Chagas disease
Chagas disease is an infection caused by the “Trypanosoma cruzi” parasite which is transmitted through the bites of an insect (the “kissing bug”). The disease can also be spread from mother to child (vertical transmission), through blood transfusion, organ donation from people infected with the disease or from eating food contaminated with the parasite. For the moment, the number of new cases has been reduced thanks to policies to eliminate the insect in countries where it is endemic, as well as thanks to screening programmes aimed at blood and organ donors and pregnant women. The future challenges to cure this disease are maintaining and increasing these measures in addition to developing new treatment evolution and response markers for patients in the chronic phase, and new drugs to treat the disease.
What is Chagas disease?
Chagas disease is endemic to Latin America and is a global health challenge due to migration from countries in the region. Transmission via insect is mainly found in Bolivia, which has the highest number of cases. There are also infections in north-west Argentina, Peru, Paraguay, Ecuador, Nicaragua and southern Mexico. Outside these areas it is more commonly transmitted from mother to child.
Symptoms
Most patients with Chagas disease do not show any symptoms, which makes it difficult to detect. The disease develops in two phases:
- Acute: there are no symptoms and this means it goes undetected or is confused with other diseases. After an incubation period of 7-10 days, the acute phase resembles a case of flu, so it usually goes unnoticed.
- Chronic: in 30-40% of cases the disease results in cardiac and/or gastrointestinal complications which may be serious and therefore require specific treatment.
Who is affected by Chagas disease?
This disease affects six to seven million people, but 60 million are estimated to be at risk of infection. There are 11,000 cases in Catalonia.
Diagnosis
- In the acute phase (mainly in babies) the disease is diagnosed by detecting the parasite in the blood. Microscopy and molecular techniques (PCR) are used for this.
- In the chronic phase (when acquired in childhood), the disease is diagnosed by detecting antibodies in the serum. In this phase of the disease, molecular techniques work in cases where the disease has been reactivated or as a marker of the failure of a specific treatment.
Typical treatment
There are currently two drugs that are used to treat Chagas disease: Benznidazole and Nifurtimox. Specific treatment is needed to address any cardiac and/or gastrointestinal complications that may arise.
Prevention
Since 2011, Catalonia has implemented the “Protocol for screening and diagnosing Chagas disease in pregnant Latin American women and their babies”. This programme allows possible congenital cases to be detected, and at the same time actively screens blood and organ donations from donors.