Leprosy

LEPROSYNadine Chase & Priyanka Patel

TAXONOMY Genus: Mycobacterium Family:

Mycobacteriaceae Mycobacterium Leprae

Acid-fast Bacillus Gram Positive Bacillus shape Single arrangement Aerobic Optimum growth

temperature is 30° Trivia

Can not be grown in culture

http://asylumeclectica.com/asylum/malady/archives/leprosy/leprosy4.jpg

Sehgal, Alfica. Leprosy, Deadly Diseases and Epidemics. Philadelphia, PA, 2006.

Sehgal, Alfica. Leprosy, Deadly Diseases and Epidemics. Philadelphia, PA, 2006.

TYPES Tuberculoid Leprosy

Pauci-bacillary (PB) LeprosyWell defined skin lesions that are numb

1-5 skin lesions Lepromatous Leprosy

Multi-bacillary (MB) LeprosyChronically stuffy noseMany skin lesions and nodules>5 skin lesions

TARGET TISSUES Skin tissue Peripheral nerves Mucus membranes Bacteria prefers outer cooler parts of

the body

Sehgal, Alfica. Leprosy, Deadly Diseases and Epidemics. Philadelphia, PA, 2006.

ECOLOGY Widespread organism living in water and food sources

Obligate Parasites (cannot live independently)

Fish Insects

INFECTION PROCESS Not very contagious Air born disease

Droplets discharged from the respiratory tract

Nasal secretions Prolonged contact with

excretions from lesions Slow replication time Long incubation period

INFECTION PROCESS CONT. Affinity for

macrophages and Schwann cells

In Schwann cellMycobacterium binds

to the G domain of alpha chain of laminin 2 in the basal lamina

Stimulates cell mediated immune response which causes swelling, chronic inflammatory response

Ultimately leads to axonal (nerve) death

http://www.med.nyu.edu/news_and_views/images/leprosy.jpg

NERVE CELL

Normal Nerve Cell Nerve Cell enlargement

Arnold, Harry. Modern Concepts of Leprosy. Springfield, IL, 1953.

PREVENTATIVE MEASURES Avoid contact with infected persons

99% of the population have natural immunity http://www.ruggedelegantliving.com/journal/images/2003/05/01/sars.mask.jpg

SYMPTOMS Long incubation

period Skin lesions with

decreased sensitivity

Numbness Muscle weakness Cosmetic

Disfiguration Death is usually

caused by a secondary opportunistic disease

http://www.wrongdiagnosis.com/l/leprosy/deaths.htm

DIAGNOSTIC TEST Leprosy Skin Test

Inactive Leprosy-causing bacteria injected into skin

Body will react to the Leprosy antigens

Check injection 3 days and 28 days later

Positive skin reaction is seen in Tuberculoid Leprosy only

Normal result: little to no skin irritation around injection site

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

DIAGNOSTIC TEST: SKIN BIOPSY Shave Biopsy

Least invasiveSuperficial

layers of lesion scraped off

No stitches required

Bacteria can be identified on a slide

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

DIAGNOSTIC TEST: SKIN BIOPSY Punch Biopsy

Small cylinder of skin removed

Sizes vary depending on size of lesion

May require stitches

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

DIAGNOSTIC TEST: SKIN BIOPSY Excisional

BiopsyLocal anesthetic applied

Entire lesion is removed

Stitches are usually needed

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

DIAGNOSTIC TEST: Methacholine sweat testing

An intradermal injection of methacholine demonstrates the absence of sweating in leprous lesions.

Helpful to identify diagnosis when lesions are not visible on dark skin individuals

Arnold, Harry. Modern Concepts of Leprosy. Springfield, IL, 1953.

TREATMENTS Multi-drug therapy PB Leprosy

Two Drugs: Rifampicin and Dapsone for 6 months

MB LeprosyThree Drugs:

Rifampicin, Dapsone, Clofazimine for 12 months

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

Sehgal, Alfica. Leprosy, Deadly D

iseases and Epidemics. Philadelphia, PA, 2006.

TREATMENTS CONT. Special Footwear to prevent foot

ulcers

Grunberg, E., Babger, LF, et al. Leprosy. New York, 1951.

EPIDEMIOLOGY Age

Children are more susceptibleBimodal age distribution with peaks at ages 10-14 and 35-44 with higher susceptibilities in younger years

SexHigher infection rate in males compare to females

Ratio of infection is 2:1

EPIDEMIOLOGY CONT. Race

African blacks are highly susceptible to the tuberculoid form of leprosy

Caucasians and Chinese are more susceptible to the lepromatous type of Leprosy

Its more rural than urban disease in Asia and Pacific Basin

http://tmcr.usuhs.mil/tmcr/chapter34/large34/34-01.jpg

MORBIDITY AND MORTALITY 2002 Data

1,000 deaths in North and South America 96 cases in the U.S

3,000 deaths in South East Asia 1,000 death in Eastern Mediterranean 1,000 deaths Western Pacific

2005 Data 166 new cases were reported in U.S. 60% of these cases occurred in:

California Louisiana Massachusetts New York Texas

HANSEN DISEASE (LEPROSY)Number of reported cases, by

yearUnited States, 1973-2003

www.cdc.gov/epo/dphsi/annsum/2003/slides/hansgraf.ppt

RESEARCH Attempt to identify new drugs that can

stop the neural damage caused by the bacteria

Bacteria needs to recognize certain type glycoprotein on the cell surface to bind with and subsequently enter the cell

If these glycoprotein can be identified and a drug can interfere with the binding between the bacterium and the protein, this could potentially prevent entry of the bacteria and stop neural damage

A TWIN STUDY Leprosy has been found to NOT be

hereditary If twin siblings become infected, the

disease is passed from one to the other solely because of the proximity in which they live

Twin A acquired the disease at age 15 Twin B at age 19 The disease effects the twins

differently

TWIN STUDY

Twin A Twin BChakravartti, M.R. and Vogel, F. A Twin Study on Leprosy. Germany, 1973.

REFERENCES Arnold, Harry. Modern Concepts of Leprosy. Springfield, IL, 1953.

Chakravartti, M.R. and Vogel, F. A Twin Study on Leprosy. Germany, 1973.

Grunberg, E., Babger, LF, et al. Leprosy. New York, 1951.

http://www.cdc.gov/ncidod/dbmd/diseaseinfo/hansens_t.htm

http://www.nlm.nih.gov/medlineplus/ency/article/003383.htm

http://tmcr.usuhs.mil/tmcr/chapter34/large34/34-01.jpg

http://www.wrongdiagnosis.com/l/leprosy/deaths.htm

“Leprosy. “eMedicine from webmed. http://www.sunysccc.edu/academic/mst/microbes/16mlepr.htm 21 July 2007.

“Leprosy, The Disease” World Health Organization; Regional Office for Southeast Asia.www.searo.who.int/En/Section10/section20/section57_8963.htm. 22 December 2006.

Sehgal, Alfica. Leprosy, Deadly Diseases and Epidemics. Philadelphia, PA, 2006.