Fungal diseases represent a growing global health crisis, exacerbated by limited therapeutic options and the rise of antifungal resistance. A deeper understanding of the molecular mechanisms governing host-pathogen interactions is crucial for developing novel strategies. Small non-coding RNAs (sncRNAs), a diverse class of regulatory molecules under 200 nucleotides, have emerged as critical players in modulating the host immune response to infection. This article bridges traditional review with emerging perspectives to comprehensively explore sncRNAs in fungal pathogenesis. We highlight how microRNAs (miRNAs), such as miR-155 and miR-146a, act as first responders to balance pro and anti-inflammatory signaling and serve as promising clinical biomarkers. Futhermore, we examine the biotechnological and therapeutic potential of piwi-interacting RNAs (piRNAs) and small interfering RNAs (siRNAs) as novel antifungal agents, alongside the complex dynamics of cross-kingdom RNAi (ckRNAi) as mechanism of virulence. Finally, we propose novel functional roles for understudied classes, suggesting that small nucleolar RNA (snoRNAs) regulate immune cell differentiation and small nuclear RNA (snRNAs) drive alternative splicing during fungal adaptation. By defining these specific mechanisms and identifying critical knowledge gaps, this review outlines actionable future directions for exploiting sncRNAs in the diagnosis and the targeted treatment of fungal infections.
Chromoblastomycosis (CBM) is a chronic skin and subcutaneous infection mainly caused by Fonsecaea pedrosoi , a dematiaceous fungus with various morphotypes. Characteristic sclerotic cells—globe-shaped, multiseptated and pigmented—are found in lesions of infected individuals, though their differentiation in the host remains poorly understood. To evaluate in vitro activity of five antifungal drugs—itraconazole (ITZ), posaconazole (PCZ), voriconazole (VCZ), fluconazole (FCZ), and caspofungin (CAS)—against Fonsecaea spp. conidia or sclerotic cells, assessing their minimum inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) and correlated the ITZ MIC with patients' clinical evolution. Forty-three clinical isolates of Fonsecaea spp . and the F. pedrosoi strain ATCC 46428 were assessed for susceptibility to ITZ, PCZ, VCZ, FCZ, and CAS following Clinical Laboratory Standard Institute guidelines (CLSI) (document M38-A2). MIC values were determined after 5 days of incubation at 30°C, followed by MFC determination, with geometric mean MIC (GMMIC) and MFC (GMMFC) used for comparison. PCZ was the most effective antifungal drug, with geometric mean MICs of 0.3 µg/mL (conidia) and 1 µg/mL (sclerotic), and MFCs of 2.98 and 6.72 µg/mL, respectively. Clinical follow-up revealed that higher ITZ MIC values (0.9 µg/mL) correlated with poor patient outcomes compared to lower values in improved or cured patients. These findings highlight PCZ and VCZ as promising options for CBM treatment, especially for patients not responding to ITZ.
OBJECTIVES:We investigated the prevalence of anti-phenolic glycolipid-I (PGL-I) IgM antibodies among temporarily unfit blood donors at the Pará State Blood Bank (HEMOPA), located in the Amazon region of northern Brazil. Using an arbitrary high cutoff for optical density (OD ≥0.750) in ELISA, a subset of donors was invited for clinical evaluation for leprosy. METHODS:Temporarily unfit individuals were invited to participate, and blood samples were collected for anti-PGL-I IgM titration by ELISA. Donors with high OD values were referred for clinical examination, slit skin smear (SSS) bacilloscopy, and quantitative PCR (qPCR) targeting M. leprae-specific repetitive element (RLEP) sequences from dermal scrapes of the earlobes and peripheral blood. RESULTS:From an annual average of 2762 temporarily unfit donors (2019-2023), 500 (16.6%) were tested for anti-PGL-I IgM. Of these, 20/500 (4.0%) had high antibody titres, and 8/20 (40.0%) attended clinical evaluation, resulting in 5/8 (62.5%) newly diagnosed cases of leprosy. Among these, Mycobacterium leprae detection yielded positivity rates of 2/8 (25.0%) by SSS bacilloscopy, 3/7 (42.9%) by qPCR of dermal scrapes, and 2/8 (25.0%) by qPCR of peripheral blood. CONCLUSIONS:Using an anti-PGL-I IgM cutoff of OD ≥0.750, we identified a significant proportion of undiagnosed leprosy cases among temporarily unfit blood donors. These findings support the need for targeted leprosy screening in this population. Regardless of qPCR results, individuals with clinical signs of leprosy require appropriate treatment and assessment of their eligibility for blood donation.
Leprosy is a chronic bacterial infection mainly caused by Mycobacterium leprae that primarily affects skin and peripheral nerves. Due to its ability to absorb carbon from the host cell, the bacillus became dependent on energy production, mainly through oxidative phosphorylation. In fact, variations in genes of Complex I of oxidative phosphorylation encoded by mtDNA have been associated with several diseases in humans, including bacterial infections, which are possible influencers in the host response to leprosy. Here, we investigated the presence of variants in the mtDNA genes encoding Complex I regarding leprosy, as well as the analysis of their pathogenicity in the studied cohort. We found an association of 74 mitochondrial variants with either of the polar forms, Pole T (Borderline Tuberculoid) or Pole L (Borderline Lepromatous and Lepromatous) of leprosy. Notably, six variants were exclusively found in both clinical poles of leprosy, including m.4158A>G and m.4248T>C in MT-ND1, m.13650C>A, m.13674T>C, m.12705C>T and m.13263A>G in MT-ND5, of which there are no previous reports in the global literature. Our observations reveal a substantial number of mutations among different groups of leprosy, highlighting a diverse range of consequences associated with mutations in genes across these groups. Furthermore, we suggest that the six specific variants exclusively identified in the case group could potentially play a crucial role in leprosy susceptibility and its clinical differentiation. These variants are believed to contribute to the instability and dysregulation of oxidative phosphorylation during the infection, further emphasizing their significance.
OBJECTIVES:Cutaneous hyperpigmentation is one of the main adverse effects encountered in patients undergoing leprosy treatment with multidrug therapy (WHO-MDT). This adverse effect has been described as intolerable and capable of contributing to social stigma. The objectives of this study were to quantify the variation in skin colour induced by clofazimine during and after treatment and to assess the related stigma. METHODS:This observational cross-sectional study objectively measured skin colour in 51 patients by reading the individual typology angle (ITA°) with a spectrophotometer, followed by the application of the Stigma Scale of the Explanatory Model Interview Catalogue (EMIC). RESULTS:Skin hyperpigmentation was observed in 100% of the individuals. They showed more negative ITA° values in lesion areas than non-lesion areas, particularly in sun-exposed regions. Clofazimine-induced cutaneous hyperpigmentation was not homogeneous and seemed to follow the lesion locations. The mean EMIC score was 18.8 points. CONCLUSION:All patients presented skin hyperpigmentation caused by clofazimine, detectable through spectrophotometry. Hyperpigmentation strongly impacted the social domain, indicating the intersectionality of disease and skin colour stigma, contributing to the social isolation of these patients. Health authorities should consider the negative impact of clofazimine on treatment adherence.
Leprosy, or Hansen’s Disease, is a chronic infectious disease caused by Mycobacterium leprae that affects millions of people worldwide. Despite persistent efforts to combat it leprosy remains a significant public health concern particularly in developing countries. The underlying pathophysiology of the disease is not yet fully understood hindering the development of effective treatment strategies. However, recent studies have shed light on the potential role of microRNAs (miRNAs), small non-coding RNA molecules that can regulate gene expression, as promising biomarkers in various disease, including leprosy. This study aimed to validate a set of nine circulating miRNAs to propose new biomarkers for early diagnosis of the disease. Hsa-miR-16-5p, hsa-miR-106b-5p, hsa-miR-1291, hsa-miR-144-5p, and hsa-miR-20a-5p showed significant differential expression between non-leprosy group (non-LP) and leprosy group (LP), accurately discriminating between them (AUC > 0.75). In addition, our study revealed gender-based differences in miRNA expression in LP. Notably, hsa-miR-1291 showed higher expression in male LP, suggesting its potential as a male-specific biomarker. Similarly, hsa-miR-16-5p and hsa-miR-20a-5p displayed elevated expression in female LP, indicating their potential as female-specific biomarkers. Additionally, several studied miRNAs are involved in the dysregulation of apoptosis, autophagy, mitophagy, cell cycle, and immune system in leprosy. In conclusion, the validation of miRNA expression highlights several miRNAs as potential biomarkers for early diagnosis and provides new insights into the pathogenesis of the disease.
IntroductionHansen's disease (HD) primarily infects peripheral nerves, with patients without HD being free of peripheral nerve damage. Household contacts (HHCs) of patients with HD are at a 5–10 times higher risk of HD than the general population. Neural thickening is one of the three cardinal signs that define a case of HD according to WHO guidelines, exclusively considering palpation examination that is subjective and may not detect the condition in the earliest cases even when performed by well-trained professionals. High-resolution ultrasound (HRUS) can evaluate most peripheral nerves, a validated technique with good reproducibility allowing detailed and accurate examination.ObjectiveThis study aimed to use the peripheral nerve HRUS test according to the HD protocol as a diagnostic method for neuropathy comparing HHCs with healthy volunteers (HVs) and patients with HD.MethodsIn municipalities from 14 different areas of Brazil we selected at random 83 HHC of MB-patients to be submitted to peripheral nerve ultrasound and compared to 49 HVs and 176 HD-patients.ResultsHousehold contacts assessed by HRUS showed higher median and mean absolute peripheral nerve cross-sectional area (CSA) values and greater asymmetries (ΔCSA) compared to HVs at the same points. Median and mean absolute peripheral nerve CSA values were higher in patients with HD compared to HCCs at almost all points, while ΔCSA values were equal at all points. Mean ± SD focality (ΔTpT) values for HHCs and patients with HD, respectively, were 2.7 ± 2.2/2.6 ± 2.2 for the median nerve, 2.9 ± 2.7/3.3 ± 2.9 for the common fibular nerve (p > 0.05), and 1.3 ± 1.3/2.2 ± 3.9 for the ulnar nerve (p < 0.0001).DiscussionConsidering HRUS findings for HHCs, asymmetric multiple mononeuropathy signs (thickening or asymmetry) in at least 20% of the nerves evaluated could already indicates evidence of HD neuropathy. Thus, if more nerve points are assessed in HHCs (14 instead of 10), the contacts become more like patients with HD according to nerve thickening determined by HRUS, which should be a cutting-edge tool for an early diagnosis of leprosy cases.
Leprosy, also known as Hansen’s, is one of the listed neglected tropical diseases as a major health problem global. Treatment is one of the main alternatives, however, the scarcity of medication and its poor distribution are important factors that have driven the spread of the disease, leading to irreversible and multi-resistant complications. This paper uses a distribution methodology to optimize medication administration, taking into account the most relevant attributes for the epidemiological profile of patients and the deficit in treatment via Polychemotherapy. Multi-criteria Decision Methods were applied based on AHP-Electre model in a database with information from patients in the state of Para between 2015 and 2020. The results pointed out that 84% of individuals did not receive any treatment and, among these, the method obtained a gain in the distribution of 68% in patients with positive diagnosis for leprosy.
Introduction:After three years since the beginning of the pandemic, the new coronavirus continues to raise several questions regarding its infectious process and host response. Several mutations occurred in different regions of the SARS-CoV-2 genome, such as in the spike gene, causing the emergence of variants of concern and interest (VOCs and VOIs), of which some present higher transmissibility and virulence, especially among patients with previous comorbidities. It is essential to understand its spread dynamics to prevent and control new biological threats that may occur in the future. In this population_based retrospective observational study, we generated data and used public databases to understand SARS-CoV-2 dynamics. Methods:We sequenced 1,003 SARS-CoV-2 genomes from naso-oropharyngeal swabs and saliva samples from Pará from May 2020 to October 2022. To gather epidemiological data from Brazil and the world, we used FIOCRUZ and GISAID databases. Results:Regarding our samples, 496 (49.45%) were derived from female participants and 507 (50.55%) from male participants, and the average age was 43 years old. The Gamma variant presented the highest number of cases, with 290 (28.91%) cases, followed by delta with 53 (5.28%). Moreover, we found seven (0.69%) Omicron cases and 651 (64.9%) non-VOC cases. A significant association was observed between sex and the clinical condition (female, p = 8.65e-08; male, p = 0.008961) and age (p = 3.6e-10). Discussion:Although gamma had been officially identified only in December 2020/January 2021, we identified a gamma case from Belém (capital of Pará State) dated May 2020 and three other cases in October 2020. This indicates that this variant was circulating in the North region of Brazil several months before its formal identification and that Gamma demonstrated its actual transmission capacity only at the end of 2020. Furthermore, the public data analysis showed that SARS-CoV-2 dispersion dynamics differed in Brazil as Gamma played an important role here, while most other countries reported a new infection caused by the Delta variant. The genetic and epidemiological information of this study reinforces the relevance of having a robust genomic surveillance service that allows better management of the pandemic and that provides efficient solutions to possible new disease-causing agents.
Introduction:Leprosy, an infectious disease caused by Mycobacterium leprae, remains a public health concern in endemic countries, particularly in Brazil. In this study, we conducted an active surveillance campaign in the hyperendemic city of Castanhal in the northeastern part of the state of Pará using clinical signs and symptoms combined with serological and molecular tools to diagnose new cases and to identify drug resistance of circulating M. leprae strains and their distribution in the community.Methods:During an active surveillance of one week, we enrolled 318 individuals using three different strategies to enroll subjects for this study: (i) an active survey of previously treated cases from 2006 to 2016 found in the Brazil National Notifiable Disease Information System database (n = 23) and their healthy household contacts (HHC) (n = 57); (ii) an active survey of school children (SC) from two primary public schools in low-income neighborhoods (n = 178), followed by visits to the houses of these newly diagnosed SC (n = 7) to examine their HHC (n = 34) where we diagnosed additional new cases (n = 6); (iii) and those people who spontaneously presented themselves to our team or the local health center with clinical signs and/or symptoms of leprosy (n = 6) with subsequent follow-up of their HHC when the case was confirmed (n = 20) where we diagnosed two additional cases (n = 2). Individuals received a dermato-neurological examination, 5 ml of peripheral blood was collected to assess the anti-PGL-I titer by ELISA and intradermal earlobe skin scrapings were taken from HHC and cases for amplification of the M. leprae RLEP region by qPCR.Results:Anti-PGL-I positivity was highest in the new leprosy case group (52%) followed by the treated group (40.9%), HHC (40%) and lowest in SC (24.6%). RLEP qPCR from SSS was performed on 124 individuals, 22 in treated cases, 24 in newly diagnosed leprosy cases, and 78 in HHC. We detected 29.0% (36/124) positivity overall in this sample set. The positivity in treated cases was 31.8% (7/22), while in newly diagnosed leprosy cases the number of positives were higher, 45.8% (11/23) and lower in HHC at 23.7% (18/76). Whole genome sequencing of M. leprae from biopsies of three infected individuals from one extended family revealed a hypermutated M. leprae strain in an unusual case of primary drug resistance while the other two strains were drug sensitive.Discussion:This study represents the extent of leprosy in an active surveillance campaign during a single week in the city of Castanhal, a city that we have previously surveyed several times during the past ten years. Our results indicate the continuing high transmission of leprosy that includes fairly high rates of new cases detected in children indicating recent spread by multiple foci of infection in the community. An unusual case of a hypermutated M. leprae strain in a case of primary drug resistance was discovered. It also revealed a high hidden prevalence of overt disease and subclinical infection that remains a challenge for correct clinical diagnosis by signs and symptoms that may be aided using adjunct laboratory tests, such as RLEP qPCR and anti-PGL-I serology.
Background In recent years, a mitochondria/immune system interaction has been proposed, so that variants of mitochondrial genome and levels of heteroplasmy might deregulate important metabolic processes in fighting infections, such as leprosy. We sequenced the whole mitochondrial genome to investigate variants and heteroplasmy levels, considering patients with different clinical forms of leprosy and household contacts. Results We found 116 variants in at least two of the subtypes of the case group (Borderline Tuberculoid, Borderline Lepromatous, Lepromatous), suggesting a possible clinical significance to these variants. Notably, 15 variants were exclusively found in these three clinical forms, of which five variants stands out for being missense (m.3791T > C in MT-ND1 , m.5317C > A in MT-ND2 , m.8545G > A in MT-ATP8 , m.9044T > C in MT-ATP6 and m.15837T > C in MT-CYB) . In addition, we found 26 variants shared only by leprosy poles, of which two are characterized as missense (m.4248T > C in MT-ND1 and m.8027G > A in MT-CO2 ). Conclusion We found a significant number of variants and heteroplasmy levels in the leprosy patients from our cohort, suggesting for the first time that the mitogenome might be involved with the leprosy process, distinction of clinical forms and severity. Thus, future studies are needed to help understand the genetic consequences of this variants.
Leprosy remains a major public health problem in the world. Despite the availability of treatment, the disease continues to be neglected. Treatment is one of the main alternatives, however, the scarcity of medication and its poor distribution are important factors that have driven the spread of the disease, leading to irreversible and multi-resistant complications. This paper uses a distribution methodology to optimise medication administration, taking into account the most relevant attributes for the epidemiological profile of patients and the deficit in treatment via polychemotherapy. Multi-criteria decision methods were used applied in a database with information from patients in the State of Pará between 2015 and 2020. The results pointed out that 84% of individuals did not receive any treatment and of these, the method obtained a gain in the distribution of 68% in patients with positive diagnosis for leprosy.
Introduction:The detection of leprosy in children is an important epidemiological marker of the disease, indicating the community's early exposure to Mycobacterium leprae and active transmission of the infection.Methods:In order to detect new cases among children by combining clinical evaluation and laboratory tests, we conducted an active case finding among individuals under 15 years old on Caratateua Island, located in the city of Belém, in the Pará state, an endemic region in the Amazon. Dermato-neurological examination, collection of 5 mL of peripheral blood for IgM anti-PGL-I antibody titration, and intradermal scraping for bacilloscopy and amplification of the specific RLEP region by qPCR were performed.Results:Out of the 56 examined children, 28/56 (50%) new cases were identified. At the time of evaluation, 38/56 (67.8%) children presented one or more clinical alterations. Seropositivity was detected in 7/27 (25.9%) new cases and 5/24 (20.8%) undiagnosed children. DNA amplification of Mycobacterium leprae was observed in 23/28 (82.1%) of new cases and in 5/26 (19.2%) of non-cases. Out of the total cases, 11/28 (39.2%) were exclusively diagnosed by clinical evaluation performed during the active case finding. Seventeen new cases (60.8%) were detected considering the clinical alterations found in addition to positive results for qPCR. In this group, 3/17 (17.6%) qPCR-positive children presented significant clinical changes 5.5 months after the first evaluation.Discussion:Our research detected a number of cases 5.6 times higher compared to the total number of pediatric cases recorded throughout the year 2021 in the municipality of Belém, which shows a critical scenario of underdiagnosing of leprosy among children under 15 years old in the region. We propose the use of qPCR technique to identify new cases among children with oligosymptomatic or early disease in endemic areas, in addition to the training of Primary Health Care professionals and the implementation of the Family Health Strategy coverage in the visited area.
Introduction Hansen's disease (HD) is the most common cause of treatable peripheral neuropathy in the world that may or may not involve skin manifestations, and physical examination based on simplified neurologic evaluation is a subjective and inaccurate procedure. High-resolution ultrasound (HRUS) can be used to evaluate peripheral nerves and is a validated technique of good reproducibility, permitting a detailed and precise examination. Objectives We proposed to establish objective criteria for absolute values of the measurement of the CSA of peripheral nerves and their indices of the ΔCSA and ΔTpT in the diagnosis of Hansen's disease neuropathy as compared with healthy voluntaries. Materials and methods In municipalities from different regions of Brazil, we randomly selected 234 volunteer Brazilian patients diagnosed with leprosy to be submitted to peripheral nerve echography and compared with 49 healthy Brazilian volunteers. Results Hansen Disease assessed by high resolution ultrasound is a primarily neural disease that leads to multiple hypertrophic mononeuropathy characterized by CSA values exceeding normal limits (Med CT = 10.2 mm2; UT = 9.8 mm2; UPT = 9.3 mm2; CFFH = 18.3 mm2; T = 9.6 mm2), and the pattern of asymmetry (ΔCSA>2.5 mm2 with RR 13) and focality (ΔTPT > 2.5 mm2 with RR 6.4) of this thickening has higher sensitivity (76,1%) and specificity (87,8 %) for its early diagnosis that laboratory tests. Analyzing each subject, the percentage of thickened nerves detected among the total number of nerves assessed was higher among patients with HD than among healthy individuals (p < 0.0001). Individuals with two or more thickened nerves were at 24.1 times higher relative risk (95% CI: 6.74–88.98) of HD.
Leprosy is a chronic neurodermatological disease caused by the bacillus Mycobacterium leprae. Recent studies show that SNPs in genes related to miRNAs have been associated with several diseases in different populations. This study aimed to evaluate the association of twenty-five SNPs in genes encoding miRNAs related to biological processes and immune response with susceptibility to leprosy and its polar forms paucibacillary and multibacillary in the Brazilian Amazon. A total of 114 leprosy patients and 71 household contacts were included in this study. Genotyping was performed using TaqMan Open Array Genotyping. Ancestry-informative markers were used to estimate individual proportions of case and control groups. The SNP rs2505901 (pre-miR938) was associated with protection against the development of paucibacillary leprosy, while the SNPs rs639174 (DROSHA), rs636832 (AGO1), and rs4143815 (miR570) were associated with protection against the development of multibacillary leprosy. In contrast, the SNPs rs10739971 (pri-let-7a1), rs12904 (miR200C), and rs2168518 (miR4513) are associated with the development of the paucibacillary leprosy. The rs10739971 (pri-let-7a1) polymorphism was associated with the development of leprosy, while rs2910164 (miR146A) and rs10035440 (DROSHA) was significantly associated with an increased risk of developing multibacillary leprosy.
Diagnostic tests for leprosy are limited, especially to identify early leprosy cases. We performed active case findings of leprosy to validate three potential antigen candidates and one molecular target. Cases were diagnosed by characteristic skin lesions, nerve enlargement, or skin sensation loss. Serum samples obtained from all subjects were tested by ELISA to assess antibody titers to three Mycobacterium leprae specific antigens: NDO-BSA, LID-1, and NDO-LID. Most of the field cases on Mosqueiro Island, northern Brazil, also collected slit skin smear for qPCR. Active case finding diagnosed 105 new cases of leprosy out of 894 subjects (11.7%), revealing a high prevalence of M. leprae in the region. With the use of amplification of the M. leprae -specific RLEP by qPCR, 68/79 (86.07%) of these cases were positive, confirming leprosy in subjects diagnosed in the field. Patients diagnosed at the leprosy reference center showed much higher antibody titers to all three antigens, while titers of patients from the field were significantly lower. Our results support previous findings that active surveillance by experienced leprologists can diagnose additional cases based on clinical findings, that many would not be identified using ELISA assay with the available biomarkers, and that RLEP qPCR may be used to confirm the majority of the field cases.
The number of new cases of leprosy reported worldwide has remained essentially unchanged for the last decade despite continued global use of free multidrug therapy (MDT) provided to any diagnosed leprosy patient. In order to more effectively interrupt the chain of transmission, new strategies will be required to detect those with latent disease who contribute to furthering transmission. To improve the ability to diagnose leprosy earlier in asymptomatic infected individuals, we examined the combined use of two well-known biomarkers of M. leprae infection, namely the presence of M. leprae DNA by PCR from earlobe slit skin smears (SSS) and positive antibody titers to the M. leprae-specific antigen, Phenolic Glycolipid I (anti-PGL-I) from leprosy patients and household contacts living in seven hyperendemic cities in the northern state of Pará, Brazilian Amazon. Combining both tests increased sensitivity, specificity and accuracy over either test alone. A total of 466 individuals were evaluated, including 87 newly diagnosed leprosy patients, 52 post-treated patients, 296 household contacts and 31 healthy endemic controls. The highest frequency of double positives (PGL-I+/RLEP+) were detected in the new case group (40/87, 46%) with lower numbers for treated (12/52, 23.1%), household contacts (46/296, 15.5%) and healthy endemic controls (0/31, 0%). The frequencies in these groups were reversed for double negatives (PGL-I-/RLEP-) for new cases (6/87, 6.9%), treated leprosy cases (15/52, 28.8%) and the highest in household contacts (108/296, 36.5%) and healthy endemic controls (24/31, 77.4%). The data strongly suggest that household contacts that are double positive have latent disease, are likely contributing to shedding and transmission of disease to their close contacts and are at the highest risk of progressing to clinical disease. Proposed strategies to reduce leprosy transmission in highly endemic areas may include chemoprophylactic treatment of this group of individuals to stop the spread of bacilli to eventually lower new case detection rates in these areas.
Background This study evaluates an active search strategy for leprosy diagnosis based on responses to a Leprosy Suspicion Questionnaire (LSQ), and analyzing the clinical, immunoepidemiological and follow-up aspects for individuals living in a prison population. Methods A cross-sectional study based on a questionnaire posing 14 questions about leprosy symptoms and signs that was distributed to 1,400 prisoners. This was followed by dermatoneurological examination, anti-PGL-I serology and RLEP-PCR. Those without leprosy were placed in the Non-leprosy Group (NLG, n = 1,216) and those diagnosed with clinical symptoms of leprosy were placed in the Leprosy Group (LG, n = 34). Findings In total, 896 LSQ were returned (64%), and 187 (20.9%) of the responses were deemed as positive for signs/symptoms, answering 2.7 questions on average. Clinically, 1,250 (89.3%) of the prisoners were evaluated resulting in the diagnosis of 34 new cases (LG), based on well-accepted clinical signs and symptoms, a new case detection rate of 2.7% within this population, while the NLG were comprised of 1,216 individuals. The confinement time medians were 39 months in the LG while it was 36 months in the NLG (p>0.05). The 31 leprosy cases who responded to the questionnaire (LSQ+) had an average of 1.5 responses. The symptoms “anesthetized skin area” and “pain in nerves” were most commonly mentioned in the LG while “tingling, numbness in the hands/feet”, “sensation of pricks and needles”, “pain in nerves” and “spots on the skin” responses were found in more than 30% of questionnaires in the NLG. Clinically, 88.2% had dysesthetic macular skin lesions and 97.1% presented some peripheral nerve impairment, 71.9% with some degree of disability. All cases were multibacillary, confirming a late diagnosis. Anti-PGL-I results in the LG were higher than in the NLG (p<0.0001), while the RLEP-PCR was positive in 11.8% of the patients. Interpretation Our findings within the penitentiary demonstrated a hidden prevalence of leprosy, although the individuals diagnosed were likely infected while living in their former communities and not as a result of exposure in the prison. The LSQ proved to be an important screening tool to help identify leprosy cases in prisons.
Leprosy, which is caused by the human pathogen Mycobacterium leprae , causes nerve damage, deformity and disability in over 200,000 people every year. Because of the long doubling time of M. leprae (13 days) and the delayed onset of detectable symptoms, which is estimated to be approximately 3–7 years after infection, there is always a large percentage of subclinically infected individuals in the population who will eventually develop the disease, mainly in endemic countries. piRNAs comprise the largest group of small noncoding RNAs found in humans, and they are distinct from microRNAs (miRNAs) and small interfering RNAs (siRNAs). piRNAs function in transposon silencing, epigenetic regulation, and germline development. The functional role of piRNAs and their associated PIWI proteins have started to emerge in the development of human cancers and viral infections, but their relevance to bacterial diseases has not been investigated. The present study reports the piRNome of human skin, revealing that all but one of the piRNAs examined are downregulated in leprosy skin lesions. Considering that one of the best characterized functions of piRNAs in humans is posttranscriptional mRNA silencing, their functions are similar to what we have described for miRNAs, including acting on apoptosis, M. leprae recognition and engulfment, Schwann cell (SC) demyelination, epithelial–mesenchymal transition (EMT), loss of sensation and neuropathic pain. In addition to new findings on leprosy physiopathology, the discovery of relevant piRNAs involved in disease processes in human skin may provide new clues for therapeutic targets, specifically to control nerve damage, a prominent feature of leprosy that has no currently available pharmaceutical treatment.
BackgroundLeprosy is a debilitating, infectious disease caused by Mycobacterium leprae leading to skin and nerve damage and often lifelong handicaps. The unabated rate of new leprosy case detection indicates that transmission of M. leprae is persistent and that current measures for prevention and multidrug therapy (MDT) are insufficient. Contact with M. leprae-infected individuals is a risk factor for development of leprosy. Thus, detection of M. leprae-infected individuals without clinical symptoms, allowing informed decision making on who needs treatment at a preclinical stage, is vital to interrupt transmission and can help prevent leprosy.Immunoprophylaxis by vaccination or post-exposure prophylaxis (PEP) with antibiotics provide effective strategies for the prevention of leprosy. To target individuals unknowingly spreading leprosy bacilli, methods allowing objective measurement of M. leprae infection are needed. Besides antibody (Ab) levels that correspond with bacterial load and higher risk of progression to leprosy, detection of cytokine profiles can provide significant added value to identify infection.MethodsQuantitative detection of anti-PGL-I IgM antibodies, and cytokines such as IP-10 was performed on lateral flow (LF) test strips utilising the luminescent up-converting particle (UCP) technology. Precise amounts of fingerstick (FS)-blood samples were collected using disposable heparinised capillaries. Ab and cytokine levels in both FS-blood and serum from leprosy patients in South-Africa, Brazil, Bangladesh and the Netherlands and (their) contacts were measured using a portable reader.ResultsExcellent correlation was demonstrated between data for anti-PGL-I IgM Ab and cytokines obtained with serum and FS blood from the same individuals.ConclusionThe quantitative UCP-LF test strips detecting anti-PGL-I IgM Ab and cytokines for the detection of M. leprae infection is compatible with fingerstick blood allowing near-patient testing and immediate appropriate follow-up counselling.