The Effect of Door Openings on Numbers of Colony Forming Units in the Operating Room during Hip Revision Surgery.

BACKGROUND: The aim of this study was to investigate the effect of door opening rates on air quality in the operation room during hip revision surgery by measuring the number of colony forming units per cubic meter (CFU/m(3)). METHODS: During 70 hip revision operations the number of CFU/m(3) was measured at four time points. Factors that may influence air quality were recorded, including the number of persons present, duration of surgery, and door opening rates. The measured CFU/m(3) was dichotomized as either acceptable (≤20 CFU/m(3)) or not acceptable (>20 CFU/m(3)). To determine whether door openings were associated with CFU/m(3) values, we used generalized linear mixed models to model the dichotomized repeatedly measured CFU/m(3) values. RESULTS: The median number of door openings per operation was eight (range, 0-72), the median duration of surgery was 145 min (range, 60-285), and the median number of persons present during surgery was eight (range, 5-10). Adjusted for number of persons in the operation room and duration of surgery, the number of door openings per operation was associated (odds ratio [OR] 1.05 [95% confidence interval {CI} 1.02-1.09]; p = 0.003) with an unacceptable number of CFU/m(3). CONCLUSIONS: In conclusion, a substantial association between number of door openings and an unacceptable number (>20) of CFU/m(3) was found. Adjusted for number of persons in the operation room and duration of surgery, every door opening increased the odds of unacceptable CFU/m(3) values by 5%. Number of persons present during surgery and duration of surgery were not related to CFU/m(3).

Impregnation of bone chips with antibiotics and storage of antibiotics at different temperatures: an in vitro study.

BACKGROUND: Allograft bone used in joint replacement surgery can additionally serve as a carrier for antibiotics and serve as a prophylaxis against infections. However, in vitro dose-response curves for bone chips impregnated with different kinds of antibiotics are not available. In addition, while it would be desirable to add the antibiotics to allograft bone chips before these are stored in a bone bank, the effects of different storage temperatures on antibiotics are unknown. METHODS: Five different antibiotics (cefazolin, clindamycin, linezolid, oxacillin, vancomycin) were stored, both as pills and as solutions, at -80 degrees C, -20 degrees C, 4 degrees C, 20 degrees C and 37 degrees C; in addition, bone chips impregnated with cefazolin and vancomycin were stored at -80 degrees C and -20 degrees C. After 1 month, 6 months and 1 year, the activity of the antibiotics against Staphylococcus epidermidis was measured using an inoculated agar. The diameter of the S. epidermidis-free zone was taken as a measure of antibiotic activity. In a separate experiment, in vitro dose-response curves were established for bone chips impregnated with cefazolin and vancomycin solutions at five different concentrations. Finally, the maximum absorbed amounts of cefazolin and vancomycin were established by impregnating 1 g of bone chips with 5 ml of antibiotic solution. RESULTS: A decrease of the S. epidermidis-free zone was seen with oxacillin and cefazolin solutions stored at 37 degrees C for 1 month, with vancomycin stored at 37 degrees C for 6 months and with cefazolin and oxacillin solutions stored at 20 degrees C for 6 months. The activity of the other antibiotic solutions, pills and impregnated bone chips was not affected by storage. The in vitro dose-response curves show that the free-zone diameter increases logarithmically with antibiotic concentration. The absorbed antibiotic amount of one gram bone chips was determined. CONCLUSIONS: Storage of antibiotics in frozen form or storage of antibiotic pills at temperatures up to 37 degrees C for 12 months does not affect their activity. However, storage of antibiotic solutions at temperatures above 20 degrees C does affect the activity of some of the antibiotics investigated. The in vitro dose-response curve can be used to determine the optimal concentration(s) for local application. It provides the opportunity to determine the antibiotic content of bone chips, and thus the amount of antibiotics available locally after application.

Microbiological examination of donated human cardiac tissue in heart valve banking.

OBJECTIVE: Microbiological examination of donated human cardiac tissue is a necessary procedure for Heart Valve Banks to determine the biological safety of preserved allografts. Test protocols must be validated to prevent false-negative outcomes that pose a risk of infection to recipients of the tissue. The Heart Valve Bank in Rotterdam evaluated a validated, alternative entry test for donated tissues to compare the performance of its standard microbiological examinations. METHODS: Samples of explanted heart transport medium from 275 donors were examined for the presence of microorganisms using blood culture flasks (standard test) and fluid thioglycolate medium (alternative test). Results were compared with the outcome of microbiological assessment of subvalvular myocardial fragments and the cryoprotective medium that were collected before and after treatment of the grafts with antibiotics, respectively. RESULTS: Microorganisms, mainly skin flora, were detected in transport medium of 177 hearts (64%). The alternative validated culture method detected a growth in 80 transport medium samples that was not identified by the standard method. Microorganisms were only identified in the cultivated cardiac tissue fragments from 56 donors (20%). After antibiotic treatment of the tissue, microorganisms could still be encountered in cryoprotective medium samples from 55 donors (20%). Most of the contaminants in these final samples were identified as Propionibacterium species and Corynebacterium species and had already been detected in the transport medium by the alternative validated culture method. CONCLUSIONS: The use of blood culture flasks for microbiological assessment of non-blood liquid media and the cultivation of myocardial tissue fragments may hamper detection of certain microorganisms and therefore provide less complete information about microbiological safety. Heart Valve Banks may want to review their microbiological examination and decontamination procedures regarding the ability to detect and eliminate anaerobic skin flora, respectively.

Early small bowel perforation and cochleovestibular impairment as rare complications of typhoid fever.

Two Indian migrant workers suffering from fever and malaise were admitted to the hospital directly after arrival in the Netherlands. The first patient was 25-year-old man who had fever and rigors on admission. The patient was treated for presumptive typhoid fever with ciprofloxacin. Cefotaxime was added the following day because of the possibility of a nalidixic-acid resistant strain of S. typhi. The clinical course was complicated by a small bowel perforation on the third day of the disease. Blood cultures grew a nalidixic acid resistant strain of Salmonella enterica serovar typhi. The patient recovered completely. The second patient, a 22-year-old man, suffered from fever, malaise and hearing loss. A sensorineural hearing loss with vestibular dysfunction was diagnosed. Cultures of blood and bone marrow aspirate showed a nalidixic acid resistant strain of S. typhi. Treatment with ciprofloxacin and ceftazidime improved the hearing loss significantly. The clinical features of typhoid fever are heterogeneous and rare complications may occur. The emergence of multidrug and nalidixic acid resistance may complicate further the treatment of this serious systemic infection.

Nontuberculous mycobacteria, zambia.

Clinical relevance of nontuberculous mycobacteria (NTM) isolated from 180 chronically ill patients and 385 healthy controls in Zambia was evaluated to examine the contribution of these isolates to tuberculosis (TB)-like disease. The proportion of NTM-positive sputum samples was significantly higher in the patient group than in controls; 11% and 6%, respectively (p<0.05). NTM-associated lung disease was diagnosed for 1 patient, and a probable diagnosis was made for 3 patients. NTM-positive patients and controls were more likely to report vomiting and diarrhea and were more frequently underweight than the NTM-negative patients and controls. Chest radiographs of NTM-positive patients showed deviations consistent with TB more frequently than those of controls. The most frequently isolated NTM was Mycobacterium avium complex. Multiple, not previously identified mycobacteria (55 of 171 NTM) were isolated from both groups. NTM probably play an important role in the etiology of TB-like diseases in Zambia.

Isolation of nontuberculous mycobacteria in Zambia: eight case reports.

The isolation of nontuberculous mycobacteria (NTM) raises the question of their clinical significance, especially in an African setting. We found a high percentage of NTM isolated from various specimens, including ones that are normally sterile, among 213 patients in Zambia. Because tuberculosis can affect all parts of the body, we decided to include patients who had signs and symptoms in any part of the body for more than 2 weeks. Most patients had tractus respiratorius (80%) and tractus digestivus (10%) symptoms. During three consecutive days, sputum was collected and two separate sputum specimens were cultured for mycobacteria. Depending on the clinical picture, pleural effusion, ascites, abscess material, or enlarged lymph nodes were also cultured for mycobacteria. A specimen from one sterile body site was collected from 25 patients (60% human immunodeficiency virus [HIV] positive). NTM were isolated from 8 of these 25 specimens. Mycobacterium lentiflavum was isolated from four patients, and Mycobacterium goodii was isolated from one patient. In order to exclude the possibility of laboratory cross-contamination, a novel amplified fragment length polymorphism DNA typing method for M. lentiflavum was developed. Genetic variation was detected, rendering the likelihood of laboratory contamination unlikely. Clinically relevant infection due to NTM occurs in both HIV-positive and HIV-negative patients in Zambia, and their clinical impact seems to be underestimated. This is the first report of M. lentiflavum and M. goodii infections in Africa.

Evaluation of plasma lactate as a parameter for disease severity on admission in travelers with Plasmodium falciparum malaria.

BACKGROUND: Rapid immunochromatographic dipstick assays are used increasingly in many tropical and Western countries as a tool to diagnose Plasmodium falciparum malaria. However, these tests do not provide any information about the severity of the infection. We evaluated the usefulness of plasma lactate as a parameter for disease severity on admission in imported P. falciparum malaria. METHODS: In a cohort of 61 nonimmune travelers with imported P. falciparum malaria, plasma lactate levels on admission were related to the severity of the infection. Results from 12 of 61 patients fulfilled the criteria of severe malaria. RESULTS: Logistic regression analysis showed that a plasma lactate level above the upper range of normal was associated with an odds ratio of 31 (95% CI 6-164) for severe malaria. As a continuous variable, a 1 mmol/L increase in plasma lactate level was associated with an odds ratio of 12 (95% CI 3-50) for severe malaria. The sensitivity of an increased plasma lactate level on admission for severe malaria was 67% with a specificity of 94%. CONCLUSIONS: A timely determination of plasma lactate on admission may be helpful in the assessment of disease severity in travelers with imported P. falciparum malaria. An increased plasma lactate level should raise suspicion of a severe P. falciparum malaria infection, in particular when concomitant infections are not considered likely.

Helicobacter cinaedi-associated bacteraemia and erysipelas in an immunocompetent host: a diagnostic challenge.

Helicobacter cinaedi was initially recovered from homosexual men infected with human immunodeficiency virus. Later, it was also isolated from patients with chronic alcoholism, and anecdotally from non-immunocompromized men, women, and children. We describe a case of H. cinaedi-associated bacteraemia and erysipelas in a homosexual but immunocompetent male and the diagnostic problems in identifying the causative organism.

Comparison of NaOH-N-acetyl cysteine and sulfuric acid decontamination methods for recovery of mycobacteria from clinical specimens.

We compared the NaOH-N-acetyl cysteine (NaOH-NALC) and the sulfuric acid decontamination procedure in the detection of mycobacteria using the Mycobacteria Growth Indicator Tube (MGIT). In total 219 sputum specimens were collected from 142 Zambian patients and subjected to mycobacterial culture. One half of the specimen was decontaminated with NaOH-NALC and the other half was decontaminated with sulfuric acid. From the 438 samples a total of 261 (60%) cultures yielded growth of mycobacteria, consisting of 22 different species. The sulfuric acid method was more successful than the NaOH-NALC method in recovering mycobacteria in MGITs (146 versus 115 respectively, p = 0.001). Of the 146 positive mycobacterial cultures recovered after sulfuric acid decontamination 28 were Mycobacterium tuberculosis, 84 nontuberculous mycobacteria (NTM) and 34 acid fast bacterial isolates which could not be identified to the species level. The 115 mycobacteria recovered by the NaOH-NALC method consisted of 34 M. tuberculosis strains, 55 NTM and 26 acid fast bacteria that could not be identified. The most frequently isolated NTM were Mycobacterium lentiflavum and Mycobacterium intracellulare. Comparing the two decontamination methods the recovery of NTM in the sulfuric acid group was significant higher than in the NaOH-NALC group (p = 0.001). In contrast, no significant difference was found for the recovery of M. tuberculosis. These results show that the decontamination method used affects the recovery of nontuberculous mycobacteria in particular.

Bacterial contamination of femoral head allografts from living donors.

We analyzed the bacterial contamination rate of femoral head allografts from living donors and determined the true bacterial load with cultures from the grafts in their entirety in a specially prepared medium. During 4 years we took swab cultures from 2,679 grafts of which 2,414 (90%) were negative. In a period of 12 months, grafts rejected for reasons other than infectious disease were cultured in their entirety to determine the true bacterial load. Of the 106 grafts included, 15 were contaminated. Microorganisms were isolated from 10 of the 91 initially swab culture-negative grafts (9%) and from only 5 of the 15 swab culture-positive grafts, most of which were normal skin contaminants. Swab culture negative grafts apparently may still be contaminated. It seems wise to subject all femoral head allografts from living donors to antibacterial processing.