Hansen’s Disease (Leprosy) and Hearing Loss, Modern Treatment and Cure (part 7)

HHTM staff: Today’s post continues the discussion of Hansen’s disease, leprosy, as part of HHTM’s infectious diseases series.  Last post described the difficulties of differential diagnosis and early philosophies of care and treatment of this little-understood but stigmatizing disease.

Leprosariums in the 19th and 20th century isolated and quarantined-for-life those thought to have leprosy.  Carville was one of those places in the US, but that facility went beyond confinement in search of treatment and cure, eventually succeeding in both. 

 

Treatment and Cure

 

http://web.stanford.edu/class/humbio103/ParaSites2005/Leprosy/history.htmUntil the mid-20th century, treatment was little better than in the age of alchemists and didn’t change much for centuries.  At leprosariums and elsewhere throughout the world, the only “medical” treatment was painful injections of chaulmoogra nut oil, which may or may not have helped but certainly did not cure.

Carville was a success in terms of finding a cure for the disease.  Promin, “The Miracle of Carville”, was discovered in 1941.  It was a sulfa drug, delivered by multiple, painful injections.

Carville research produced dapsone in the 1950s, a sulfa drug with anti-inflammatory properties.  Dapsone came in pill form, making it an easier and less painful treatment.  However, like malarial treatments, the leprosy bacillus quickly developed resistance to the drug.

Clinical researchers on the island of Malta developed a multi-drug treatment (MDT) program in the 1970s, by combining dapsone, rifampicin, and clofazimine.  Again, the parallels to malaria are notable.  MDTs, some including dapsone, were developed in that time for malaria as well; required treatment periods are lengthy for both diseases (6-12+ months for leprosy to prevent recurrence).    Even though it takes a long time to eradicate the disease from the body, those with leprosy are not communicable once it commences.  Quarantine and isolation are not indicated.

Antibiotic treatment is effective for leprosy at early and intermediate stages (Han et al, 2008).  But, it’s clear that early detection is unlikely, which is why discouraging comments like this appear in the scientific/medical literature:

Even with proper multidrug therapy (MDT), the consequent sensory and motor damage results in the deformities and disabilities associated with leprosy.

 

No Vaccine for Leprosy

 

Efforts to develop a specific vaccine for leprosy have been ongoing since 1921.  Tuberculosis vaccines are used in different parts of the world to combat leprosy, but they are not used in the US.  That is due in part because their efficacy is not proven, and because of the low incidence of cases reported.

Low does not mean inconsequential.  In 2009, 213 new cases were reported and it is thought that incidence may be higher than reported due to those who have the disease but do not report it.  This is especially the case for new immigrants who fear for their immigration status.  It is noteworthy that 65% of the 2009 cases in the US occurred in mainly high-immigration locales:  California, Florida, Texas, New York, Massachusetts, Hawaii, and Louisiana.

 

 What Are Audiologists to Make of This Information?

 

Understanding the difficulties  and delays in diagnosis is important for any health care professional, especially those who have long-term contact with patients who live active lifestyles that include global travel. Knowing the signs and symptoms, expanding history-taking to include important lifestyle information (place of origin, lifelong travel events), and knowing the sketchy nature of reported incidence in the US are valuable additions to Audiologists assessment protocols.

Treatments can effectively cure the disease, but effects of the disease on the peripheral nervous system before diagnosis are irreversible.  Such effects may include peripheral portions of hearing and balance innervation.

 

References

Masaki, T., et al. (2013). Reprogramming Adult Schwann Cells to Stem Cell-like Cells by Leprosy Bacilli Promotes Dissemination of Infection. Cell, 152: 51–67. DOI: 10.1016/j.cell.2012.12.014

Wegner, M. Mighty Bugs: Leprosy Bacteria Turn Schwann Cells into Stem Cells. Cell, 152(1–2) 17 January 2013, pp 15-16.

photos courtesy of haiku deck and  Stanford University