Publications by authors named "Anouk Van Hooij"

Background: Detection of infection with Mycobacterium leprae allows timely prophylactic treatment, thereby reducing transmission as well as the risk of permanent, leprosy-associated nerve damage. However, since there is no worldwide-implemented standard test for M. leprae infection, detection of infection in asymptomatic individuals remains a major challenge for control programs in endemic areas.

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Leprosy is a poverty-associated infectious disease in humans caused by or , often resulting in skin and peripheral nerve damage, which remains a significant public health concern in isolated areas of low- and middle-income countries. Previous studies reported leprosy in red squirrels in the British Isles, despite the fact that autochthonous human cases have been absent for centuries in this region. To investigate the extent of and presence in wild red squirrels in the northern UK, we analyzed 220 blood/body cavity fluid samples from opportunistically sampled red squirrels (2004-2023) for specific antibodies against phenolic glycolipid-I, a cell wall component specific for these leprosy bacilli.

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Article Synopsis
  • IgM antibodies against phenolic glycolipid I (PGL-I) are important for indicating past infections and the prevalence of leprosy in a population, but they cannot differentiate between recent and past infections.
  • Researchers conducted a serosurvey in leprosy-endemic villages in Bihar, India, using a simple fingerstick blood test to assess anti-PGL-I IgM levels among children aged 3-11 years.
  • The results showed an 11.58% seroprevalence, suggesting a consistent infection rate compared to other areas, highlighting the test's potential as a practical tool for monitoring recent leprosy transmission in children as part of eradication efforts.
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Bovine tuberculosis (bTB), caused by () infection in cattle, is an economically devastating chronic disease for livestock worldwide. Efficient disease control measures rely on early and accurate diagnosis using the tuberculin skin test (TST) and interferon-gamma release assays (IGRAs), followed by culling of positive animals. Compromised performance of TST and IGRA, due to BCG vaccination or co-infections with non-tuberculous mycobacteria (NTM), urges improved diagnostics.

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Background: transcriptomic and human host immune gene expression signatures that demonstrate a plausible association with type I (T1R) and type II reactions (T2R) aid in early diagnosis, prevention of nerve damage and consequent demyelinating neuropathy in leprosy. The aim of the study is to identify and host-associated gene-expression signatures that are associated with reactional states in leprosy.

Methods: The differentially expressed genes from the whole transcriptome of were determined using genome-wide hybridization arrays with RNA extracted from skin biopsies of 20 T1R, 20 T2R and 20 non reactional controls (NR).

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Diagnostic services for tuberculosis (TB) are not sufficiently accessible in low-resource settings, where most cases occur, which was aggravated by the COVID-19 pandemic. Early diagnosis of pulmonary TB can reduce transmission. Current TB-diagnostics rely on detection of in sputum requiring costly, time-consuming methods, and trained staff.

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Bovine tuberculosis (bTB), caused by , is a globally prevalent infectious disease with significant animal welfare and economic impact. Difficulties in implementing test-and-slaughter measures in low- and middle-income countries (LMICs) and the underperformance of the current diagnostics establish a clear need to develop improved diagnostics. Adaptive immunity biomarkers other than IFNγ could be useful as suggested by various gene expression studies; however, a comprehensive assessment at the protein level is lacking.

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Leprosy has been described in Eurasian red squirrel (; ERS) carcasses since 2014. Studies of ERS carcasses have not provided information about incubation or disease progression in this host but have provided important insights into pathogen presence and distribution throughout the United Kingdom. Here we present field study data on 31 live ERS from an island population naturally infected with that were assessed longitudinally over a 2-yr time period.

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Nonhuman primates (NHPs) are relevant models to study the pathogenesis of tuberculosis (TB) and evaluate the potential of TB therapies, but rapid tools allowing diagnosis of active pulmonary TB in NHPs are lacking. This study investigates whether low complexity lateral flow assays utilizing upconverting reporter particles (UCP-LFAs) developed for rapid detection of human serum proteins can be applied to detect and monitor active pulmonary TB in NHPs. UCP-LFAs were used to assess serum proteins levels and changes in relation to the MTB challenge dosage, lung pathology, treatment, and disease outcome in experimentally MTB-infected macaques.

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Leprosy is an infectious disease caused by with tropism for skin and peripheral nerves. Incessant transmission in endemic areas is still impeding elimination of leprosy. Although detection of infection remains a challenge in asymptomatic individuals, the presence of antibodies specific for phenolglycolipid-I (PGL-I) correlate with bacterial load.

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The World Health Organization (WHO) endorsed diagnosis of leprosy (also known as Hansen's disease) entirely based on clinical cardinal signs, without microbiological confirmation, which may lead to late or misdiagnosis. The use of slit skin smears is variable, but lacks sensitivity. In 2017-2018 during the ComLep study, on the island of Anjouan (Union of the Comoros; High priority country according to WHO, 310 patients were diagnosed with leprosy (paucibacillary = 159; multibacillary = 151), of whom 263 were sampled for a skin biopsy and fingerstick blood, and 260 for a minimally-invasive nasal swab.

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Leprosy is an infectious disease caused by Mycobacterium leprae leading to irreversible disabilities along with social exclusion. Leprosy is a spectral disease for which the clinical outcome after M. leprae infection is determined by host factors.

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Background: Leprosy elimination primarily targets transmission of Mycobacterium leprae which is not restricted to patients' households. As interruption of transmission is imminent in many countries, a test to detect infected asymptomatic individuals who can perpetuate transmission is required. Antibodies directed against M.

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The presence of and in Eurasian red squirrel (, ERS) carcasses throughout the British Isles, and leprosy as a disease, have recently been reported using histological and molecular diagnostic methods. In 2016, the first longitudinal study of ERS affected by leprosy was initiated. One of the main challenges was the reliable diagnosis of leprosy in live ERS, which is important for (a) welfare and case management and (b) surveillance or pretranslocation screening efforts.

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Background: Leprosy, a chronic infectious disease caused by Mycobacterium leprae, is often late- or misdiagnosed leading to irreversible disabilities. Blood transcriptomic biomarkers that prospectively predict those who progress to leprosy (progressors) would allow early diagnosis, better treatment outcomes and facilitate interventions aimed at stopping bacterial transmission. To identify potential risk signatures of leprosy, we collected whole blood of household contacts (HC, n=5,352) of leprosy patients, including individuals who were diagnosed with leprosy 4-61 months after sample collection.

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Mycobacterium leprae, the causative agent of leprosy, is still actively transmitted in endemic areas reflected by the fairly stable number of new cases detected each year. Recognizing the signs and symptoms of leprosy is challenging, especially at an early stage. Improved diagnostic tools, based on sensitive and specific biomarkers, that facilitate diagnosis of leprosy are therefore urgently needed.

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To end the decade-long, obstinately stagnant number of new leprosy cases, there is an urgent need for field-applicable diagnostic tools that detect infection with , leprosy's etiologic agent. Since immunity against is characterized by humoral and cellular markers, we developed a lateral flow test measuring multiple host proteins based on six previously identified biomarkers for various leprosy phenotypes. This multi-biomarker test (MBT) demonstrated feasibility of quantitative detection of six host serum proteins simultaneously, jointly allowing discrimination of patients with multibacillary and paucibacillary leprosy from control individuals in high and low leprosy endemic areas.

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Point-of-care (POC) diagnostic tests for the rapid detection of individuals infected with Mycobacterium leprae, the causative pathogen of leprosy, represent efficient tools to guide therapeutic and prophylactic treatment strategies in leprosy control programs, thus positively contributing to clinical outcome and reducing transmission of this infectious disease. Levels of antibodies directed against the M. leprae-specific phenolic glycolipid I (PGL-I) closely correlate with an individual's bacterial load and a higher risk of developing leprosy.

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Leprosy is a chronic infectious disease, caused by , that can lead to severe life-long disabilities. The transmission of is continuously ongoing as witnessed by the stable new case detection rate. The majority of exposed individuals does, however, not develop leprosy and is protected from infection by innate immune mechanisms.

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, the causative agent of leprosy, is an unculturable bacterium with a considerably reduced genome (3.27 Mb) compared to homologues mycobacteria from the same ancestry. In 2001, the genome of was first described and subsequently four genotypes (1-4) and 16 subtypes (A-P) were identified providing means to study global transmission patterns for leprosy.

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Early diagnosis of leprosy is challenging, particularly its inflammatory reactions, the major cause of irreversible neuropathy in leprosy. Current diagnostics cannot identify which patients are at risk of developing reactions. This study assessed blood RNA expression levels as potential biomarkers for leprosy.

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Background: Transmission of Mycobacterium leprae, the pathogen causing leprosy, is still persistent. To facilitate timely (prophylactic) treatment and reduce transmission it is vital to both early diagnose leprosy, and identify infected individuals lacking clinical symptoms. However, leprosy-specific biomarkers are limited, particularly for paucibacillary disease.

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Objectives: New user-friendly diagnostic tests for detection of individuals infected by Mycobacterium leprae (M. leprae), the causative pathogen of leprosy, can help guide therapeutic and prophylactic treatment, thus positively contributing to clinical outcome and reduction of transmission. To facilitate point-of-care testing without the presence of phlebotomists, the use of fingerstick blood (FSB) rather than whole blood-derived serum is preferred.

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Leprosy remains persistently endemic in several low- or middle income countries. Transmission is still ongoing as indicated by the unabated rate of leprosy new case detection, illustrating the insufficiency of current prevention methods. Therefore, low-complexity tools suitable for large scale screening efforts to specifically detect M.

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Background: Notwithstanding its beneficial immunoprophylactic outcomes regarding leprosy and childhood TB, BCG vaccination may cause adverse events, particularly of the skin. However, this local hyper-immune reactivity cannot be predicted before vaccination, nor is its association with protection against leprosy known. In this study we investigated the occurrence of adverse events after BCG (re)vaccination in contacts of leprosy patients and analyzed whether the concomitant systemic anti-mycobacterial immunity was associated with these skin manifestations.

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