Tuesday, December 27, 2011

What should be the correct strategy to diminishing the burden of leprosy?

Leprosy Mailing List – December 24th, 2011
Ref.:    What should be the correct strategy to diminishing the burden of leprosy?
From: J. A. Barreto, Bauru, SP, Brazil

Dear Salvatore,                                                                 
Concerning the letters of Dr N. Cardona Castro and Dr W Nogueira [Dec 8th and Dec 19th, 2011], we must remember that the decision to eliminate leprosy was based on the fact that MDT cured leprosy patients, or at least that the release from treatment is higher after 24 doses of MDT-MB than after 10 years of dapsone monotherapy.  Unfortunately, this strategy does not act to prevent - infected and thus susceptible peoples to develop leprosy.  There is no vaccine, incubation time is long and asymptomatic, and the people affected are usually poor and have a low cultural status. 
In my PhD thesis, in 2008, I reevaluated lepromatous leprosy patients treated with MDT 24 doses, as well as their household contacts in the state of Santa Catarina, were leprosy was eliminated since 1997.  With a median time interval of 11 years after treatment, more than 90% of them did not have clinical evidences of disease activity, though the presence of M. leprae in environment did not change.  Once I found 6 new cases among 187 contacts evaluated.  Also, IgM for PGL1 and or the detection of M. leprae DNA in nasal mucosa were found in 20 to 30% from contacts of healed patients.  The disease development rate among household contacts was the same as observed by Doull in the Phillipines 80 years ago, i.e., more than 6 cases per year per 1000 exposed, i.e., even with 100% of BCG vaccination in the household contacts, susceptible individuals developed the disease as in the past.
Why this happened?  Because the diagnosis leprosy is still centralized in reference centers, and thus the access to it is difficult.  A fact that is typical for areas where leprosy is not a public health problem, which explains the gap in time of more than 8 years between the diagnosis of leprosy in the contact and the diagnosis of the index case (lepromatous).  What should be the correct strategy to diminishing the burden of leprosy?
We, certainly, must keep the goal of elimination, since this put leprosy in focus. The following steps must be reinforced:
First: recognition that the disease is a problem.  This must be linked to several other factors, from which bacilli are only one.  The Brazilian government surely diminished poverty and improved education, but eradication of misery is a long journey to go.
Second: teaching leprosy in Universities, since most of health professionals (like me in the past) think it does not exist, or that it is rare.  Many are afraid to became sick too when attending the patients due to ignorance about the disease.
Finally, improvement of the capability of health professionals who are in the field, with a strategy of in service training, like DAHW is doing in the states of Mato Grosso and Mato Grosso do Sul.

J. A. Barreto, Leprologist and Dermatologist, PhD, Bauru, Brazil

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