Novel preventative strategies against invasive aspergillosis

Effects of indoor environmental parameters related to building heating, ventilation, and air conditioning systems on patients' medical outcomes: A review of scientific research on hospital buildings

The indoor environment of a mechanically ventilated hospital building controls infection rates as well as influences patients' healing processes and overall medical outcomes. This review covers the scientific research that has assessed patients' medical outcomes concerning at least one indoor environmental parameter related to building heating, ventilation, and air conditioning (HVAC) systems, such as indoor air temperature, relative humidity, and indoor air ventilation parameters. Research related to the naturally ventilated hospital buildings was outside the scope of this review article. After 1998, a total of 899 papers were identified that fit the inclusion criteria of this study. Of these, 176 papers have been included in this review to understand the relationship between the health outcomes of a patient and the indoor environment of a mechanically ventilated hospital building. The purpose of this literature review was to summarize how indoor environmental parameters related to mechanical ventilation systems of a hospital building are impacting patients. This review suggests that there is a need for future interdisciplinary collaborative research to quantify the optimum range for HVAC parameters considering airborne exposures and patients' positive medical outcomes.

The impact of portable high-efficiency particulate air filters on the incidence of invasive aspergillosis in a large acute tertiary-care hospital

BACKGROUND

Worldwide, the frequency of invasive fungal infections has been increasing, with a corresponding increase in the numbers of high-risk patients. Exposure reduction through the use of high-efficiency particulate air (HEPA) filters has been the preferred primary preventive strategy for these high-risk patients. Although the efficiency and benefits of fixed HEPA filters is well proven, the benefits of portable HEPA filters are still inconclusive.

METHODS

This was a retrospective study to assess the impact of 48 portable HEPA filter units deployed in selected wards in Singapore General Hospital, an acute tertiary-care hospital in Singapore. Data were extracted between December 2005 and June 2008 on the diagnoses at discharge and microbiological and histological laboratory findings. All patients with possible, probable, or proven invasive aspergillosis (IA) were included.

RESULTS

In wards with portable HEPA filters, the incidence rate of IA of 34.61/100,000 patient-days in the pre-installation period was reduced to 17.51/100,000 patient-days in the post-installation period (P = .01), for an incidence rate ratio of 1.98 (95% confidence interval [CI], 1.10-2.97). In wards with no HEPA filters, there was no significant change in the incidence rate during the study period. Portable HEPA filters were associated with an adjusted odds ratio of 0.49 (95% CI, 0.28-0.85; P = .01), adjusted for diagnosis and length of hospital stay.

CONCLUSIONS

Portable HEPA filters are effective in the prevention of IA. The cost of widespread portable HEPA filtration in hospitals will be more than offset by the decreases in nosocomial infections in general and in IA in particular.

The microbiology and risk of infection following open, agricultural upper extremity injuries

PURPOSE

This study was designed to determine the microbiology and risk of infection following open, agricultural, upper extremity injuries. Specifically, we sought to evaluate the microbiology of the wounds at the time of initial treatment and the development of any subsequent infections, determine whether the development of subsequent infection was related to injury severity, and clarify whether the microorganisms isolated at the time of initial treatment and development of subsequent infection were susceptible to the initial antibiotic prophylaxis.

METHODS

A retrospective chart review of 214 patients was conducted.

RESULTS

The initial injuries were classified into 1 of 3 groups, with 1 being the least severe and 3 being the most severe. Twenty-six were type 1 injuries, 94 type 2, and 94 type 3 injuries. Forty patients developed infection following the injury. Seventeen had superficial wound infection, 16 had deep soft tissue infections, and 7 developed osteomyelitis. Six went on to an amputation due to infection. Fifteen of the infections were polymicrobial. The number of patients who developed infection in the first 6 months following injury was 2, 14, and 24 for type 1, 2, and 3 injuries respectively (p=.07).

CONCLUSIONS

Empiric antimicrobial regimens for the management of infection requiring surgical debridement following open upper extremity agricultural injury should be active against staphylococci, aerobic gram-negative bacilli, and anaerobes, but not necessarily against fungi. These antibiotics ideally should be administered on initial presentation of the patient to the emergency department. Prospective studies with emphasis on timely acquisition of cultures and sensitivities are needed to determine optimal prophylactic antimicrobial therapy for these injuries and directed antibiotic regimens for the infections that may develop.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Successful combination of antifungal agents and surgical resection for pulmonary aspergillosis in a child with Hodgkin disease: review of the literature

The authors report on a 14-year-old adolescent boy suffering of Hodgkin disease in remission, who developed autoimmune anemia and thrombopenia. He was treated with high-dose steroids and he developed serious invasive lung aspergillosis, which was treated with antifungal agents and surgical intervention. Children suffering from cancer are prone to develop systemic fungal infections secondary to the severe immunosuppression caused by the disease itself and the antineoplastic therapy. Intravenous antifungal medications and, when feasible, surgery are used for treatment of pulmonary aspergillosis. Factors related to better outcome are early diagnosis, remission of underlying disease, aggressive antifungal therapy, and recovery from neutropenia.