Single-Dose Rifapentine in Household Contacts of Patients with Leprosy.

BACKGROUND: Previous studies have suggested that a single dose of rifampin has protective effects against leprosy in close contacts of patients with the disease. Rifapentine was shown to have greater bactericidal activity against Mycobacterium leprae than rifampin in murine models of leprosy, but data regarding its effectiveness in preventing leprosy are lacking. METHODS: We conducted a cluster-randomized, controlled trial to investigate whether single-dose rifapentine is effective in preventing leprosy in household contacts of patients with leprosy. The clusters (counties or districts in Southwest China) were assigned to one of three trial groups: single-dose rifapentine, single-dose rifampin, or control (no intervention). The primary outcome was the 4-year cumulative incidence of leprosy among household contacts. RESULTS: A total of 207 clusters comprising 7450 household contacts underwent randomization; 68 clusters (2331 household contacts) were assigned to the rifapentine group, 71 (2760) to the rifampin group, and 68 (2359) to the control group. A total of 24 new cases of leprosy occurred over the 4-year follow-up, for a cumulative incidence of 0.09% (95% confidence interval [CI], 0.02 to 0.34) with rifapentine (2 cases), 0.33% (95% CI, 0.17 to 0.63) with rifampin (9 cases), and 0.55% (95% CI, 0.32 to 0.95) with no intervention (13 cases). In an intention-to-treat analysis, the cumulative incidence in the rifapentine group was 84% lower than that in the control group (cumulative incidence ratio, 0.16; multiplicity-adjusted 95% CI, 0.03 to 0.87; P = 0.02); the cumulative incidence did not differ significantly between the rifampin group and the control group (cumulative incidence ratio, 0.59; multiplicity-adjusted 95% CI, 0.22 to 1.57; P = 0.23). In a per-protocol analysis, the cumulative incidence was 0.05% with rifapentine, 0.19% with rifampin, and 0.63% with no intervention. No severe adverse events were observed. CONCLUSIONS: The incidence of leprosy among household contacts over 4 years was lower with single-dose rifapentine than with no intervention. (Funded by the Ministry of Health of China and the Chinese Academy of Medical Sciences; Chinese Clinical Trial Registry number, ChiCTR-IPR-15007075.).

Determination of Lipoprotein Z-Specific IgA in Tuberculosis and Latent Tuberculosis Infection.

Tuberculosis (TB) remains one of the most severe infectious diseases. It is still of paramount importance to establish more accurate, rapid, and efficient diagnostic methods. Since infection with Mycobacterium tuberculosis (M. tb) is largely mediated through the respiratory tract, IgA responses against mycobacterial proteins are worthy of investigation for their potential clinical utility. In this study, the IgA response targeting lipoprotein Z (LppZ) was determined by using a homemade ELISA with plasma of TB patients (N = 125), LTBI individuals (N = 92), healthy controls (HCs) (N = 165), as well as TB patients undergoing anti-TB treatment (N = 9). In parallel the antigen-specific IFN-γ release from PBMCs triggered by LppZ and M. tb-specific ESAT-6 or CFP-10 was detected by using an ELISPOT assay. It was found that the LppZ-specific IgA level was dramatically higher in TB patients than in HCs (p < 0.0001). Compared to that before anti-TB treatment, the LppZ-specific IgA level decreased substantially after 2 months of anti-TB treatment (p = 0.0297) and remained at low levels until the end of the treatment. What is more, pulmonary TB patients exhibited significantly higher LppZ-specific IgA-values than extra-pulmonary TB patients (p = 0.0296). Interestingly, the LppZ-specific IgA-values were negatively correlated to the amounts of IFN-γ released in response to LppZ with statistical significance (r = -0.5806, p = 0.0002). LppZ-specific IgA level was also higher in LTBI individuals than in HCs (p < 0.0001). Additionally there were some PPD+ HC individuals with high LppZ-specific IgA levels but the potential of this assay for identifying leaky LTBI in PPD+ HCs needs to be further investigated through follow-up studies. The sensitivity of detecting TB solely with ESAT-6 or CFP-10-specific IFN-γ release was increased by including the LppZ-specific IgA results, respectively, from 86.11 to 100% and 88.89 to 100%; the sensitivity of screening for LTBI was increased from 80.36 to 83.93% and 57.14 to 69.64%, respectively. The higher LppZ-specific IgA responses in TB and LTBI populations than in controls indicated high immunoreactivity to LppZ upon M. tb infection. Although the assay was not efficient enough for independent application in sero-diagnosis, LppZ-specific IgA might become a complementary biomarker for the improvement of TB and LTBI screening.

RifZ (AMED_0655) Is a Pathway-Specific Regulator for Rifamycin Biosynthesis in Amycolatopsis mediterranei.

Rifamycin and its derivatives are particularly effective against the pathogenic mycobacteria Mycobacterium tuberculosis and Mycobacterium leprae Although the biosynthetic pathway of rifamycin has been extensively studied in Amycolatopsis mediterranei, little is known about the regulation in rifamycin biosynthesis. Here, an in vivo transposon system was employed to identify genes involved in the regulation of rifamycin production in A. mediterranei U32. In total, nine rifamycin-deficient mutants were isolated, among which three mutants had the transposon inserted in AMED_0655 (rifZ, encoding a LuxR family regulator). The rifZ gene was further knocked out via homologous recombination, and the transcription of genes in the rifamycin biosynthetic gene cluster (rif cluster) was remarkably reduced in the rifZ null mutant. Based on the cotranscription assay results, genes within the rif cluster were grouped into 10 operons, sharing six promoter regions. By use of electrophoretic mobility shift assay and DNase I footprinting assay, RifZ was proved to specially bind to all six promoter regions, which was consistent with the fact that RifZ regulated the transcription of the whole rif cluster. The binding consensus sequence was further characterized through alignment using the RifZ-protected DNA sequences. By use of bionformatic analysis, another five promoters containing the RifZ box (CTACC-N8-GGATG) were identified, among which the binding of RifZ to the promoter regions of both rifK and orf18 (AMED_0645) was further verified. As RifZ directly regulates the transcription of all operons within the rif cluster, we propose that RifZ is a pathway-specific regulator for the rif cluster.IMPORTANCE To this day, rifamycin and its derivatives are still the first-line antituberculosis drugs. The biosynthesis of rifamycin has been extensively studied, and most biosynthetic processes have been characterized. However, little is known about the regulation of the transcription of the rifamycin biosynthetic gene cluster (rif cluster), and no regulator has been characterized. Through the employment of transposon screening, we here characterized a LuxR family regulator, RifZ, as a direct transcriptional activator for the rif cluster. As RifZ directly regulates the transcription of the entire rif cluster, it is considered a pathway-specific regulator for rifamycin biosynthesis. Therefore, as the first regulator characterized for direct regulation of rif cluster transcription, RifZ may provide a new clue for further engineering of high-yield industrial strains.

How to improve early case detection in low endemic areas with pockets of leprosy: a study of newly detected leprosy patients in Guizhou Province, People's Republic of China.

Although leprosy in China is controlled at a low endemic level, the number of new cases in Guizhou province has shown no significant decrease over the past 20 years. Guizhou remains the province with the second highest prevalence in China. The authors conducted a study in which the characteristics of newly detected leprosy cases, found between 2008 and 2012 in Guizhou, were analysed. These cases represented people from pocket areas of leprosy in a generally low endemic environment. The purpose of the study was to understand characters of newly detected cases, strong points and weakness of routine detection approaches for improving the effectiveness of early case detection in the future. The analysis considered data that was collected from a 'Leprosy Management Information' report system and also from annual statistical reports of leprosy that reflect the situation throughout the province. 1274 new patients were detected in Guizhou from 2008 to 2012. That number included 58 (4.6%) children (0-14 years old). The average age of patients at diagnosis was 42.6 ± 16.5 years. The proportion of people with WHO Grade 2 disability (WHO DG2) among new patients was 35.7% and the proportion of people with Grade 1 disability (DG1) constituted 10.1%. The average delay before diagnosis after the onset of symptoms of leprosy was 41.7 ± 49.8 months. Suspect survey was a major method by which most cases were detected. Trough this method 790 (62.0%) new patients were detected. It was also in this group that the highest proportion of people with WHO DG2 359 of 790 (45.4%) was reported. Self- reporting, diagnosis at a general skin clinic, household contact examination, and spot surveys accounted for 13.0%, 11.8%, 11.5% and 1.7% of other cases detected respectively. It was generally found that cases detected through household contact examinations were earlier cases (delay to diagnosis < 24 months = 70.7%). It was also recorded that fewer of these had WHO DG2 (12.9%). The proportion of men with WHO DG2 was higher than that of females (38.2% compared with 28.8%). The proportion of Han Chinese new cases with WHO DG2 was significantly higher than that of the main minority group (41.5% compared with 29.2%). The proportion of new cases among the main minority group who self-reported (50%) was significantly higher than those detected through other detection approaches. Detecting leprosy early in low endemic situations where pockets persist was difficult to achieve. The authors suggest that if more early patients are to be detected earlier, the quality of suspect surveys and household contact examination should be improved. Professional training and supervision might affect that result. Greater emphasis should be given to the role of general skin clinics as surveillance sites and advocacy for new health policy that will enhance the detection leprosy should be sustained.

Genomewide association study of leprosy.

BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae.

Government health workers as implementers of prevention of disability measures: an assessment of a prevention of disability project in selected counties of Guizhou Province, Peoples' Republic of China.

OBJECTIVE: The purpose of this study was to assess the effectiveness of government health workers as agents for the prevention of disability. DESIGN: A prevention of disability (POD) project for people affected by leprosy was conducted in nine counties of Guizhou Province, Peoples' Republic of China. The project was implemented by government health workers. In accordance with the principles and national criteria of the National Centre for Leprosy Control (NCLC) POD Pilot programme, 1215 people affected by leprosy were selected, followed up and assessed with the use of impairment summary forms through which essential indicators were routinely collected. RESULTS: Most improvements of disabilities occurred in the 1st year of the POD project. Fifty five people with neuritis were detected and treated with prednisolone out of 262 new patients; 47 of these improved; 1130 people completed a 3-year self-care programme; 88.5% of red eyes, 83.9% of hand ulcers and 62.8% of simple foot ulcer cases healed during that period. One hundred and ninety six people who presented with complicated ulcers were treated; of these 73 (37.2%) people presented with feet free of ulcers at the end of the project period. CONCLUSION: The POD project was a cost-effective method of preventing further disability occurrence among people affected by leprosy. Government health workers were generally able to implement and monitor the project effectively. Most of people affected by leprosy were satisfied that the improvements in their disabilities had been due to self-care. The programme had helped them to increase their confidence to implement self-care activities.

The sustainability of self-care in two counties of Guizhou Province, Peoples' Republic of China.

This paper presents the findings of a follow-up survey conducted in two rural counties of Guizhou Province, PRC where a programme to prevent disabilities amongst leprosy affected people had been conducted. An initial 3-year programme had been conducted. One year after the final evaluation of the programme, a team was deployed to conduct a survey in the area. The objective of the survey was to establish the level of adherence to self-care. It was found that 87% of the sample of people living in leprosy villages that were surveyed (n = 31) and 50% of the sample of people living in general communities (n = 50) had continued to apply self-care. Interviews with family members suggested that 18 of the 27 self-care practising subjects living in the leprosy villages received encouragement or active support from family members (9 were single people). Twenty three of the 25 self-care practising subjects living in the communities also received family support (2 were single people). Family support was a highly significant factor influencing adherence in the community (OR = 15.8, CI = 3.0 to 83) but it may not have been the primary motivating factor in the leprosy villages where single people were just as likely to have adhered to self-care than people who were living in families (OR 0.5, CI = 0.06 to 4.2). The prevalence of foot ulceration among that population was recorded but a hypothetical association between the prevalence of foot ulceration and self-care adherence could not be investigated due to insufficient data to address the potential effects of confounding variables. Thirty-eight percent of subjects who did not practice self-care presented with ulceration or foot cracks (n = 29) compared with only 25% of people who did (n = 52).

[Study on the living condition of people affected by leprosy in Guizhou province].

OBJECTIVE: To study the marriage status, labour ability, income and other living condition of people affected by leprosy, and to provide information on prevention, cure and salvation programs from the government. METHODS: Based on the standardized national criteria and method, all registered people affected by leprosy in the whole province were asked to fill in a nationally standardized Form. RESULTS: Out of the 13,034 cases, 91.19% were farmers and only 13.01% of the teenagers were at school. On 12,816 patients at age for marriage, there were more unmarried males than females, more living in the leprosy villages than those living outside of the leprosy village (P < 0.01). Disability rate in leprosy villages was seen more than outside of the leprosy village. Per capita average annual income for the people affected by leprosy was only half of the average individual income in the whole province and 1/4 of the individual income in the nation. CONCLUSION: The living condition of those leprosy-affected people, particularly living in leprosy villages, called for special attention and the government should take comprehensive prevention to publicize the knowledge on leprosy to reduce fear and discrimination against them.