SUMMARY Chromoblastomycosis (CBM), also known as chromomycosis, is one of the most prevalent implantation fungal infections, being the most common of the gamut of mycoses caused by melanized or brown-pigmented fungi. CBM is mainly a tropical or subtropical disease that may affect individuals with certain risk factors around the world. The following characteristics are associated with this disease: (i) traumatic inoculation by implantation from an environmental source, leading to an initial cutaneous lesion at the inoculation site; (ii) chronic and progressive cutaneous and subcutaneous tissular involvement associated with fibrotic and granulomatous reactions associated with microabscesses and often with tissue proliferation; (iii) a nonprotective T helper type 2 (Th2) immune response with ineffective humoral involvement; and (iv) the presence of muriform (sclerotic) cells embedded in the affected tissue. CBM lesions are clinically polymorphic and are commonly misdiagnosed as various other infectious and noninfectious diseases. In its more severe clinical forms, CBM may cause an incapacity for labor due to fibrotic sequelae and also due to a series of clinical complications, and if not recognized at an early stage, this disease can be refractory to antifungal therapy.
Chromoblastomycosis is one of the most frequent infections caused by melanized fungi. It is a subcutaneous fungal infection, usually an occupational related disease, mainly affecting individuals in tropical and temperate regions. Although several species are etiologic agents, Fonsecaea pedrosoi and Cladophialophora carrionii are prevalent in the endemic areas. Chromoblastomycosis lesions are polymorphic and must be differentiated from those associated with many clinical conditions. Diagnosis is confirmed by the observation of muriform cells in tissue and the isolation and the identification of the causal agent in culture. Chromoblastomycosis still is a therapeutic challenge for clinicians due to the recalcitrant nature of the disease, especially in the severe clinical forms. There are three treatment modalities, i.e., physical treatment, chemotherapy and combination therapy but their success is related to the causative agent, the clinical form and severity of the chromoblastomycosis lesions. There is no treatment of choice for this neglected mycosis, but rather several treatment options. Most of the patients can be treated with itraconazole, terbinafine or a combination of both. It is also important to evaluate the patient's individual tolerance of the drugs and whether the antifungal will be provided for free or purchased, since antifungal therapy must be maintained in long-term regimens. In general, treatment should be guided according to clinical, mycological and histopathological criteria.
Leprosy is a chronic human disease caused by the yet-uncultured pathogenMycobacterium leprae. Although readily curable with multidrug therapy (MDT), over 200,000 new cases are still reported annually. Here, we obtainM. lepraegenome sequences from DNA extracted directly from patients’ skin biopsies using a customized protocol. Comparative and phylogenetic analysis of 154 genomes from 25 countries provides insight into evolution and antimicrobial resistance, uncovering lineages and phylogeographic trends, with the most ancestral strains linked to the Far East. In addition to known MDT-resistance mutations, we detect other mutations associated with antibiotic resistance, and retrace a potential stepwise emergence of extensive drug resistance in the pre-MDT era. Some of the previously undescribed mutations occur in genes that are apparently subject to positive selection, and two of these (ribD,fadD9) are restricted to drug-resistant strains. Finally, nonsense mutations in thenthexcision repair gene are associated with greater sequence diversity and drug resistance.
Mycobacterium leprae (M. leprae) is a human pathogen and the causative agent for leprosy, a chronic disease characterized by lesions of the skin and peripheral nerve damage. Zoonotic transmission of M. leprae to humans by nine-banded armadillos (Dasypus novemcinctus) has been shown to occur in the southern United States, mainly in Texas, Louisiana, and Florida. Nine-banded armadillos are also common in South America, and residents living in some areas in Brazil hunt and kill armadillos as a dietary source of protein. This study examines the extent of M. leprae infection in wild armadillos and whether these New World mammals may be a natural reservoir for leprosy transmission in Brazil, similar to the situation in the southern states of the U.S. The presence of the M. leprae-specific repetitive sequence RLEP was detected by PCR amplification in purified DNA extracted from armadillo spleen and liver tissue samples. A positive RLEP signal was confirmed in 62% of the armadillos (10/16), indicating high rates of infection with M. leprae. Immunohistochemistry of sections of infected armadillo spleens revealed mycobacterial DNA and cell wall constituents in situ detected by SYBR Gold and auramine/rhodamine staining techniques, respectively. The M. leprae-specific antigen, phenolic glycolipid I (PGL-I) was detected in spleen sections using a rabbit polyclonal antibody specific for PGL-I. Anti-PGL-I titers were assessed by ELISA in sera from 146 inhabitants of Belterra, a hyperendemic city located in western Pará state in Brazil. A positive anti-PGL-I titer is a known biomarker for M. leprae infection in both humans and armadillos. Individuals who consumed armadillo meat most frequently (more than once per month) showed a significantly higher anti-PGL-I titer than those who did not eat or ate less frequently than once per month. Armadillos infected with M. leprae represent a potential environmental reservoir. Consequently, people who hunt, kill, or process or eat armadillo meat are at a higher risk for infection with M. leprae from these animals. Armadillos have been shown to be a natural reservoir of Mycobacterium leprae infection in the southern states of the U.S. and have been implicated in the zoonotic transmission of leprosy to humans. To investigate this in Brazil, we conducted surveys of armadillos in western Pará state in the Brazilian Amazon region where leprosy is hyperendemic in humans. Individuals living in the small town of Belterra were surveyed for the extent and frequency of interaction with armadillos (hunting, preparing the meat for cooking, or eating the meat for food). We also took samples of liver and spleen from armadillos to look for M. leprae infection in the tissues. We found that a majority of residents had some contact with armadillos (~65%) and that infection by M. leprae in armadillos in this area was also very high (62%). Those individuals who ate armadillo meat more than once a month had a significantly higher antibody titer to the M. leprae-specific antigen, PGL-I. Understanding the dynamics of leprosy transmission in different geographic regions and knowing the behavioral risks of humans interacting with potentially infected animals will help clarify the relative risk of zoonotic transmission of leprosy in this region.
6 February 2014 in PLOS Neglected Tropical Diseases
More than 200,000 new cases of leprosy were reported by 105 countries in 2011. The disease is a public health problem in Brazil, particularly within high-burden pockets in the Amazon region where leprosy is hyperendemic among children. We applied geographic information systems and spatial analysis to determine the spatio-temporal pattern of leprosy cases in a hyperendemic municipality of the Brazilian Amazon region (Castanhal). Moreover, we performed active surveillance to collect clinical, epidemiological and serological data of the household contacts of people affected by leprosy and school children in the general population. The occurrence of subclinical infection and overt disease among the evaluated individuals was correlated with the spatio-temporal pattern of leprosy. The pattern of leprosy cases showed significant spatio-temporal heterogeneity (p<0.01). Considering 499 mapped cases, we found spatial clusters of high and low detection rates and spatial autocorrelation of individual cases at fine spatio-temporal scales. The relative risk of contracting leprosy in one specific cluster with a high detection rate is almost four times the risk in the areas of low detection rate (RR = 3.86; 95% CI = 2.26–6.59; p<0.0001). Eight new cases were detected among 302 evaluated household contacts: two living in areas of clusters of high detection rate and six in hyperendemic census tracts. Of 188 examined students, 134 (71.3%) lived in hyperendemic areas, 120 (63.8%) were dwelling less than 100 meters of at least one reported leprosy case, 125 (66.5%) showed immunological evidence (positive anti-PGL-I IgM titer) of subclinical infection, and 9 (4.8%) were diagnosed with leprosy (8 within 200 meters of a case living in the same area). Spatial analysis provided a better understanding of the high rate of early childhood leprosy transmission in this region. These findings can be applied to guide leprosy control programs to target intervention to high risk areas. Leprosy can lead to physical disabilities and deformities if not diagnosed and treated early. Even today, the disease affects more than 200,000 people per year, particularly the poorest people from developing countries, such as India, Brazil and Indonesia. Cases among children <15 years old have been used as an important indicator of recent transmission in the community. Recently, geographic information systems and spatial analysis have become important tools for epidemiology, helping to understand the transmission dynamics of several diseases. In this work, we determined the spatial and temporal distribution of leprosy in a hyperendemic municipality of the Brazilian Amazon region. In association with clinical, epidemiological and serological data of household contacts and school children in the general population, we further correlated the occurrence of subclinical infection and overt disease with the distribution of reported cases. We identified heterogeneity in the distribution of leprosy, with significant clusters of high and low detection rates. Our analysis revealed that children with leprosy or those harboring subclinical infection were in close proximity to spatial and temporal clusters of leprosy cases. These findings can be applied to guide leprosy control programs to target intervention more systematically to areas where the risk of leprosy is high.
1 February 2004 in Revista do Instituto de Medicina Tropical de São Paulo
We report the isolation of Fonsecaea pedrosoi from thorns of the plant Mimosa pudica L. at the place of infection identified by one of our patients. Clinical diagnosis of chromoblastomycosis was established by direct microscopic examination and cultures from the patient's lesion. The same species was isolated from the patient and from the plant. Scanning electron microscopy of the surface of the thorns showed the characteristic conidial arrangement of F. pedrosoi. These data indicate that M. pudica could be a natural source of infection for the fungus F. pedrosoi.