The Utility of Microbial Cell-Free DNA in the Rapid Diagnosis of Chagas Disease: Chagas Disease Case Series

Abstract Background Chagas disease (CD) is a leading tropical disease and the most prevalent parasitic infection in Latin America, affecting >7 million people globally and ∼240 000–350 000 individuals within the United States. Though known to be endemic to Latin America, prevalence in the United States is also increasing with improved recognition of locally acquired cases, especially in Texas. Autochthonous cases occur throughout the Southern United States, but the geographic range is anticipated to shift northwards as a result of climate change. Chagas disease is referred to as a “silent and silenced disease” by the World Health Organization as most people show no signs or symptoms for years following acute infection, and it primarily affects individuals who are socioeconomically disadvantaged. Historically, Chagas disease has been underrecognized. In the absence of treatment, infected individuals progress to a clinically silent or “indeterminate form” of infection that persists for life. While most patients with indeterminate Chagas disease do not have long-term sequelae, ∼30%–40% will develop end-organ cardiac or gastrointestinal disease decades after infection. Due to its protean clinical presentations, diagnosis requires a high clinical index of suspicion and knowledge of the epidemiology. Traditionally, the diagnosis is based on serology, visualization of the parasite in blood, and polymerase chain reaction (PCR), all of which require suspecting the infection. Microbial cell-free DNA (mcfDNA) of blood can serve as a useful tool for detection of Trypanosoma cruzi even when Chagas disease is not suspected. Results Here we present 7 cases, 3 children and 4 adults, who presented with nonspecific manifestations; CD was not in the initial differential diagnosis in 5 of them. Chagas disease was ultimately diagnosed by Karius Spectrum test. In 1 case, the test was sent to expedite diagnosis in the setting of suspected Chagas reactivation.