 "A public health official holds up three Triatoma dimidiatas, a type of bloodsucking insect that spreads Chagas disease, in San Pedro Sula, Honduras, March 18, 2008. File Image/Reuters")
A potentially life-threatening disease spread by an insect known as the kissing bug is becoming a concern across the United States.
Chagas disease, caused by the parasite Trypanosoma cruzi (T. cruzi), has traditionally been regarded as a health issue limited to Latin America.
However, evidence now suggests that it is firmly taking root in parts of the US, with increasing calls from health authorities for it to be officially recognised as endemic within the country.
The Centers for Disease Control and Prevention (CDC) recently published findings in its Emerging Infectious Diseases journal, warning that both the parasite and its insect carrier are far more widespread than previously understood.
Based on their research, kissing bugs have been found in 32 states, and locally acquired human cases have been confirmed in eight states, indicating that transmission is happening within US borders and not only from international travel.
Where in the US have kissing bug infections been recorded?
Kissing bugs, scientifically known as triatomines, are native to the Americas and have been part of the ecosystem for centuries.
These nocturnal insects are blood feeders and have a distinctive habit of biting humans and animals around the mouth or eyes while they sleep, which led to their nickname.
While sightings of the bugs were historically limited to certain areas, recent reports show their range has expanded dramatically.
The CDC confirmed that these insects have now been identified across 32 states, including much of the South and Central US. They are particularly common in Texas and surrounding regions.
The areas with documented human infections include Texas, Arizona, California, Louisiana, Missouri, Mississippi, Arkansas, and Tennessee.
Texas has reported the highest concentration of these cases.
Also Read | Drink more, worry less: How water could be your new stress buster
In addition to humans, animals have tested positive for the parasite in several other states such as New Mexico, Oklahoma, Nebraska, Alabama, Georgia, Florida, South Carolina, North Carolina, Kentucky, Virginia, and Maryland.
According to experts, wildlife and domestic pets serve as reservoir hosts for the parasite, meaning they help sustain and spread the infection.
“Autochthonous (or, locally acquired) human cases have been reported in 8 states, most notably in Texas. Labelling the United States as non-Chagas disease-endemic perpetuates low awareness and underreporting,” the CDC report stated.
How is the kissing bug disease transmitted?
The kissing bug spreads T. cruzi in a unique and indirect way. When it feeds on blood, the insect defecates near the bite site.
The parasite is present in the bug’s droppings rather than its saliva. When a person scratches the bite or touches their face, they can unintentionally rub the contaminated feces into their skin, eyes, or mouth, giving the parasite a pathway into the body.
“People might scratch or rub bug feces into a bite wound, their eyes, or mouth without realising it, which allows the parasite to enter their body,” the CDC explained.
This method of transmission makes Chagas disease different from other insect-borne illnesses such as malaria or dengue.
The disease cannot spread through casual human contact like a cold or flu, nor does it move directly from person to person in everyday interactions.
However, there are other possible routes of infection:
Blood transfusions or organ transplants from infected donors.
Contaminated food or beverages containing the parasite.
Mother-to-child transmission during pregnancy.
Because half of all kissing bugs may carry T. cruzi, the risk of infection remains significant wherever the insect is present.
What do we know about the kissing bug itself?
Triatomines are small to medium-sized insects, generally half an inch to one inch in length. Adult bugs have a flat, dark body with distinctive orange or red markings.
Unlike ticks, which attach themselves to a host for extended periods, kissing bugs feed quickly and move away once they have taken a blood meal.
Also Read | How safe are sleep gummies for kids?
Texas A&M University’s Kissing Bug Community Science Programme reports that they feed multiple times during their lifespan and take several minutes to complete a single meal.
The bugs are mostly active at night, hiding in cracks, piles of wood, or other clutter during the day.
Their life cycle begins when they hatch from small eggs, and they can survive for up to two years in favourable conditions.
What are the symptoms of the kissing bug disease?
Chagas disease progresses in two stages: acute and chronic. Each stage presents different challenges for diagnosis and treatment.
The acute stage occurs shortly after a person is infected and typically lasts for up to two months. During this period, symptoms may be mild or absent, making detection difficult.
According to the CDC, signs in this phase can include:
Fever
Fatigue
Body aches
Headache
Rash
Loss of appetite
Diarrhea
Vomiting
A unique symptom associated with early infection is Romaña’s sign, which involves significant swelling of one eyelid.
This occurs when the parasite enters the body through the eye or when bug feces are accidentally rubbed into a bite near the eye.
If Chagas disease is identified and treated during the acute phase, the chances of avoiding long-term damage are much higher.
Unfortunately, because the symptoms resemble other common illnesses, many cases go undiagnosed at this stage.
If untreated, the parasite can remain in the body for years, silently causing harm.
The chronic phase may last for decades or even a lifetime.
During this stage, the parasite primarily attacks the heart and digestive system, leading to severe complications in 20 per cent to 30 per cent of infected individuals.
The CDC lists several serious outcomes of chronic Chagas disease:
Enlarged heart (cardiomegaly), which can lead to heart failure.
Irregular heart rhythms, posing a risk of sudden cardiac arrest.
Digestive system enlargement, including the esophagus or colon, causing difficulty eating, swallowing, or passing stool.
In the most severe cases, the condition can lead to sudden death, particularly from heart-related complications.
Why is this a public health concern in the US?
The CDC estimates that over 280,000 people in the US may already be infected with T. cruzi. Alarmingly, fewer than 2 per cent of these individuals are aware of their condition.
In some areas, the concentration of cases is especially high. For example, Los Angeles County alone may have around 45,000 infections, according to UCLA Health.
Between 2000 and 2018, only 29 confirmed locally acquired human infections were officially documented in the US. Experts believe the actual number is much higher, with most cases simply never identified or reported.
Also Read | What is the flesh-eating screwworm parasite detected in a person in the US for the first time?
This gap in reporting has led to calls for Chagas disease to be reclassified as endemic in the United States.
Officially recognising the disease as endemic would help secure funding, improve diagnostic efforts, and increase public education about prevention and treatment.
While the overall number of documented cases in the US is still relatively low compared to Latin America, the growing presence of kissing bugs and increasing reports of local infections indicate that the problem is expanding.
With over 8 million people infected worldwide, public health officials stress that awareness is critical.
How to protect yourselves against Chagas?
Since no vaccine currently exists for Chagas disease, prevention focuses on minimising exposure to kissing bugs and reducing the likelihood of infection.
Recommended preventive measures:
Seal gaps and cracks in windows, doors, and walls to keep insects out.
Use insect repellents and wear long sleeves and pants in areas where the bugs are common.
Clear clutter such as woodpiles, rock piles, and trash near homes, which provide hiding places for bugs.
Stay in well-constructed housing when travelling in areas where Chagas is common.
Wash fruits and vegetables thoroughly, as contaminated food can also carry the parasite.
Regularly check pets for bites or signs of illness, as they can bring infected bugs closer to humans.
Did climate change help the spread of this disease?
Scientists are also examining the role of environmental changes in the spread of kissing bugs. Warmer temperatures create conditions that are more favourable for the insects, potentially allowing them to expand their range northward.
While the CDC notes that there is not yet sufficient data to conclusively prove a geographic expansion, researchers are observing a rising number of encounters between humans and these bugs.
The CDC report highlights several factors contributing to greater public awareness. “Invasion into homes, human bites, subsequent allergic reactions or exposure to T. cruzi parasites, and increasing frequency of canine diagnoses have led to growing public awareness.”
Also Watch:
With inputs from agencies