The Chagas disease increases a person’s risk of death, according to a new study published May 18 in the journal PLOS Neglected Tropical Diseases. The illness is transmitted by kissing bugs, small insects that like to bite humans around their lips and faces while they sleep.
When a kissing bug bites a person, it defecates into the wound with feces that harbor an infectious parasite known as Trypanosoma cruzi. The parasite enters the bloodstream and infects the person with the Chagas disease or trypanosomiasis.
The Chagas disease is usually considered to be mild or asymptomatic among some people. However, the new study claims that it’s responsible for more deaths than previously thought.
Kissing bugs who spread Chagas disease are present in 25 U.S. states
The study found that people infected with the Chagas disease have a doubled or tripled risk of death, compared to people without the disease.
“In every age category, people who had Chagas died more than people who didn’t have Chagas,” said Dr. Ligia Capuani, an infectious disease researcher at Faculdade de Medicina da Universidade de Sao Paulo, who led the investigation, according to CNN. “So if you’re infected early in life, you should be treated.”
Capuani explained that diagnosis is often a challenge in many parts of Central and South America, where the disease is more often. She noted that most people usually found out they are infected with the Chagas disease only when they donate blood. The kissing bugs responsible for infecting people with the illness have been reported in 25 U.S. states, with the largest concentration in the South of the country.
Chagas disease affects the heart
The research team from the University of Sao Paulo analyzed data from over 8,500 people who donated blood between 1996 and 2000 and compared mortality rates among people who tested positive and negative for infection with the T. cruzi parasite. The subjects were followed for up to 14 years.
“People with Chagas had a two or three times higher risk of dying,” said Dr. Ester Cerdeira Sabino, one of the study’s co-authors who led the team at the Brazilian University, according to CNN.
The researchers noted that the leading causes of death among those who tested positive for the Chagas disease were related to heart diseases, the most common symptom of the infection. Sabino noted that in the positive group there was 17 times the risk of cardio disease.
According to the World Health Organization, more than 6 million people are estimated to be infected in the world. The WHO said that 30 percent of individuals chronically infected are developing heart issues and around 10 percent are developing digestive neurological or gastrointestinal symptoms.
The Centers for Disease Control and Prevention estimate that there are over 300,000 cases of Chagas in the United States, and most of those people contracted the disease in other countries.
Some patients experience acute and sudden symptoms during the first two months of infection, when T. cruzi parasite numbers in the blood are at their peak, including fatigue, rash, fever, diarrhea, and swollen eyelids. However, whether the Chagas is acute or chronic, most people remain symptom-free.
Capuani and Sabino believe their findings draw attention to a serious and greater impact on health, due to infection.
“What the parasite does to the body takes a long; (it) slowly goes into the heart and destroys it,” said Sabino, according to CNN. “We have measured accurately the risk of death, (as) a lot of mortality data doesn’t account for Chagas.”
In the new study, 40 percent of people who tested positive for Chagas disease did not have the infection stated on their death certificate, even if the deaths were due to heart illness-related causes.
Kissing bugs need to be controlled to stop spread of the disease
According to the WHO, two antiparasitic drugs are currently available to treat infection, called benznidazole and nifurtimox, both of which are usually 100 percent effective if given soon after infection. However, the effectiveness of the drugs fades the longer someone is infected. Adverse effects also occur in over 40 percent of patients, and their treatment can take up to two months.
There is no vaccine against the Chagas disease. Health officials noted that the best means of prevention is controlling the kissing bugs that spread the disease, either by using insecticides or by improving homes, as the bugs usually live in the walls or roof cracks of poorly constructed houses. Another means of prevention includes treating people early on, so they are unable to spread the parasites to others, either by the kissing bugs biting them or through blood transfusions or donations.
Sabino said that most people who are infected carry on with their lives, unaware they were bitten. She added that a lot of mortality data doesn’t account for Chagas so that people may underestimate the effect of the disease. Capuani and Sabino believe that more attention needs to be given to the Chagas disease, as it is still present in the world and causing death.