Healthcare Hygiene magazine September 2023 September 2023

under the microscope

By Priya Dhagat , MS , MLS ( ASCP ) CM , CIC

Leprosy in the Limelight

Last month , news of leprosy ( Hansen ’ s Disease ) in Florida made headlines after a case report was published as a research letter by the Centers for Disease Control and Prevention ( CDC ), sparking fears that the disease is endemic in the state and yet another infectious disease to worry about .

The case report described a 54-year-old man who sought treatment at a dermatology clinic for a painful and progressive rash , with lesions on his extremities , trunk and face . He has lived in Florida his entire life , works as a landscaper , and did not report recent travel , exposure to armadillos , prolonged contact with individuals from

Historically , leprosy was feared as a highly contagious disease caused by a punishment from God which elicited harsh social stigma , prejudice , and ostracization from communities . We now know that the disease still exists in many countries , takes time to spread to others , and is easily treatable once recognized .” leprosy-endemic countries , or contact with someone known to have leprosy . After biopsies from multiple sites , Hansen ’ s Disease was confirmed . According to the CDC report , leprosy in the United States previously affected persons who had immigrated from leprosy-endemic areas , but roughly 34 percent of new case-patients from 2015 through 2020 appeared to have locally acquired the disease . The absence of traditional epidemiological risk factors in recent cases in Florida likely supports environmental reservoirs as a potential source of transmission , according to the CDC research letter .

However , despite known for being an age-old disease of the past , Hansen ’ s Disease is quite common . The World Health Organization states that the disease is still reported in over 120 countries with more than 200,000 new cases reported every year , the majority in South-East Asia . In the U . S ., there were 159 new cases reported in 2020 ( the most recent year for which data are available ) and 110 of those new cases were reported in Florida , California , Louisiana , Hawaii , New York , Oregon , and Texas , per the National Hansen ’ s Disease Program .

Hansen ’ s Disease is caused by infection with the bacteria Mycobacterium leprae , an acid-fast , gram-positive obligate intracellular bacillus which cannot grow outside of a host cell and is completely dependent on host cells for survival .

Transmission is thought to occur through respiratory droplets produced when an infected person coughs or sneezes . Unlike influenza or COVID-19 , prolonged close contact with someone with untreated leprosy over a long period of time is needed to become infected . Contact with infected armadillos , a known animal reservoir for the bacteria , may also lead to infection .

M . leprae targets , invades , and reprograms key genes of cells in the peripheral nervous system ( specifically Schwann cells ) thereby disrupting and halting myelination processes . Ultimately ,

infection affects the skin , peripheral nerves , upper respiratory tract mucosa , and eyes .

Diagnosis is based on hypopigmented or erythematous macules with sensory loss , thickened peripheral nerves , or a positive acid-fast smear or skin biopsy . However , due to the slow-growing nature of M . leprae and an extremely long incubation period , the development of symptoms can be years and most patients present with a form of neuropathy .

If not diagnosed early or left untreated , infection can cause permanent neuropathic damage resulting in paralysis , blindness , disfigurement , and disability . The characteristic skin conditions are a result of uncontrolled bacterial growth within the skin and peripheral nerves that form neuropathic ulcers which can lead to the destruction of muscles , cartilage , and bones . Other key signs and symptoms include discolored skin patches , painless ulcers on the soles of feet , swelling on the face , loss of eyebrows and eyelashes , numbness to affected skin areas , muscle weakness , enlarged nerves , and eye or vision problems .

Although there has been an uptick in cases per the CDC report , the overall risk of infection is still considered to be very low considering more than 95 percent of all people have natural immunity to the bacteria . During care of patients in healthcare settings , routine infection prevention strategies , including following standard precautions , should be followed .

Priya Dhagat , MS , MLS ( ASCP ) CM , CIC , is an infection preventionist and the associate director of the system-wide Special Pathogens Program within the Department of Emergency Management at New York City Health + Hospitals , overseeing special pathogen preparedness and response efforts across New York City Health + Hospitals frontline healthcare facilities . Additionally , she supports and offers subject matter expertise for infection prevention topics for the National Emerging Special Pathogens Training and Education Center ( NETEC ).

Healthcare Hygiene magazine September 2023 September 2023 | Page 8

under the microscope

under the microscope

Leprosy in the Limelight