Laboratory-acquired infections and pathogen escapes worldwide between 2000 and 2021: a scoping review.

Laboratory-acquired infections (LAIs) and accidental pathogen escape from laboratory settings (APELS) are major concerns for the community. A risk-based approach for pathogen research management within a standard biosafety management framework is recommended but is challenging due to reasons such as inconsistency in risk tolerance and perception. Here, we performed a scoping review using publicly available, peer-reviewed journal and media reports of LAIs and instances of APELS between 2000 and 2021. We identified LAIs in 309 individuals in 94 reports for 51 pathogens. Eight fatalities (2·6% of all LAIs) were caused by infection with Neisseria meningitidis (n=3, 37·5%), Yersinia pestis (n=2, 25%), Salmonella enterica serotype Typhimurium (S Typhimurium; n=1, 12·5%), or Ebola virus (n=1, 12·5%) or were due to bovine spongiform encephalopathy (n=1, 12·5%). The top five LAI pathogens were S Typhimurium (n=154, 49·8%), Salmonella enteritidis (n=21, 6·8%), vaccinia virus (n=13, 4·2%), Brucella spp (n=12, 3·9%), and Brucella melitensis (n=11, 3·6%). 16 APELS were reported, including those for Bacillus anthracis, SARS-CoV, and poliovirus (n=3 each, 18·8%); Brucella spp and foot and mouth disease virus (n=2 each, 12·5%); and variola virus, Burkholderia pseudomallei, and influenza virus H5N1 (n=1 each, 6·3%). Continual improvement in LAI and APELS management via their root cause analysis and thorough investigation of such incidents is essential to prevent future occurrences. The results are biased due to the reliance on publicly available information, which emphasises the need for formalised global LAIs and APELS reporting to better understand the frequency of and circumstances surrounding these incidents.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Foot and Mouth Disease Virus.

Introduction: Foot and mouth disease (FMD) is a highly contagious infection of cloven-hoofed animals. The Biosafety Research Road Map reviewed scientific literature regarding the foot and mouth disease virus (FMDV). This project aims to identify gaps in the data required to conduct evidence-based biorisk assessments, as described by Blacksell et al., and strengthen control measures appropriate for local and national laboratories. Methods: A literature search was conducted to identify potential gaps in biosafety and focused on five main sections: the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Results: The available data regarding biosafety knowledge gaps and existing evidence have been collated. Some gaps include the need for more scientific data that identify the specific safety contribution of engineering controls, support requirements for showering out after in vitro laboratory work, and whether a 3- to 5-day quarantine period should be applied to individuals conducting in vitro versus in vivo work. Addressing these gaps will contribute to the remediation and improvement of biosafety and biosecurity systems when working with FMDV.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Crimean Congo Haemorrhagic Fever Virus and Lassa Virus.

Introduction: Crimean Congo Hemorrhagic Fever (CCHF) virus and Lassa virus (LASV) are zoonotic agents regarded as high-consequence pathogens due to their high case fatality rates. CCHF virus is a vector-borne disease and is transmitted by tick bites. Lassa virus is spread via aerosolization of dried rat urine, ingesting infected rats, and direct contact with or consuming food and water contaminated with rat excreta. Methods: The scientific literature for biosafety practices has been reviewed for both these two agents to assess the evidence base and biosafety-related knowledge gaps. The review focused on five main areas, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Results: There is a lack of data on the safe collection and handling procedures for tick specimens and the infectious dose from an infective tick bite for CCHF investigations. In addition, there are gaps in knowledge about gastrointestinal and contact infectious doses for Lassa virus, sample handling and transport procedures outside of infectious disease areas, and the contribution of asymptomatic carriers in viral circulation. Conclusion: Due to the additional laboratory hazards posed by these two agents, the authors recommend developing protocols that work effectively and safely in highly specialized laboratories in non-endemic regions and a laboratory with limited resources in endemic areas.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Zoonotic Avian Influenza and Mycobacterium tuberculosis.

Introduction: The Biosafety Research Road Map reviewed the scientific literature on a viral respiratory pathogen, avian influenza virus, and a bacterial respiratory pathogen, Mycobacterium tuberculosis. This project aims at identifying gaps in the data required to conduct evidence-based biorisk assessments, as described in Blacksell et al. One significant gap is the need for definitive data on M. tuberculosis sample aerosolization to guide the selection of engineering controls for diagnostic procedures. Methods: The literature search focused on five areas: routes of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination methods. Results: The available data regarding biosafety knowledge gaps and existing evidence have been collated and presented in Tables 1 and 2. The guidance sources on the appropriate use of biosafety cabinets for specific procedures with M. tuberculosis require clarification. Detecting vulnerabilities in the biorisk assessment for respiratory pathogens is essential to improve and develop laboratory biosafety in local and national systems.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Mpox/Monkeypox Virus.

Introduction: The virus formerly known as monkeypox virus, now called mpoxv, belongs to the Orthopoxvirus genus and can cause mpox disease through both animal-to-human and human-to-human transmission. The unexpected spread of mpoxv among humans has prompted the World Health Organization (WHO) to declare a Public Health Emergency of International Concern (PHEIC). Methods: We conducted a literature search to identify the gaps in biosafety, focusing on five main areas: how the infection enters the body and spreads, how much of the virus is needed to cause infection, infections acquired in the lab, accidental release of the virus, and strategies for disinfecting and decontaminating the area. Discussion: The recent PHEIC has shown that there are gaps in our knowledge of biosafety when it comes to mpoxv. We need to better understand where this virus might be found, how much of it can spread from person-to-person, what are the effective control measures, and how to safely clean up contaminated areas. By gathering more biosafety evidence, we can make better decisions to protect people from this zoonotic agent, which has recently become more common in the human population.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in Human and Veterinary Laboratories.

Introduction: Lack of evidence-based information regarding potential biological risks can result in inappropriate or excessive biosafety and biosecurity risk-reduction strategies. This can cause unnecessary damage and loss to the physical facilities, physical and psychological well-being of laboratory staff, and community trust. A technical working group from the World Organization for Animal Health (WOAH, formerly OIE), World Health Organization (WHO), and Chatham House collaborated on the Biosafety Research Roadmap (BRM) project. The goal of the BRM is the sustainable implementation of evidence-based biorisk management of laboratory activities, particularly in low-resource settings, and the identification of gaps in the current biosafety and biosecurity knowledge base. Methods: A literature search was conducted for the basis of laboratory design and practices for four selected high-priority subgroups of pathogenic agents. Potential gaps in biosafety were focused on five main sections, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Categories representing miscellaneous, respiratory, bioterrorism/zoonotic, and viral hemorrhagic fever pathogens were created within each group were selected for review. Results: Information sheets on the pathogens were developed. Critical gaps in the evidence base for safe sustainable biorisk management were identified. Conclusion: The gap analysis identified areas of applied biosafety research required to support the safety, and the sustainability, of global research programs. Improving the data available for biorisk management decisions for research with high-priority pathogens will contribute significantly to the improvement and development of appropriate and necessary biosafety, biocontainment and biosecurity strategies for each agent.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-SARS-CoV-2.

Introduction: The SARS-CoV-2 virus emerged as a novel virus and is the causative agent of the COVID-19 pandemic. It spreads readily human-to-human through droplets and aerosols. The Biosafety Research Roadmap aims to support the application of laboratory biological risk management by providing an evidence base for biosafety measures. This involves assessing the current biorisk management evidence base, identifying research and capability gaps, and providing recommendations on how an evidence-based approach can support biosafety and biosecurity, including in low-resource settings. Methods: A literature search was conducted to identify potential gaps in biosafety and focused on five main sections, including the route of inoculation/modes of transmission, infectious dose, laboratory-acquired infections, containment releases, and disinfection and decontamination strategies. Results: There are many knowledge gaps related to biosafety and biosecurity due to the SARS-CoV-2 virus's novelty, including infectious dose between variants, personal protective equipment for personnel handling samples while performing rapid diagnostic tests, and laboratory-acquired infections. Detecting vulnerabilities in the biorisk assessment for each agent is essential to contribute to the improvement and development of laboratory biosafety in local and national systems.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Bacillus anthracis and Brucella melitensis.

Introduction: Brucella melitensis and Bacillus anthracis are zoonoses transmitted from animals and animal products. Scientific information is provided in this article to support biosafety precautions necessary to protect laboratory workers and individuals who are potentially exposed to these pathogens in the workplace or other settings, and gaps in information are also reported. There is a lack of information on the appropriate effective concentration for many chemical disinfectants for this agent. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of personal protective equipment (PPE) during the slaughter of infected animals, and handling of contaminated materials. B. melitensis is reported to have the highest number of laboratory-acquired infections (LAIs) to date in laboratory workers. Methods: A literature search was conducted to identify potential gaps in biosafety and focused on five main sections including the route of inoculation/modes of transmission, infectious dose, LAIs, containment releases, and disinfection and decontamination strategies. Results: Scientific literature currently lacks information on the effective concentration of many chemical disinfectants for this agent and in the variety of matrices where it may be found. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of PPE during the slaughter of infected animals, and handling contaminated materials. Discussion: Clarified vulnerabilities based on specific scientific evidence will contribute to the prevention of unwanted and unpredictable infections, improving the biosafety processes and procedures for laboratory staff and other professionals such as veterinarians, individuals associated with the agricultural industry, and those working with susceptible wildlife species.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Shigella spp.

Introduction: Shigella bacteria cause shigellosis, a gastrointestinal infection most often acquired from contaminated food or water. Methods: In this review, the general characteristics of Shigella bacteria are described, cases of laboratory-acquired infections (LAIs) are discussed, and evidence gaps in current biosafety practices are identified. Results: LAIs are undoubtedly under-reported. Owing to the low infectious dose, rigorous biosafety level 2 practices are required to prevent LAIs resulting from sample manipulation or contact with infected surfaces. Conclusions: It is recommended that, before laboratory work with Shigella, an evidence-based risk assessment be conducted. Particular emphasis should be placed on personal protective equipment, handwashing, and containment practices for procedures that generate aerosols or droplets.

High Mortality and Coinfection in a Prospective Cohort of Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome Patients with Histoplasmosis in Guatemala.

Histoplasmosis is one of the most common and deadly opportunistic infections among persons living with human immunodeficiency virus (HIV)/acquired immune deficiency syndrome in Latin America, but due to limited diagnostic capacity in this region, few data on the burden and clinical characteristics of this disease exist. Between 2005 and 2009, we enrolled patients ≥ 18 years of age with suspected histoplasmosis at a hospital-based HIV clinic in Guatemala City. A case of suspected histoplasmosis was defined as a person presenting with at least three of five clinical or radiologic criteria. A confirmed case of histoplasmosis was defined as a person with a positive culture or urine antigen test for Histoplasma capsulatum. Demographic and clinical data were also collected and analyzed. Of 263 enrolled as suspected cases of histoplasmosis, 101 (38.4%) were confirmed cases. Median time to diagnosis was 15 days after presentation (interquartile range [IQR] = 5-23). Crude overall mortality was 43.6%; median survival time was 19 days (IQR = 4-69). Mycobacterial infection was diagnosed in 70 (26.6%) cases; 26 (25.7%) histoplasmosis cases were coinfected with mycobacteria. High mortality and short survival time after initial symptoms were observed in patients with histoplasmosis. Mycobacterial coinfection diagnoses were frequent, highlighting the importance of pursuing diagnoses for both diseases.

Antimicrobial Resistance Among Nontyphoidal Salmonella Isolated From Blood in the United States, 2003-2013.

BACKGROUND: Salmonella causes an estimated 100 000 antimicrobial-resistant infections annually in the United States. Salmonella antimicrobial resistance may result in bacteremia and poor outcomes. We describe antimicrobial resistance among nontyphoidal Salmonella blood isolates, using data from the National Antimicrobial Resistance Monitoring System. METHODS: Human nontyphoidal Salmonella isolates from 2003 to 2013 were classified as fully susceptible, resistant to ≥1 antimicrobial agent, or resistant to a first-line agent. Logistic regression was used to compare resistance patterns, serotypes, and patient characteristics for Salmonella isolated from blood versus stool and to determine resistance trends over time. RESULTS: Approximately 20% of blood isolates had antimicrobial resistance to a first-line treatment agent. Bacteremia was associated with male sex, age ≥65 years, and specific serotypes. Blood isolates were more likely to be resistant to ≥1 agent for serotypes Enteritidis, Javiana, Panama, and Typhimurium. Blood isolates were most commonly resistant to tetracycline (19%), and more likely resistant to a first-line agent (odds ratio, 1.81; 95% confidence interval, 1.56-2.11) than stool isolates. Ceftriaxone resistance increased in blood isolates from 2003 to 2013 (odd ratio, 1.12; 95% confidence interval, 1.02-1.22). CONCLUSIONS: Resistance to first-line treatment agents in patients with Salmonella bacteremia is a concern for public health and for informing clinical decisions. Judicious antimicrobial use is crucial to limit resistance.

Clinical and Laboratory Profile of Persons Living with Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome and Histoplasmosis from a Colombian Hospital.

Histoplasmosis is common among persons living with human immunodeficiency virus/acquired immune deficiency syndrome (PLWHA) in Latin America, but its diagnosis is difficult and often nonspecific. We conducted prospective screening for histoplasmosis among PLWHA with signs or symptoms suggesting progressive disseminated histoplasmosis (PDH) and hospitalized in Hospital La María in Medellín, Colombia. The study's aim was to obtain a clinical and laboratory profile of PLWHA with PDH. During 3 years (May 2008 to August 2011), we identified 89 PLWHA hospitalized with symptoms suggestive of PDH, of whom 45 (51%) had histoplasmosis. We observed tuberculosis (TB) coinfection in a large proportion of patients with PDH (35%), so all analyses were performed adjusting for this coinfection and, alternatively, excluding histoplasmosis patients with TB. Results showed that the patients with PDH were more likely to have Karnofsky score ≤ 30 (prevalence ratio [PR] = 1.98, 95% confidence interval [CI] = 0.97-4.06), liver compromised with hepatomegaly and/or splenomegaly (PR = 1.77, CI = 1.03-3.06) and elevation in serum of alanine aminotransferase and aspartate aminotransferase to values > 40 mU/mL (PR = 2.06, CI = 1.09-3.88 and PR = 1.53, CI = 0.99-2.35, respectively). Using multiple correspondence analyses, we identified in patients with PDH a profile characterized by the presence of constitutional symptoms, namely weight loss and Karnofsky classification ≤ 30, gastrointestinal manifestations with alteration of liver enzymes and hepatosplenomegaly and/or splenomegaly, skin lesions, and hematological alterations. Study of the profiles is no substitute for laboratory diagnostics, but identifying clinical and laboratory indicators of PLWHA with PDH should allow development of strategies for reducing the time to diagnosis and thus mortality caused by Histoplasma capsulatum.

Validation of an enzyme-linked immunosorbent assay that detects Histoplasma capsulatum antigenuria in Colombian patients with AIDS for diagnosis and follow-up during therapy.

We validated an antigen capture enzyme-linked immunosorbent assay (ELISA) in Colombian persons with AIDS and proven histoplasmosis and evaluated the correlation between antigenuria and clinical improvement during follow-up. The sensitivity of the Histoplasma capsulatum ELISA was 86%, and the overall specificity was 94%. The antigen test successfully monitored the response to therapy.

Development of a loop-mediated isothermal amplification method for detection of Histoplasma capsulatum DNA in clinical samples.

Improved methods for the detection of Histoplasma capsulatum are needed in regions with limited resources in which the organism is endemic, where delayed diagnosis of progressive disseminated histoplasmosis (PDH) results in high mortality rates. We have investigated the use of a loop-mediated isothermal amplification (LAMP) assay to facilitate rapid inexpensive molecular diagnosis of this disease. Primers for LAMP were designed to amplify the Hcp100 locus of H. capsulatum. The sensitivity and limit of detection were evaluated using DNA extracted from 91 clinical isolates of known geographic subspecies, while the assay specificity was determined using DNA extracted from 50 other fungi and Mycobacterium tuberculosis. Urine specimens (n = 6) collected from HIV-positive individuals with culture- and antigen-proven histoplasmosis were evaluated using the LAMP assay. Specimens from healthy persons (n = 10) without evidence of histoplasmosis were used as assay controls. The Hcp100 LAMP assay was 100% sensitive and specific when tested with DNA extracted from culture isolates. The median limit of detection was ≤6 genomes (range, 1 to 300 genomes) for all except one geographic subspecies. The LAMP assay detected Hcp100 in 67% of antigen-positive urine specimens (4/6 specimens), and results were negative for Hcp100 in all healthy control urine specimens. We have shown that the Hcp100 LAMP assay is a rapid affordable assay that can be used to expedite culture confirmation of H. capsulatum in regions in which PDH is endemic. Further, our results indicate proof of the concept that the assay can be used to detect Histoplasma DNA in urine. Further evaluation of this assay using body fluid samples from a larger patient population is warranted.

Diagnostic Methods for Histoplasmosis: Focus on Endemic Countries with Variable Infrastructure Levels.

Diagnosis of histoplasmosis remains challenging in resource-limited regions where HIV/AIDS is epidemic and histoplasmosis is endemic. Early and rapid detection of histoplasmosis is essential to preventing morbidity and mortality, yet few diagnostic options are available in low-resource areas of the world. The aim of this review is to provide an overview of the current status of the diagnosis of histoplasmosis, including an update on recent developments and utilization of new technologies. We discuss the specific diagnostic challenges faced in endemic regions, emphasizing the need for greater availability and standardization of rapid diagnostics for this endemic and neglected disease. While significant progress has been made in the development of new methods, clinical utility must be established by means of formal and extensive clinical studies.

Analysis of inteins in the Candida parapsilosis complex for simple and accurate species identification.

Inteins are coding sequences that are transcribed and translated with flanking sequences and then are excised by an autocatalytic process. There are two types of inteins in fungi, mini-inteins and full-length inteins, both of which present a splicing domain containing well-conserved amino acid sequences. Full-length inteins also present a homing endonuclease domain that makes the intein a mobile genetic element. These parasitic genetic elements are located in highly conserved genes and may allow for the differentiation of closely related species of the Candida parapsilosis (psilosis) complex. The correct identification of the three psilosis complex species C. parapsilosis, Candida metapsilosis, and Candida orthopsilosis is very important in the clinical setting for improving antifungal therapy and patient care. In this work, we analyzed inteins that are present in the vacuolar ATPase gene VMA and in the threonyl-tRNA synthetase gene ThrRS in 85 strains of the Candida psilosis complex (46 C. parapsilosis, 17 C. metapsilosis, and 22 C. orthopsilosis). Here, we describe an accessible and accurate technique based on a single PCR that is able to differentiate the psilosis complex based on the VMA intein. Although the ThrRS intein does not distinguish the three species of the psilosis complex by PCR product size, it can differentiate them by sequencing and phylogenetic analysis. Furthermore, this intein is unusually present as both mini- and full-length forms in C. orthopsilosis. Additional population studies should be performed to address whether this represents a common intraspecific variability or the presence of subspecies within C. orthopsilosis.

Preliminary laboratory report of fungal infections associated with contaminated methylprednisolone injections.

In September 2012, the Centers for Disease Control and Prevention (CDC) initiated an outbreak investigation of fungal infections linked to injection of contaminated methylprednisolone acetate (MPA). Between 2 October 2012 and 14 February 2013, the CDC laboratory received 799 fungal isolates or human specimens, including cerebrospinal fluid (CSF), synovial fluid, and abscess tissue, from 469 case patients in 19 states. A novel broad-range PCR assay and DNA sequencing were used to evaluate these specimens. Although Aspergillus fumigatus was recovered from the index case, Exserohilum rostratum was the primary pathogen in this outbreak and was also confirmed from unopened MPA vials. Exserohilum rostratum was detected or confirmed in 191 specimens or isolates from 150 case patients, primarily from Michigan (n=67 patients), Tennessee (n=26), Virginia (n=20), and Indiana (n=16). Positive specimens from Michigan were primarily abscess tissues, while positive specimens from Tennessee, Virginia, and Indiana were primarily CSF. E. rostratum antifungal susceptibility MIC50 and MIC90 values were determined for voriconazole (1 and 2 µg/ml, respectively), itraconazole (0.5 and 1 µg/ml), posaconazole (0.5 and 1 µg/ml), isavuconazole (4 and 4 µg/ml), and amphotericin B (0.25 and 0.5 µg/ml). Thirteen other mold species were identified among case patients, and four other fungal genera were isolated from the implicated MPA vials. The clinical significance of these other fungal species remains under investigation. The laboratory response provided significant support to case confirmation, enabled linkage between clinical isolates and injected vials of MPA, and described significant features of the fungal agents involved in this large multistate outbreak.

PRP8 intein in cryptic species of Histoplasma capsulatum: evolution and phylogeny.

The PRP8 intein is the most widespread intein among the Kingdom Fungi. This genetic element occurs within the prp8 gene, and is transcribed and translated simultaneously with the gene. After translation, the intein excises itself from the Prp8 protein by an autocatalytic splicing reaction, subsequently joining the N and C terminals of the host protein, which retains its functional conformation. Besides the splicing domain, some PRP8 inteins also have a homing endonuclease (HE) domain which, if functional, makes the intein a mobile element capable of becoming fixed in a population. This work aimed to study (1) The occurrence of this intein in Histoplasma capsulatum isolates (n=99) belonging to different cryptic species collected in diverse geographical locations, and (2) The functionality of the endonuclease domains of H. capsulatum PRP8 inteins and their phylogenetic relationship among the cryptic species. Our results suggest that the PRP8 intein is fixed in H. capsulatum populations and that an admixture or a probable ancestral polymorphism of the PRP8 intein sequences is responsible for the apparent paraphyletic pattern of the LAmA clade which, in the intein phylogeny, also encompasses sequences from LAmB isolates. The PRP8 intein sequences clearly separate the different cryptic species, and may serve as an additional molecular typing tool, as previously proposed for other fungi genus, such as Cryptococcus and Paracoccidioides.

Detection of fungal DNA in human body fluids and tissues during a multistate outbreak of fungal meningitis and other infections.

Exserohilum rostratum was the major cause of an outbreak of fungal infections linked to injections of contaminated methylprednisolone acetate. Because almost 14,000 persons were exposed to product that was possibly contaminated with multiple fungal pathogens, there was unprecedented need for a rapid throughput diagnostic test that could detect both E. rostratum and other unusual agents of fungal infection. Here we report development of a novel PCR test that allowed for rapid and specific detection of fungal DNA in cerebrospinal fluid (CSF), other body fluids and tissues of infected individuals. The test relied on direct purification of free-circulating fungal DNA from fluids and subsequent PCR amplification and sequencing. Using this method, we detected Exserohilum rostratum DNA in 123 samples from 114 case-patients (28% of 413 case-patients for whom 627 samples were available), and Cladosporium DNA in one sample from one case-patient. PCR with novel Exserohilum-specific ITS-2 region primers detected 25 case-patients with samples that were negative using broad-range ITS primers. Compared to fungal culture, this molecular test was more sensitive: of 139 case-patients with an identical specimen tested by culture and PCR, E. rostratum was recovered in culture from 19 (14%), but detected by PCR in 41 (29%), showing a diagnostic sensitivity of 29% for PCR compared to 14% for culture in this patient group. The ability to rapidly confirm the etiologic role of E. rostratum in these infections provided an important contribution in the public health response to this outbreak.

Molecular analyses of Fusarium isolates recovered from a cluster of invasive mold infections in a Brazilian hospital.

BACKGROUND: Invasive fusariosis (IF) is a rare but often fatal fungal infection in immunosuppressed patients. In 2007, cases of IF above the expected epidemiologic baseline were detected in the hematology ward of a hospital in Rio de Janeiro, Brazil. Possible sources of infection were investigated by performing environmental sampling and patient isolate collection, followed by molecular typing. Isolates from dermatology patients with superficial fusariosis were included in the study for comparison to molecular types found in the community. METHODS: Environmental sampling focused on water-related sources in and around the hematology ward. Initially, we characterized 166 clinical and environmental isolates using the Fusarium translation elongation factor 1α (EF-1α) genetic locus. Isolates included 68 collected from water-related sources in the hospital environment, 55 from 18 hematology patients, and 43 from the skin/nails of 40 outpatients seen at the hospital dermatology clinic. Multi-locus sequence typing was performed on Fusarium solani species complex (FSSC) species 1 and 2 isolates to investigate their relatedness further. RESULTS: Most of the hematology samples were FSSC species 2, with species type FSSC 2-d the most commonly isolated from these patients. Most of the outpatient dermatology samples were also FSSC 2, with type 2-d again predominating. In contrast, environmental isolates from water sources were mostly Fusarium oxysporum species complex (FOSC) and those from air samples mostly Fusarium incarnatum-equiseti species complex (FIESC). A third of the environmental samples were FSSC, with species types FSSC 1-a and FSSC 1-b predominating. CONCLUSIONS: Fusarium isolate species types from hematology patient infections were highly similar to those recovered from dermatology patients in the community. Four species types (FSSC 1-a, 1-b, 2-d and 2-f) were shared between hematology patients and the environment. Limitations in environmental sampling do not allow for nosocomial sources of infection to be ruled out. Future studies will focus on environmental factors that may have influenced the prevalence of FSSC fusariosis in this hematology ward.