Leprosy is an ancient disease. It is the oldest disease known to be related to humans. The evidence can be traced back to 2000 BC. Typical bone erosions and deformities were found in Indian cemeteries.
Therefore, many people may think that this disease is a relic of the past, which is natural. My research in 2018 in a state where this disease is prevalent in Brazil showed that leprosy is much closer than we thought. The disease is spreading in armadillos. Although these animals are not exactly the cute types that attract humans, contact between armadillos and humans is spreading. And, when the species do interact, the armadillo is returning leprosy to humans.
Unsightly animals, worse
Leprosy, also known as Hansen’s disease, is caused by a bacterial infection Mycobacterium leprosyIt can lead to skin lesions, nerve damage, disfigurement and disability, leading to the common social stigma of patients with this disease. It is mainly spread from person to person through aerosol infection or coughing and sneezing.
Usually, infection requires close contact with an untreated infected person. As long as three to seven years after infection, symptoms develop slowly. This is rare in the United States. In the past 10 years, an average of less than 200 cases have been diagnosed each year, most of which are people who have migrated from foreign countries where the disease is endemic. It is mainly found in tropical countries such as Brazil, India, Indonesia and other countries in Africa, Southeast Asia and Pacific Islands. There were 214,783 new cases worldwide in 2016.
Although medicines for the treatment and cure of leprosy are cheap and free for anyone diagnosed with leprosy, the high incidence in dozens of countries over the past few decades has made this number less. Too much drop. The root cause of the persistently high prevalence rate remains poverty, poor sanitation and malnutrition, and lack of medical services to treat those who are diagnosed before neurological damage and disability occur.
Salmon, Commonly referred to as the nine-banded armadillo in the United States or the chicken-armadillo in Brazil, is the only species whose range includes North America, Central America, and South America. These armadillos first expanded from Mexico to Texas in the 1850s, and then went north and east into the Gulf states of the southern United States. In the late 1940s, another group of armadillos escaped from central Florida and spread throughout Florida, eventually merging with Mexico. Texas armadillo in Panhandle, Florida in the early 1970s.
Around this time, Dr. Eleanor Storrs discovered that the armadillo was infected Jatropha In the experiment, the symptoms of leprosy will eventually appear, even with the same skin and nerve damage as human cases.Soon thereafter, she and her team discovered that armadillos living in the wild in Texas and Louisiana were naturally infected. Jatropha. Analysis of bacteria-specific antibodies in archived serum samples indicated that animals in the area have likely been infected since the 1960s. Exactly how armadillos were infected by humans is unclear, but one theory is that they picked them up from contaminated soil by digging.Surveys of armadillos in Gulf states found that as many as 20% of people were infected Jatropha.
In the beginning, the armadillo’s susceptibility to leprosy promoted the development of science and medicine. Because they are the only animals other than humans that can isolate bacteria, armadillos enable scientists to study leprosy and possible treatments.
Today, there are millions of armadillos in the southern United States, and people interact with them in various ways. Animal leather carapace is made into wallets and boots. Some are kept as pets at home, or taken to zoos, children’s schools, and county fairs to entertain people in armadillo competitions. In some areas, people chase them to barbecue.
All these exposures will eventually have consequences. In 2011, Dr. Richard Truman from the National Hansen’s Disease Program in Baton Rouge, Louisiana, published a study showing that the strains that infect most armadillos and leprosy patients in Texas and Louisiana are the same. The disease is a zoonotic infection that is transmitted to humans.
In 2015, another study by the same group found that another strain that exists only in central Florida caused a second batch of cases in armadillos and humans. Both of these reports have caused widespread media coverage, and people are a little surprised and shocked by this, because this clumsy rather than cute animal is spreading the oldest and most frightening disease to humans. However, once the excitement disappears, most people may resume their behavior towards these animals, ignoring the risks that may be involved.
Look around: the same in Brazil
Two points stand out about Brazil. The armadillo is native to South America. Leprosy was brought to Brazil by European explorers through the slave trade in West Africa 500 years ago, and has a history of hundreds of years.Knowing this, our research team wanted to know how many people had contact with armadillos in Brazil and whether this would lead to the spread of leprosy in these animals, as shown in the southern United States.
Our research focused on people living in the western rural area of Pará State in the western Amazon River in the city of Belterra. People living there often consume armadillos as a source of protein. People in this town interact a lot with armadillos: 19% of them hunt animals in the forest every year, and 65% of them clean meat, cook or eat armadillos.The percentage of people who have a positive antibody reaction to the bacteria (63% are positive, the area is normal) indicates that most people have been infected by the bacteria Jatropha.
Surprisingly, 62% of hunters killed armadillos, showing an infection Jatropha, This rate is three times that of Texas and Louisiana. Most importantly, a group of 27 individuals who ate armadillo meat had 50% higher antibody levels than the other populations, indicating that increased consumption almost doubled the risk of disease. The study concluded that leprosy, similar to the southern states of the United States, was spread from armadillos to Brazilian people.
The broader information about this work is that wild animals have a variety of diseases that can be transmitted to humans, especially when they may come into contact with blood or eat meat. Although leprosy is still a disease that few people worry about in the United States, people should pay attention to the interaction with armadillos.
This article is republished from The Conversation, a non-profit news website dedicated to sharing the ideas of academic experts.
John Stewart Spencer received funding from the Heiser Programme of the New York Community Leprosy Research Foundation, and was awarded the 2015-2016 Brazilian scholar J. William Fulbright ( J. William Fulbright) scholarship.