The Leishmania species cause a variety of human disease syndromes. Methods for diagnosis and species differentiation are insensitive and many require invasive sampling. Although quantitative PCR (qPCR) methods are reported for leishmania detection, no systematic method to quantify parasites and determine the species in clinical specimens is established. We developed a serial qPCR strategy to identify and rapidly differentiate Leishmania species and quantify parasites in clinical or environmental specimens. SYBR green qPCR is mainly employed, with corresponding TaqMan assays for validation. The screening primers recognize kinetoplast minicircle DNA of all Leishmania species. Species identification employs further qPCR set(s) individualized for geographic regions, combining species-discriminating probes with melt curve analysis. The assay was sufficient to detect Leishmania parasites, make species determinations, and quantify Leishmania spp. in sera, cutaneous biopsy specimens, or cultured isolates from subjects from Bangladesh or Brazil with different forms of leishmaniasis. The multicopy kinetoplast DNA (kDNA) probes were the most sensitive and useful for quantification based on promastigote standard curves. To test their validity for quantification, kDNA copy numbers were compared between Leishmania species, isolates, and life stages using qPCR. Maxicircle and minicircle copy numbers differed up to 6-fold between Leishmania species, but the differences were smaller between strains of the same species. Amastigote and promastigote leishmania life stages retained similar numbers of kDNA maxi-or minicircles. Thus, serial qPCR is useful for leishmania detection and species determination and for absolute quantification when compared to a standard curve from the same Leishmania species.

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In leprosy, classic diagnostic tools based on bacillary counts and histopathology have been facing hurdles, especially in distinguishing latent infection from active disease and diagnosing paucibacillary clinical forms. Serological tests and IFN-gamma releasing assays (IGRA) that employ humoral and cellular immune parameters, respectively, are also being used, but recent results indicate that quantitative PCR (qPCR) is a key technique due to its higher sensitivity and specificity. In fact, advances concerning the structure and function of the Mycobacterium leprae genome led to the development of specific PCR-based gene amplification assays for leprosy diagnosis and monitoring of household contacts. Also, based on the validation of point-of-care technologies for M. tuberculosis DNA detection, it is clear that the same advantages of rapid DNA detection could be observed in respect to leprosy. So far, PCR has proven useful in the determination of transmission routes, M. leprae viability, and drug resistance in leprosy. However, PCR has been ascertained to be especially valuable in diagnosing difficult cases like pure neural leprosy (PNL), paucibacillary (PB), and patients with atypical clinical presentation and histopathological features compatible with leprosy. Also, the detection of M. leprae DNA in different samples of the household contacts of leprosy patients is very promising. Although a positive PCR result is not sufficient to establish a causal relationship with disease outcome, quantitation provided by qPCR is clearly capable of indicating increased risk of developing the disease and could alert clinicians to follow these contacts more closely or even define rules for chemoprophylaxis.

Summary Lobomycosis, a disease caused by the uncultivable dimorphic onygenale fungi Lacazia loboi, remains to date as an enigmatic illness, both due to the impossibility of its aetiological agent to be cultured and grown in vitro, as well as because of its unresponsiveness to specific antifungal treatments. It was first described in the 1930s by Brazilian dermatologist Jorge Lobo and is known to cause cutaneous and subcutaneous localised and widespread infections in humans and dolphins. Soil and vegetation are believed to be the chief habitat of the fungus, however, increasing reports in marine mammals has shifted the attention to the aquatic environment. Infection in humans has also been associated with proximity to water, raising the hypothesis that L. loboi may be a hydrophilic microorganism that penetrates the skin by trauma. Although its occurrence was once thought to be restricted to New World tropical countries, its recent description in African patients has wrecked this belief. Antifungals noted to be effective in the empirical management of other cutaneous/subcutaneous mycoses have proven unsuccessful and unfortunately, no satisfactory therapeutic approach for this cutaneous infection currently exists.

Paracoccidioidomycosis is the most prevalent systemic mycosis in Latin America. It is becoming globally relevant, as increasing numbers of cases have been detected in returning travellers and immigrants from endemic regions. It is characterized by pulmonary involvement, lymphadenopathy, and chronic progression of mucocutaneous lesions. Untreated, systemic disease can be severe and fatal. Skin features are common and characteristic, enabling the dermatologist to diagnose infection early and prevent the development of serious sequelae. This review outlines the clinical features and management of paracoccidioidomycosis and discusses notable recent developments in molecular diagnosis, prognostics and therapies.

Lobomycosis is a rare chronic fungal infection of the subcutaneous tissue found in South America, mainly in Brazil. It is caused by Lacazia loboi. Its clinical manifestations are dermal nodules, either lenticular or in plaques, and keloidlike lesions that can resemble nodular leprosy or leishmaniasis, other subcutaneous mycoses (sporotrychosis, chromomycosis, paracoccidioidomycosis), keloids, and malignant tumors. Diagnosis is made by the histopathological findings of the fungus. For treatment, surgical removal of the lesions, followed by itraconazole and clofazimine for disseminated lesions, has been used with variable results.

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In this review, the most relevant and current epidemiological data, the main clinical, laboratory and therapeutical aspects of leprosy are presented. Detailed discussion of the main drugs used for leprosy treatment, their most relevant adverse effects, evolution of the therapeutic regimen, from dapsone as a monotherapy to the proposed polychemotherapy by World Health Organization (WHO) can be found in this CME. We specifically highlight the drug acceptability, reduction in treatment duration and the most recent proposal of a single therapeutic regimen, with a fixed six months duration, for all clinical presentations, regardless of their classification.