Another common parasitic infection, that from Taxoplasmosis gondii, has been linked to cases of schizophrenia. As we know, cats are a definitive host for this parasite.
In a 2014 piece sited in the NY Times article, the author discusses a group of parasites that have been linked to mental performance and illness. The author states, "These chronic infections may partially account for the achievement gap noted among socioeconomically disadvantaged students." He further states, "additional information has determined that the neglected infections of poverty also cause important psychiatric and neurological effects on vulnerable populations in the southern United States." A table from that article summarizes this impact.
(Hotez, 2014. JAMA Psychiatry. 2014;71(10):1099-1100)
CDC web site for neglected parasitic infections (NPIs).
JAMA Psychiatry
https://jamanetwork.com/journals/jamapsychiatry/fullarticle/1895572
Neglected Infections of Poverty in the United States and Their Effects on the Brain
Peter J. Hotez, MD, PhD1,2,3
Author Affiliations |Article Information
JAMA Psychiatry. 2014;71(10):1099-1100. doi:10.1001/jamapsychiatry.2014.1045
A group of neglected infections are emerging as important causes of psychiatric and mental illness among vulnerable populations living in extreme poverty in the United States. These chronic infections may partially account for the achievement gap noted among socioeconomically disadvantaged students.
The neglected tropical diseases (NTDs) are a group of chronic parasitic and related infections that can last decades or even the lifetime of an individual. During this time, they produce long-lasting and debilitating effects that impair productive capacity and child development. Indeed, the NTDs have actually been shown to trap people in poverty through these adverse effects.
The NTDs are not rare diseases. Quite the opposite—the NTDs are now recognized as the most common afflictions of impoverished people living in low- and middle-income countries of Africa, Asia, and Latin America. The NTDs are also considered a major reason why the “bottom billion” (ie, the 1.3 billion) people living below the poverty level cannot escape poverty.
In 2008, I identified a group of neglected parasitic and related infections of poverty among the extreme poor in the United States that closely resemble the NTDs in terms of their ability to produce chronic, debilitating, and poverty-promoting effects.1 A new review reveals that these neglected infections remain widespread and disproportionately affect selected vulnerable populations, including African American and Hispanic populations living in poverty and the homeless.2 Texas, the Gulf Coast region, and other parts of the southern United States represent the major affected areas, most likely because of their association with the extreme poverty in these regions.2
Now, additional information has determined that the neglected infections of poverty also cause important psychiatric and neurological effects on vulnerable populations in the southern United States (Table). Toxocariasis is a larval parasitic worm infection of the brain and viscera that results from accidental ingestion of Toxocara species eggs shed by dogs and cats. The eggs are nearly ubiquitous in disadvantaged urban and rural environments—the seroprevalence among disadvantaged African American populations exceeds 20%.1,2 An estimated 2.8 million African American individuals have toxocariasis.1 In a large survey of the US population,3 it was recently found that children who are seropositive for Toxocara infection (a marker of exposure and infection) scored significantly lower on the Wechsler Intelligence Scale for Children–Revised and the Wide Range Achievement Test–Revised than did seronegative children. Toxocariasis is also associated with epilepsy and may be an important cause of epilepsy among African American children.2
Summary of the Effect of Neglected Infections of Poverty on the Mental Health of the US Population
[Table above]
Summary of the Effect of Neglected Infections of Poverty on the Mental Health of the US Population
Persons with toxocariasis are also more likely to be co-infected with Toxoplasma gondii, a parasitic protozoan that causes toxoplasmosis. Both of these zoonotic infections can be acquired from cats. Like toxocariasis, toxoplasmosis also disproportionately occurs among non-Hispanic black individuals and is linked to poverty.4 Approximately 1 million new cases occur annually in the United States.2 A recent body of literature has identified provocative associations between toxoplasmosis and adult psychiatric illness, possibly a long-term consequence from congenital Toxoplasma infection and the resulting disruptions in fetal neurodevelopment.5,6 Specifically, seropositivity for toxoplasmosis has been strongly linked to bipolar mood disorder and schizophrenia.5,6 Still another congenital infection that causes intellectual disabilities (as well as losses in hearing and vision) and disproportionately affects African American children is congenital cytomegalovirus (CMV) infection.1 In pregnancy, non-Hispanic black women are at substantially increased risk of acquiring primary CMV infection compared with non-Hispanic white women, especially during teen pregnancies.1 An estimated 27 000 new cases of congenital CMV infection occur annually.1
Beyond African American individuals, 2 neglected infections of poverty also affect other vulnerable populations in the United States. Neurocysticercosis, a larval pork tapeworm infection, is an important cause of epilepsy and chronic headaches in mostly Hispanic individuals.2 My previous estimate indicates that between 41 000 and 169 000 people are living with cysticercosis in the United States.1 Several studies have identified cognitive impairments in patients with neurocysticercosis and even dementia. In addition, the largest numbers of new cases of West Nile virus (WNV) infection are currently found in Texas—during a 2012 WNV outbreak there, almost 2000 cases were reported. Homeless populations are considered at risk for acquiring WNV infection. Neuroinvasive WNV infection has now been linked to chronic depression in a high proportion of patients.7
The links between these neglected infections of poverty and psychiatric and neurologic illnesses have potentially important implications for mental health care providers. The neglected infections outlined here are not rare diseases in the United States, and millions of people in this country are estimated to be living with chronic toxocariasis, toxoplasmosis, CMV infection, neurocysticercosis, and WNV infection. Together, they likely account for a substantial yet hidden burden of mental illness in the United States. These infections can be extremely challenging to diagnose, manage, treat, or prevent. A national awareness program should be implemented that would include specific commitments to the training of psychiatrists and mental health care professionals, with opportunities for joint patient management with experts in infectious and tropical diseases.
CDC web site for neglected parasitic infections (NPIs).
JAMA Psychiatry
https://jamanetwork.com/journals/jamapsychiatry/fullarticle/1895572
Neglected Infections of Poverty in the United States and Their Effects on the Brain
Peter J. Hotez, MD, PhD1,2,3
Author Affiliations |Article Information
JAMA Psychiatry. 2014;71(10):1099-1100. doi:10.1001/jamapsychiatry.2014.1045
A group of neglected infections are emerging as important causes of psychiatric and mental illness among vulnerable populations living in extreme poverty in the United States. These chronic infections may partially account for the achievement gap noted among socioeconomically disadvantaged students.
The neglected tropical diseases (NTDs) are a group of chronic parasitic and related infections that can last decades or even the lifetime of an individual. During this time, they produce long-lasting and debilitating effects that impair productive capacity and child development. Indeed, the NTDs have actually been shown to trap people in poverty through these adverse effects.
The NTDs are not rare diseases. Quite the opposite—the NTDs are now recognized as the most common afflictions of impoverished people living in low- and middle-income countries of Africa, Asia, and Latin America. The NTDs are also considered a major reason why the “bottom billion” (ie, the 1.3 billion) people living below the poverty level cannot escape poverty.
In 2008, I identified a group of neglected parasitic and related infections of poverty among the extreme poor in the United States that closely resemble the NTDs in terms of their ability to produce chronic, debilitating, and poverty-promoting effects.1 A new review reveals that these neglected infections remain widespread and disproportionately affect selected vulnerable populations, including African American and Hispanic populations living in poverty and the homeless.2 Texas, the Gulf Coast region, and other parts of the southern United States represent the major affected areas, most likely because of their association with the extreme poverty in these regions.2
Now, additional information has determined that the neglected infections of poverty also cause important psychiatric and neurological effects on vulnerable populations in the southern United States (Table). Toxocariasis is a larval parasitic worm infection of the brain and viscera that results from accidental ingestion of Toxocara species eggs shed by dogs and cats. The eggs are nearly ubiquitous in disadvantaged urban and rural environments—the seroprevalence among disadvantaged African American populations exceeds 20%.1,2 An estimated 2.8 million African American individuals have toxocariasis.1 In a large survey of the US population,3 it was recently found that children who are seropositive for Toxocara infection (a marker of exposure and infection) scored significantly lower on the Wechsler Intelligence Scale for Children–Revised and the Wide Range Achievement Test–Revised than did seronegative children. Toxocariasis is also associated with epilepsy and may be an important cause of epilepsy among African American children.2
Summary of the Effect of Neglected Infections of Poverty on the Mental Health of the US Population
[Table above]
Summary of the Effect of Neglected Infections of Poverty on the Mental Health of the US Population
Persons with toxocariasis are also more likely to be co-infected with Toxoplasma gondii, a parasitic protozoan that causes toxoplasmosis. Both of these zoonotic infections can be acquired from cats. Like toxocariasis, toxoplasmosis also disproportionately occurs among non-Hispanic black individuals and is linked to poverty.4 Approximately 1 million new cases occur annually in the United States.2 A recent body of literature has identified provocative associations between toxoplasmosis and adult psychiatric illness, possibly a long-term consequence from congenital Toxoplasma infection and the resulting disruptions in fetal neurodevelopment.5,6 Specifically, seropositivity for toxoplasmosis has been strongly linked to bipolar mood disorder and schizophrenia.5,6 Still another congenital infection that causes intellectual disabilities (as well as losses in hearing and vision) and disproportionately affects African American children is congenital cytomegalovirus (CMV) infection.1 In pregnancy, non-Hispanic black women are at substantially increased risk of acquiring primary CMV infection compared with non-Hispanic white women, especially during teen pregnancies.1 An estimated 27 000 new cases of congenital CMV infection occur annually.1
Beyond African American individuals, 2 neglected infections of poverty also affect other vulnerable populations in the United States. Neurocysticercosis, a larval pork tapeworm infection, is an important cause of epilepsy and chronic headaches in mostly Hispanic individuals.2 My previous estimate indicates that between 41 000 and 169 000 people are living with cysticercosis in the United States.1 Several studies have identified cognitive impairments in patients with neurocysticercosis and even dementia. In addition, the largest numbers of new cases of West Nile virus (WNV) infection are currently found in Texas—during a 2012 WNV outbreak there, almost 2000 cases were reported. Homeless populations are considered at risk for acquiring WNV infection. Neuroinvasive WNV infection has now been linked to chronic depression in a high proportion of patients.7
The links between these neglected infections of poverty and psychiatric and neurologic illnesses have potentially important implications for mental health care providers. The neglected infections outlined here are not rare diseases in the United States, and millions of people in this country are estimated to be living with chronic toxocariasis, toxoplasmosis, CMV infection, neurocysticercosis, and WNV infection. Together, they likely account for a substantial yet hidden burden of mental illness in the United States. These infections can be extremely challenging to diagnose, manage, treat, or prevent. A national awareness program should be implemented that would include specific commitments to the training of psychiatrists and mental health care professionals, with opportunities for joint patient management with experts in infectious and tropical diseases.
Article continues
New York Times
https://www.nytimes.com/2018/01/16/health/toxocara-children-new-york-playgrounds.html
The Parasite on the Playground
Roundworm eggs, shed by stray dogs, can be ingested by children playing outside. The worm’s larvae have been found in the brain, experts say, perhaps impairing development.
By LAURA BEILJAN. 16, 2018
Millions of American children have been exposed to a parasite that could interfere with their breathing, liver function, eyesight and even intelligence. Yet few scientists have studied the infection in the United States, and most doctors are unaware of it.
The parasites, roundworms of the genus Toxocara, live in the intestines of cats and dogs, especially strays. Microscopic eggs from Toxocara are shed in the animals’ feces, contaminating yards, playgrounds and sandboxes.
These infectious particles cling to the hands of children playing outside. Once swallowed, the eggs soon hatch, releasing larvae that wriggle through the body and, evidence suggests, may even reach the brain, compromising learning and cognition.
The Centers for Disease Control and Prevention periodically tracks positive tests for Toxocara through the National Health and Nutrition Examination Survey. The latest report, published in September in the journal Clinical Infectious Diseases, estimated that about 5 percent of the United States population — or about 16 million people — carry Toxocara antibodies in their blood, a sign they have ingested the eggs.
But the risk is not evenly shared: Poor and minority populations are more often exposed. The rate among African Americans was almost 7 percent, according to the C.D.C. Among people living below the poverty line, the infection rate was 10 percent.
The odds of a positive test rise with age, but it’s unknown whether this reflects recent infections or simply an accumulation of antibodies from past encounters.
Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, calls Toxocara both one of the most common parasites in the country and arguably the most neglected.
In some cases, larvae from Toxocara enter the eyes and cause blindness. They can also infect the liver and lungs, leading to a potentially damaging inflammatory reaction.
Usually, however, signs of infection are more subtle: a slight fever, fatigue, abdominal pain and cough — symptoms that describe any number of illnesses. Few pediatricians think to test for Toxocara.
Untreated, the infection may clear on its own after months or even years, “but we don’t know for sure,” Dr. Hotez said.
A C.D.C. survey published in October found that 85 percent of pediatricians admitted to only passing familiarity with the infection, called toxocariasis; given a description of symptoms, slightly less than half of the doctors correctly diagnosed it.
When infection is recognized, it can be treated with the anti-parasitic drug albendazole, Dr. Hotez said.
“Nobody is dying here,” he said, “but it is potentially causing developmental delays that are affecting quality of life, and the economic impact is far greater. It could trap children in poverty.”
In 2014, he published his only contribution to a mental health journal, in JAMA Psychiatry, arguing that parasitic infections such as toxocariasis “likely account for a substantial yet hidden burden of mental illness in the United States.”
To what extent, no one can say. The scientific literature contains only scattered reports of Toxocara worms discovered in the central nervous system.
“We know that larvae go to the brain in humans,” said Celia Holland, a parasitology professor at Trinity College Dublin in Ireland. But beyond that fact, she says, “we know very little.”
Article continues
New York Times
https://www.nytimes.com/2018/01/16/health/toxocara-children-new-york-playgrounds.html
The Parasite on the Playground
Roundworm eggs, shed by stray dogs, can be ingested by children playing outside. The worm’s larvae have been found in the brain, experts say, perhaps impairing development.
By LAURA BEILJAN. 16, 2018
Millions of American children have been exposed to a parasite that could interfere with their breathing, liver function, eyesight and even intelligence. Yet few scientists have studied the infection in the United States, and most doctors are unaware of it.
The parasites, roundworms of the genus Toxocara, live in the intestines of cats and dogs, especially strays. Microscopic eggs from Toxocara are shed in the animals’ feces, contaminating yards, playgrounds and sandboxes.
These infectious particles cling to the hands of children playing outside. Once swallowed, the eggs soon hatch, releasing larvae that wriggle through the body and, evidence suggests, may even reach the brain, compromising learning and cognition.
The Centers for Disease Control and Prevention periodically tracks positive tests for Toxocara through the National Health and Nutrition Examination Survey. The latest report, published in September in the journal Clinical Infectious Diseases, estimated that about 5 percent of the United States population — or about 16 million people — carry Toxocara antibodies in their blood, a sign they have ingested the eggs.
But the risk is not evenly shared: Poor and minority populations are more often exposed. The rate among African Americans was almost 7 percent, according to the C.D.C. Among people living below the poverty line, the infection rate was 10 percent.
The odds of a positive test rise with age, but it’s unknown whether this reflects recent infections or simply an accumulation of antibodies from past encounters.
Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine in Houston, calls Toxocara both one of the most common parasites in the country and arguably the most neglected.
“We know in some cases it is linked to lower intelligence and epilepsy,” he said. “So if you were to look at disadvantaged kids living in poverty who are also doing lower on tests of school performance, what percentage of that can be attributed to this worm?”
While much is still unknown, “there’s enough here to warrant doing a major study on a large number of children.”
While much is still unknown, “there’s enough here to warrant doing a major study on a large number of children.”
At the moment, research into Toxocara among Americans is so lacking that the National Institutes of Health funding website lists no grants to study it. Even many of the most basic questions are unanswered, including how often ingested eggs progress to full-blown infection.
Among the country’s overlooked parasitic infections, “Toxocara is probably the one that affects the broadest range of people,” said Sue Montgomery, lead of the epidemiology team at the parasitic diseases branch of the C.D.C. “Dogs and cats are everywhere. Many of them may carry the parasites.”
Studies indicate that owned pets who receive regular veterinary care rarely carry Toxocara. Poorer neighborhoods bear a disproportionate share of strays. In one survey, 8,700 unowned dogs were said to be roaming parts of Dallas.
A survey of New York City playgrounds, presented at a medical conference last year, sampled 21 parks across the city. Toxocara eggs were found in nine parks. Three quarters of samples taken in the Bronx contained eggs in the larval stage, which are more infectious. No parks in Manhattan had eggs with larvae.
Among the country’s overlooked parasitic infections, “Toxocara is probably the one that affects the broadest range of people,” said Sue Montgomery, lead of the epidemiology team at the parasitic diseases branch of the C.D.C. “Dogs and cats are everywhere. Many of them may carry the parasites.”
Studies indicate that owned pets who receive regular veterinary care rarely carry Toxocara. Poorer neighborhoods bear a disproportionate share of strays. In one survey, 8,700 unowned dogs were said to be roaming parts of Dallas.
A survey of New York City playgrounds, presented at a medical conference last year, sampled 21 parks across the city. Toxocara eggs were found in nine parks. Three quarters of samples taken in the Bronx contained eggs in the larval stage, which are more infectious. No parks in Manhattan had eggs with larvae.
In some cases, larvae from Toxocara enter the eyes and cause blindness. They can also infect the liver and lungs, leading to a potentially damaging inflammatory reaction.
Usually, however, signs of infection are more subtle: a slight fever, fatigue, abdominal pain and cough — symptoms that describe any number of illnesses. Few pediatricians think to test for Toxocara.
Untreated, the infection may clear on its own after months or even years, “but we don’t know for sure,” Dr. Hotez said.
A C.D.C. survey published in October found that 85 percent of pediatricians admitted to only passing familiarity with the infection, called toxocariasis; given a description of symptoms, slightly less than half of the doctors correctly diagnosed it.
When infection is recognized, it can be treated with the anti-parasitic drug albendazole, Dr. Hotez said.
“Nobody is dying here,” he said, “but it is potentially causing developmental delays that are affecting quality of life, and the economic impact is far greater. It could trap children in poverty.”
In 2014, he published his only contribution to a mental health journal, in JAMA Psychiatry, arguing that parasitic infections such as toxocariasis “likely account for a substantial yet hidden burden of mental illness in the United States.”
To what extent, no one can say. The scientific literature contains only scattered reports of Toxocara worms discovered in the central nervous system.
“We know that larvae go to the brain in humans,” said Celia Holland, a parasitology professor at Trinity College Dublin in Ireland. But beyond that fact, she says, “we know very little.”
Article continues
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