Effectiveness of patient and staff cohorting to reduce the risk of vancomycin-resistant enterococcus (VRE) acquisition: a retrospective cohort study during a VRE outbreak in Japan

BACKGROUND

Patient and staff cohorting is part of a bundle approach in the response to multi-drug-resistant organisms, but its effectiveness is not fully clarified. This study compared the risks of acquiring vancomycin-resistant Enterococcus faecium (VREfm) at a hospital during a VREfm outbreak based on contact characteristics in order to better understand the effectiveness of cohorting.

METHODS

Exposure came from contact with patients with VREfm (infectors), including existing patients with VREfm and patients who acquired VREfm during the study period. Contact was defined as length of contact time, degree of sharing space, and care by the same nurses as those caring for infectors between January and March 2018. The outcome was VREfm acquisition as determined through monthly stool or rectal screening cultures. Incidence rates were calculated based on contact patterns, and incidence rate ratios (IRRs) were compared.

FINDINGS

Among 272 inpatients (4038 patient-days), 43 patients acquired VREfm with the same or similar pulsotype. Incidence rates were 8.45 per 1000 patient-days when susceptible inpatients were on the same ward as an infector but cared for by different nurses (reference), 16.96 when susceptible inpatients were on the same ward as an infector and cared for by the same nurses [IRR 2.01, 95% confidence interval (CI) 0.62-10.28], and 52.91 when susceptible inpatients shared a room with an infector (IRR 6.26, 95% CI 1.61-35.40).

CONCLUSION

Compared with susceptible inpatients in a different room from infectors and not being cared for by the same nurses, the risk of VREfm acquisition could be six times higher for susceptible inpatients who are in the same room as infectors, and could be double for susceptible inpatients cared for by the same nurses as infectors.

A DNS Study of Closure Relations for Convection Flux Term in Transport Equation for Mean Reaction Rate in Turbulent Flow

The present work aims at modeling the entire convection flux ρ u W ¯ in the transport equation for a mean reaction rate ρW ¯ in a turbulent flow, which (equation) was recently put forward by the present authors. In order to model the flux, several simple closure relations are developed by introducing flow velocity conditioned to reaction zone and interpolating this velocity between two limit expressions suggested for the leading and trailing edges of the mean flame brush. Subsequently, the proposed simple closure relations for ρ u W ¯ are assessed by processing two sets of data obtained in earlier 3D Direct Numerical Simulation (DNS) studies of adiabatic, statistically planar, turbulent, premixed, single-step-chemistry flames characterized by unity Lewis number. One dataset consists of three cases characterized by different density ratios and is associated with the flamelet regime of premixed turbulent combustion. Another dataset consists of four cases characterized by different low Damköhler and large Karlovitz numbers. Accordingly, this dataset is associated with the thin reaction zone regime of premixed turbulent combustion. Under conditions of the former DNS, difference in the entire, ρuW ¯ , and mean, ũ ρW ¯ , convection fluxes is well pronounced, with the turbulent flux, ρ u '' W '' ¯ , showing countergradient behavior in a large part of the mean flame brush. Accordingly, the gradient diffusion closure of the turbulent flux is not valid under such conditions, but some proposed simple closure relations allow us to predict the entire flux ρ u W ¯ reasonably well. Under conditions of the latter DNS, the difference in the entire and mean convection fluxes is less pronounced, with the aforementioned simple closure relations still resulting in sufficiently good agreement with the DNS data.

Effectiveness of washed platelet concentrate and red cell transfusions for a patient with anhaptoglobinemia with antihaptoglobin antibody

A 71-year-old Japanese male with myelodysplastic syndrome progressing to overt leukaemia and hepatocellular carcinoma developed dyspnea and urticaria immediately after infusion of platelet concentrate (PC). He exhibited an identical reaction following blood transfusion. Serum haptoglobin was undetectable. The patient was determined to be homozygous for Hp(del) by polymerase chain reaction (PCR). Antibody to haptoglobin was detected by enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. No antibodies against human leucocyte antigen (HLA) or platelet-specific antigens were detected. Washed PC and washed red blood cells were effective in preventing the transfusion-related anaphylactoid reactions.

[B precursor lymphoblastic leukemia/lymphoma manifested at onset as hemophagocytic syndrome]

A 20 year-old male patient was admitted to our department for the treatment of recurrence of fever and pancytopenia developed despite of temporal remission of hemophagocytosis syndrome that had been treated with large doses of methylprednisolone in our hospital. Superficial lymph nodes were not palpable. CT scan and echography revealed neither findings of splenohepatomegalia or enlargement of intraabdominal lymph nodes. Bone marrow aspiration showed an increase of histiocytes, the cells phagocytizing erythrocytes and platelets, and a negative test for peroxidase stain. Analysis of surface antigens showed that 11.3% of cells were blast cells positive for CD10, CD19, CD20, CD34 and TdT. Bone marrow biopsy revealed a localized increase in tumor cells positive for L26, CD10 and negative for UCHL-1. Because of the absence of detectable tumor masses and the difficulty in differentiating between malignant lymphoma and lymphatic leukemia, we diagnosed the condition as B precursor lymphoblastic leukemia/lymphoma. If diagnosed with malignant lymphoma preceded by hemophagocytic syndrome(LAHS), he might have a rare type of LAHS-associated malignant lymphoma since histological examination did not reveal diffuse large cell lymphoma, a condition found in most patients with LAHS-associated malignant lymphoma. Whereas if diagnosed as ALL, he was the first adult patient with ALL with HPS at onset as far as we know. In any of these possibilities, the case was considered rare.

[Recurrent hemolytic uremic syndrome induced by pranoprofen]

A 25-year-old woman was admitted to our hospital because of dark red urine in 1993. A diagnosis of hemolytic uremic syndrome (HUS) because of findings of hemolytic anemia with fragmented erythrocytes, thrombocytopenia, and renal dysfunction. The patient achieved remission with steroids and diuretics. In 1998 she caught a cold and happened to take the nonsteroidal anti-inflammatory drug, pranoprofen. Six hours later, she was rehospitalized because of dark red urine. Hemolytic anemia, fragmented erythrocytes, thrombocytopenia and renal dysfunction were observed again, also. A diagnosis of HUS was made. The patient was treated with steroid pulse therapy, infusion of fresh plasma, and plasma exchange transfusion. She recovered completely. In 1993 she had taker pranoprofen just prior to her first HUS episode. This was a recurrent case of HUS induced by pranoprofen.

[Human parvovirus B19-induced aplastic crisis in a patient treated with fibrin sealant]

A 42-year-old woman underwent a myomectomy on March 31, 1998. On the 10th postoperative day, leukopenia and reticulocytopenia were observed. Bone marrow aspiration revealed severe erythroblastopenia with giant proerythroblasts, suggesting a recent parvovirus infection. Both anti-parvovirus B19 IgM antibody and IgG antibody seroconversion was observed, and human parvovirus B19 DNA was detected by polymerase chain reaction (PCR) methods. The hematologic data on the patient rapidly improved thereafter. It was determined that acute-phase serum had inhibited CFU-E and BFU-E derived colony formation. Based on these findings, parvovirus B19-induced aplastic crisis was diagnosed. Fibrin sealant, which is a typical hemostatic agent produced from blood, had been during the operation. Human parvovirus B19 DNA was detected in the fibrin sealant by PCR. Our case report documents the transmission of human parvovirus B19 by fibrin sealant.

[Recovery from out-of-hospital cardiac arrest after mild hypothermia: report of two cases]

We report two patients with out-of-hospital cardiac arrest who recovered after hypothermia therapy. A 25-year-old man and a 16-year-old boy were transferred to our hospital after cardiopulmonary arrest due to idiopathic ventricular fibrillation and hypertrophic cardiomyopathy, respectively. We carried out hypothermia therapy using cooling blankets, and the patients were maintained at 32-33 degrees C for 96 and 36 h, respectively. After slow rewarming, they regained consciousness and recovered. During hypothermia, hypokalemia and arrhythmia occurred. Their arrest times (no spontaneous circulation and no CPR) were 10 min and 8 min, and CPR times (no spontaneous circulation while CPR was being performed) were 24 min and 20 min, respectively. In cases where the duration of ischemia is prolonged, the prognosis is expected to be poor. Therefore, we believe that hypothermia therapy is beneficial for such patients.

Anaesthesia for Treacher Collins syndrome using a laryngeal mask airway

Patients with Treacher Collins syndrome pose a serious problem to anaesthetists in maintaining their airway because of retrognathia. Two patients with Treacher Collins syndrome undergoing tympanoplasty are reported in whom a laryngeal mask was used in place of an endotracheal tube for airway maintenance.