Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by the acid-fast rod Mycobacterium leprae. It primarily affects the skin and peripheral nervous system, and the course of the disease is influenced by individual susceptibility to M. leprae.
While historically uncommon in the United States, leprosy cases have shown a gradual increase in incidence in recent years, particularly in the southeastern states, with central Florida being a significant hotspot. This article explores a case of lepromatous leprosy in a 54-year-old man from central Florida and reviews the mounting epidemiological evidence supporting leprosy as an endemic process in the region.
The Case of Lepromatous Leprosy in Central Florida
A 54-year-old man presented with a painful and progressive erythematous rash that began on his distal extensor extremities and eventually spread to involve his trunk and face. The patient denied any domestic or foreign travel, exposure to armadillos, contact with immigrants from leprosy-endemic countries, or connections with known leprosy patients.
He had lived in central Florida his entire life, worked in landscaping, and spent extended periods outdoors. Biopsies revealed the characteristic diffuse dermal infiltrate composed of disorganized aggregates of foamy histiocytes and lymphocytes, with acid-fast bacilli found within histiocytes and cutaneous nerve twigs, confirming the diagnosis of lepromatous leprosy.
The patient was prescribed triple therapy with dapsone, rifampin, and clofazimine under the guidance of the National Hansen’s Disease Program.
Transmission of Leprosy and Suspected Routes
The transmission of leprosy is not fully understood, but prolonged person-to-person contact through respiratory droplets is the most widely recognized route. Interestingly, a significant number of unrelated leprosy cases in the southern United States were found to carry the same unique strain of M. leprae as nine-banded armadillos in the region, suggesting a possible zoonotic transmission.
Additionally, a systematic review analyzing studies conducted from 1945 to 2019 supports the increasing role of both anthroponotic (human-to-human) and zoonotic transmission of leprosy.
However, recent reports show that many leprosy cases in the eastern United States, including central Florida, lacked zoonotic exposure or recent residence outside the country. This has led to speculation that international migration of individuals with leprosy might be a potential source of autochthonous (locally acquired) transmission.
Reports from Spain have linked an increase in autochthonous leprosy cases to an increase in migration from other countries. The rise in international migrants in North America also coincides with the increasing incidence of leprosy, suggesting a possible link between migration and the disease’s spread.
The Emergence of Endemic Leprosy in Central Florida
The case presented in central Florida adds to the growing evidence that the region represents an endemic location for leprosy. This indicates that leprosy is now established and actively transmitting within the area. While the number of reported cases in the United States has been increasing, the proportion of new diagnoses in individuals born outside the United States has been declining since 2002. This suggests that leprosy has become an endemic disease process in Florida, and further research is warranted to investigate other potential methods of autochthonous transmission.
The Importance of Surveillance and Contact Tracing
Leprosy is a reportable condition in the state of Florida, and practitioners are required to report cases promptly. Contact tracing is essential in identifying sources of infection and reducing transmission. In the case presented, contact tracing was conducted by the National Hansen’s Disease Program but failed to identify any associated risk factors, including travel, zoonotic exposure, occupational connections, or personal contacts. The absence of traditional risk factors in many recent cases in Florida, coupled with the significant proportion of residents who spend extensive time outdoors, suggests that environmental reservoirs could play a role in leprosy transmission.
The rising incidence of leprosy in the United States, particularly in central Florida, indicates that the disease is becoming endemic in the region. Healthcare professionals should be vigilant about considering leprosy in the appropriate clinical context, even in the absence of traditional risk factors.
Efforts to report incidence and conduct further research into transmission routes can help identify and mitigate the spread of leprosy. Continued surveillance and contact tracing are essential to understanding the underlying factors contributing to the emergence of leprosy as an endemic disease process in central Florida and other affected regions.
Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae. It is a slow-growing bacterium, which means that it can take many years for symptoms to develop after infection. Leprosy affects the skin, the peripheral nerves, and the lining of the upper respiratory tract.
The symptoms of leprosy vary depending on the type of leprosy a person has. There are two main types of leprosy: tuberculoid leprosy and lepromatous leprosy.
- Tuberculoid leprosy is the milder form of leprosy. It is characterized by skin lesions that are raised, pale, and have a well-defined border. There is also nerve damage in tuberculoid leprosy, but it is usually not severe.
- Lepromatous leprosy is the more severe form of leprosy. It is characterized by skin lesions that are red, scaly, and have an ill-defined border. There is also extensive nerve damage in lepromatous leprosy, which can lead to disability.
In addition to skin lesions and nerve damage, leprosy can also cause other symptoms, such as:
- Eye problems, such as keratitis and uveitis
- Bone and joint problems, such as arthritis
- Mental health problems, such as depression and anxiety
Leprosy is spread through close contact with an infected person. The bacteria that cause leprosy are found in the nasal secretions of infected people. These bacteria can be spread through the air when an infected person coughs or sneezes. Leprosy can also be spread through contact with the skin lesions of an infected person.
However, leprosy is not easily spread. It takes prolonged and close contact with an infected person to become infected. For example, you would not be likely to get leprosy from shaking hands with an infected person.
Leprosy is curable. Treatment for leprosy involves taking a combination of antibiotics for several months. With early diagnosis and treatment, leprosy can be cured and disability can be prevented.
There is no vaccine for leprosy. However, there are a number of things you can do to reduce your risk of getting leprosy, such as:
- Avoiding close contact with people who have leprosy
- Washing your hands frequently
- Covering your mouth and nose when you cough or sneeze
If you think you may have leprosy, it is important to see a doctor right away. Early diagnosis and treatment are essential for preventing disability.
Here are some additional facts about leprosy:
- Leprosy has been around for centuries. The earliest known written records of leprosy date back to 600 BC.
- Leprosy was once a very feared disease. In the Middle Ages, people with leprosy were often forced to live in isolation.
- Leprosy is not as common as it used to be. In 1985, there were an estimated 5.2 million cases of leprosy worldwide. By 2020, that number had dropped to 200,000 cases.
- Leprosy is still a major public health problem in some parts of the world, such as India, Brazil, and Indonesia.
If you have any questions about leprosy, please talk to your doctor.
reference link : https://wwwnc.cdc.gov/eid/article/29/8/22-0367_article
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