RESUMEN
Background: In endemic regions of several countries, the prevalence of leprosy has not come down to the level of elimination. On the contrary, new cases are being detected in large numbers. Clinically, it is frequently noted that despite completion of multibacillary multidrug therapy for 12 months, the lesions remain active, especially in cases with high bacteriological indices. Aim: The present study focused on finding out the viable number of Mycobacterium leprae during the 12-month regimen of multibacillary multidrug therapy, at six and 12 months intervals and, attempting to determine their role in disease transmission. Methods: Seventy eight cases of multibacillary leprosy cases were recruited from leprosy patients registered at The Leprosy Mission hospitals at Shahdara (Delhi), Naini (Uttar Pradesh) and Champa (Chhattisgarh), respectively. Slit skin smears were collected from these patients which were transported to the laboratory for further processing. Ribonucleic acid was extracted by TRIzol method. Total Ribonucleic acid was used for real-time reverse transcription-polymerase chain reaction (two-step reactions). A standard sample with a known copy number was run along with unknown samples for a reverse transcription-polymerase chain reaction. Patients were further assessed for their clinical and molecular parameters during 6th month and 12th month of therapy. Results: All 78 new cases showed the presence of a viable load of bacilli at the time of recruitment, but we were able to follow up only on 36 of these patients for one year. Among these, using three different genes, 20/36 for esxA, 22/36 for hsp18 and 24/36 for 16S rRNA cases showed viability of M. leprae at the time of completion of 12 months of multidrug therapy treatment. All these positive patients were histopathologically active and had bacillary indexes ranging between 3+ and 4+. Patients with a high copy number of the Mycobacterium leprae gene, even after completion of treatment as per WHO recommended fixed-dose multidrug therapy, indicated the presence of live bacilli. Limitations: Follow up for one year was difficult, especially in Delhi because of the migratory nature of the population. Patients who defaulted for scheduled sampling were not included in the study. Conclusion: The presence of a viable load of bacilli even after completion of therapy may be one of the reasons for relapse and continued transmission of leprosy in the community
RESUMEN
Background & objectives: The reported low relapse rates after 24 months multidrug therapy (MDT) for multibacillary leprosy (MB) led to the recommendation of reducing duration of therapy to 12 months. However, only a few reports exist on long term follow up data after 12 months fixed duration therapy (FDT). The present study was done to assess the incidence of relapse in MB leprosy patients after 12 months treatment. Methods: The leprosy patients detected in field surveys during 2001-2006 in Agra district, Uttar Pradesh, India, were put on WHO-MDT and followed up for treatment completion, relapse, reactions and development of disability. The assessment was done clinically by following up the patients until January 2011. Data collected were analyzed for risk and survival analysis. Results: The incidence of relapse was found to be 1.97/100 person years of follow up. The incidence of relapse by age (34 yr vs >34 yr), sex (male vs female), delay in detection (<36 months vs >36 months) and smear status (smear +ve vs -ve) was not found to be significantly different but patients with no nerve involvement were observed to have significantly higher relapses than those with three or more nerve involvement (P<0.05). Similarly, borderline-borderline and BB with reaction (BB/BBR) patients were observed to have significantly high relapses than among those with borderline tuberculoid or BT with reaction (BT/BTR) or borderline lipromatous/lepromatous/neuritic (BL/LL/N) type of leprosy (P<0.01). Interpretation & conclusion: From the observations in the study, it can be suggested that relapses occur in 12 months FDT and almost as much as reported in 24 months FDT for MB leprosy. Although, early relapses may be due to insufficient treatment, late relapses may be due to persistent dormant mycobacteria. However, a study relating to immunological response of treatment and change in immunological profile relating to the occurrence of relapses and its clinical correlates may suggest better information on causes of relapses.