Chagas disease - a new public health threat for Americans?

Date: Nov-05-2014 Chagas disease - a parasitic infection that can cause severe heart disease

and death if not caught and treated early - affects millions of people

worldwide, mainly in Latin America. Now, new research suggests it is

increasingly being seen in the southern US and poses an emerging potential

public health threat for Americans.

Experts say a large area of the southern US faces a tangible but mostly unrecognized risk of contracting Chagas disease.

Researchers from Baylor College of Medicine in Houston, TX, presented

the results of their work on 4th November at the 63rd Annual Meeting of the

American Society of Tropical Medicine and Hygiene (ASTMH) in New Orleans,

LA.

They say a large area of the southern US faces a tangible but mostly

unrecognized risk of contracting Chagas disease.

Chagas disease (American trypanosomiasis) is caused by Trypanosoma

cruzi, a protozoan parasite related to the African

Trypanosoma that causes sleeping sickness (African

trypanosomiasis).

The infection occurs via bloodsucking bugs that carry the parasite. The

bugs are sometimes called "kissing bugs" because they feed on people's

faces during the night. The parasite transfers to the new host via the

feces of the kissing bug. This is deposited on the skin and then gets into

the bloodstream either via the bite, or through other means, for instance

when the person scratches the bite site.

Once the parasite enters the bloodstream, it travels to the heart and

settles there, and damages the heart muscle. Up to 30% of infected people

have chronic heart disorders and up to 10% get sick with other health

problems including digestive and neurological disorders.

Many infected people do not realize they have Chagas until symptoms

become severe - and even then, they can be misdiagnosed as other

conditions, such as cardiovascular disease.

Chagas disease - which can also be spread through the blood supply from

donors infected with the parasite - can be cured if caught early. It

affects about 8 million people worldwide, mostly in Mexico, Central America

and South America.

Cases of Chagas disease increasing in Texas

However, the Baylor researchers say cases of Chagas disease are

increasingly being seen in Texas, and at higher levels than previously

thought. They also believe a high percentage of American cases have become

infected inside the US.

The team reports some of its findings in the American Journal of Tropical

Medicine and Hygiene. Commenting on those findings, and those of other

studies they conducted, Baylor epidemiologist Melissa Nolan Garcia,

says:

"We were astonished to not only find such a high rate of individuals

testing positive for Chagas in their blood, but also high rates of heart

disease that appear to be Chagas-related. We've been working with

physicians around the state to increase awareness and diagnosis of this

important emerging infectious disease."

Ms. Garcia says they see Chagas disease as a "silent killer:"

"People don't normally feel sick," she explains, "so they don't seek

medical care, but it ultimately ends up causing heart disease in about 30% of those who are infected."

Chagas disease could be going undetected in Americans due to low

awareness

The Baylor team suggests Chagas disease is an emerging public health

concern not only for Texas - where their research was conducted - but also

for other parts of the US. According to the Centers for Disease Control and Prevention

(CDC), kissing bugs are found across half of the US.

In the US, Chagas disease is considered one of the neglected parasitic

infections, a group of five parasitic diseases that the CDC have

targeted for public health action.

The Baylor team suggests there could be cases of Chagas in Americans who

are infected through kissing bug bites that are undiagnosed because of low

awareness of the disease among US health professionals.

The team presented the results of several studies to back up their

suggestions. One of these, published in the journal Epidemiology and

Infection, is an analysis of routine testing of Texas blood donors

from 2008 to 2012. Since 2007, all potential blood donors in the US are

screened for exposure to the Chagas disease parasite.

From their analysis, the Baylor team found 1 in every 6,500 donors

tested positive for the Chagas parasite, which is 50 times higher than the

CDC's one in 300,000 estimate of the national infection rate.

In August 2014, Medical News Today learned how the World Health

Organization (WHO), the Universitat Politècnica de Catalunya, and

other academic centers are setting up a global scientific database on Chagas

disease.

Written by Catharine Paddock PhD

Not to be reproduced without permission.

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Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.