Methicillin-resistant Staphylococcus aureus and antimicrobial use in Belgian hospitals

OBJECTIVE

To investigate relationships between the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and the use of different classes of antimicrobials in Belgian hospitals.

DESIGN

Using Pearson correlation coefficients, the number of new nosocomial MRSA-colonized or -infected patients in the second half of 1994 and the first half of 1995 reported by the national MRSA surveillance program was compared with use of various antimicrobial classes as reported by the National Institute for Sickness and Disability Insurance. Relationships between different classes of antimicrobials were evaluated in a correlation matrix. MRSA incidence, antimicrobial use, and potential confounding factors were included in a multiple linear regression analysis.

SETTING

50 hospitals in Belgium.

RESULTS

The use of a number of different classes of antimicrobials was interrelated. In the multivariate analysis, the incidence of nosocomial MRSA increased with increasing use of ceftazidime and cefsulodin (P=.0003), amoxicillin with clavulanic acid (P=.02), and quinolones (P=.005). No association was found between MRSA incidence and total antimicrobial use.

CONCLUSIONS

The relationships between antimicrobial use and MRSA are complex. Interventions aimed at promoting more rational prescribing patterns should be supported by adequate experimental and epidemiological evidence. Advice for preventing and controlling MRSA has focused mainly on hygienic measures and precautions to avoid cross-transmission; the role of relieving antimicrobial pressure needs to be clarified.

[Popliteal vein aneurysm]

The popliteal vein aneurysm is a rare condition that can lead to local symptoms, thrombosis and pulmonary embolism. We report the case of a 67 years old, otherwise healthy white male, who presented to us with localised swelling and pain in the left popliteal fossa. Duplex ultrasound and venography were obtained, confirming the diagnosis of popliteal vein aneurysm. The patient underwent tangential aneurysmectomy and lateral venorrhaphy, recovery was uneventful remaining asymptomatic. The reconstruction was demonstrated patent on a duplex scan. The popliteal vein aneurysm is a potentially fatal condition for which surgical treatment is recommended.

Transient myeloproliferative disorder with 11q23 aberration in two neonates with Down syndrome

Infants with Down syndrome may develop a transient myeloproliferative disorder (TMD) with the features of acute leukemia but resolving in a spontaneous remission. Chromosomal aberrations in addition to trisomy 21 have only rarely been described. In many cases of infant acute leukemia band q23 of chromosome 11 is involved in nonrandom translocations, often resulting in a rearrangement of the ALL-1 (MLL, HRX, HTRX 1) gene. Generally, this translocation carries a bad prognosis. We describe two newborn girls with Down syndrome and TMD in whom the constitutional trisomy 21 was combined with an acquired abnormality of chromosome 11. During the TMD the morphological and immunologic features were consistent with those of megakaryoblastic leukemia. The chromosome 11 abnormalities were del(ll)(q23), but rearrangements of the ALL-1 gene were not found. Our patients had remissions that occurred spontaneously or after a mild chemotherapy. The important finding is that additional chromosomal changes may occur during TMD in Down syndrome. The fact that the abnormality was in region 11q23 raises the question of whether the risk for developing leukemia is increased under these conditions.

[Inferior vena cava filters. Indications and results in 111 patients]

BACKGROUND

Anticoagulation is the treatment of choice for deep vein thrombosis and pulmonary embolism. Occasionally this treatment is contraindicated or fails to prevent pulmonary embolism. In these patients, inferior cava vein interruption is indicated and filter insertion is the procedure commonly performed.

AIM

To report the results of inferior cava vein filter insertions in 111 patients.

PATIENTS AND METHODS

A retrospective review of patients in whom inferior cava vein filters were inserted was performed.

RESULTS

During the period 1983-1997, filters were inserted in 111 patients (56 female) aged 15 to 93 years old. Indications were pulmonary embolism with contraindication or failure of anticoagulation therapy or poor respiratory function (58 patients), deep vein thrombosis and contraindication for anticoagulation (32 patients) and other indications in 20 patients. In 47 patients, treated before 1993, the insertion required a cut-down. Since then, a percutaneous approach was used in the remaining 64 cases. Three insertion attempts failed, all using cut-down. One of these patients died due to a massive pulmonary embolism. In 88% of the patients the jugular vein was the access site and in 10 patients, the filter was deliberately deployed above the renal veins. There was no mortality or complications. Patients were followed during a maximal period of 147 months and 27 died of unrelated disorders. Survival at 5 and 10 years was 63 and 47% respectively. Symptomatic inferior cava vein obstruction was detected in 5 patients during the follow up period.

CONCLUSIONS

Inferior cava vein filter insertion is a safe measure to prevent pulmonary embolism and its consequences.

Surgical prophylaxis in Belgian hospitals: estimate of costs and potential savings

Between 1991 and 1995 the Belgian National Program for Surveillance of Hospital Infections (NSIH) collected data on perioperative antibiotic prophylaxis in 72 acute care hospitals. From the costs of prophylactic antibiotics for six categories of surgical procedure and from discharge summaries for hospitalization episodes nationwide, annual drug costs were estimated for 73% of Belgian surgical activity. Costs of antibiotics used in these surgical activities were estimated at 386-410 million Belgian francs (Bf) per year (US$12.1-12.9 million). After agreeing recommendations for best practice, the hypothetical costs of 'optimal' antimicrobial prophylaxis were calculated for the same selection of surgical procedures. It was calculated that savings of at least 194 million Bf (US$6.1 million) could be made if recommendations were followed closely. Only the costs borne by the National Health Insurance Institute for reimbursement of the dispensed drugs were considered in this study. Other direct costs, such as those related to drug storage, dispensing and administration, were not included.

P300 from a single-stimulus paradigm: passive versus active tasks and stimulus modality

The P300 component of the event-related brain potential (ERP) was elicited with auditory and visual stimuli in separate experiments. Each study compared an oddball paradigm that presented both target and standard stimuli with a single-stimulus paradigm that presented a target but no standard stimuli. Subjects were instructed in different conditions either to ignore the stimuli, press a response key to the target, or maintain a mental count of the targets. For the passive ignore conditions, P300 amplitude from the single-stimulus paradigm was larger than that from the oddball paradigm. For the active tasks, P300 amplitude from the oddball paradigm was larger than that from the single-stimulus paradigm. For the press and count conditions, P300 amplitude and latency were highly similar for the oddball and single-stimulus procedures. The findings suggest that the single-stimulus paradigm can provide reliable cognitive measures in clinical/applied testing for both passive and active response conditions.

Nasopharyngeal carcinoma in childhood and adolescence: concept and preliminary results of the cooperative GPOH study NPC-91. Gesellschaft für Pädiatrische Onkologie und Hämatologie

BACKGROUND

The increasing use of chemotherapy has improved the prognosis of patients with nasopharyngeal carcinoma (NPC), and the authors demonstrated the beneficial effect of adjuvant interferon (IFN)-beta in a previous pilot study of children with advanced stage NPC. The current multi-institutional, cooperative GPOH (Gesellschaft für Pädiatrische Onkologie und Hämatologie) study NPC-91 was begun in 1992 to determine the efficacy of preradiation chemotherapy, radiotherapy, and adjuvant IFN-beta, in the treatment of advanced stage NPC.

METHODS

Of a total of 22 patients, 21 had American Joint Committee on Cancer Stage III or IV disease, and 1 had Stage II disease. The median age was 12 years (range, 8-16 years). Twenty of 22 received 3 courses of preradiation chemotherapy consisting of methotrexate 120 mg/m2 on Day 1, cisplatin 100 mg/m2 on Day 1, and 5-fluorouracil 1000 mg/m2 for five days as well as 6 doses of leucovorin 25 mg/m2 every six hours beginning on Day 2. The Stage II patient received no chemotherapy, and chemotherapy was terminated for another during the first course. All patients had radiation therapy, stratified by stage. The cumulative dose to the primary sites was 59.4 gray (Gy), with single doses of 1.8 Gy. A total of 45 Gy was delivered to the neck area. Finally, all patients were treated with recombinant IFN-beta (10(5) U per kg of body weight) 3 times a week for 6 months.

RESULTS

The response rate was 91%. These patients stayed in first remission during a median follow-up of 32 months. With the exception of one reversible cardiotoxicity, moderate chemotherapy-related toxicity was observed.

CONCLUSIONS

In this study, patients with advanced stage NPC had a good prognosis with treatment consisting of neoadjuvant cisplatin and 5-fluorouracil, radiotherapy, and adjuvant IFN-beta. It is particularly noteworthy that distant metastases did not develop.

[Mycotic aneurysms and multiple peripheral embolisms in a patient with infectious endocarditis]

Sepsis from an infected cardiac valve can lead to bacterial seeding and destruction of the arterial wall with formation of a mycotic aneurysm. The natural history of these lesions is the rupture. We report the case of a 20 year old female who was admitted to our institution with massive mitral regurgitation and emboli of the central nervous system and both lower extremities. She underwent emergency valve replacement and then, staged treatment of her ischemic legs and multiple asymptomatic mycotic aneurysms: Superior mesenteric, right common iliac and left superficial femoral arteries. A splenectomy was required to treat a splenic abscess. An aneurysm of a peripheral branch of the middle cerebral artery was medically treated, demonstrating reduction in size on subsequent angiogram. She recovered uneventfully and remains asymptomatic after 20 months of follow up. The development of new diagnostic and therapeutic tools has led to a decrease of these complications during infectious endocarditis. However, in the patient with late diagnosis and symptoms in different territories, the mycotic aneurysm must be kept in mind to provide the patient with appropriate treatment.

[Abdominal aortic aneurysm: course of morbimortality of elective surgery in 20 years]

Abdominal aortic aneurysms (AAA) usually undergo progressive dilatation and eventually may rupture, complication that carries a high mortality rate. If certain clinical conditions, like operative risk and aortic diameter are met, all patients should be considered for surgical repair. Analysis of our results with the surgical treatment of asymptomatic AAA prompted this study. Out of 479 consecutive patients operated because of AAA between 1976 and 1995, 378 (79%) were electively treated. Two decades: 1976-85 (101 patients) and 1986-95 (277 patients) were compared as far as associated medical conditions, surgical procedures, complications and mortality rate. There was no difference in age, sex, risk factors and aortic diameter. During the second decade we favoured the use of aortic tube grafts (53% vs 25%, p < 0.01) and epidural anesthesia (94% vs 35%, p < 0.01). During the last decade only 53.3% of the patients received blood transfusion, compared to 95.3% during the first period (p < 0.001). Operative mortality decreased from 5.94% to 0.72% (p < 0.05). Postoperative hospital stay diminished from 11.2 +/- 8.2 to 9.6 +/- 6.3 days (p < 0.05). These results compare favourably with those reported from other academic centers and support our therapeutic approach. Our contemporary surgical results serve as a reference for future clinical evaluation of endovascular procedures currently under investigation.

[Lower extremity salvage in diabetics: microsurgical muscle transplantation with and without previous vascular reconstruction]

Soft tissues wounds with or without bony involvement are a common problem and a cause of limb loss in diabetics. Usually local care, antibiotics, minor debridement and skin grafting are enough for successful handling of these lesions. When there is associated limb ischemia, revascularization is indicated. In patients with large ulcers, proximal bony involvement and tendon exposure, the incidence of primary amputation rises, frequently being considered the only alternative. Two cases of diabetic patients with indication of primary amputation of a lower limb for large infected ulcers are reported. A microvascularized muscle transplant was used to cover large defects of soft tissue, tendons and infected bone. One patient presented also critical ischaemia of the limb, requiring iliac angioplasty and a femoro-distal by-pass with in situ greater saphenous vein previous to the muscle graft. Both patients had no postoperative complications, being able to walk two months after the operation with their useful limb. Microvascularized muscle transplant with or without revascularization is a very useful alternative to amputation in the management of complex wounds of selected diabetic patients.

[Carotid endarterectomy combined with myocardial revascularization: report of 27 patients]

Atherosclerosis is a systemic disease that may involve more than one territory. Myocardial infarction can occur after carotid endarterectomy and stroke is a well documented morbidity of coronary artery bypass grafting. To optimize results, we have performed concomitant carotid endarterectomy and myocardial revascularization in selected cases, with severe disease in both territories. During a 13-year period, 27 patients were submitted for this procedure, 21 (77.8%) were male and the average age was 67.6 years (range 59-81). All patients had high-grade internal carotid artery stenosis, five (18.5%) were symptomatic. Coronary artery disease symptoms were: unstable angina in 12 patients (44.4%) and effort angina in 15 (55.6%). Two patients (7.4%) required reintervention for postoperative bleeding. Two cases (7.4%) had transient renal dysfunction. One patient, with multiple organ failure, died on the 16th postoperative day (3.7%). Follow up was obtained in 26 patients (96.3%). Survival at 5 years was 80.6%, 95.7% of those patients were free of any neurologic symptom. Combined carotid and coronary surgery is a safe treatment option for atherosclerosis of multiple territories in selected patients; long term benefits are also obtained.

Methicillin-resistant Staphylococcus aureus epidemiology and control in Belgian hospitals, 1991 to 1995. Groupement pour le Dépistage, l'Etude et la Prévention des Infections Hospitalières

OBJECTIVES

To describe the Belgian methicillin-resistant Staphylococcus aureus (MRSA) surveillance network, the evolution of methods used in Belgian hospitals for MRSA detection and control, and MRSA incidence from 1994 to 1995.

DESIGN, SETTING, AND PARTICIPANTS

Questionnaire surveys; infection control physicians from acute-care hospitals in Belgium.

INTERVENTION

Publication of national guidelines for MRSA control in 1993.

RESULTS

The participation rate in surveys ranged from 42% to 57% of hospitals. In 1995, 88% of participants detected MRSA strains by disk diffusion tests, with little improvement in standardization since 1991. More centers employed the oxacillin agar screen method (27%), automated systems (29%), or a combination of methods (29%) than in 1991 (P < .005). Between 1991 and 1995, the proportion of hospitals reporting MRSA control measures increased from 68% to 95% (P < .01). Practices that were used increasingly included patient placement in private room (from 50% to 93%, P < .01) and hand decontamination with antiseptic (from 43% to 87%, P < .01). The proportion of centers that reported screening MRSA carriers and treating them topically increased two- and threefold, respectively (P < .05). Surveillance data from 1994 to 1995 showed that MRSA represented a mean of 21.3% of S aureus clinical isolates (range, 1.6% to 62.4%). The median incidence of nosocomial MRSA acquisition was 2.8 per 1,000 admissions, with a wide range (0 to 13.7 per 1,000 admissions) across hospitals of all sizes. The median incidence decreased over the first three semesters of surveillance in hospitals with continuous participation.

CONCLUSION

MRSA detection and control measures have improved in Belgian hospitals after publication of national guidelines. However, MRSA incidence rates show the persistence of nosocomial transmission, with large variations between centers. The national MRSA surveillance network should indicate whether control efforts eventually will curb the problem.

[Pulmonary thromboendarterectomy: a case of surgical treatment of chronic pulmonary thromboembolism under circulatory arrest with deep hypothermia]

Pulmonary thromboendarterectomy under circulatory arrest and deep hypothermia is presently a curative treatment for pulmonary hypertension secondary to chronic pulmonary artery thromboembolic occlusion, but is still not frequently performed around the world. We report here the first successful pulmonary thromboendarterectomy under circulatory arrest performed in Chile. The patient was a 37 year old white man, high school teacher, with a 5 months history of effort dyspnea and cough. Pulmonary hypertension secondary to chronic pulmonary thromboembolism was confirmed by angiography and echocardiography. The patient was operated on April 27, 1995. After the operation the patient had an immediate and maintained normalization of his pulmonary hemodynamics. He presented periods of delirium that postponed mechanical ventilation disconnection until the 7th postoperative day, after which he had an uneventful neurological recovery. Before hospital discharge a control angiography showed complete patency of the pulmonary artery system with no evidence of residual thrombi. Presently he is enjoying a normal life and back to his teaching activities.

[Metalloproteinase in carotid endarterectomy plaques: increased activity in critical stenosis zones]

BACKGROUND

The presence of metalloproteinases in atherosclerotic plaques has been described but their role is not well understood. An increased secretion of these proteolytic enzymes could explain plaque instability and distal embolization.

AIM

To measure metalloproteinase activity in atherosclerotic plaques obtained after carotid endarterectomy.

MATERIAL AND METHODS

Plaques were divided in one segment with and one segment without stenosis, the latter being used as control. Both segments were incubated in culture media for 48 h or were fixed for histology. The conditioned medium was studied using gelatin zimography and digital densitometry. Metalloproteinases were identified by their molecular weight, inhibition with EDTA or Western Blot. Standard histologic study and immunohistochemistry were done.

RESULTS

In stenotic areas, metalloproteinase 9 (92kD) secretion was 260% higher than in regular plaques (191 and 73 Kilopixels/microgram protein respectively p < 0.02). The histological study of stenotic areas showed macrophage infiltration and neoformation of blood vessels.

CONCLUSIONS

The increased secretion of cellular matrix degrading enzyme metalloproteinase 9 in stenotic areas of atherosclerotic plaques, could explain plaque instability and subsequent embolization.

HELICS: a European project to standardise the surveillance of hospital acquired infection, 1994-1995

During the 1990s several European countries began to set up national or regional networks for the surveillance of hospital acquired infections. Most of these networks were based on the US Centers for Disease Control and Prevention (CDC) National Nosocomia

[SCE rate and lymphocyte differentiation in children with acute lymphoblastic leukemia and SCE rates of leukemia patients in long-term remission]

Sister chromatid exchanges (SCE) and lymphocyte subsets of children with acute lymphoblastic leukemia (ALL) were investigated in children with ALL during chemotherapy and at least 5 years after chemotherapy. The treatment of the new admitted patients followed protocol ALL-BFM-90. Children with ALL at the time of diagnosis showed statistically significant higher SCE frequencies (4.9 +/- 0.77) than healthy controls (3.6 +/- 0.93; p = 0.002). The in vivo effects of cyclophosphamide (CP) resulted in a dramatic increase of the SCE frequency (20.5 +/- 3.76). This increased SCE level of lymphocytes might reflect an instability of DNA or a deficiency of DNA repair capacity. However, immediately one week after the administration of CP, the SCE rate decreased. This decline of SCE frequency correlates with a severe reduction of the absolute numbers of T lymphocytes. The observed reduction of SCE frequency may be due to a depletion of T lymphocytes, or a repair of DNA. The patients in long term remission ( > 5 years) have had the therapy according BFM-83 (9 pat.) and modified 'Pinkel-regime' (2 pat.). No difference was found between the SCE-rate of the patients in remission and of the age-dependent control group. These results might correlate with the low risk for future development of relaps or second malignancy.

Surgical wound infection surveillance: results from the Belgian hospital network

Since October 1992, the Belgian National Programme for the Surveillance of Hospital Infections has been implemented successfully in more than two-thirds of all Belgian acute-care institutions. Practitioners from hospitals participating in the surgical wound infection surveillance describe a selection of surgical procedures, practices connected (antimicrobial prophylaxis), and record the eventual infection, enabling the calculation of wound infection rates. The network allows comparisons of each hospital results with the national picture. From October 1992 to June 1993, 16,799 procedures were recorded by 51 hospitals; the crude incidence rate of infection was 1.47 per 100 operations. However, this figure may be an underestimation of the reality because of potentially missed post-discharge infections. Risk factors significantly associated with infection include length of preoperative stay, emergency, duration of surgery, wound contamination class, and American Society of Anesthesiologists (ASA) score. The National Nosocomial Infections Surveillance system (NNIS) risk index, a combination of the three latter shows a good correlation for predicting infection. Increased length of stay attributable to the infection was computed at 8.9 days. Micro-organisms isolated reveal a staphylococcal predominance. Antibiotic prophylaxis prescription present satisfactory quality performances regarding duration and time of initiation but rational prescribing about the indications is still of concern.