Transmission of leprosy: a study of skin and nasal secretions of household contacts of leprosy patients using PCR.

It is generally held that dissemination of Mycobacterium leprae is from nasal mucosa and not through the skin of infected patients. In this study, we evaluated M. leprae in the unbroken skin and nasal secretions of multibacillary (MB) leprosy patients and their contacts. Specimens were examined by direct microscopy and polymerase chain reaction (PCR) for M. leprae DNA. Results showed that 60% of untreated MB leprosy patients examined histologically had acid-fast bacilli in the keratin layer. By PCR studies it was found that 80% of the patients had M. leprae DNA in skin washings and 60% had M. leprae DNA on swabs obtained from the nasal mucosa. Ninety-three contacts of the untreated MB cases were also tested for exposure to M. leprae by analyzing skin washings and nasal secretions by PCR. PCR analysis showed significant skin (17% positive) and nasal muscosal (4%) exposure in contacts before instituting treatment of the index cases. After 2 months of treating the index cases, all contacts tested were negative for M. leprae DNA. These data suggested that both skin and nasal epithelia of untreated MB leprosy patients contribute to the shedding of M. leprae into the environment and contacts of untreated MB cases are at risk for contact with M. leprae through both the nasal mucosa and exposed surfaces of their skin.

Mycobacterium leprae infection and serum lactoferrin levels.

Serum lactoferrin level, using competitive enzyme linked immunosorbent assay (ELISA) method, was estimated in 298 leprosy patients admitted into the hospital and attending the out-patient department of the Schieffelin Leprosy Research and Training Center. Serum from an equal number of non-leprosy individuals served as control. Mean (SD) of serum lactoferrin in non-leprosy individuals was 0.277 (0-092) microg/ml while in leprosy patients it was 0.494 (0.394) microg/ml, the difference being significant (P=0.0001). Serum lactoferrin levels were not significantly associated with type 2 reactions (P=0.613). Serum lactoferrin was significantly associated with age (P = 0.006), duration of the disease (P=0.0001), DDS monotherapy (P =0.007), deformity (P= 0.005), average bacterial index (BI) (P=0.01) and smear positivity (P=0.0001), orbicularis oculi weakness (P= 0.001), lagophthalmos (P = 0.002), corneal opacity (P = 0.001) and cataract (P=0.004) in simple regression analysis. All these variables, with the exception of smear positivity (P=0.019), lost their significance (P>0.05) when analysed using multiple regression. Serum lactoferrin showed poor association with type 1 (P = 0.286) and type II reactions (P = 0.613) and iridocyclitis (P = 0.207). We conclude that serum lactoferrin is strongly and inversely associated with increasing BI but does not show significant association with type 2 reactions.

Elevated free tear lactoferrin levels in leprosy are associated with Type 2 reactions.

PURPOSE: To determine the association of demographics, leprosy and ocular characteristics with altered levels of lactoferrin in the tears of normal subjects and leprosy patients, and to detect the presence of antibodies to lactoferrin in these tear samples. METHOD: We collected light-stimulated tears from 298 leprosy patients and an equal number of normal subjects using the glass capillary method. Free lactoferrin levels were estimated using ELISA and the presence of antibodies to lactoferrin was detected using the immuno-blotting method. Significant associations were looked for between tear lactoferrin levels and demographic characteristics, leprosy characteristics such as type of disease, duration of disease, reactions, deformity and bacterial load, and ocular complications, using chi-square and regression analysis. RESULTS: Tear lactoferrin levels with a mean (SD) of 2.55 (2.83)mg/ml in the control group were significantly different (P<0.000) from leprosy patients with a smean (SD) of 5.66 (7.21)mg/ml. Age showed an inverse correlation with tear lactoferrin levels in controls. Increased bacterial load, grade 2 leg deformity and Type 2 reactions were significantly associated (P<0.05) with increased tear lactoferrin levels. Type 2 reactions remained significantly associated (P=0.01) on multiple regression analysis. Tear lactoferrin levels were not associated with gender, serum lactoferrin levels, Type 1 reactions, face patches, treatment status, orbicularis oculi weakness, lagophthalmos, ectropion, entropion, corneal opacity, cataract and iridocyclitis. CONCLUSION: Age is inversely related to tear lactoferrin levels in normal subjects. Free lactoferrin levels in tears are significantly higher in leprosy patients compared with normal controls. Type 2 reactions in leprosy are significantly associated with elevated tear lactoferrin levels.

Electron microscope appearance of lepromatous footpads of nude mice [corrected].

Footpad lesions of 3 nude mice infected by Mycobacterium leprae were studied at 9, 12, and 14 months after inoculation with light and electron microscope. The lesions were somewhat similar to those found in nodules in polar lepromatous leprosy. Striated muscles rather than nerves were the preferred site of the growth of M. leprae. Yet, M. leprae were identified in Schwann cells and endothelial cells, singly and in clumps. M. leprae filled macrophages, and free M. leprae were found in large numbers in the endoneurium without producing any significant demyelination.

Nine-banded armadillo and leprosy research

In this presentation an attempt has been made to describe the nine-banded armadillo as an animal model, probably the only one in which lepromatous leprosy similar to that found in humans can be experimentally produced. Some unique features of the physiology of the animal are mentioned. The pathology and the microbiology of leprosy in the armadillo are described in detail. The discovery of lepromatous leprosy in the wild armadillos in the southern parts of United States, the transmission of disease among them through trauma and thorn pricks and the pathogenesis of the disease are presented. The impact of leprosy in the wild animals may have on human leprosy is discussed.

Secondary rifampin resistance following multi-drug therapy--a case report.

This is the first report of secondary resistance to rifampin following MDT in a patient with prolonged, but irregular treatment. Repeated mouse foot-pad studies demonstrated resistance to dapsone after several years of monotherapy, and following subsequent MDT the studies demonstrated the development of resistance to rifampin.

Nine-banded armadillo and leprosy research.

In this presentation an attempt has been made to describe the nine-banded armadillo as an animal model, probably the only one in which lepromatous leprosy similar to that found in humans can be experimentally produced. Some unique features of the physiology of the animal are mentioned. The pathology and the microbiology of leprosy in the armadillo are described in detail. The discovery of lepromatous leprosy in the wild armadillos in the southern parts of United States, the transmission of disease among them through trauma and thorn pricks and the pathogenesis of the disease are presented. The impact of leprosy in the wild animals may have on human leprosy is discussed.

Dosage and site of entry influence growth and ddissemination of mycobacterium leprae in T900r mice

The role of dosage of Mycobacterium leprae and the environment of the inoculated site, in producing leprosy lesions in immunologically-suppressed, highly-susceptible T900r mice, was investigated. Various doses of M. leprae, i.e., 10(7), 10(6), 10(5), 10(4), were inoculated into both flanks and footpads of two different groups of mice. The sites of inoculation were biopsied for histopathological examination and for M. leprae counts at the end of 6, 8 and 12 months. M. leprae multiplied at the infected site and disseminated [figure: see text] to other parts of the body at all concentrations in the mice that were infected in the footpad with a temperature of 31 degrees C. In animals inoculated at the flanks with a temperature of 37 degrees C, multiplication was recorded only when the dosage of M. leprae was high and there was no dissemination of the organism in any of them. The temperature at the site of entry and the dose of infecting M. leprae may play an important role in the development of leprosy in susceptible individuals exposed to M. leprae.

Dosage and site of entry influence growth and dissemination of Mycobacterium leprae in T900r mice.

The role of dosage of Mycobacterium leprae and the environment of the inoculated site, in producing leprosy lesions in immunologically-suppressed, highly-susceptible T900r mice, was investigated. Various doses of M. leprae, i.e., 10(7), 10(6), 10(5), 10(4), were inoculated into both flanks and footpads of two different groups of mice. The sites of inoculation were biopsied for histopathological examination and for M. leprae counts at the end of 6, 8 and 12 months. M. leprae multiplied at the infected site and disseminated [figure: see text] to other parts of the body at all concentrations in the mice that were infected in the footpad with a temperature of 31 degrees C. In animals inoculated at the flanks with a temperature of 37 degrees C, multiplication was recorded only when the dosage of M. leprae was high and there was no dissemination of the organism in any of them. The temperature at the site of entry and the dose of infecting M. leprae may play an important role in the development of leprosy in susceptible individuals exposed to M. leprae.