t. cruzi prevalence in 75 specimens representing 4 separate small rodent species.

chronic chagas disease remains major health problem in many latin american countries, despite effectiveness of hygienic , preventive measures, such eliminating transmitting insects. however, several landmarks have been achieved in fight against in latin america, including reduction 72% of incidence of human infection in children , young adults in countries of southern cone initiative, , @ least 3 countries (uruguay, in 1997, , chile, in 1999, , brazil in 2006) have been certified free of vectorial , transfusional transmission. in argentina, vectorial transmission has been interrupted in 13 of 19 endemic provinces, , major progress toward goal has been made in both paraguay , bolivia.

screening of donated blood, blood components, , solid organ donors, donors of cells, tissues, , cell , tissue products t. cruzi mandated in chagas-endemic countries , has been implemented. approximately 300,000 infected people live in united states, result of immigration latin american countries, , there have been 23 cases acquired kissing bugs in united states reported between 1955 , 2014. increased population movements, possibility of transmission blood transfusion became more substantial in united states. transfusion blood , tissue products actively screened in u.s., addressing , minimizing risk.