A pair of scientists at The University of Texas at El Paso is one step closer to developing the first ever clinical Chagas disease vaccine. Chagas is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors known as kissing bugs. The bugs, which are found in our area, are shown in these lab dishes. “We dream of this a vaccine for Chagas disease], but we don’t know it is going to happen,” Almeida said. “You dream to get something to help the people and you expect to make at least a small contribution,” Maldonado shared.
What is Chagas Disease?
Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by the protist Trypanosoma cruzi. It is spread mostly by insects known as Triatominae or kissing bugs. The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild, and may include fever, swollen lymph nodes, headaches, or local swelling at the site of the bite. After 8–12 weeks, individuals enter the chronic phase of disease and in 60–70% it never produces further symptoms. The other 30 to 40% of people develop further symptoms 10 to 30 years after the initial infection, including enlargement of the ventricles of the heart in 20 to 30%, leading to heart failure. An enlarged esophagus or an enlarged colon may also occur in 10% of people.
Prevention mostly involves eliminating kissing bugs and avoiding their bites. Other preventative efforts include screening blood used for transfusions. A vaccine has not been developed as of 2013. Early infections are treatable with the medication benznidazole or nifurtimox. Medication nearly always results in a cure if given early, but becomes less effective the longer a person has had Chagas disease. When used in chronic disease, medication may delay or prevent the development of end–stage symptoms. Benznidazole and nifurtimox cause temporary side effects in up to 40% of people including skin disorders, brain toxicity, and digestive system irritation.
About the Vaccine
Second vaccine, based on synthetic parasite sugars, was tested in nonhuman primates at TBRI and yielded very promising results. The vaccine studies were funded by the Kleberg Foundation and the National Institutes of Health.
“The big problem with Chagas disease is heart failure. The inflammation in the heart and the parasitic load significantly decreased, and this vaccine is protecting the animals from the disease. These are the first synthetic vaccines tested in a non-human primate model ever.” The UTEP scientists said that 6 million to 8 million people are chronically infected with the potentially life-threatening Chagas disease. Chagas is caused by the parasite Trypanosoma cruzi, which is transmitted to animals and people by insect vectors known as kissing bugs. The disease has been endemic in Latin America, but is rapidly spreading through the U.S., Europe and other non-endemic regions as a result of globalization. Yet, there is no clinical vaccine, although there have been several experimental efforts throughout the years. The number of people infected, though, is underreported because symptoms may take decades to turn up and doctors don’t regularly test for this tropical disease.