Heterogeneous persistence of Mycobacterium leprae in oral and nasal mucosa of multibacillary patients during multidrug therapy.

BACKGROUND: Leprosy is curable by multidrug therapy (MDT) treatment regimen ranging from six to 12 months. The variable levels of tolerance and adherence among patients can, however, result in treatment failure and the emergence of drug-resistant strains. OBJECTIVES: Describe the impact of MDT over Mycobacterium leprae viability in patient's oral and nasal mucosa along treatment. METHODS: Mycobacterium leprae viability was monitored by quantitative polymerase chain reaction (qPCR) quantification of 16S rRNA in lateral and contralateral scrapings of oral and nasal mucosa of 10 multibacillary patients along the initial five months of treatment. FINDINGS: The results demonstrated high heterogenicity of M. leprae viability among patients and between nasal and oral samples. Of six patients who presented good adherence and tolerance to the treatment, only four displayed absence of M. leprae viability in both samples three months after the first MDT dose, while for the other two, the absence of M. leprae viability in the oral and nasal cavities was only detected five months after the first dose. MAIN CONCLUSIONS: We concluded that qPCR of 16S rRNA for the determination of M. leprae viability in nasal and oral scraping samples could represent an interesting approach to monitor treatment efficacy.

Early detection of M. leprae by qPCR in untreated patients and their contacts: results for nasal swab and palate mucosa scraping.

To verify if the hard palate mucosa can be a site of relevance in the early molecular detection of Mycobacterium leprae in leprosy cases and their household contacts and if there is a correlation of results in nasal swab with those of the scraping of the palate mucosa. The quantitative polymerase chain reaction technique was used. Sample included 78 patients with untreated leprosy (G1), their 54 household contacts (G2), and 80 healthy individuals for the negative control (G3). The presence of M. leprae in both G1 and G2 was observed with the nasal swab and the palate mucosa scrapings methods, and it was shown that the sensitivity between the qPCR exams for RLEP and 85B genes is equivalent, with no statistically significant differences (G1 positivity of 35% in the hard palate mucosa and 44% for the nasal one, p = 0.3731 and for G2 of 31 and 38%, respectively, p = 0.6774). Results support the fact that the buccal mucosa and nasal mucosa may be important sites of primary infection of leprosy with repercussion in the transmission chain and that asymptomatic household contacts are heavily harbored by the causative agent of leprosy, which has a critical significance in the prevention and control action of this disease, since the evaluation of these sites arises as of importance in the early detection of M. leprae. Close monitoring and chemoprophylaxis of household contacts appear to be critical to attain interruption of the transmission of leprosy in endemic countries.

Early detection of M. leprae by qPCR in untreated patients and their contacts: results for nasal swab and palate mucosa scraping

To verify if the hard palate mucosa can be a site of relevance in the early molecular detection of Mycobacterium leprae in leprosy cases and their household contacts and if there is a correlation of results in nasal swab with those of the scraping of the palate mucosa. The quantitative polymerase chain reaction technique was used. Sample included 78 patients with untreated leprosy (G1), their 54 household contacts (G2), and 80 healthy individuals for the negative control (G3). The presence of M. leprae in both G1 and G2 was observed with the nasal swab and the palate mucosa scrapings methods, and it was shown that the sensitivity between the qPCR exams for RLEP and 85B genes is equivalent, with no statistically significant differences (G1 positivity of 35% in the hard palate mucosa and 44% for the nasal one, p = 0.3731 and for G2 of 31 and 38%, respectively, p = 0.6774). Results support the fact that the buccal mucosa and nasal mucosa may be important sites of primary infection of leprosy with repercussion in the transmission chain and that asymptomatic household contacts are heavily harbored by the causative agent of leprosy, which has a critical significance in the prevention and control action of this disease, since the evaluation of these sites arises as of importance in the early detection of M. leprae. Close monitoring and chemoprophylaxis of household contacts appear to be critical to attain interruption of the transmission of leprosy in endemic countries

Molecular Evidence for the Aerial Route of Infection of Mycobacterium leprae and the Role of Asymptomatic Carriers in the Persistence of Leprosy.

BACKGROUND: Leprosy persists as a public health problem. The chain of transmission and mechanism of infection are not completely understood. In the current study, we investigated the route of infection and of disease onset, from airway exposure, colonization, and bloodstream dissemination. METHODS: Mycobacterium leprae DNA was detected through quantitative polymerase chain reaction in nasal vestibule, nasal turbinate mucosa, and peripheral blood samples, along with anti-phenolic glycolipid I serology and skin tests from the same individual, from 113 leprosy patients and 104 household contacts of patients (HHCs). Bivariate statistics and multiple correspondence analysis were employed. RESULTS: The rates of DNA positivity among patients were 66.4% (75 of 113) for nasal swab samples, 71.7% (81 of 113) for nasal turbinate biopsy samples, 19.5% (22 of 113) for blood samples, with seropositivity of 62.8% (71 of 113 samples) and with increasing incidences toward the multibacillary pole of the clinical spectrum. Positivity among HHCs were as follows: 49% (51 of 104) for nasal swab samples, 53.8% (56 of 104) for nasal biopsy samples, 6.7% (7 of 104) for blood samples, and 18.3% (19 of 104 samples) for anti-phenolic glycolipid I serology. During the follow-up of 5-7 years, out of 104 HHCs, 7 developed leprosy (6.7%). Risk for the disease outcome was estimated by comparing results in HHCs who develop leprosy with those not affected. Neither nasal passage nor mucosa positivity was determinant of later disease onset; however, blood presence increased the risk for disease development (relative risk/positive likelihood ratio, 5.54; 95% confidence interval, 1.30-23.62), as did seropositivity (positive likelihood ratio, 3.69 [1.67-8.16]; relative risk, 5.97 [1.45-24.5]). CONCLUSIONS: Our findings strongly suggest that the aerosol route of infection and transmission is predominant and that HHCs contribute to the infection risk to themselves and probably to others.

Widespread nasal carriage of Mycobacterium lepraeamong a healthy population in a hyperendemic region of northeastern Brazil.

A case-control study was conducted to determine the presence ofMycobacterium lepraeDNA in nasal secretions of leprosy cases and nonleprosy individuals in Fortaleza, Brazil. It included 185 cases identified by physicians at the Dona Libânia National Reference Centre for Sanitary Dermatology (CDERM). A control group (Co) (n = 136) was identified among individuals from CDERM not diagnosed as leprosy cases. To augment the spatial analysis of M. leprae specific repetitive element (RLEP) positive prevalence, an external group (EG) (n = 121), a convenience sample of healthy students, were included. Polymerase chain reaction for the RLEP sequence was conducted for all participants. Prevalence of RLEP positivity for cases and Co were 69.2% and 66.9%, respectively, significantly higher than for EG (28.1%), and reported elsewhere. Male sex, belonging to a lower socioeconomic status (D/E), history of a previous contact with a case and being older, were associated with being a leprosy case. Our geographical analysis demonstrated that the bacillus is widespread among the healthy population, with clusters of RLEP positive multibacillary cases concentrated in distinct areas of the city. Our results suggest that in endemic areas, as in Fortaleza, surveillance for both nonhousehold leprosy contacts and members of the general population living in cluster areas should be implemented.

Widespread nasal carriage of Mycobacterium lepraeamong a healthy population in a hyperendemic region of northeastern Brazil

A case-control study was conducted to determine the presence ofMycobacterium lepraeDNA in nasal secretions of leprosy cases and nonleprosy individuals in Fortaleza, Brazil. It included 185 cases identified by physicians at the Dona Libânia National Reference Centre for Sanitary Dermatology (CDERM). A control group (Co) (n = 136) was identified among individuals from CDERM not diagnosed as leprosy cases. To augment the spatial analysis of M. leprae specific repetitive element (RLEP) positive prevalence, an external group (EG) (n = 121), a convenience sample of healthy students, were included. Polymerase chain reaction for the RLEP sequence was conducted for all participants. Prevalence of RLEP positivity for cases and Co were 69.2% and 66.9%, respectively, significantly higher than for EG (28.1%), and reported elsewhere. Male sex, belonging to a lower socioeconomic status (D/E), history of a previous contact with a case and being older, were associated with being a leprosy case. Our geographical analysis demonstrated that the bacillus is widespread among the healthy population, with clusters of RLEP positive multibacillary cases concentrated in distinct areas of the city. Our results suggest that in endemic areas, as in Fortaleza, surveillance for both nonhousehold leprosy contacts and members of the general population living in cluster areas should be implemented.

Anti-PGL1 salivary IgA/IgM, serum IgG/IgM, and nasal Mycobacterium leprae DNA in individuals with household contact with leprosy.

OBJECTIVES: Leprosy household contacts represent a group at high risk of developing the disease. The aim of this study was to detect Mycobacterium leprae subclinical infection in this group through serological and molecular parameters. METHODS: Serum anti-PGL1 IgG/IgM and salivary anti-PGL1 IgA/IgM was investigated using an ELISA, and nasal carriage of M. leprae DNA was detected by PCR, in leprosy household contacts of paucibacillary (PB) and multibacillary (MB) household leprosy patients (n=135), their index cases (n=30), and in persons living in a low endemic city (n=17). RESULTS: Salivary anti-PGL1 IgA and IgM and serum anti-PGL1 IgG showed good correlation comparing contacts and index cases (p<0.01, p<0.005, and p<0.0001, respectively). This was not observed for serum anti-PGL1 IgM (p>0.05). A high frequency of anti-PGL1 IgM positivity was found in IgG-negative samples (p<0.0001). For IgG-positive samples, IgM antibodies were also positive in most of the samples. None of the 17 volunteers living in a low endemic city presented seropositivity for IgG; however, two of them showed positivity for anti-PGL1 IgM. M. leprae DNA was found in the nasal swabs of nine out of the 85 MB household leprosy contacts (10.6%) and in three out of the 50 PB household leprosy contacts (6.0%). CONCLUSION: We strongly suggest that serum IgG/IgM and salivary anti-PGL1 IgA/IgM measurements are used to follow leprosy household contacts.

Bacterial load in the nose and its correlation to the immune response in leprosy patients.

INTRODUCTION: Leprosy, whose etiologic agent is M. leprae, has its clinical manifestations correlated with distinct immunologic forms. The mechanism of infectivity and dissemination of the disease are not completely known, although the nasal mucosa is supposed to have an important role in pathogenesis. OBJECTIVE: To correlate the clinical and bacteriological parameters with that of nasal biopsy and immunological tests, such as lepromin and ML-Flow results, in untreated leprosy patients. MATERIAL AND METHOD: Two hundred and twenty-two patients were evaluated, clinically classified and subjected to skin smear, nasal biopsy, ML-Flow, and Mitsuda test. RESULTS: 689% of the cases were borderline cases. Nasal biopsy revealed 91.4% positivity in those who had specific antibodies against M. leprae on blood sample. Lepromatous leprosy cases were 100% positive on ML-flow test, had a large involvement in the nasal mucosa (91%), positive skin smears (100%) and negative Mitsuda test. Nasal bacillary index showed a good correlation with ML-Flow and had similar results when compared to skin smear. The tests agreement was good, revealing that nasal biopsy can be reliable in the diagnosis of multibacillary clinical forms and in the evaluation of the immunological status of leprosy patients. CONCLUSION: The presence of disseminated bacilli in the nasal mucosa was similar to skin involvement, when correlated with Mitsuda test and ML-Flow. As a result, the role of nasal bacillary index may play an important role in the clinical and immunologic characterization of leprosy patients.

Cohort study of the seasonal effect on nasal carriage and the presence of Mycobacterium leprae in an endemic area in the general population.

Leprosy continues to be a significant health problem in certain pockets in developing countries. Better understanding of the transmission and source of the infection would help to decipher the transmission link, leading to control of the spread of the disease. The nose is considered to be a portal of entry, suggesting an aerial route for transmission through droplet infection. The evidence suggests that many individuals from endemic countries carry Mycobacterium leprae in their nasal cavities without having obvious symptoms of leprosy. The objective of the present study was to assess the presence of M. leprae on the nasal mucosa in the general population from a leprosy-endemic pocket. M. leprae detection was carried out using PCR targeting RLEP. Four hundred subjects from an area highly endemic for leprosy were included in the study and followed up during three different seasons--winter, summer, and monsoon--for evidence of nasal exposure to M. leprae. PCR positivity for M. leprae was observed in 29%, 21% and 31% of the samples collected in winter, summer and the monsoon season, respectively. Twenty-six individuals from the cohort showed amplification for M. leprae for all seasons. Our results are consistent with reports in the literature showing widespread exposure to M. leprae in the endemic community. The results also suggest possible association of the environmental conditions (climate) with the transmission pattern and levels of exposure to M. leprae. However, the present study indicated that the population from highly endemic pockets will have exposure to M. leprae irrespective of season.

Unveiling healthy carriers and subclinical infections among household contacts of leprosy patients who play potential roles in the disease chain of transmission

Leprosy transmission still occurs despite the availability of highly effective treatment. The next step towards successfully eliminating leprosy is interrupting the chain of transmission of the aetiological agent, Mycobacterium leprae. In this investigation, we provide evidence that household contacts (HHCs) of leprosy patients might not only have subclinical infections, but may also be actively involved in bacilli transmission. We studied 444 patients and 1,352 contacts using anti-phenolic glycolipid-I (PGL-I) serology and quantitative polymerase chain reaction (qPCR) to test for M. leprae DNA in nasal swabs. We classified the patients according to the clinical form of their disease and the contacts according to the characteristics of their index case. Overall, 63.3% and 34.2% of patients tested positive by ELISA and PCR, respectively. For HHCs, 13.3% had a positive ELISA test result and 4.7% had a positive PCR test result. The presence of circulating anti-PGL-I among healthy contacts (with or without a positive PCR test result from nasal swabs) was considered to indicate a subclinical infection. DNA detected in nasal swabs also indicates the presence of bacilli at the site of transmission and bacterial entrance. We suggest that the concomitant use of both assays may allow us to detect subclinical infection in HHCs and to identify possible bacilli carriers who may transmit and disseminate disease in endemic regions. Chemoprophylaxis of these contacts is suggested.

Genotyping of Mycobacterium leprae in Myanmar and possible transmission modes.

The polymorphism of TTC repeats in Mycobacterium leprae was examined using bacilli from slit skin samples of leprosy patients attending at Central Special Skin Clinic, Yangon General Hospital and nasal swabs of their contacts to elucidate the possible mode of leprosy transmission. It was found that bacilli with different TTC genotypes were distributed among same household contacts and also harbored bacilli in patients were different TTC genotype from that harbored on the nasal mucus of the healthy contacts. Genotypes of TTC repeats were found to differ between husband under treatment and his wife and also mother under treatment and her sons living in same house. This study revealed that TTC genotype of bacilli harbored by household contacts was different with the TTC genotype by index cases. These results indicate that the family members get transmission from outside the dwellings rather than from commonly supposed their MB index cases. There might have been some infectious sources to which the populace had been commonly exposed outside the dwellings.

Unveiling healthy carriers and subclinical infections among household contacts of leprosy patients who play potential roles in the disease chain of transmission.

Leprosy transmission still occurs despite the availability of highly effective treatment. The next step towards successfully eliminating leprosy is interrupting the chain of transmission of the aetiological agent, Mycobacterium leprae. In this investigation, we provide evidence that household contacts (HHCs) of leprosy patients might not only have subclinical infections, but may also be actively involved in bacilli transmission. We studied 444 patients and 1,352 contacts using anti-phenolic glycolipid-I (PGL-I) serology and quantitative polymerase chain reaction (qPCR) to test for M. leprae DNA in nasal swabs. We classified the patients according to the clinical form of their disease and the contacts according to the characteristics of their index case. Overall, 63.3% and 34.2% of patients tested positive by ELISA and PCR, respectively. For HHCs, 13.3% had a positive ELISA test result and 4.7% had a positive PCR test result. The presence of circulating anti-PGL-I among healthy contacts (with or without a positive PCR test result from nasal swabs) was considered to indicate a subclinical infection. DNA detected in nasal swabs also indicates the presence of bacilli at the site of transmission and bacterial entrance. We suggest that the concomitant use of both assays may allow us to detect subclinical infection in HHCs and to identify possible bacilli carriers who may transmit and disseminate disease in endemic regions. Chemoprophylaxis of these contacts is suggested.

[Reliability and agreement of two smear reading scales for classification and monitoring of multidrug therapy in leprosy patients]. / Confiabilidad y concordancia de dos escalas de lectura de baciloscopias para clasificación y seguimiento del tratamiento con múltiples medicamentos de los pacientes con lepra.

INTRODUCTION: After the clinical diagnosis of leprosy, classification methods are necessary to define a treatment and prognosis of patients consistent with bacterial load. Bacteria are detected in skin smear, and bacterial load typically is established by the internationally used Ridley's logarithmic scale, However, in Colombia an alternative semiquantitative scale is used. OBJECTIVE: The interobserver reproducibility was established for the Ridley and Colombia scales, and the level of correlation-matching was identified between the bacillary indices obtained in order to assess the degree of interchangeability. MATERIALS AND METHODS: Standardization was attained by a reading of the smears by 2 readers with subsequent, blinded evaluation of inter-observer agreement. Each reader quantified the bacterial load of for each sample (n=325) using the Colombian and the Ridley scales. The degree of interobserver agreement was assessed with weighted kappa coefficient. The level of correlation and agreement between the measurements of the bacillary index was established with coefficient of Lin. RESULTS: The interobserver weighted kappa coefficient was 0.83 for the Colombia scale and 0.85 for the Ridley scale. The Lin coefficient was 0.96 for the correlation-matching of bacillary indexes. CONCLUSIONS: Interobserver agreement obtained for both scales was excellent as the correlation-matching bacillary indices determined with both methods. With the cut-off points yielded a good level of agreement, ensuring interchangeability between the scales defining the high or low bacterial load.

Nasal mucosa study of leprosy contacts with positive serology for the phenolic glycolipid 1 antigen.

UNLABELLED: Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The disease more frequently affects the nasal mucosa and can occur independently of its clinical form or even before lesions on the skin or on other parts of the body. It is necessary to employ epidemiological surveillance of household contacts with new leprosy cases for early disease diagnosis. AIM: identify specific and early leprosy lesions through endoscopic, baciloscopy, histopathology exams, and real time polymerase chain reaction of the nasal cavity mucosa on household and peridomiciliary contacts with positive serology for the phenolic glycolipid 1 antigen. METHODOLOGY: Between 2003 at 2006 there was a prospective cross-sectional clinical study with 31 contacts with patients with leprosy with positive serology against PGL-1, 05 negative controls and 01 positive control. RESULTS: Between seropositive contacts, real-time PCR was positive for M. leprae DNA in 06 (19.35%) of them and the higher number of genome copies were found in contacts who became sick. CONCLUSION: Nasal mucosa tests alone did not enable the early diagnosis of Leprosy. However, through the combination of various methods, tests on the contacts can help identify subclinical infection and monitor the contacts that could be responsible for spreading the disease.

Estudo da mucosa nasal de contatos de hanseníase, com positividade para o antígeno glicolipídio fenólico 1 / Nasal mucosa study of leprosy contacts with positive serology for the phenolic glycolipid 1 antigen

A hanseníase é uma doença infecciosa de evolução crônica causada pelo Mycobacterium leprae que acomete com maior frequência a mucosa nasal. Esse acometimento independe da forma clínica da doença e pode ocorrer mesmo antes do aparecimento de lesões na pele ou em outras partes do corpo. Faz-se necessário a vigilância epidemiológica dos contatos de casos novos de hanseníase para o diagnóstico precoce da doença. OBJETIVOS: Identificar lesões específicas e precoces de hanseníase por meio de exame endoscópico, baciloscópico, histopatológico e da reação em cadeia da polimerase em Tempo Real da mucosa das cavidades nasais dos contatos domiciliares e peridomiciliares com sorologia positiva para o antígeno glicolipídio fenólico. MATERIAL E MÉTODOS: Estudo prospectivo transversal em 31 contatos de pacientes de hanseníase com sorologia positiva (PGL-1), 05 controles negativos e 01 positivo no período de 2003 a 2006. RESULTADOS: Entre os contatos soropositivos a PCR-RT foi positiva para a presença de DNA de M. leprae em 06 (19,35 por cento) destes e o maior número de cópias do genoma do bacilo foi encontrado no contato que adoeceu. CONCLUSÃO: Isoladamente os exames da mucosa nasal não permitiram o diagnóstico precoce da hanseníase, mas com a combinação de vários métodos, o exame dos contatos pôde ajudar na identificação da infecção subclínica e monitoramento daqueles que poderiam ter papel importante na transmissão da doença.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The disease more frequently affects the nasal mucosa and can occur independently of its clinical form or even before lesions on the skin or on other parts of the body. It is necessary to employ epidemiological surveillance of household contacts with new leprosy cases for early disease diagnosis. AIM: identify specific and early leprosy lesions through endoscopic, baciloscopy, histopathology exams, and real time polymerase chain reaction of the nasal cavity mucosa on household and peridomiciliary contacts with positive serology for the phenolic glycolipid 1 antigen. METHODOLOGY: Between 2003 at 2006 there was a prospective cross-sectional clinical study with 31 contacts with patients with leprosy with positive serology against PGL-1, 05 negative controls and 01 positive control. RESULTS: Between seropositive contacts, real-time PCR was positive for M. leprae DNA in 06 (19.35 percent) of them and the higher number of genome copies were found in contacts who became sick. CONCLUSION: Nasal mucosa tests alone did not enable the early diagnosis of Leprosy. However, through the combination of various methods, tests on the contacts can help identify subclinical infection and monitor the contacts that could be responsible for spreading the disease.

Contribution of nasal biopsy to leprosy diagnosis.

BACKGROUND: The nasal mucosa plays the main role as the entry and the exit of leprosy bacilli and the nasal involvement may precede the skin lesions by several years. Nasal biopsy has been used in research but its clinical application has not been described. We evaluated the contribution of the nasal biopsy for the diagnosis of leprosy and its correlation to skin biopsy and skin smear in untreated patients. METHODS: We evaluated changes in nasal biopsy in 227 leprosy patients. Patients were clinically classified and skin and nasal biopsies and skin smear were performed. RESULTS: Nasal biopsy showed positivity in 100% of the lepromatous spectrum decreasing toward the tuberculoid (TT) pole. Patients with TT or indeterminate forms did not present any nasal alterations, showing that they are the true paucibacillary forms. Also, the nasal biopsies of two patients were the only exam to show positivity. The bacillary index of the nasal biopsy was strongly correlated to skin biopsy and slit-skin smear. Additionally, the agreement among the exams was good, revealing the reliability of the nasal biopsy in leprosy diagnosis. CONCLUSION: The present study showed a rate of 48% of positivity in nasal biopsy of untreated patients, correlating well with skin biopsy and skin smear. Thus, the method in leprosy diagnosis and clinical form classification has shown great reliability.

[Detection of Mycobacterium leprae DNA in nasal swab]. / Deteccção do DNA de Mycobacterium leprae em secreção nasal.

Studies have demonstrated high sensibility of the polimerase chain reaction (PCR) technique in the identification of the Mycobacterium leprae DNA . This study aimed to evalue the PCR sensibility at the detection of the M. leprae DNA in nasal swab of leprosy patients and to compare the results with the bacilloscopy and multibacillary (MBs) and paucibacilares (PBs) forms. Nasal secretion samples of 24 leprosy patients were collected, and were preserved in one and two lise's solution. The PCR results were highly significant (p <0.0000) and they revealed grater sensibility than bacilloscopy, in several clinical forms. Nevertheless, still different studies are necessary, testing new markers and preservatives, with the purpose of lifting up the sensibility of this technique, in nasal secretion samples.

Deteccção do DNA de Mycobacterium leprae em secreção nasal / Detección del ADN de Mycobacterium leprae en secreción nasal / Detection of Mycobacterium leprae DNA in nasal swab

Estudos têm demonstrado alta sensibilidade da técnica da reação em cadeia de polimerase (PCR) na identificação do DNA do Mycobacterium leprae. Este estudo objetivou avaliar a sensibilidade da PCR na detecção do DNA do M. leprae em "swab" nasal de pacientes hansenianos e comparar os resultados com a baciloscopia e formas multibacilares (MBs) e paucibacilares (PBs). Foram coletadas amostras de secreção nasal de 24 pacientes hansenianos, conservadas em solução de lise um e dois. Os resultados da PCR foram altamente significativos (p<0.0000) e revelaram maior sensibilidade do que a baciloscopia, nas diversas formas clínicas. Contudo, são necessários ainda outros estudos, testando novos marcadores e conservantes, com o intuito de elevar a sensibilidade dessa técnica, em amostras de secreção nasal.

Studies have demonstrated high sensibility of the polimerase chain reaction (PCR) technique in the identification of the Mycobacterium leprae DNA . This study aimed to evalue the PCR sensibility at the detection of the M. leprae DNA in nasal swab of leprosy patients and to compare the results with the bacilloscopy and multibacillary (MBs) and paucibacilares (PBs) forms. Nasal secretion samples of 24 leprosy patients were collected, and were preserved in one and two lise's solution. The PCR results were highly significant (p <0.0000) and they revealed grater sensibility than bacilloscopy, in several clinical forms. Nevertheless, still different studies are necessary, testing new markers and preservatives, with the purpose of lifting up the sensibility of this technique, in nasal secretion samples.

Los estudios han demostrado una alta sensibilidad de la técnica de Reacción en Cadena de la Polimerasa (PCR) para identificar el ADN de Mycobacterium leprae. El objetivo del estudio fue evaluar la sensibilidad de la PCR en la detección de ADN de M. leprae en hisopo nasal de los pacientes hansenianos y comparar los resultados con la baciloscopía y las formas multibacilares (MBs) y paucibacilares (PBS). Se obtuvieron muestras de secreción nasal de 24 pacientes hansenianos, conservados en solución de lisis uno y dos. Los resultados de la PCR fueron muy significativas (p <0.0000) y mostró una mayor sensibilidad que la baciloscopía, en diferentes formas clínicas. Sin embargo, otros estudios son aún necesarios, el ensayo de nuevos marcadores y conservantes con el fin de aumentar la sensibilidad de esta técnica, en muestras de secreción nasal.

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.

Midfacial leprosy.

Leprosy is a chronic bacterial disease that has many clinical presentations. We are reporting a patient who presented with an erythematous plaque over the nose, which was proved to be due to leprosy. We think that this type of clinical feature is not a common presentation for leprosy.