And, bedbugs can be found in all states and all cities.
Dr. Peter Hotez of the National School of Tropical Medicine says low-income neighborhoods like Houston’s Fourth Ward are at greater risk for infection due to factors such as a lack of screens and piles of trash.
HOUSTON — A broken screen hangs off a window frame on a house on Worms Street. The windows are smashed, the front door hinges are loose. In the yard, an old tire, a lopsided pink tricycle and three rusty buckets lie amid garbage bags and old furniture.
Like many streets in Houston’s Greater Fifth Ward, Worms Street offers the perfect environment for the spread of tropical diseases.
Many of these infections aren’t new to the state, but rising temperatures and high poverty rates create what experts call a perfect storm for these diseases to spread in Texas.
Partly because of living conditions like these, lower-income Texans are at higher risk of infection with tropical diseases compared with wealthier Texans.
Smashed windows and broken screens grant easy access to insects that carry parasites. Overturned buckets and abandoned tires capture pools of water where mosquitoes carrying viruses such as West Nile and dengue like to breed.
Tropical diseases affect Texans of all backgrounds. But poverty is the biggest risk factor for infection, experts say. The diseases trap the poor in a cycle of illness and poverty and can contribute to rising poverty rates in some neighborhoods.
Those neighborhoods aren’t only in New Delhi or Nairobi. They’re here in Texas. Although most of the 1.5 billion people infected with a tropical disease live in the developing world, poor people living in wealthy countries are at risk.
That includes an estimated 12 million Americans who are infected with a tropical disease.
“We found that most of the world’s neglected diseases — meaning worm infections, meaning Chagas disease, meaning leishmaniasis and leprosy — actually occur in G20 countries, the 20 wealthiest economies in the world,” says Dr. Peter Hotez, dean of the National School of Tropical Medicine in Houston.
On this recent afternoon, Hotez walks along Worms Street, exploring the Fifth Ward.
“It’s a lot like walking through a town in the developing world,” says Hotez, pointing to a pile of trash in front of a house. “People don’t realize that right here in Texas, in wealthy cities like Houston, we have families who live in conditions like this.”
In a 2002 outbreak of West Nile virus in the Houston area, researchers at the University of Texas Health Science Center found that neighborhoods home to low-income families with low education levels were more likely to be infested with virus-carrying mosquitoes.
Being poor in Texas also means you’re more likely to die from a tropical disease.
In 2006, researchers at the University of Cincinnati found that poor Texans infected with West Nile virus were more likely to die from the disease compared with wealthier Texans.
Because of their predilection for the poor, Hotez calls these infections “the forgotten diseases of forgotten people.”
Poorer and sicker
Dilapidated housing lets in the bugs, and low-income families’ lack of access to quality health care allows the infections to fester.
For these families, living in poverty and working multiple jobs to support relatives means getting to see a doctor can be tough. Getting a diagnosis can be even tougher.
And when you do get an appointment and make it to the doctor’s office on time, chances are the doctor won’t know what’s wrong with you.
Medical education in the U.S. doesn’t include much training on tropical diseases.
That’s why Texans with a tropical disease called leishmaniasis have been sent home with antibiotics even though the disease is caused by a parasite and antibiotics won’t work.
It’s why blood donors in Houston who tested positive for Chagas disease at the blood center were told by their family doctors that the results must be a mistake.
Misdiagnosis can mean years of unexplained, untreated symptoms.
A third of patients infected with the parasite that causes Chagas disease suffer heart failure.
Years of chest pain, breathlessness and fatigue can make it hard to keep a job.
Leishmaniasis causes disfiguring skin sores that can take a year to heal. The disease is also known as the Baghdad boil because it is seen in troops returning home from the Middle East. It’s now found in North Texas and Oklahoma, where it is spread by sand flies.
Sores can occur all over the body, but patients with sores on their faces can find it especially difficult to leave the home and earn a living.
Infection with West Nile virus, even the milder form of the disease known as West Nile fever, can cause depression, memory problems and aches and pains that last for years after the initial infection.
For low-income families without a financial safety net, infection with a tropical disease means time off work, loss of employment and expensive medical bills.
Everyone pays the price for outbreaks of tropical diseases. Researchers at the University of Pittsburgh found that the societal and health care cost for each person diagnosed with Chagas disease in the U.S. is more than $90,000.
The cost of the 2012 West Nile virus outbreak in Dallas-Fort Worth was more than $47.6 million, according to a study by Dr. Kristy Murray, a tropical disease expert at Baylor College of Medicine.
For individual patients, the long-term cost of West Nile virus infection can range from $3,000 to more than $30,000 depending on the severity of illness.
For families already living on the precipice of poverty, infection with Chagas disease, West Nile virus or another tropical disease can be the breaking point.
Children’s learning ability
For children, infection with a tropical disease can mean a mistaken diagnosis of a learning difficulty.
Some tropical diseases slow a child’s ability to learn; they can stunt the child’s intellectual growth. Teachers and doctors can mislabel children as “slow” or “challenging to teach” when in fact they have a treatable infection.
This could partly explain the achievement gap between poor children and wealthier children, experts say. And because the symptoms of some tropical diseases mimic other illnesses, they can be difficult to catch and treat early, especially for children with poor access to health care.
Infection with the eggs of a roundworm found in dog and cat feces can cause symptoms that mimic asthma.
The disease, called toxocariasis, occurs when the worm larvae settle in various organs. If they settle in a child’s lungs, they can cause chest pain and difficulty breathing, which can be misdiagnosed as asthma.
When the worm larvae settle in a child’s brain, they can cause headaches and seizures that can be misdiagnosed as epilepsy. Larvae in the brain can also hinder a child’s ability to learn and reach his or her developmental milestones on time. The infection can be treated with antiparasitic medicines if diagnosed accurately.
Texas is home to nearly 7 million children, and more than 1.7 million of them live in poverty. Researchers worry that poor children are both more vulnerable to getting these infections and less likely to be diagnosed quickly.
“There is a link with poverty where more disadvantaged children might suffer longer,” says Dr. Rima McLeod, an infectious disease doctor at the University of Chicago. McLeod’s research looks at a different parasite called Toxoplasma gondii that can infect unborn babies and cause lifelong disability.
You might have heard of Toxoplasma gondii if you’ve ever accompanied a pregnant woman to a prenatal health check. Doctors and midwives advise women to stay away from cat litter during pregnancy because the parasite, which is found in cat feces, can be passed from mother to baby.
That results in a condition called congenital toxoplasmosis where babies are born with hearing loss, eye damage, enlarged organs, seizures and intellectual disability.
McLeod said as many as 4,000 babies are born with congenital toxoplasmosis in the U.S. each year, and she believes that pregnant women should be routinely tested for the infection because early treatment has better results.
“But right now we’re seeing that pregnant women who do get tested are from more well-resourced backgrounds. They have access to doctors who do more thorough screenings,” she said. “Women from disadvantaged backgrounds don’t get that same level of screening.”
We might be more aware of tropical diseases these days because public health agencies and researchers are keeping a closer eye on some of them.
But across the world, rising temperatures and high poverty rates are contributing to more frequent and bigger outbreaks of these diseases.
An outbreak of the mosquito-borne virus chikungunya in the Caribbean in 2013 — the first time an outbreak ever occurred in the Americas — lasted at least six months and sickened more than 30,000 people.
Since then, a handful of cases have been reported in Texas in travelers returning from the Caribbean.
Because Texas is home to the type of mosquitoes that can spread chikungunya, public health experts worry that local outbreaks of the disease could soon become the norm in the same way that West Nile virus is now a yearly occurrence.
And because poorer Texas neighborhoods were found to be heavily infested with the mosquitoes that spread West Nile virus, these experts worry that the same will be true for other diseases spread by mosquitoes such as chikungunya and dengue.
“Our government has been great about taking on these diseases in poor countries across the world like in Africa and Asia, but we need greater attention to these diseases in the U.S., in places like this,” says Hotez, waving an arm in the direction of the dilapidated houses on Houston’s Worms Street.
“These diseases keep poor people poor.”
Dr. Seema Yasmin’s reporting on this story was undertaken while she was a National Health Journalism Fellow at the University of Southern California’s Center for Health Journalism. Yasmin, a physician and former CDC epidemiologist, is a professor at the University of Texas at Dallas.