Primary prevention
Despite the success of vaccines against several infectious diseases, there are no available vaccines for Chagas disease mainly due to the weak immune response of the host against T. cruzi and the strategies developed by the parasite to escape the host immune system.[119]
The World Health Organization has included Chagas disease in their 2021 - 2030 road map for neglected tropical diseases which lists key targets for the prevention, control, elimination, and eradication of the disease by the end of the decade.[120] Primary prevention strategies are based on the control of human population exposure to Trypanosoma cruzi. The complex interaction between triatomines, animal reservoirs, and human populations must be evaluated. While control of both vectorial and blood transfusion transmission of T. cruzi has been successful in many regions of Latin America and the US, some ecosystem approaches to control are under-utilised. These include: reservoir studies and surveillance; environmental education and surveillance; traveller orientation; and strong policies in favour of sustainable development and decreasing social inequalities. Health education of at-risk people living in endemic active areas is very important to reduce the incidence of the disease.[121][122][123]
Depending on the geographical area, preventative and control measures include:
Reduction of triatomine colonies inside dwellings (e.g., by using mosquito nettings on windows)
Residual insecticide spraying of houses and surrounding areas
House improvements and house cleanliness to prevent vector infestation
Use of repellents and clothes with long sleeves during activities at night in the forest (hunting, fishing, camping), as well as the use of bed nets.
Avoiding consumption of raw homemade products and other possibly contaminated products in endemic areas; high-risk food should be pasteurised
Screening of blood donors
Testing of organ, tissue, or cell donors and receivers
Screening of newborns and other children of infected mothers to provide early diagnosis and treatment.
An increased number of cases due to oral transmission have been observed, including familial micro-epidemics in Latin American countries, principally Brazil.[9] This demonstrates the need for better food safety practices in endemic regions.
As vector control has led to great advances in many endemic countries, screening of blood and organs for donation has become crucial to control transmission.[12][29][124] In the US, screening for T. cruzi in donated blood was not widely practised until 2007. Blood donations that are found to be reactive by blood screening tests are then tested using radio-immunoprecipitation assay (RIPA). This is the standard serological screening test in the US although other serological screening tests may be used in different countries. Donors who are positive in the screening test are excluded from blood donation, regardless of their RIPA results.
Sylvatic populations of triatomines represent a new challenge in vector control transmission.[48][125][126] Owing to ecological changes, contacts of humans and domestic animals with sylvatic populations have been increasing. A co-ordinated multi-country programme, targeting the reduction of transmission by vectors and via blood transfusion in the Southern Cone, Andean, Amazonian, and Central American countries, has succeeded in significantly reducing the transmission of Chagas disease.
Secondary prevention
Chagas disease is a reportable condition in some countries.
Primary chemoprophylaxis in uninfected people who plan to visit endemic regions is not recommended, considering the extremely low risk of the infection, and the risks of adverse events with the use of the specific treatment.
Effective approaches for eliminating vector-borne transmission of Trypanosoma cruzi to humans include health education for people at risk for acquiring the infection; improvement in socio-economic conditions; and triatomine control by the use of residual insecticides.
Patients must be counselled not to donate blood or solid organs. People who are diagnosed with indeterminate Chagas disease are typically identified by screening processes before these procedures.
If the patient has family members with a similar history of possible exposure to the parasite in endemic settings, they should be tested. Children of infected women should also be tested for the disease. In pregnant women or infants with acute Chagas disease, breastfeeding must be evaluated, to assess the possibility of transmission by bleeding nipple fissures. No other approaches for reducing this risk of vertical transmission have been defined. There are no sexual restrictions for patients with Chagas disease.
Laboratory personnel and researchers who work with or manipulate T. cruzi or infected triatomines should always take protective measures.
People who travel to endemic areas should take general measures to protect themselves from the disease.
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