It’s sometimes called “the kiss of death.”
American trypanosomiasis, more commonly known as Chagas disease, is classified as one of the 10 most important neglected tropical diseases by the World Health Organization (WHO). It’s caused by the bite of a bug from the Triatominae family, commonly referred to as “kissing bugs”, that directly transmit the parasite T. cruzi to mammals, including humans, through their feces after they have bitten and taken a blood meal from their host. How do they do this? By biting humans around their lips and faces as they sleep – hence the nickname “kissing bugs.”
Endemic in Mexico, Central and South America, an estimated 8 million people are infected by the protozoan parasite Trypanosoma cruzi (T. cruzi infection), resulting in at least 10,000 directly attributable deaths per year.
Given that surveillance and diagnostic testing for Chagas disease is limited, the true disease and mortality burden are likely much higher than what is reported. In the U.S., there are an estimated 300,000 immigrants who are chronically infected with T. cruzi and sporadic cases of U.S.-acquired infection are on the rise in the Southwest, where the arthropod vector can commonly be found.
Interestingly, the arthropod vectors – ie, the kissing bugs — that carry T. cruzi have diversified very fast evolutionarily, particularly in South America, resulting in 151 species of the subfamily Triatominae, all considered capable of carrying T. cruzi. Researchers are interested in learning if the species diversity of Triatominae and differing geographic locations influence Chagas disease transmission cycles.
Here’s the tricky part about Chagas disease: a person infected with T. cruzi usually undergoes both an acute and chronic phase of disease and is never completely cured. The acute phase often goes undiagnosed as symptoms may be mild and non-specific (fever, fatigue and body aches) or the infected individual may be completely asymptomatic. Once the acute phase resolves, the individual goes into what is referred to as the chronic phase, where the infection is dormant and the individual is asymptomatic.
The majority of people with chronic infection remain asymptomatic for life; however 20-40% will eventually develop serious medical issues including life-threatening cardiomyopathy and/or digestive disorders. Often this lag time between initial infection and more severe symptoms are barriers to proper diagnosis and therefore treatment. And, while treatment effectively suppresses T. cruzi, limiting disease symptoms, it does not cure chronically infected individuals. Fortunately, new drugs are in the pipeline for development that specifically target the parasite, potentially being able to cure the infection.
While promising new drugs are being researched, accurate and timely identification of cases of Chagas disease is a critical component to begin treatments faster and to improve surveillance and monitor disease burden. To that end, IDRI, in collaboration with InBios, has developed technology to rapidly and affordably test for Chagas disease, an improvement upon the current standard—a nonspecific blood smear to look for parasites. We’re pleased to be playing stopping the “kiss of death.”