Bacilloscopy and polymerase chain reaction of slit-skin smears and anti-phenolic glycolipid-I serology for Hansen's disease diagnosis

Slit skin smear versus anti-phenolic glycolipid-I serology in diagnosis of leprosy: a cross sectional study

Leprosy is a chronic infectious disease which mainly affects the skin, nasal mucosa, and peripheral nerves. The aim of this study was to compare between the efficacies of serum anti-phenolic glycolipid 1 (APGL-I) level versus slit skin smear (SSS) in diagnosis of leprosy. This study involved 58 leprosy cases who were clinically examined, slit-skin smears were taken from all at diagnosis from four sites and APGL-I levels were seroassayed using ELISA. The mean age of studied group was 39.42 ± 15.2, 44.8% of patients were males and 55.2% were females. The majority of patients (72.4%) had multibacillary leprosy (MBL) followed by (27.6%) of patients had paucibacillary leprosy (PBL). SSS had sensitivity of 71.5% and specificity of 84% (area under curve; AUC = 0.763, 95% CI 0.427-0.823) while APGL-I had a sensitivity of 80% and specificity of 85% (area under curve; AUC = 0.830, 95% CI 0.424-0.852). Both serum Anti-PGL-1 levels and slit skin smear are useful in diagnosing leprosy, but their effectiveness depends on disease stage and patient's immune response. Being inexpensive, easy and noninvasive technique, APGL1 can be an adjunct method for the detection of leprosy in the population while slit skin smear having higher specificity. Combining both methods or using sequential diagnostic approaches could enhance accuracy and reduce missed diagnoses.

Fever of unknown origin, blood and cerebrospinal fluid involvement: a leprosy case report

Leprosy is a chronic infectious disease that mainly affects the skin and peripheral nerves, it can also invade deeper tissues and organs, including mucous membranes, lymph nodes, testes, eyes, and internal organs. Severe cases can result in deformities and disabilities. We encountered the case of a 39-year-old male with unexplained fever, headache and rash. The patient's lesions were taken for histopathological examination and slit skin smear analysis. Further, the patient was detected of Mycobacterium leprae (M.leprae) nucleic acid sequences in the cerebrospinal fluid (CSF) and plasma, and M.leprae gene targets in the skin lesion tissue and blood. The patient was eventually diagnosed with multibacillary leprosy and type II leprosy reaction. These results suggest the possibility of bacteremia in patients with leprosy to some extent, and observation implies the potential invasion of CSF by M.leprae or its genetic material.

An update of the diagnosis, treatment, and prevention of leprosy: A narrative review

Leprosy is an infectious disease that remains a public health concern. It is caused by acid-fast Bacillus leprae, which primarily affects the skin and peripheral nerves, potentially leading to long-term disability and stigma. However, current and previous efforts have focused on developing better diagnostic and therapeutic interventions for leprosy, and its prevention needs to be addressed. In this review, we organize the currently published papers and provide updates on the global epidemiology, diagnosis, treatment, and prevention of leprosy. Several online databases, including MEDLINE (National Library of Medicine, Bethesda, MD), PubMed, EMBASE, Web of Science, and Google Scholar, were searched to collect relevant published papers. As a public health issue, the World Health Organization set the goal of leprosy elimination with a prevalence of <1 case per 10,000 people, which was achieved in 2000 and in most countries by 2010, mainly owing to the treatment of leprosy using drugs starting in 1980 and no-cost access for patients since 1995. Although diagnostic and therapeutic techniques have improved, the new occurrence of leprosy remains a critical global disease burden. With continuous technological improvements in diagnosing and treating leprosy, obtaining more relevant healthcare knowledge and preventing leprosy disability are crucial.

Diagnosis and Treatment of Leprosy in Taiwan during the COVID-19 Pandemic: A Retrospective Study in a Tertiaty Center

Currently, over 200,000 new cases of leprosy are reported annually worldwide. Although leprosy was thought to have been eradicated in Taiwan, a few new cases still occur annually. Protean clinical manifestations of leprosy and immunological reactions result in delayed diagnoses. In addition, drug-resistant leprosy is emerging and poses treatment challenges. In this retrospective study, we collected and analyzed the clinicopathological features, leprosy type, treatment response, and relapse rate of patients with leprosy in our hospital between January 2009 and November 2022. We found that 54% of patients were Indonesian, and borderline lepromatous leprosy was predominant (39%); moreover, histoid leprosy and the Lucio phenomenon were also reported. Polymerase chain reaction analysis identified four positive cases, including a dapsone-resistant (4%) case. Our findings indicated good control of leprosy and a lower rate of dapsone resistance than that reported by the World Health Organization (4% vs. 13%) from 2009 to 2015. We found that the patient profile in terms of the treatment duration, recurrence rate, systemic symptoms, and neurological symptoms did not differ between before and during the pandemic. We report the recent advances in leprosy diagnosis, drug-resistant gene mutations, post-exposure prophylaxis, vaccination, and the effect of coronavirus disease 2019 on leprosy to facilitate updated leprosy diagnosis and management.

Serological testing for Hansen’s disease diagnosis: Clinical significance and performance of IgA, IgM, and IgG antibodies against Mce1A protein

Hansen’s disease (HD) is an infectious, treatable, and chronic disease. It is the main cause of infectious peripheral neuropathy. Due to the current limitations of laboratory tests for the diagnosis of HD, early identification of infected contacts is an important factor that would allow us to control the magnitude of this disease in terms of world public health. Thus, a cross-sectional study was conducted in the Brazilian southeast with the objective of evaluating humoral immunity and describing the accuracy of the immunoassay based on IgA, IgM, and IgG antibodies against surface protein Mce1A of Mycobacterium, the predictive potential of these molecules, the clinical significance of positivity, and the ability to segregate new HD cases (NC; n = 200), contacts (HHC; n = 105), and healthy endemic controls (HEC; n = 100) as compared to α-PGL-I serology. α-Mce1A levels for all tested antibodies were significantly higher in NC and HHC than in HEC (p &lt; 0.0001). The performance of the assay using IgA and IgM antibodies was rated as highly accurate (AUC &gt; 0.85) for screening HD patients. Among HD patients (NC), positivity was 77.5% for IgA α-Mce1A ELISA, 76.5% for IgM, and 61.5% for IgG, while α-PGL-I serology showed only 28.0% positivity. Multivariate PLS-DA showed two defined clusters for the HEC and NC groups [accuracy = 0.95 (SD = 0.008)] and the HEC and HHC groups [accuracy = 0.93 (SD = 0.011)]. IgA was the antibody most responsible for clustering HHC as compared to NC and HEC, evidencing its usefulness for host mucosal immunity and as an immunological marker in laboratory tests. IgM is the key antibody for the clustering of NC patients. Positive results with high antibody levels indicate priority for screening, new clinical and laboratory evaluations, and monitoring of contacts, mainly with antibody indexes ≥2.0. In light of recent developments, the incorporation of new diagnostic technologies permits to eliminate the main gaps in the laboratory diagnosis of HD, with the implementation of tools of greater sensitivity and accuracy while maintaining satisfactory specificity.