Health experts are calling on government officials to relabel a ‘silent killer’ disease spread by bugs as ‘endemic’ in the US.
Chagas disease is a dangerous infection caused by the parasite Trypanosoma cruzi.
The parasite is generally transmitted through accidentally ingesting feces of triatomine bugs, nicknamed ‘kissing bugs’, which are known to bite humans and animals.
The first known case of human Chagas disease in the US was contracted by an infant in 1955 in Corpus Christi, Texas – the child’s home was known to be infested with kissing bugs.
Since then, kissing bugs have been detected in 32 states, and scientists believe Chagas has blighted at least 300,000 Americans, though the count could be much higher as the disease often goes undiagnosed.
Recently, a woman in Texas spoke out to raise awareness of the disease. Sandra Youngblood discovered she had Chagas after a blood donation in 2018. Blood is screened for the disease before being used for donation.
However, she ‘ignored the recommendation to seek medical attention until 2021.’
She said she experienced some early symptoms of the disease, including headaches and reduced appetite, but said the CDC and her doctors said her condition was progressing slowly and she’d likely feel more symptoms in her 50s and 60s.
Triatomine bugs, nicknamed ‘kissing bugs’, carry the parasite Trypanosoma cruzi, which causes Chagas disease
Youngblood told KCEN-TV she thinks she contracted the disease from bed bugs while living in Florida, but isn’t sure.
Little is known about the prevalence of Chagas across the country, as it is not reportable at the national level and only estimates can be given. Still, health leaders say that reclassifying it as endemic will help spread awareness and improve tracking.
According to the CDC, the term ‘endemic’ is used to denote the ‘constant presence/usual prevalence of a disease or infectious agent in a population within a geographic area’.
Dr William Schaffner, a professor of medicine, specializing in infectious diseases, at Vanderbilt University Medical Center, told the Daily Mail that deforestation and migration have caused the global spread of Chagas – originally a tropical disease confined to rural areas of Latin America.
He said there is evidence to suggest that climate change is also linked to an increase in cases across the southern US, as warmer temperatures and increased rainfall have expanded the bugs’ breeding grounds.
He also said the new data indicates that infected kissing bugs are more common than previously thought.
Several factors have led to the increase in diagnoses, he added, including ‘more diagnostic awareness among doctors’ and ‘climate change enlarging the spread of the kissing bug vector’.
Chagas has earned a reputation as a ‘silent killer’ because it can live in the body for decades without being detected.
There is no mortality rate for it in the US, but in Brazil, health experts found the annual average mortality proportion for the disease was 1.6 deaths per 100,000 infected people.
Chagas is often asymptomatic, with 70 to 80 percent of infected people remaining symptom-free their entire lives. Though, for some, signs of infection include fever, fatigue, body aches, headache, rash and loss of appetite.
Over time, parasites can move to the tissues and cause chronic infections. This can lead to various complications, including bowel damage and issues passing stool, trouble eating, blood clots, heart failure, abnormal heart rhythms and even sudden death.
The above map shows US states with reported wild, domestic or captive animals exposed to Trypanosoma cruzi locally, states with reported autochthonous human Chagas disease, and all states with reported triatomines
Researchers from the University of Florida say that California, Texas and Florida are home to the most people suffering from chronic cases of Chagas.
An estimated 70,000 to 100,000 people in California have Chagas disease, making it the state with the most cases in the US.
Experts from the Center of Excellence for Chagas Disease (CECD) say this is because Los Angeles is home to a large population of people born in Latin America.
The CECD performed a study of Chagas disease in this population and found that 1.24 percent, or about one out of 100, had the infection that causes Chagas disease.
They said that they were ‘likely infected in their home countries, although it is not impossible that some would have been infected in California’.
Janeice Smith, a retired teacher in Florida, believes she got Chagas in 1966 when her family went on vacation in Mexico.
She returned home feeling tired and with a high fever. She also developed a severe eye infection, which caused it to become itchy and swollen.
Her parents rushed her to the hospital, where she was admitted for several weeks until her symptoms lessened, but doctors could not determine what caused her illness.
It was only about 60 years later that Smith discovered a link to Chagas when she signed up to donate blood – she was denied when the infection was detected in her donation.
Smith said after doing further research, she realized the disease was responsible for a string of ailments she had been blighted with into adulthood, including sight problems and acid reflux.
A graph showing yearly reported cases of human Chagas disease in Texas
She told the Daily Mail that along with a run of severe symptoms, being diagnosed with Chagas left her feeling isolated.
‘One of the worst things for me was being diagnosed with something I had never heard of. Then I was left on my own to find qualified care,’ the Floridian explained.
‘After that, it took going through hoops to be retested numerous times before the CDC would give my doctor approval to treat me. Even my family didn’t believe me that it was a real disease.’
Following the discovery of Chagas in her system, Smith founded the National Kissing Bug Alliance to help raise awareness about the condition.
As there is no mandated testing for Chagas, many people only find out they have the disease when they donate blood. (All donors are screened for antibodies to the Trypanosoma cruzi parasite.)
While data is limited, researchers in Florida and Texas, who have spent 10 years tracking the transmission of Chagas, collected 300 kissing bugs in 23 Florida counties. More than a third of them were in people’s homes.
One in three bugs tested carried Trypanosoma cruzi and infected people and animals in more than half of the counties examined.
The team said the bugs enter homes as more people build property on previously undeveloped land that served as the insects’ natural habitat.
Now, health experts across the country are urging people in the states where kissing bugs live to reduce their exposure, by doing things such as keeping wood piles outside and away from where pets sleep.
The above graph shows which food sources kissing bugs relied on, depending on where they were found. Bugs in homes most often fed on humans, while those outside focused on wild mammals
Kissing bugs, which range from 0.5 to 1.25 inches long, are blood-feeding insects that tend to hide during the day in dark areas of homes like ceilings and cracks in the walls. They then come out to feed at night.
They have been known to attach to animals and then transfer to humans.
Most people don’t feel the bite of a kissing bug due to anesthetic-like molecules in their saliva, but it usually leaves an itchy, red welt behind.
Dr Norman Beatty, an assistant professor of medicine in the University of Florida’s Division of Infectious Diseases and Global Medicine, revealed that allergic reactions to kissing bug bites are common, and anaphylaxis has resulted in at least one documented death in Arizona.
The infection can be treated with anti-parasitic medications and therapies for secondary issues like heart rhythm disorders.