Outbreak Of Invasive Aspergillosis Research Articles

Outbreak of invasive aspergillosis in heart transplant recipients: The role of screening computed tomography scans in asymptomatic patients and universal antifungal prophylaxis.

BackgroundDelays in diagnosing pulmonary invasive aspergillosis (IA), a significant cause of morbidity and mortality among heart transplant recipients (HTRs), may impact on successful treatment. The appropriate screening strategy for IA in these patients remains undefined, particularly in the setting of nosocomial outbreaks. We describe our experience employing chest computed tomography (CT) scans as a screening method for IA. In addition, we comment on antimicrobial prophylaxis in HTRs in the setting of an outbreak.MethodsScreening CT scans of the chest and serum galactomannan (GM) were performed in HTRs during an outbreak that followed the index case of IA. Abnormal CT findings prompted a diagnostic workup. Antimicrobial prophylaxis for new transplants recipients included intravenous micafungin while hospitalized, followed by outpatient inhaled amphotericin B for up to 3 months.ResultsDuring a 10‐month period, five cases of IA were identified among HTRs. Two additional asymptomatic patients were diagnosed with IA among 15 asymptomatic HTRs who underwent screening chest CT scans. Among the five cases of IA in HTRs, two of five (40%) had a partial response and the other three failed voriconazole therapy. Complete response to voriconazole therapy assessed at 12 weeks was achieved in these two asymptomatic HTRs diagnosed via screening CTs. Serum GM was positive only in one of the symptomatic cases. The negative predictive value of CT scans was 100% (95% confidence interval, 71.5%‐100%).ConclusionsIn an outbreak setting, screening CT scans of the chest may aid in early detection of asymptomatic HTRs with IA and improve outcome.

Outbreak of Invasive Aspergillosis After Major Heart Surgery Caused by Spores in the Air of the Intensive Care Unit

Outbreaks of invasive aspergillosis (IA) are believed to be caused by airborne Aspergillus conidia. Few studies have established a correlation between high levels of Aspergillus fumigatus conidia and the appearance of new cases of IA or have demonstrated matching genotypes between clinical isolates and those from the environment. We detected an outbreak of IA (December 2006 through April 2008) in the major heart surgery intensive care unit (MHS-ICU) of our institution. Our local surveillance program consists of monthly environmental air sampling in operating rooms and ICUs for quantitative and qualitative identification of filamentous fungi. During the study period, we obtained 508 environmental samples from 3 different periods: 6 months before the outbreak, during it, and 6 months after it. Available environmental and clinical strains were genotyped according to the short tandem repeats assay. Seven patients developed proven or probable IA (5 with lung infection, 1 with mediastinitis, and 1 with lung infection and mediastinitis). A. fumigatus was involved in 6 cases. The underlying conditions of the patients were heart transplantation (n = 3), corticosteroid-dependent conditions (n = 2), and diabetes mellitus (n = 2). The mortality rate was 85.7%. Before and after the outbreak (±6 months), the median airborne A. fumigatus conidia levels were 0 colony-forming units (CFUs) per cubic meter, and no cases of IA occurred during these periods. However, during the outbreak period, the occurrence of the 6 cases of IA caused by A. fumigatus was linked to peaks of abnormally high A. fumigatus airborne conidia levels (175, 50, 25, 20, 160, and 400 CFUs/m(3)) in the MHS-ICU, whereas counts in the air of both operating rooms remained negative. Matches between A. fumigatus genotypes collected from the air of the MHS-ICU and from representative clinical samples were found in 3 of the 6 patients. The outbreak abated when high-efficiency particulate air filters were installed in the affected areas. Our study revealed that abnormally high levels of airborne A. fumigatus conidia correlated with new cases of IA, even in patients who were not severely immunocompromised. The demonstration of matches between air and clinical genotypes reinforces the role of environmental air in the acquisition of IA during the period following MHS. Environmental monitoring of Aspergillus spores in the air of postoperative units is mandatory, even when these units receive nonimmunocompromised patients undergoing major surgery.

Central Nervous System Aspergillosis causing Spinal Cord Compression

Central nervous system (CNS) aspergillosis is a rare and uniformly fatal complication of disseminated disease, involving the cerebral hemispheres and cerebellum in the majority of cases. It is a ubiquitous mold and refers to a group of diseases caused by monomorphic mycelial fungi of the genus Aspergillosis fumigatus. Outbreaks of invasive aspergillosis are a problem in immunocompromized persons after they are exposed to air-borne spores.1 Aspergillosis causing spinal cord compression due to epidural abscess formation and hypertrophic pachymeningitis is a rare entity, thus such a case is presented herewith. A 16-yrs old male was diagnosed in early childhood of chronic granulomatous disease with recurrent abscess formation of lymph nodes and pneumonias. He was on regular daily trimethoprim-sulphamethaxazole prophylaxis. At twelve years of age, he developed osteomyelitis of the right 10th rib and underwent resection and the necrotic material grew Aspergillosis fumigatus. He was treated with amphotericin infusion for three weeks followed by itraconazole for a month. Three years later, he developed progressive weakness of both legs with difficulty in walking. Clinical examination revealed that the patient had spastic paraperesis at a D10 spinal level with spinal tenderness at D7-D9. There was no obvious swelling in the paraspinal region at that time. The bladder and bowel functions were intact although he had little hesitancy of micturation. The MRI of the thoracic spine revealed paravertebral soft tissue density in the lower dorsal region D6-D8 with liquefaction in the centre consistent with abscess. There was also a moth-eaten appearance and destruction of D7 vertebral body, (Fig. 1). Orthopedician was consulted, the abscess was drained followed by laminectomy of D6 to D11 vertebrae and decompression was performed. The abscess material grew Aspergillosis fumigatus. He was started on high-dose amphotericin B for 30 days. Later, itraconazole was given for a month. He also received broad-spectrum antibiotics, namely imipenum, ciprofloaxacin and amikacin during the postoperative period. He developed thrombophlebitis at the injection site, and later episodes of hypokalemia which were managed by potassium upplements. He was then put on plaster jacket and discharged. On reviewing him after a month, he was paraplegic with Grade 2/5 power in legs and had urinary and bowel involvement. Figure 1 MRI dorsal spine -T1 weighted sagittal contrast- showing extradural aspergillosis compressing spinal cord D6-8 with collapse of D7 vert. body There was also abscess formation at the operation site with sinus, discharging pus. The wound swab grew aspergillosis and he was given a six-week course of amphotericin B and itraconazole. Bone marrow transplantation was planned but he developed persistent fever and the blood culture revealed Acenobacter. Despite treatment with many antibiotics, the patient died of septicemia. CNS aspergillosis primarily affects adults. It occurs as a sino-cranial infection in all the reported cases and spinal cord involvement is either due to contiguous spread from the lungs or affecting cord prior to lungs indirectly by hematogenous route.2 Recently, there has been some increase in the incidence of invasive aspergillosis in the acquired immunocompromized individuals.3 Thus disseminated aspergillosis is a devastating disease in the immunocompromized patients and the ultimate prognosis is bad. The neurological disability was worse despite aggressive management.

Utility of a microsatellite assay for identifying clonally related outbreak isolates of Aspergillus fumigatus

A microsatellite assay based on short tandem repeats (STR Af) has been recently described as a discriminatory, high throughput assay for fingerprinting Aspergillus fumigatus isolates. However, the STR Af assay has not been tested for its utility in outbreak settings where it is critical to distinguish clonal clusters from genetically unrelated genotypes. In the present study, employing a panel of epidemiologically linked A. fumigatus isolates obtained from 6 different outbreaks of invasive aspergillosis (IA), we demonstrate that the STR Af assay can be a valuable molecular tool to support epidemiological investigations. We also report for the first time the detection of microvariation events in the A. fumigatus population studied.

The Role of Environmental and Electronic Surveillance in the Control of Invasive Aspergillosis among Ambulatory Hematologic Transplant Patients

ISSUE: Invasive Aspergillosis (IA) is a frequent and morbid complication of hematologic transplantation. Construction in health care facilities has been associated with outbreaks of IA among immunocompromised patients, and effective infection control programs in hospitals have been shown to decrease nosocomial IA. Little is known about acquisition of IA in the outpatient setting where an increasing fraction of health care associated with transplantation is occurring. PROJECT: We developed a novel electronic surveillance system for the detection of communicable diseases among ambulatory hematologic transplant patients. During the course of an extensive addition to the ambulatory cancer care clinic, we initiated outdoor and indoor environmental sampling for Aspergillus. Results from air sampling were correlated with microbiologically confirmed cases of Aspergillus from the electronic surveillance database. RESULTS: Microbiologic evidence of Aspergillosis was identified in 42 ambulatory transplant patients in 2005. Concentrations of Aspergillus within the ambulatory clinic remained uniformly low both prior to and throughout construction. The burden of Aspergillus isolated outside varied widely, and followed a previously described seasonal pattern. Cases of IA were closely correlated with the outdoor Aspergillus concentrations. Download : Download full-size image LESSONS LEARNED: Electronic surveillance for communicable disease among high-risk ambulatory patients may yield important information about trends in infections. The risk of IA among ambulatory hematologic transplant patients is strongly correlated with ambient concentrations of Aspergillus. The role of infection control and antifungal prophylaxis in protecting ambulatory at-risk patients needs to be reevaluated.

Outbreak of invasive aspergillosis among renal transplant recipients.

Invasive aspergillosis (IA) is rare among renal transplant recipients (RTRs). We investigated a cluster of IA among RTRs at a California hospital from January to February 2001, when construction was ongoing. We conducted a cohort study among RTRs who were hospitalized between January 1 and February 5, 2001, to determine risk factors for IA. IA was defined using established guidelines. Four IA cases occurred among 40 RTRs hospitalized during the study period. Factors associated with an increased risk of IA included prolonged hemodialysis, lengthy corticosteroid treatment posttransplant, and use of sirolimus alone or with mycophenolate (P<0.05). After the study period, three additional RTRs developed IA; two Aspergillus isolates recovered from these patients had indistinguishable profiles by DNA fingerprinting, suggesting common-source exposure. This study suggests that immunosuppressed RTRs can be at an increased risk for IA. Measures to prevent IA in these patients should be taken during hospital construction.

Invasive Aspergillosis Outbreak on a Hematology-Oncology Ward

An outbreak of invasive aspergillosis occurred in a community hospital in temporal association with construction activity. Epidemiological investigation showed that patients who are at highest risk comprise a small group and are readily identifiable. Clinicians should strive to protect these patients, following guidelines published by the Centers for Disease Control and Prevention.

Pseudoepidemic of Aspergillus niger infections traced to specimen contamination in the microbiology laboratory.

We report a pseudo-outbreak of Aspergillus niger that followed building construction in our clinical microbiology laboratory. Because outbreaks of invasive aspergillosis have been linked to hospital construction, strategies to minimize dust in patient care areas are common practice. We illustrate that the impact of false-positive cultures on patient care should compel laboratories to prevent specimen contamination during construction.

Airborne Fungal Spore Monitoring in a Protective Environment during Hospital Construction, and Correlation with an Outbreak of Invasive Aspergillosis

Evaluate aerobiological monitoring for fungal spores during hospital construction and correlate results with an outbreak of invasive aspergillosis (IA).Prospective air sampling for molds was done using the gravity air-settling plate (GASP) method.A university medical center special care unit consisting of single-patient rooms with high-efficiency particulate air filtration under positive pressure.Five neutropenic patients who subsequently developed IA.Four of the five patients with IA were housed in rooms adjacent to a construction staging area. Aerobiological monitoring detected an increase in the number of airborne fungal spores including Aspergillus species in these rooms; however, increased counts preceded IA diagnosis by 1 to 7 days in only three of the five patients. Swab cultures of the exhaust vents within each room confirmed results from air-settling plates. Follow-up monitoring, using the GASP method, demonstrated that control procedures were effective in reducing air mold contamination.The GASP method, although able to demonstrate that infection control measures reduced mold contamination of the air, was insensitive to detect levels of mold contaminates in time to prevent IA.

Airborne Fungal Spore Monitoring in a Protective Environment During Hospital Construction, and Correlation with an Outbreak of Invasive Aspergillosis

Evaluate aerobiological monitoring for fungal spores during hospital construction and correlate results with an outbreak of invasive aspergillosis (IA). Prospective air sampling for molds was done using the gravity air-settling plate (GASP) method. A university medical center special care unit consisting of single-patient rooms with high-efficiency particulate air filtration under positive pressure. Five neutropenic patients who subsequently developed IA. Four of the five patients with IA were housed in rooms adjacent to a construction staging area. Aerobiological monitoring detected an increase in the number of airborne fungal spores including Aspergillus species in these rooms; however, increased counts preceded IA diagnosis by 1 to 7 days in only three of the five patients. Swab cultures of the exhaust vents within each room confirmed results from air-settling plates. Follow-up monitoring, using the GASP method, demonstrated that control procedures were effective in reducing air mold contamination. The GASP method, although able to demonstrate that infection control measures reduced mold contamination of the air, was insensitive to detect levels of mold contaminates in time to prevent IA.

An outbreak of invasive aspergillosis in a haematologic unit.

Within a period of 15 months 8 cases of invasive pulmonary aspergillosis were seen in a haematologic unit; 7 of them between January and October 1984. No previous cases of invasive aspergillosis had been encountered during the existence of the unit since 1979. Environmental studies did not prove a single likely source for the fungal spores. Previous window renovation with concomitant fiber deposits on ventilation grids, poor sealing of air filter fittings in patient rooms, occasional ventilation through windows in the ward, and low speed of booster fans in the ventilation system may have created a condition favourable for the entry of Aspergillus fumigatus spores into the patient rooms. Environmental sanitation including cleaning of the ventilation ducts and change of filters in the ventilation system stopped the outbreak. Two sporadic cases have appeared during a follow-up period of 26 months.