Today is World Chagas Disease Day. This year's theme is Finding and reporting every case to defeat Chagas disease.
Despite progress, the global case detection rate for Chagas disease is low (estimated to be around 10%), posing a substantial barrier to accessing treatment and care and in preventing transmission.
Often termed as a "silent and silenced disease", many people with Trypanosoma cruzi infection (the parasite that causes the disease) develop no symptoms or unspecific mild symptoms. Moreover, many countries with cases lack systems to track the number of affected people and active transmission routes.
According to the World Health Organization (WHO), an estimated 6–7 million people are infected with T. cruzi worldwide, with about 10 000 deaths every year.
In his message to commemorate World Chagas Disease Day 2022, WHO's Director-General, Dr Tedros Adhanom Ghebreyesus, reaffirmed WHO's commitment to working alongside countries to defeat the disease.
"WHO is committed to working side-by-side with all affected countries to increase their ability to prevent, find, report and provide care for every single case, to defeat Chagas disease."
Chagas disease remains a public health problem, especially in several endemic areas of continental Latin America, where the burden on health systems is high. The disease is curable when treatment is provided soon after infection.
"Reporting each acute and chronic case is crucial to break the epidemiological silence of Chagas disease," said Dr Pedro Albajar Viñas, who leads WHO's global Chagas disease programme. "Through better awareness, we can overcome the prejudice and neglect associated with this disease."
Over the past decades, Chagas disease has been detected in several countries outside Latin America, including the United States of America and Canada and in many European and some African, Eastern Mediterranean and Western Pacific countries.
Left undiagnosed and untreated in its chronic phase, Chagas disease can result in arrythmias and dilated cardiomyopathy, leading to sudden death or heart failure, with relatively frequent digestive clinical manifestations and thrombotic vascular accidents and neurological sequela.
In 2019, the Seventy-second World Health Assembly decided to establish World Chagas Disease Day, to be celebrated on 14 April, to raise public awareness about the disease.
The road map for neglected tropical diseases 2021–2030 identifies five main objectives to achieve the targets for elimination of Chagas disease by 2030:
- verification of interruption of vectorial domiciliary transmission;
- verification of interruption of transmission by blood transfusion;
- verification of interruption of transmission by organ transplantation;
- elimination of the congenital form of the disease; and
- 75% coverage of antiparasitic treatment of the eligible population.
Faster data exchange and monitoring are making it possible to share updated information, monitor advances and verify achievements. Better diagnostic tools and protocols can accelerate the detection of patients.
To attain the goal of elimination of T. cruzi transmission and provide health care for infected people or those suffering from the disease in both endemic and non-endemic areas, it is critical to increase networking globally and to reinforce regional and national capacities.
The disease
Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite T. cruzi.
In Latin America, T. cruzi parasites are mainly transmitted by contact with faeces/urine of infected blood-sucking triatomine bugs (vectorial transmission). These bugs typically live in the wall or roof cracks of homes and peridomiciliary structures, such as chicken coops, pens and warehouses, in rural or suburban areas. Normally, they hide during the day and become active at night when they feed on animal blood, including human blood. The triatomine bug usually bites an exposed area of skin such as the face (hence its common name, the "kissing bug"), then defecates or urinates close to the bite. The parasites enter the body when the person instinctively smears the bug's faeces or urine into the bite, other skin breaks, the eyes or the mouth. Oral transmission with contaminated food is another potential means of transmission together with vectorial transmission.
For centuries, the disease remained a Latin American problem of rural populations. However, the movement of people from rural to urban areas – and eventually to other continents – has increased the relevance of other transmission channels, such as blood transfusion, congenital transmission and organ transplantation.
There is no vaccine against Chagas disease.
Domiciliary vectorial control and transfusional control, together with active screening of girls and women of childbearing age to prevent congenital transmission, remain the most effective control tools in Latin America.
Chagas disease was named after Carlos Ribeiro Justiniano Chagas, a Brazilian physician and researcher who discovered the disease in 1909.
