Review article: treatment of Clostridium difficile infection

AIM: A systematic review of controlled trials of therapy of Clostridium difficile intestinal infection using methodology described by the Cochrane Collaboration. METHODS: Trials were identified by searching computer databases over the years 1978-1996. Trials were included if they were (a) prospective randomized, controlled trials and (b) included patients with symptomatic disease. The primary end-point was clinical resolution of diarrhoea. Secondary end-points were clinical relapse and stool clearance of C. difficile and C. difficile toxin. RESULTS: Nine trials (469 patients) satisfying the inclusion criteria were identified. Two trials were placebo controlled. Six trials compared vancomycin to other antibiotics (fusidic acid, bacitracin, teicoplanin and metronidazole). For clinical resolution response rates ranged from 21 (placebo) to 100% (vancomycin). On pooling the trials, no antibiotic showed clear therapeutic superiority. Rates of clinical relapse ranged from 5 to 42%. Only one trial showed significant advantage of one antibiotic over another for prevention of relapse (teicoplanin vs. fusidic acid). CONCLUSION: The published data are limited, and further studies are required.     

Clostridium difficile colitis associated with chronic renal failure

BACKGROUND: Clostridium difficile-associated diarrhoea (CDAD) is a potentially life-threatening illness which has been shown to be more common and more severe in patients with chronic renal failure (CRF) than in other groups. A review of CDAD in our nephrology unit was carried out. METHODS: A review of microbiology and histology records identified 32 cases of CDAD in the nephrology unit over a 24-month period. Patient notes were reviewed to identify risk factors, clinical features and outcome. Available isolates of C. difficile underwent 16S ribosomal RNA typing. RESULTS: The incidence of CDAD in the nephrology unit was 10.7 per 1000 admissions, compared to 2.7 per 1000 in other areas of the hospital (P<0.0001). CDAD was considered the sole or principal cause of death in six (19%) and was considered a contributing factor in a further seven (22%). Mortality was significantly higher among patients with established CRF (P=0.04). Seven cases occurred as a cluster, over a 1-month period. Isolates from this cluster, along with comparative strains from other areas of the hospital, were found to be PCR type 1. Diarrhoea occurred in 28 (89%) of cases, pyrexia in 17 (53%) and ileus or abdominal pain in 14 (44%). Six patients responded to discontinuation of antibiotics alone and 22 required metronidazole and/or vancomycin. Three patients had colectomy and one caecostomy because of toxic megacolon. Four patients died before specific therapy could be given and in two of these cases the diagnosis was made at autopsy. Twenty-six patients had a record of recent antibiotic therapy. Of these, 15 had at least one agent considered to be inappropriate (excessively broad spectrum agent in 11, excessive duration of therapy in four). Nine patients had only received antibiotics prior to admission. CONCLUSIONS: CDAD carries a high mortality in nephrology patients, especially those with established CRF. The diagnosis may be missed if a careful antibiotic history is not taken, including agents received prior to admission. Rational antibiotic prescribing and adherence to infection control measures are vital to reduce the incidence of this serious condition.     

Observations on the risk of resistance with the extended use of vancomycin

OBJECTIVE: To document the risk of the development of vancomycin-resistant bacteria in a population of seriously burned patients during a 10-year period of common vancomycin hydrochloride use. DESIGN: Retrospective study. SETTING: The US Army Institute of Surgical Research, Burn Center, Fort Sam Houston, Tex. POPULATION AND METHODS: Microbiology, infection, and antibiotic use records collected during the hospitalization of 2266 consecutively admitted seriously burned patients were reviewed. Vancomycin was the primary therapeutic agent used for gram-positive infections and was also used as a perioperative prophylactic antibiotic during burn wound excision. This policy was established prior to this review because of a high incidence of methicillin-resistant Staphylococcus aureus colonization and an anecdotal association of increased beta-lactam resistance in endemic gram-negative pathogens associated with the use of penicillinase-resistant penicillins and cephalosporins. MAIN OUTCOME MEASURES: Isolation of vancomycin-resistant enterococci (VRE) or other gram-positive organisms resistant to vancomycin. RESULTS: Examinations of 15 125 gram-positive isolates, including 957 enterococci, for in vitro sensitivity to vancomycin yielded 3 VRE isolates in 3 patients. Vancomycin was used prior to VRE isolation in one of these patients. Resistance was found in 3 other organisms (2 Corynebacterium species, 1 Lactobacillus species). Vancomycin was used prior to these isolations in 2 of 3 patients. None of the vancomycin-resistant organisms was associated with infection and all 6 patients survived. Vancomycin-resistant enterococci or other vancomycin-resistant gram-positive organisms were not found in 663 patients treated with vancomycin for documented gram-positive infections or in 1027 patients where perioperative vancomycin was used. CONCLUSION: Use of vancomycin as the primary therapeutic agent in seriously burned patients was not associated with increased risk of VRE isolation or VRE infection.     

Pharmacoeconomics of intravenous antibiotic use in serious infection

A pharmacoeconomic study of 15 antibiotics available in Barbados was performed. The antibiotics studied were amoxycillin/clavulanate, ampicillin, ampicillin/sulbactam, cefazolin, cefotaxime, ceftazidime, ceftriaxone, clindamycin, cloxacillin, cotrimoxazole, gentamicin, imipenem, metronidazole, piperacillin, piperacillin/tazobactam, and vancomycin. The costs of use of these compounds were calculated for a five-day course using a formula comprising eight categories: antibiotic purchase cost, maintenance of intravenous access, drug delivery cost, drug monitoring cost, dose readjustment, general monitoring cost, 'sharps' disposal cost and adverse effects. The costs of adverse effects were not included in this study due to lack of accurate data. The total cost of antibiotic use (in U.S. dollars) ranged from $42.52 to $463.73 per five-day course. Generic compounds were less expensive ($45.52 - $98.23) than brand-name compounds ($106.18 - $106.18 - $463.73). Antibiotic purchase costs accounted for proportions of total costs ranging from 7 to 93%. Non-drug costs represented a much greater proportion of total costs of generic compounds. For most compounds the non-drug costs were related to the frequency of dosing, but for gentamicin the non-drug costs were relatively higher because of the need for monitoring of serum gentamicin levels. Efficacy and freedom from side-effects will remain the most important determinants in the choice of antibiotic therapy. However, pharmacoeconomic analyses can provide prescribers with the information required to make cost-effective choices for treatment of their patients.     

Early eradication of pathogens from middle ear fluid during antibiotic treatment of acute otitis media is associated with improved clinical outcome

OBJECTIVE: To determine the relation between early bacteriologic eradication and clinical outcome of acute otitis media (AOM) in infants and young children treated with various antibiotics. STUDY DESIGN: The study group consisted of patients ages 3 to 24 months seen at the Pediatric Emergency Room with: (1) symptoms and physical findings consistent with AOM of < or = 7 days duration; (2) no spontaneous perforation or tympanostomy tubes; (3) positive initial middle ear fluid culture; and (4) a follow-up to at least Day 10+/-2 of the study with a second culture performed 72 to 96 h after initiation of antibiotic treatment. Any patient with a positive middle ear fluid culture 72 to 96 h after initiation of antibiotic treatment was considered to have bacteriologic failure. Otologic evaluation was done by an otolaryngologist unaware of the culture results and of the study drug allocation. A clinical score based on body temperature, report of irritability and ear tugging observed by the parents and the appearance and redness of the ear drum as observed by the otolaryngologist was also used for clinical evaluation. RESULTS: The study group consisted of 123 patients, of whom 57 (46%) had positive middle ear fluid 72 to 96 h after initiation of antibiotic treatment. Clinical failure was observed in 21 of 57 (37%) patients in whom bacteriologic eradication did not occur vs. only 2 of 66 (3%) patients with bacteriologic eradication after 3 to 4 days of treatment (P < 0.001). Clinical score for both moderate and severe disease decreased significantly faster in those with bacteriologic eradication than in those in whom middle ear fluid was still culture-positive 72 to 96 h after initiation of treatment. CONCLUSION: Clinical failures in our population were associated with inability to eradicate the causative organisms of AOM from the middle ear fluid within 3 to 4 days after initiation of antibiotic therapy. Most patients (including those without bacteriologic eradication) improved after 3 to 4 days of treatment, but patients with sterile middle ear fluid felt better after 3 to 4 days of treatment than patients in whom middle ear fluid was still culture-positive.     

Stimulation by leptin of 3H GDP binding to brown adipose tissue of fasted but not fed rats

We conducted a retrospective review of 125 patients undergoing high-dose therapy and stem cell rescue in order to evaluate the incidence of documented infection and the utility of the administration of vancomycin empirically. All patients received prophylactic oral quinolone therapy. Because neutropenia in this setting is relatively brief, 21 patients never manifested fever, and no patient died of infection. Of the remaining 104 patients, positive blood cultures were obtained in only 10, nine with a gram stain positive and one with a gram stain negative organism. Sixty-two patients without any evidence of gram positive infection received vancomycin according to the existing algorithm for care of neutropenic fevers. In this population of patients, empiric administration of vancomycin for neutropenic fevers without culture documentation appears to be unnecessary, could be discontinued safely and at substantial cost savings, and might slow the appearance of vancomycin-resistant organisms.     

Metronidazole. A therapeutic review and update

The nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment. Anaerobic bacteria which are typically sensitive are primarily Gram-negative anaerobes belonging to the Bacteroides and Fusobacterium spp. Gram-positive anaerobes such as peptostreptococci and Clostridia spp. are likely to test sensitive to metronidazole, but resistant isolates are probably encountered with greater frequency than with the Gram-negative anaerobes. Gardnerella vaginalis is a pleomorphic Gram-variable bacterial bacillus that is also susceptible to metronidazole. Helicobacter pylori has been strongly associated with gastritis and duodenal ulcers. Classic regimens for eradicating this pathogen have included metronidazole, usually with acid suppression medication plus bismuth and amoxicillin. The activity of metronidazole against anaerobic bowel flora has been used for prophylaxis and treatment of patients with Crohn's disease who might develop an infectious complication. Treatment of Clostridium difficile-induced pseudomembraneous colitis has usually been with oral metronidazole or vancomycin, but the lower cost and similar efficacy of metronidazole, coupled with the increased concern about imprudent use of vancomycin leading to increased resistance in enterococci, have made metronidazole the preferred agent here. Metronidazole has played an important role in anaerobic-related infections. Advantages to using metronidazole are the percentage of sensitive Gram-negative anaerobes, its availability as oral and intravenous dosage forms, its rapid bacterial killing, its good tissue penetration, its considerably lower chance of inducing C. difficile colitis, and expense. Metronidazole has notable effectiveness in treating anaerobic brain abscesses. Metronidazole is a cost-effective agent due to its low acquisition cost, its pharmacokinetics and pharmacodynamics, an acceptable adverse effect profile, and its undiminished antimicrobial activity. While its role as part of a therapeutic regimen for treating mixed aerobic/anaerobic infections has been reduced by newer, more expensive combination therapies, these new combinations have not been shown to have any therapeutic advantage over metronidazole. Although the use of metronidazole on a global scale has been curtailed by newer agents for various infections, metronidazole still has a role for these and other therapeutic uses. Many clinicians still consider metronidazole to be the 'gold standard' antibiotic against which all other antibiotics with anaerobic activity should be compared.     

Clostridium difficile-associated diarrhea and colitis: clinical manifestations, diagnosis, and treatment

PURPOSE: This review examines the pathogenesis, clinical manifestations, diagnosis, and current medical and operative strategies in the treatment of Clostridium difficile diarrhea and colitis. Prevention and future avenues of research are also investigated. METHODS: A review of the literature was conducted with the use of MEDLINE. RESULTS: C. difficile is a gram-positive, spore-forming bacterium capable of causing toxigenic colitis in susceptible patients, usually those receiving antibiotics. Overgrowth of toxigenic strains may result in a spectrum of disease, including becoming an asymptomatic carrier, diarrhea, self-limited colitis, fulminant colitis, and toxic megacolon. Diagnosis requires a high index of suspicion and depends on clinical data, laboratory stool studies (enzyme-linked immunoabsorbent assay and cytotoxin test), and endoscopy in selected cases. Protocols for treatment of primary and relapsing infections are provided in algorithm format. Discontinuation of antibiotics may be enough to resolve symptoms. Medical management with oral metronidazole or vancomycin is the first-line therapy for those with symptomatic colitis. Teicoplanin, Saccharomyces spp. and Lactobacillus spp., and intravenous IgG antitoxin are reserved for more recalcitrant cases. Refractory or relapsing infections may require vancomycin given orally or other newer modalities. Fulminant colitis and toxic megacolon warrant subtotal colectomy. Cost, in terms of extended hospital stay, medical and surgical management, and, in some cases, ward closure, is thought to be formidable. Review of perioperative antibiotic policies and analysis of hospital formularies may contribute to prevention and decreased costs. CONCLUSION: C. difficile diarrhea and colitis is a nosocomial infection that may result in significant morbidity, mortality, and medical costs. Standard laboratory studies and endoscopic evaluation assist in the diagnosis of clinically suspicious cases. Appropriate perioperative antibiotic dosing, narrowing the antibiotic spectrum when treating infections, and discontinuing antibiotics at appropriate intervals prevent toxic sequelae.     

Clostridium difficile infection is a risk factor for bacteremia due to vancomycin-resistant enterococci (VRE) in VRE-colonized patients with acute leukemia

A cohort study was conducted in a cancer center to identify risk factors for bacteremia with vancomycin-resistant enterococci (VRE) in neutropenic cancer patients colonized with VRE. There were 10 patients with VRE bacteremia among 56 colonized with VRE, of whose charts 51 were available for review. One hundred percent of patients with VRE bacteremia (10 of 10) vs. 56% of patients without VRE bacteremia (23 of 41) had acute leukemia (P = .01, Fisher's exact test). Four of the 10 patients with VRE bacteremia had a positive Clostridium difficile toxin assay within 6 days of their first positive VRE blood culture. Both C. difficile infection and antimicrobial (vancomycin and ciprofloxacin) use during VRE colonization were significant risk factors for VRE bacteremia in univariate analysis. When a Cox proportional hazards model was used to account for differences in follow-up time, C. difficile infection was the only statistically significant risk factor (risk ratio, 8.2; P = .007) for VRE bacteremia in VRE-colonized patients with acute leukemia.     

Metronidazole- and clarithromycin-resistant Helicobacter pylori in dyspeptic patients in western Sydney as determined by testing multiple isolates from different gastric sites

It is unknown whether antibiotic susceptibility testing of antral isolates alone is representative of Helicobacter pylori susceptibility. We aimed to determine: (i) the prevalence of metronidazole- and clarithromycin-resistant strains in infected dyspeptic patients; and (ii) whether there is consistency in the susceptibility to metronidazole and clarithromycin among isolates cultured from different gastric sites. Antral, body and fundus biopsies were taken from 242 consecutive patients and cultured on blood agar under micro-aerophilic conditions for 5-7 days. Isolates from 66 patients (13 had one, 15 had two and 38 had three isolates) were tested for susceptibility to metronidazole and clarithromycin using previously validated disc diffusion tests. Of the 66 patients, 42 (64%) had strains resistant to metronidazole while four (6.1%) had clarithromycin-resistant strains. The prevalence of metronidazole resistance was not significantly different between men and women (65% vs 60%) or across different age groups. In five (9.4%) of the 53 patients with multiple isolates, discrepant results for metronidazole susceptibility were observed: susceptible antral and body isolates but resistant fundus isolates in two cases and susceptible antral isolates but resistant body and fundus isolates in the others. Clarithromycin susceptibilities were consistent among the isolates cultured from different gastric sites in all patients. It is concluded that metronidazole-resistant strains of H. pylori are common while clarithromycin-resistant strains are rare. Metronidazole susceptibility testing of antral isolates does not appear to be representative of isolates from the body and fundus in a subset of patients.     

Effect of rapid viral diagnosis on the management of children hospitalized with lower respiratory tract infection

BACKGROUND: Although rapid viral tests are commonly used in children with lower respiratory tract infection, their effect on patient management has not been studied. OBJECTIVES: To examine how physicians utilize an enzyme immunoassay for respiratory syncytial virus (RSV EIA) and a centrifugation-enhanced cellular immunofluorescence assay for multiple viral pathogens [viral respiratory panel (VRP)] in children hospitalized with respiratory illness; to determine the effect of testing on length of stay, antibiotic use and costs; and to determine physician attitudes toward RSV testing. DESIGN AND SETTING: Prospective study and survey at a large children's hospital. PATIENTS: Previously healthy children < 24 months of age consecutively admitted between January 1 and February 11, 1995, with symptoms of lower respiratory tract infection. RESULTS: Of 200 patients 160 were tested by RSV EIA; 92 were positive and 68 were negative. Tested children were younger, more tachypneic and more likely to require oxygen than those not tested. Overall the length of stay was similar in RSV-positive and -negative patients. Although equal proportions of each group were given antibiotic therapy, RSV-positive children received antibiotic therapy for fewer days than RSV-negative children (median 2 vs. 3 days; P = 0.0387). However, a crude cost analysis did not support a strategy of testing all bronchiolitis patients for RSV. Sixty-five of the 68 RSV-negative children were tested for RSV and other pathogens by VRP. In 55 cases the results were not available until after patient discharge and could not have influenced their management. One hundred three physicians caring for children in the study were surveyed. Of 75 respondents almost all thought that RSV EIA results influenced their management of patients and were important to parents. CONCLUSIONS: Most children hospitalized with symptoms of lower respiratory tract infection were tested for viral pathogens. The VRP provided little clinically useful information. In contrast RSV EIA results may have been used by clinicians to make antibiotic decisions. Physicians felt that rapid testing for RSV was important.     

Impact of a vancomycin restriction policy on use and cost of vancomycin and incidence of vancomycin-resistant Enterococcus

OBJECTIVE: To review the appropriateness of vancomycin therapy, changes in vancomycin use, and the incidence of vancomycin-resistant Enterococcus (VRE) after implementation of a limited restriction policy requiring approval from the Infectious Diseases Approval service to continue vancomycin therapy beyond 72 hours. DESIGN: A prospective chart review was conducted in April 1995. Pharmacy billing data and infection control data were compared before and after policy implementation. SETTING: A 725-bed university teaching institution. PATIENTS: All patients receiving vancomycin during April 1995. MAIN OUTCOME MEASURES: Appropriateness of use was based on the Centers for Disease Control and Prevention (CDC) recommendations for prudent vancomycin use. RESULTS: A total of 333 courses of vancomycin therapy were reviewed. Vancomycin use was appropriate in 219 (66%) courses. Of the 114 courses that did not meet the CDC guidelines, 76 (67%) were for empiric use, 35 (31%) were for prophylactic use, and 3 (3%) were for therapeutic use. Overall, the total number of grams used decreased 9%, grams per 1000 patient-days decreased by 10, and the total number of patients exposed to vancomycin decreased 0.5%. Several services had large decreases in vancomycin use. Vancomycin expenditures decreased by $15788 for the 7-month time period. The incidence of VRE remained unchanged, at 30% of all enterococcal isolates 2 years after policy implementation. CONCLUSIONS: The limited restriction policy was effective in decreasing the total grams of vancomycin used. However, one-third of vancomycin therapy was inappropriate and the incidence of VRE was unchanged. A more stringent restriction policy could potentially increase appropriate use, further decrease the amount of vancomycin used, and decrease the incidence of VRE.     

Guidelines for early identification of Alzheimer Disease

BACKGROUND: The emergence of methicillin-resistant Staphylococcus aureus and its multidrug-resistant property has led to the search for an effective antibiotic to combat staphylococcal sepsis. At present, vancomycin remains the most effective antibiotic. This study evaluated the in vitro efficacy of netilmicin (an aminoglycoside) and compared its activity with 4 other antibiotics, viz. vancomycin, amikacin, tobramycin and ofloxacin. METHODS: The minimum inhibitory concentration of the antibiotics was determined by the agar dilution method. Thirty strains each of methicillin-resistant and -susceptible S. aureus isolated from pus and blood cultures were included. RESULTS: The susceptibility to netilmicin was found to be 100% and was the same as that observed for vancomycin. CONCLUSION: All the methicillin-resistant S. aureus strains tested showed 100% susceptibility to netilmicin, suggesting its use in patients with such infections as an alternative to vancomycin. However, this finding needs to be verified in the clinical setting.     

Clostridium difficile infections. Current aspects

Clostridium difficile is a gram-positive anaerobe that forms subterminal spores. It is now one of major nosocomial pathogens, mainly in older patients, because of its ability to persist in the environment and to become established in the gastrointestinal tract once the natural microflora has been modified by antibiotic therapy. Toxigenic strains of C. difficile produce toxin A (enterotoxin) or toxin B (cytotoxin) or both with cause the cytotoxic effect "rounding". C. difficile can spread from patient to patient and, probably, the primary way by which the organism is spread is by health care workers. C. difficile causes intestinal diseases ranging by mild diarrhea (antibiotic associated diarrhea) to fatal pseudomembranous colitis (PMC). The current therapy is based on oral administration of metronidazole or vancomycin . In patients non responders or that continue to relapse can be used other forms of therapy: antibiotic (teicoplanine, bacitracine, rifamixine); anion exchange resin (colestipol, colestiramine); probiotic therapy (S. boulardii, lactobacilli and fecal enemas). New and improved studies will lead to new and better ways of treating patients and better understanding of this unusual pathogen and how it causes diseases.     

Lipid metabolism in pregnancy. VIII. Effects of dietary fat versus carbohydrate on lipoprotein and hepatic lipids and tissue triglyceride lipases

From 1324 patients with antibiotic-associated diarrhea (AAD) 1643 stool samples were analyzed by a cell test for Clostridium difficile toxin in stool filtrates and cultivation for occurrence of C. difficile strains. In patients with no detectable toxin in their stool strains of C. difficile were isolated in 2.2% whereas when toxin was detectable, the isolation rate varied from 17% to 36%. Furthermore, there was a correlation between toxin titre in stool filtrate and production of cytotoxin in vitro by the corresponding C. difficile strains. Five clostridial strains, not belonging to the species C. difficile, were found to produce typical cytotoxin in vitro. However, five strains identified as C. difficile by biochemical reactions and gas liquid chromatography, did not produce an extracellular cytotoxin. The antibiotic susceptibility patterns of the Clostridium strains were investigated. No correlation was recognized between antibiotic resistance of isolated Clostridium strains and the AAD-inducing antibiotic penicillins and linco/clindamycin. Neither did cases of relapse of diarrheal disease after vancomycin treatment harbour C. difficile strains with increased resistance to vancomycin. It is concluded that the pathogenesis of antibiotic-associated enterocolitis is more complex than a mere intestinal overgrowth of resistant strains of C. difficile.     

Reduced E-cadherin expression correlates with unfavorable prognosis in adenoid cystic carcinoma of salivary glands of the oral cavity

OBJECTIVE: To describe the epidemiology, diagnosis, risk factors, patient impact, and treatment strategies for recurrent Clostridium difficile-associated disease (CDAD). DESIGN: Data were collected as part of a blinded, placebo-controlled clinical trial testing a new combination treatment for recurrent CDAD. Retrospective data regarding prior CDAD episodes were collected from interviews and medical-chart review. Prospective data on the current CDAD episode, risk factors, and recurrence rates were collected during a 2-month follow-up. SETTINGS: National referral study. PARTICIPANTS: Patients with recurrent CDAD. INTERVENTIONS: Treatment with a 10-day course of low-dose (500 mg/d) or high-dose (2 g/d) vancomycin or metronidazole (1 g/d). RESULTS: Recurrent CDAD was found to have a lengthy course involving multiple episodes of diarrhea, abdominal cramping, nausea, and fever. CDAD may recur over several years despite frequent treatment with antibiotics. Recurrence rates were similar regardless of the choice or dose of antibiotic. Recurrent CDAD is not a trivial disease: patients may have multiple episodes (as many as 14), may require hospitalization, and the mean lifetime cost of direct medical care was $10,970 per patient. Fortunately, the disease does not become progressively more severe as the number of episodes increase. Two risk factors predictive for recurrent CDAD were found: increasing age and a decreased quality-of-life score at enrollment. CONCLUSIONS: Recurrent CDAD is a persistent disease that may result in prolonged hospital stays, additional medical costs, and rare serious complications.     

The economic cost of a streptococcal tonsillitis episode

OBJECTIVE: To estimate the cost of a streptococcal tonsillitis episode from the data of a questionnaire. SETTING: Five primary health centres in the west of Sweden. PARTICIPANTS: 101 consecutive patients treated for streptococcal tonsillitis. MAIN OUTCOME MEASURE: The cost estimation included costs for physician visit and drug, travel costs to and from the primary health centre, cost of lost production resulting from the patient's or the guardian's absence from work for physician visit or sick-leave, and cost of telephone consultation with a physician or nurse. RESULTS: The period of illness was on average seven days, time to recovery after treatment five days, and the mean period of sick-leave 2.5 days. The total cost of a tonsillitis episode was about SEK 3,300 (385 USD). Of this sum, the cost for the antibiotic accounted for only 3% and loss of production for 75%. CONCLUSION: Differences in the cost of drugs only have a minor influence on the total cost, while factors causing loss of production, such as efficacy and side effects of the drug, have a greater influence. Economic evaluation of pharmaceuticals will be more relevant in the future, and in the search for the most effective treatment, cost effective studies will be integrated with clinical trials.     

Porphyromonas gingivalis invades human pocket epithelium in vitro

The present study examined the adhesive and invasive potential of Porphyromonas gingivalis interacting with human pocket epithelium in vitro. Pocket epithelial tissue, obtained during periodontal surgery of patients with advanced periodontal disease, generated a stratified epithelium in culture. P. gingivalis strains W50 and FDC 381 (laboratory strains), OMGS 712, 1439, 1738, 1739 and 1743 (clinical isolates) as well as Escherichia coli strain HB101 (non-adhering control) were tested with respect to epithelial adhesion and invasion. Adhesion was quantitated by scintillation spectrometry after incubation of radiolabeled bacteria with epithelial cells. The invasive ability of P. gingivalis was measured by means of an antibiotic protection assay. The epithelial multilayers were infected with the test and control strains and subsequently incubated with an antibiotic mixture (metronidazole 0.1 mg/ml and gentamicin 0.5 mg/ml). The number of internalized bacteria surviving the antibiotic treatment was assessed after plating lyzed epithelial cells on culture media. All tested P. gingivalis strains adhered to and entered pocket epithelial cells. However, considerable variation in their adhesive and invasive potential was observed. E. coli strain HB101 did not adhere or invade. Transmission electron microscopy revealed that internalization of P. gingivalis was preceded by formation of microvilli and coated pits on the epithelial cell surfaces. Intracellular bacteria were most frequently surrounded by endosomal membranes; however, bacteria devoid of such membranes were also seen. Release of outer membrane vesicles (blebs) by internalized P. gingivalis was observed. These results support and extend previous work from this laboratory which demonstrated invasion of a human oral epithelial cell-line (KB) by P. gingivalis.