Review Article Could Histoplasma Capsulatum Be Related to Healthcare-Associated Infections?
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Hindawi Publishing Corporation BioMed Research International Volume 2015, Article ID 982429, 11 pages http://dx.doi.org/10.1155/2015/982429 Review Article Could Histoplasma capsulatum Be Related to Healthcare-Associated Infections? Laura Elena Carreto-Binaghi,1 Lisandra Serra Damasceno,2 Nayla de Souza Pitangui,3 Ana Marisa Fusco-Almeida,3 Maria José Soares Mendes-Giannini,3 Rosely Maria Zancopé-Oliveira,2 and Maria Lucia Taylor1 1 Departamento de Microbiolog´ıa-Parasitolog´ıa,FacultaddeMedicina,UniversidadNacionalAutonoma´ de Mexico´ (UNAM), CircuitoInterior,CiudadUniversitaria,AvenidaUniversidad3000,04510Mexico,´ DF, Mexico 2Instituto Nacional de Infectologia Evandro Chagas, Fundac¸ao˜ Oswaldo Cruz (FIOCRUZ), Avenida Brasil 4365, Manguinhos, 21040-360 Rio de Janeiro, RJ, Brazil 3Departamento de Analises´ Cl´ınicas, Faculdade de Cienciasˆ Farmaceuticas,ˆ Universidade Estadual Paulista (UNESP), Rodovia Araraquara-JauKm1,14801-902Araraquara,SP,Brazil´ Correspondence should be addressed to Maria Lucia Taylor; [email protected] Received 30 October 2014; Revised 12 May 2015; Accepted 12 May 2015 Academic Editor: Kurt G. Naber Copyright © 2015 Laura Elena Carreto-Binaghi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Healthcare-associated infections (HAI) are described in diverse settings. The main etiologic agents of HAI are bacteria (85%) and fungi (13%). Some factors increase the risk for HAI, particularly the use of medical devices; patients with severe cuts, wounds, and burns; stays in the intensive care unit, surgery, and hospital reconstruction works. Several fungal HAI are caused by Candida spp., usually from an endogenous source; however, cross-transmission via the hands of healthcare workers or contaminated devices can occur. Although other medically important fungi, such as Blastomyces dermatitidis, Paracoccidioides brasiliensis,andHistoplasma capsulatum, have never been considered nosocomial pathogens, there are some factors that point out the pros and cons for this possibility. Among these fungi, H. capsulatum infection has been linked to different medical devices and surgery implants. The filamentous form of H. capsulatum may be present in hospital settings, as this fungus adapts to different types of climates and has great dispersion ability. Although conventional pathogen identification techniques have never identified H. capsulatum in the hospital environment, molecular biology procedures could be useful in this setting. More research on H. capsulatum as a HAI etiologic agent is needed, since it causes a severe and often fatal disease in immunocompromised patients. 1. Introduction surgical procedures related to specific therapies, in addition to the large number of immunocompromised patients who The term healthcare-associated infection (HAI) refers to are hospitalized [3]. It is estimated that every day one out of infections associated with healthcare delivery in any setting 25 hospital patients has, at least, one HAI. In 2011, there were (e.g., hospitals, long-term care facilities, ambulatory settings, 722,000 HAI in the United States’ hospitals and about 75,000 and home care). This term reflects the inability to determine hospital patients with HAI died during their hospitalization. with certainty where the pathogen is acquired since patients More than half of all HAI occurred outside the intensive care may be colonized or exposed to potential pathogens outside unit [4]. the healthcare setting, before receiving healthcare or during HAI commonly occur by direct transmission from indi- healthcare delivery [1, 2]. vidual to individual or through fomites manipulated by In recent years, there has been an overall increase in HAI, healthcare workers, as well as through surfaces and devices which is likely a consequence of the advances in medical and contaminated by biofilms (surgical instruments, catheters, 2 BioMed Research International mechanical ventilation systems, and others) [5, 6]. Other duration of hospital stay, prolonged use of intravascular mechanisms of transmission are aerial dispersion of oppor- catheters, parenteral lipid formulations, and prior exposure tunistic or environmental microorganisms and endogenous to broad spectrum antibiotics (including antifungal therapy) dissemination of commensal or opportunistic pathogens [7– are important predisposing conditions identified in these 9]. outbreaks [13, 14, 16–18]. Although the role of the inanimate hospital environment The occurrence of invasive fungal infections (IFIs) inthespreadofHAIhasbeencontroversial,nowadays depends on several factors like the time of exposure to an molecular biology methodologies are being used to identify infectious agent, the patient’s immune status, the pathogen’s pathogens, measure the quality of environmental and hand virulence factors, and the host-pathogen interaction [19]. IFI hygiene over time, and establish a link between outbreaks associated with healthcare is mainly caused by opportunistic and cross-transmission events, according to geographic and fungi, from endogenous or environmental sources, which temporal variables [8]. form biofilms in fomites and abiotic surfaces [9]. Currently, changes in morbidity and mortality patterns Species of filamentous fungi, such as Aspergillus spp. [20, due to aging of the world population, treatments with 21], Rhizopus spp. [22], Rhizomucor spp. [22, 23], Absidia immunosuppressive drugs, and the use of invasive devices corymbifera [22, 24], Fusarium spp. [25–27], Paecilomyces (particularly long-term ones) have led to a rise in the need spp. [28, 29], Curvularia spp. [30], Phialemonium spp. [31– of healthcare facilities for patients who are more susceptible 34], and Scedosporium spp. [35–37], have been particularly to opportunistic infections [10]. Environmental disturbances associated with HAI in patients with hematologic diseases. associated with construction activities near health insti- The most common sources reported in the above-mentioned tutions pose additional airborne and waterborne disease filamentous fungal infections were contamination of medical threats for those patients who are at risk for healthcare- supplies, like intravenous solutions, contact lens solutions associated fungal infections [2]. Particularly, hospitalized [38, 39], bandages [24], pressure cuffs, and invasive devices patients could be exposed to infective fungal propagules such (endotracheal tubes) [11, 21–23, 40]. Besides, other species as microconidia and small hyphal fragments of Histoplasma of fungi such as Aureobasidium spp. [41], Trichosporon spp. capsulatum that thrive in bat and bird droppings, deposited [42, 43], Rhodotorula spp. [44–46], and Phaeoacremonium in the surrounding hospital recreational areas. parasiticum [47]havebeenimplicatedinnosocomialpseu- Thus,theaimsofthispaperweretoreviewthereported dooutbreaks through contamination of endoscopes. cases of H. capsulatum infections in healthcare settings, in A very important opportunistic fungus, Pneumocystis order to propose the different factors that could be related to jirovecii, has also been associated with HAI by person- healthcare-associated histoplasmosis and discuss the features to-person airborne transmission [48–58]. Infection by P. thatcouldfavorthepresenceofthisfungusinthehospital jirovecii presents as an interstitial pneumonia in immuno- environment. compromised hosts, particularly HIV patients; in this group, pneumocystosis is considered an AIDS-definitory condition, 2. Etiologic Agents of HAI when CD4+ T lymphocytes are below 200 cells/L[59]. Cur- rently, an increase of pneumocystosis in non-HIV patients The etiologic agents of HAI are mainly bacteria (85%) and is being observed, especially in patients with transplants, fungi (13%), in contrast to viruses and parasites that are rarely individuals with autoimmune disorders or malignancies, and reported. Some environmental factors have been identified those using immunosuppressive treatments, like steroids and to increase the risk for fungal HAI, particularly the use of immunobiological drugs [50, 55, 60–62]. Molecular biology medical devices, like central venous and urinary catheters; techniques have detected a high prevalence of colonization thepresenceofseverecuts,wounds,andburns;staysin (10–55%) in immunocompromised patients and in the gen- the intensive care unit, surgery, and hospital reconstruction eralpopulation.IndividualscolonizedbyP. jirov e c ii can works [4]. be considered reservoirs and therefore contribute to the Host factors, such as extremes of age and underlying transmission of this pathogen among immunosuppressed diseases, human immunodeficiency virus/acquired immune patients in the hospital environment [62]. deficiency syndrome (HIV/AIDS), malignancy, and trans- Other important respiratory pathogens, such as Blas- plants, can increase susceptibility to infection, as well as a tomyces dermatitidis, Paracoccidioides brasiliensis,andH. variety of medications that alter the normal flora, like antimi- capsulatum, have never been associated with infections in crobial agents, gastric acid suppressants, steroids, antirejec- the hospital environment; however, B. dermatitidis has been tion drugs, antineoplastic agents, and immunosuppressive found in pseudooutbreaks associated with contaminated drugs [2]. bronchoscopes [63]. MostHAIassociatedwithfungiarecausedbyCandida spp. These infections