Leprosy in Colombia

High seropositivity against NDO-LID in a group of household contacts of leprosy patients. Are we close to leprosy elimination in Colombia?

INTRODUCTION

Leprosy is a chronic infectious disease caused by two mycobacteria (Mycobacterium leprae and Mycobacterium lepromatosis). The household contacts (HHC) of leprosy index cases are at higher risk of being infected with these mycobacteria. Therefore, serological testing in HHC would be an effective strategy to eliminate leprosy in Colombia.

OBJECTIVE

To determine the seroprevalence and factors associated with the infection by M. leprae in HHC.

METHODS

An observational study was conducted in 428 HHC located in the Colombian Caribbean, Andean, Pacific, and Amazonian regions. We evaluated the seropositivity and titrations of IgM, IgG, and protein A against NDO-LID.

RESULTS

The evaluated HHC showed high seropositivity, precisely 36.9% anti-NDO-LID IgM, 28.3% anti-NDO-LID IgG, and 47.7% protein A. Furthermore, Protein A showed a greater capacity to detect infected individuals than other anti-NDO-LID conjugates (p < 0.0001). This study did not show differences in the seropositivity according to sex or age of the HHC (p > 0.05). Higher seropositivity for IgM was evidenced mainly in HHC located in the Colombian Pacific region (p 0.001). This research did not show differences in the seropositivity for these serological tests between HHC of PB or MB leprosy patients (p > 0.05).

CONCLUSION

Leprosy transmission is still active between Colombian HHC. Consequently, controlling leprosy transmission in this population is fundamental to eradicating this disease.

Automated chronic wounds medical assessment and tracking framework based on deep learning

Chronic wounds are a latent health problem worldwide, due to high incidence of diseases such as diabetes and Hansen. Typically, wound evolution is tracked by medical staff through visual inspection, which becomes problematic for patients in rural areas with poor transportation and medical infrastructure. Alternatively, the design of software platforms for medical imaging applications has been increasingly prioritized. This work presents a framework for chronic wound tracking based on deep learning, which works on RGB images captured with smartphones, avoiding bulky and complicated acquisition setups. The framework integrates mainstream algorithms for medical image processing, including wound detection, segmentation, as well as quantitative analysis of area and perimeter. Additionally, a new chronic wounds dataset from leprosy patients is provided to the scientific community. Conducted experiments demonstrate the validity and accuracy of the proposed framework, with up to 84.5% in precision.

Association of the rs2111234, rs3135499, rs8057341 polymorphisms in the NOD2 gene with leprosy: A case-control study in the Norte de Santander, Colombia population

BACKGROUND

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. The development of leprosy involves several factors, including the causative agent, the individual host's immune response, environmental factors, and the genetic background of the host. Specifically, the host's innate immune response, encoded by genes, determines their susceptibility to developing leprosy post-infection. Polymorphic variants in the nucleotide-binding oligomerization domain 2 (NOD2) gene are associated with leprosy among populations in a variety of endemic areas around the world. Colombia, a country located in the tropical zone, has several leprosy-endemic regions, including Norte de Santander. The aim of this study was to analyze the rs7194886, rs2111234, rs3135499, and rs8057341 single nucleotide polymorphisms (SNPs) in the NOD2 gene using a case-control study to determine whether they confer greater or lesser susceptibility to the development of leprosy.

METHODOLOGY

The TaqMan qPCR amplification system was used for SNPs detection.

FINDINGS

An association between the A-rs8057341 SNP (p = 0,006286) and resistance to leprosy was found. However, the rs3135499 (p = 0,9063) and rs2111234 (p = 0.1492) were not found to be associated with leprosy susceptibility. In addition, the rs7194886 SNP was not found to be in Hardy-Weinberg equilibrium (HWE) in the study population. The GAG haplotype, consisting of SNPs rs2111234-G, rs3135499-A, and rs8057341G, acts as a susceptibility factor for the development of leprosy in women. SNPs rs3135499 and rs8057341 are functionally related to decreased NOD2 expression according to an in-silico analysis.

CONCLUSIONS

The SNPs rs8057341-A was related with resistance to leprosy and the haplotype rs2111234-G, rs3135499-A and rs8057341-G SNPs was related with susceptibility in the Norte de Santander Colombia, studied population.

Neuropathic ulcers in leprosy: clinical features, diagnosis and treatment

Leprosy is a neglected disease caused by Mycobacterium leprae and Mycobacterium lepromatosis, and is related to significant disabilities resulting from the neural damage generated by this mycobacteria. Neuropathic ulcers-lesions that can appear at the plantar and extra-plantar levels-are one such disability, and diagnosis requires an adequate dermatological, neurological and microbiological evaluation. The treatment of these lesions is based on a multidisciplinary approach that includes debridement of the necrotic tissue, controlling infections, reducing pressure areas, optimising blood flow, and nerve decompression. This review aims to describe the clinical features, diagnostic methods and treatment of neuropathic ulcers in leprosy. The diagnostic methods and medical management used in leprosy ulcers are based on those used for diabetic foot. This requires radical change as these diseases are immunologically and physiologically very different.

[Epidemiological behavior of leprosy in several Latin American countries, 2011-2020Comportamento epidemiológico da hanseníase em vários países da América Latina, 2011-2020]

Objective

To describe the epidemiological behavior of leprosy in several Latin American countries during 2011-2020, based on World Health Organization (WHO) indicators.

Methods

Cross-sectional, descriptive and quantitative study with official data on incidence and prevalence in the general population, children, clinical form and cases with grade 2 disability from WHO records between 2011 and 2020. The eight countries in Latin America that reported most cases were selected and analyses were carried out using simple descriptive and comparative statistics between different variables.

Results

During the study period, 301 312 cases of leprosy were reported in the selected countries: Argentina, Brazil, Colombia, Cuba, Dominican Republic, Mexico, Paraguay, and Venezuela. Brazil is the only country in the region with a prevalence greater than 1 per 10 000, representing 93.77% of all cases. Brazil and the Dominican Republic showed an increase in prevalence during 2011-2019, while in other countries the trend was decreasing. The disease is more frequent in men, and multibacillary cases significantly exceed paucibacillary ones. Brazil showed the highest incidences of cases of childhood leprosy and grade 2 disability during the evaluated period.

Conclusion

In Latin America, leprosy is only considered a public health problem in Brazil; however, most countries in the region continue to report cases annually, revealing a lack of adequate medical care. This study confirmed the importance of active surveillance, early diagnosis and planning of actions against the disease in all the countries evaluated with the aim of reducing its transmission.

Acid-Fast Bacilli Positivity Rate and Associated Factors among Leprosy Suspected Cases attending Selected Health Facilities located in West Arsi Zone, Oromia, Ethiopia

INTRODUCTION

Leprosy is one of the neglected tropical diseases that affect skin and peripheral nervous system often results in severe, lifelong disabilities and deformities. Even though multidrug therapy was in place for more than 30 years to treat and prevent leprosy worldwide including Ethiopia, its epidemiology is not well studied in the West Arsi zone.

OBJECTIVE

The aim of this study was to determine the prevalence of acid-fast bacilli (AFB) positivity rate and associated factors among leprosy suspected cases.

METHODS

A health facility-based cross-sectional study was conducted among 422 leprosy suspected cases from August 2020 to December 2020. To detect AFB, skin slit specimens were collected and examined using the Ziehl-Neelsen staining technique. Socio-demographic and clinical data were collected using a structured questionnaire. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 24. Logistic regression was employed to determine predictors of AFB positivity rate.

RESULTS

Acid-fast bacilli were detected among 46 leprosy suspected cases which gives a prevalence of 10.9% with 95% CI (8.2‒15.6). Suspected leprosy cases with multibacillary type were 4 times more likely to be AFB positive (p=0.021) than their counterparts. Study participants who had contact with known leprosy cases were 2 times more likely to be AFB positive (p = 0.032) and those with no formal education were 2 times more likely to be AFB positive (p = 0.03). Participants who had close contact with leprosy patients for ≥3 years were 8 times more likely to be AFB positive (p = 0.02).

CONCLUSION

This study revealed a high prevalence of AFB positivity rate in the era of multidrug therapy. Types of leprosy, close contact with known leprosy cases, educational status, and duration of closer contact with leprosy cases were significantly associated with AFB positivity rate.

Epidemiological profile and tendency of leprosy in people younger than 15 years

OBJECTIVE

To evaluate the epidemiological characteristics and tendency of new leprosy cases in people younger than 15 years in the state of Bahia, Brazil, between 2007 and 2017.

METHOD

Quantitative, cross-sectional, descriptive study of cases registered in the Notifiable Diseases Information System. The sociodemographic variables were statistically analyzed through the G-test and trend classification was analyzed through linear regression, along with the tendency or percentage change.

RESULTS

The study comprised 2,298 new cases and presented decreasing rate of detection, growing proportion of investigated contacts, and decreasing proportion of healing. Paucibacillary cases are emphasized, with a 63.27% proportion and predominance among females with incomplete primary education and brown race/color living in urban zones. Regarding clinical forms, physical disabilities, and modes of detection, 26.68% were tuberculoid, 73.72% were grade zero, and 36.42% were referral, respectively.

CONCLUSION

The increased tendency in the proportion of investigated contacts and the decrease in the proportion of healing revealed a need for the health system to improve patient follow-up during treatment against leprosy.

Molecular epidemiology of leprosy: An update

Molecular epidemiology investigations are notoriously challenging in the leprosy field mainly because the inherent characteristics of the disease as well as its yet uncultivated causative agents, Mycobacterium leprae and M. lepromatosis. Despite significant developments in understanding the biology of leprosy bacilli through genomic approaches, the exact mechanisms of transmission is still unclear and the factors underlying pathological variation of the disease in different patients remain as major gaps in our knowledge about leprosy. Despite these difficulties, the last two decades have seen the development of genotyping procedures based on PCR-sequencing of target loci as well as by the genome-wide analysis of an increasing number of geographically diverse isolates of leprosy bacilli. This has provided a foundation for molecular epidemiology studies that are bringing a better understanding of strain evolution associated with ancient human migrations, and phylogeographical insights about the spread of disease globally. This review discusses the advantages and drawbacks of the main tools available for molecular epidemiological investigations of leprosy and summarizes various methods ranging from PCR-based genotyping to genome-typing techniques. We also describe their main applications in analyzing the short-range and long-range transmission of the disease. Finally, we summarise the current gaps and challenges that remain in the field of molecular epidemiology of leprosy.

Leprosy Transmission in Amazonian Countries: Current Status and Future Trends

Purpose of Review

Leprosy is one of the first pathologies described in the history of mankind. However, the ecology, transmission, and pathogenicity of the incriminated bacilli remain poorly understood. Despite effective treatment freely distributed worldwide since 1995, around 200,000 new cases continue to be detected yearly, mostly in the tropics. This review aims to discuss the unique characteristics of leprosy in Amazonian countries, which exhibit a very heterogeneous prevalence among human and animal reservoirs.

Recent Findings

Groundbreaking discoveries made in the last 15 years have challenged the dogmas about leprosy reservoirs, transmission, and treatment. The discovery of a new leprosy causative agent in 2008 and the scientific proof of zoonosis transmission of leprosy by nine-banded armadillos in the southern USA in 2011 challenged the prospects of leprosy eradication. In the Amazonian biome, nine-banded and other armadillo species are present but the lack of large-scale studies does not yet allow accurate assessment of the zoonotic risk. Brazil is the second country in the world reporting the highest number of new leprosy cases annually. The disease is also present, albeit with different rates, in all neighboring countries. Throughout the Amazonian biome, leprosy is mainly found in hyperendemic foci, conducive to the emergence and transmission of drug-resistant strains.

Summary

The deepening of current knowledge on leprosy reservoirs, transmission, and therapeutic issues, with the One Health approach and the help of molecular biology, will allow a better understanding and management of the public health issues and challenges related to leprosy in Amazonia.

Notch Signaling Pathway Expression in the Skin of Leprosy Patients: Association With Skin and Neural Damage

Introduction: Leprosy is an infectious disease caused by Mycobacterium leprae, a debilitating disease that affects the skin and peripheral nerves. It is possible that tissue changes during infection with leprosy are related to alterations in the activity of the Notch signaling pathway, an innate signaling pathway in the physiology of the skin and peripheral nerves.

Methods: This is a descriptive observational study. Thirty skin biopsies from leprosy patients and 15 from individuals with no history of this disease were evaluated. In these samples, gene expressions of cellular components associated with the Notch signaling pathway, Hes-1, Hey-1, Runx-1 Jagged-1, Notch-1, and Numb, were evaluated using q-PCR, and protein expression was evaluated using immunohistochemistry of Runx-1 and Hes-1.

Results: Changes were observed in the transcription of Notch signaling pathway components; Hes-1 was downregulated and Runx-1 upregulated in the skin of infected patients. These results were confirmed by immunohistochemistry, where reduction of Hes-1 expression was found in the epidermis, eccrine glands, and hair follicles. Increased expression of Runx-1 was found in inflammatory cells in the dermis of infected patients; however, it is not related to tissue changes. With these results, a multivariate analysis was performed to determine the causes of transcription factor Hes-1 reduction. It was concluded that tissue inflammation was the main cause.

Conclusions: The tissue changes found in the skin of infected patients could be associated with a reduction in the expression of Hes-1, a situation that would promote the survival and proliferation of M. leprae in this tissue.

Social and environmental conditions related to Mycobacterium leprae infection in children and adolescents from three leprosy endemic regions of Colombia

Background

Leprosy is is still considered a public health issue and in Colombia 7–10% of new cases are found in children, indicating both active transmission and social inequality. We hypothesized that circulating antibodies against Natural Octyl Disaccharide-Leprosy IDRI Diagnostic (NDO-LID) (a combination of Mycobacterium leprae antigens) could reveal the social and environmental aspects associated with higher frequencies of M. leprae infection among children and adolescents in Colombia.

Methods

An observational cross-sectional study was conducted involving sampling from 82 children and adolescents (younger than 18 years of age) who had household contact with index leprosy patients diagnosed in the last 5 years. Data were analyzed through bivariate analysis made by applying a Pearson x² test for qualitative variables, while quantitative variables, depending on their distribution, were analyzed using either a Student’s t-test or Mann-Whitney U test. Multivariate analysis was performed using a multiple regression and binomial logistic approach.

Results

A bivariate analysis demonstrated that antibody titers against NDO-LID were significantly greater in children and adolescents with a low socioeconomic status that had: lived in vulnerable areas of the UAChR shared region; eaten armadillo meat; exposure of over 10 years to an index case and; not received BCG immunization. Moreover, a multivariate analysis showed that residing in the UAChR region has a strong association with a greater possibility of M. leprae infection.

Conclusions

M. leprae transmission persists among young Colombians, and this is associated with social and environmental conditions. An intensification of efforts to identify new leprosy cases in vulnerable and forgotten populations where M. leprae transmission continues therefore appears necessary.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4120-2) contains supplementary material, which is available to authorized users.