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The addition of azithromycin to standard regimens for antibiotic prophylaxis before cesarean delivery may further reduce the rate of postoperative infection. We evaluated the benefits and safety of azithromycin-based extended-spectrum prophylaxis in women undergoing nonelective cesarean section.In this trial conducted at 14 centers in the United States, we studied 2013 women who had a singleton pregnancy with a gestation of 24 weeks or more and who were undergoing cesarean delivery during labor or after membrane rupture. We randomly assigned 1019 to receive 500 mg of intravenous azithromycin and 994 to receive placebo. All the women were also scheduled to receive standard antibiotic prophylaxis. The primary outcome was a composite of endometritis, wound infection, or other infection occurring within 6 weeks.The primary outcome occurred in 62 women (6.1%) who received azithromycin and in 119 (12.0%) who received placebo (relative risk, 0.51; 95% confidence interval [CI], 0.38 to 0.68; P0.001). There were significant differences between the azithromycin group and the placebo group in rates of endometritis (3.8% vs. 6.1%, P=0.02), wound infection (2.4% vs. 6.6%, P0.001), and serious maternal adverse events (1.5% vs. 2.9%, P=0.03). There was no significant between-group difference in a secondary neonatal composite outcome that included neonatal death and serious neonatal complications (14.3% vs. 13.6%, P=0.63).Among women undergoing nonelective cesarean delivery who were all receiving standard antibiotic prophylaxis, extended-spectrum prophylaxis with adjunctive azithromycin was more effective than placebo in reducing the risk of postoperative infection. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development; C/SOAP ClinicalTrials.gov number, NCT01235546 .).

Although data are limited, spontaneous abortion has been reported in as many as a fifth of pregnancies in some populations in low- and medium-income countries (LMICs).1 Miscarriages rates are noted...

Approximately 4 million babies are born each year in the United States. Of these infants, about a third are delivered by cesarean section. One of the many concerns about cesarean deliveries is the high risk of maternal infectious complications, which are 5 to 10 times more frequent than with vaginal deliveries.1 During cesarean delivery, the endometrial cavity and operative field may be seeded with pathogens, carried from the birth canal or the skin, that put mothers at risk for endometritis (incidence without prophylaxis, 4 to 18%) and of surgical-site infections (incidence without prophylaxis, 7 to 10%).2 To reduce these risks, . . .

Key Clinical PointsCare of the Asplenic Patient Asplenic patients are at risk for episodes of rapidly progressive septicemia that are fatal in up to 50% of cases. Asplenic patients should be informed that any illness with fever or severe symptoms without fever could indicate the onset of a life-threatening infection. Asplenic patients in whom fever develops should receive empirical antimicrobial therapy immediately. Vaccinations against pneumococci, Haemophilus influenzae type b, meningococci, and influenza virus are recommended for asplenic patients. Prophylactic antimicrobial therapy is generally recommended for asplenic children younger than 5 years of age and may be considered for older children and adults during the initial 1 to 2 years after splenectomy, with lifelong prophylaxis for persons who have had an episode of postsplenectomy sepsis.

Nitrofurantoin, trimethoprim–sulfamethoxazole, fosfomycin, and pivmecillinam are considered first-line agents for cystitis. Fluoroquinolones should not be routine first-line choices for cystitis, although they are first-line empirical therapy for pyelonephritis.

Nearly 1 million patients undergo knee arthroscopy in the United States every year.1 The incidence of symptomatic venous thromboembolism in this patient population is approximately 0.6%, or nearly 4000 patients per year.1,2 Published evidence for the benefit of prophylactic anticoagulation in patients undergoing knee arthroscopy has been of low or moderate quality, and on the basis of this evidence, the 2012 American College of Chest Physicians (ACCP) guidelines do not recommend the use of thromboprophylaxis in patients who do not have a history of venous thromboembolism.3 The National Institute for Health and Care Excellence (NICE) recommendations for hospitalized patients . . .

Group B streptococcal disease is one of the most common infections in the first week after birth. In 2002, national guidelines recommended universal late antenatal screening of pregnant women for colonization with group B streptococcus to identify candidates for intrapartum chemoprophylaxis.We evaluated the implementation of the guidelines in a multistate, retrospective cohort selected from the Active Bacterial Core surveillance, a 10-state, population-based system that monitors invasive group B streptococcal disease. We abstracted data from the labor and delivery records of a stratified random sample of live births and of all cases in which the newborn had early-onset group B streptococcal disease (i.e., disease in infants7 days of age) in 2003 and 2004. We compared our results with those from a study with a similar design that evaluated screening practices in 1998 and 1999.We abstracted records of 254 births in which the infant had group B streptococcal disease and 7437 births in which the infant did not. The rate of screening for group B streptococcus before delivery increased from 48.1% in 1998-1999 to 85.0% in 2003-2004; the percentage of infants exposed to intrapartum antibiotics increased from 26.8% to 31.7%. Chemoprophylaxis was administered in 87.0% of the women who were positive for group B streptococcus and who delivered at term, but in only 63.4% of women with unknown colonization status who delivered preterm. The overall incidence of early-onset group B streptococcal disease was 0.32 cases per 1000 live births. Preterm infants had a higher incidence of early-onset group B streptococcal disease than did term infants (0.73 vs. 0.26 cases per 1000 live births); however, 74.4% of the cases of group B streptococcal disease (189 of 254) occurred in term infants. Missed screening among mothers who delivered at term accounted for 34 of the 254 cases of group B streptococcal disease (13.4%). A total of 61.4% of the term infants with group B streptococcal disease were born to women who had tested negative for group B streptococcus before delivery.Recommendations for universal screening were rapidly adopted. Improved management of preterm deliveries and improved collection, processing, and reporting of culture results may prevent additional cases of early-onset group B streptococcal disease.

In this article we describe our approach to the management of wounds. Wherever possible, our recommendations are based on randomized trials. However, many of the recommendations are based on small, observational studies or expert opinion; thus, we recognize that there may be disagreement with some of our recommendations. Nevertheless, the approach we advise has been shown to be workable and useful. The primary goal in the management of wounds is to achieve rapid healing with optimal functional and aesthetic results. This is best accomplished by pre- venting infection and further trauma and by providing an environment that opti- mizes healing of the wound. All wounds should be thoroughly cleansed with tap water or normal saline. 6 For heavily contaminated wounds, high-pressure irriga- tion (>7 psi) can be achieved with the use of a 10-to-50-ml syringe and splatter shield (see the video in the Supplementary Appendix, available with the full text of this article at www.nejm.org). 7 The patient's tetanus-immunization status should be ascertained, and standard recommendations followed to ensure that the patient is protected against tetanus. A moist environment for the wound accelerates healing by preventing cellular dehydration and stimulating collagen synthesis and angiogenesis, thus improving cosmesis and reducing pain, the risk of infection, and the costs of care. 8-10 A moist environment may be created by covering the wound with a topical antimicrobial agent or by applying an occlusive dressing that reduces the loss of fluid through evaporation. Topical anti microbial agents have been shown to reduce rates of in- fection of traumatic lacerations, 11 although not of wounds caused by elective sur- gery. 12 Occlusive dressings have also been shown to reduce rates of infection. 13 Over-the-counter cyanoacrylate liquid bandages are effective for clean, simple wounds. 14 The choice of dressing depends on the cause, size, depth, location, degree of exudation, and level of contamination of the wound, as well as on cost (Table 1). There is no clinically directive evidence to support the choice of one dressing over another. 15 Occlusive dressings are less painful and more convenient for patients and may speed healing, although they are more expensive than topical antibiotics and gauze dressings. In some circumstances, however, the fact that

Ertapenem, a long-acting carbapenem, may be an alternative to the recommended prophylactic antibiotic cefotetan.In this randomized, double-blind trial, we assessed the efficacy and safety of antibiotic prophylaxis with ertapenem, as compared with cefotetan, in patients undergoing elective colorectal surgery. A successful outcome was defined as the absence of surgical-site infection, anastomotic leakage, or antibiotic use 4 weeks postoperatively. All adverse events were collected until 14 days after the administration of antibiotic prophylaxis.Of the 1002 patients randomly assigned to study groups, 901 (451 in the ertapenem group and 450 in the cefotetan group) qualified for the modified intention-to-treat analysis, and 672 (338 in the ertapenem group and 334 in the cefotetan group) were included in the per-protocol analysis. After adjustment for strata, in the modified intention-to-treat analysis, the rate of overall prophylactic failure was 40.2% in the ertapenem group and 50.9% in the cefotetan group (absolute difference, -10.7%; 95% confidence interval [CI], -17.1 to -4.2); in the per-protocol analysis, the failure rate was 28.0% in the ertapenem group and 42.8% in the cefotetan group (absolute difference, -14.8%; 95% CI, -21.9 to -7.5). Both analyses fulfilled statistical criteria for the superiority of ertapenem. In the modified intention-to-treat analysis, the most common reason for failure of prophylaxis in both groups was surgical-site infection: 17.1% in the ertapenem group and 26.2% in the cefotetan group (absolute difference, -9.1; 95% CI, -14.4 to -3.7). In the treated population, the overall incidence of Clostridium difficile infection was 1.7% in the ertapenem group and 0.6% in the cefotetan group (P=0.22).Ertapenem is more effective than cefotetan in the prevention of surgical-site infection in patients undergoing elective colorectal surgery but may be associated with an increase in C. difficile infection. (ClinicalTrials.gov number, NCT00090272 [ClinicalTrials.gov].).

Background Induction therapy reduces the frequency of acute rejection and delayed graft function after transplantation. A rabbit antithymocyte polyclonal antibody or basiliximab, an interleukin-2 receptor monoclonal antibody, is most commonly used for induction. Methods In this prospective, randomized, international study, we compared short courses of antithymocyte globulin and basiliximab in patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor. Patients taking cyclosporine, mycophenolate mofetil, and prednisone were randomly assigned to receive either rabbit antithymocyte globulin (1.5 mg per kilogram of body weight daily, 141 patients) during transplantation (day 0) and on days 1 through 4 or basiliximab (20 mg, 137 patients) on days 0 and 4. The primary end point was a composite of acute rejection, delayed graft function, graft loss, and death. Results At 12 months, the incidence of the composite end point was similar in the two groups (P=0.34). The antithymocyte globulin group, as compared with the basiliximab group, had lower incidences of acute rejection (15.6% vs. 25.5%, P=0.02) and of acute rejection that required treatment with antibody (1.4% vs. 8.0%, P=0.005). The antithymocyte globulin group and the basiliximab group had similar incidences of graft loss (9.2% and 10.2%, respectively), delayed graft function (40.4% and 44.5%), and death (4.3% and 4.4%). Though the incidences of all adverse events, serious adverse events, and cancers were also similar between the two groups, patients receiving antithymocyte globulin had a greater incidence of infection (85.8% vs. 75.2%, P=0.03) but a lower incidence of cytomegalovirus disease (7.8% vs. 17.5%, P=0.02). Conclusions Among patients at high risk for acute rejection or delayed graft function who received a renal transplant from a deceased donor, induction therapy consisting of a 5-day course of antithymocyte globulin, as compared with basiliximab, reduced the incidence and severity of acute rejection but not the incidence of delayed graft function. Patient and graft survival were similar in the two groups. (ClinicalTrials.gov number, NCT00235300 [ClinicalTrials.gov].).

Guidelines from the American Academy of Pediatrics recommend obtaining a voiding cystourethrogram and a renal ultrasonogram for young children after a first urinary tract infection; renal scanning with technetium-99m-labeled dimercaptosuccinic acid has also been endorsed by other authorities. We investigated whether imaging studies altered management or improved outcomes in young children with a first febrile urinary tract infection.In a prospective trial involving 309 children (1 to 24 months old), an ultrasonogram and an initial renal scan were obtained within 72 hours after diagnosis, contrast voiding cystourethrography was performed one month later, and renal scanning was repeated six months later.The ultrasonographic results were normal in 88 percent of the children (272 of 309); the identified abnormalities did not modify management. Acute pyelonephritis was diagnosed in 61 percent of the children (190 of 309). Thirty-nine percent of the children who underwent cystourethrography (117 of 302) had vesicoureteral reflux; 96 percent of these children (112 of 117) had grade I, II, or III vesicoureteral reflux. Repeated scans were obtained for 89 percent of the children (275 of 309); renal scarring was noted in 9.5 percent of these children (26 of 275).An ultrasonogram performed at the time of acute illness is of limited value. A voiding cystourethrogram for the identification of reflux is useful only if antimicrobial prophylaxis is effective in reducing reinfections and renal scarring. Renal scans obtained at presentation identify children with acute pyelonephritis, and scans obtained six months later identify those with renal scarring. The routine performance of urinalysis, urine culture, or both during subsequent febrile illnesses in all children with a previous febrile urinary tract infection will probably obviate the need to obtain either early or late scans.

In 1996 the American College of Obstetricians and Gynecologists, along with the American Academy of Pediatrics and the Centers for Disease Control and Prevention, recommended one of two courses for healthcare providers toidentify women who should receive intrapartum antibiotic prophylaxis to prevent group B streptococcal (GBS) disease in infants aged 1 week or less: screening by culture or assessment of clinical risk factors. These two approaches have now been compared in a retrospective cohort study of approximately 630,000 live births. Study cases were accessed in the years 1998-1999 in eight geographic areas of the United States where active surveillance for GBS infection was under way. A random sample of these areas yielded 5144 births. The 312 cases of early onset GBS disease translated into an overall incidence of 0.5 case per 1000 live births. No clinical risk factors for transmitting GBS disease were identified in 62% of cases. More than half of the women in the overall population (52%) were screened before delivery. On univariate analysis, prenatal culture screening correlated with a lower risk of early onset GBS disease than was the clinical risk-based approach; the relative risk (RR) was 0.48. The most prominent risk factors were a previous infant having GBS disease and intrapartum fever. GBS bacteriuria during pregnancy was not a factor, but more than 80% of all women with bacteriuria received intrapartum antibiotics. Screening continued to be associated with a reduced risk on multivariate analysis (RR, 0.46). Screening protected full-term infants when analyzed separately. Intrapartum antibiotic treatment was 89% effective in preventing early onset GBS disease in culture-positive women. It was estimated that, assuming perfect implementation of either strategy, intrapartum antibiotics would be used in 31% of screened women and 29% of those having risk-based assessment. These findings suggest that it makes sense to further consider a recommendation favoring universal screening to prevent GBS disease in newborn infants.

It is uncertain whether the rates and causes of early-onset sepsis (that occurring within 72 hours after birth) among very-low-birth-weight infants have changed in recent years, since antibiotics have begun to be used more widely during labor and delivery.We studied 5447 very-low-birth-weight infants (those weighing between 401 and 1500 g) born at centers of the Neonatal Research Network of the National Institute of Child Health and Human Development between 1998 and 2000 who had at least one blood culture in the first three days of life and compared them with 7606 very-low-birth-weight infants born at centers in the network between 1991 and 1993.Early-onset sepsis (as confirmed by positive blood cultures) was present in 84 infants in the more recent birth cohort (1.5 percent). As compared with the earlier birth cohort, there was a marked reduction in group B streptococcal sepsis (from 5.9 to 1.7 per 1000 live births of infants weighing 401 to 1500 g, P0.001) and an increase in Escherichia coli sepsis (from 3.2 to 6.8 per 1000 live births, P=0.004); the overall rate of early-onset sepsis was not significantly changed. Most E. coli isolates from the recent birth cohort (85 percent) were resistant to ampicillin, and mothers of infants with ampicillin-resistant E. coli infections were more likely to have received intrapartum ampicillin than were those with ampicillin-sensitive strains (26 of 28 with sensitivity data vs. 1 of 5, P=0.01). Infants with early-onset sepsis were more likely to die than uninfected infants (37 percent vs. 13 percent, P0.001), especially if they were infected with gram-negative organisms.Early-onset sepsis remains an uncommon but potentially lethal problem among very-low-birth-weight infants. The change in pathogens over time from predominantly gram-positive to predominantly gram-negative requires confirmation by ongoing surveillance.

Patients with nasal carriage of Staphylococcus aureus have an increased risk of surgical-site infections caused by that organism. Treatment with mupirocin ointment can reduce the rate of nasal carriage and may prevent postoperative S. aureus infections.We conducted a randomized, double-blind, placebo-controlled trial to determine whether intranasal treatment with mupirocin reduces the rate of S. aureus infections at surgical sites and prevents other nosocomial infections.Of 4030 enrolled patients who underwent general, gynecologic, neurologic, or cardiothoracic surgery, 3864 were included in the intention-to-treat analysis. Overall, 2.3 percent of mupirocin recipients and 2.4 percent of placebo recipients had S. aureus infections at surgical sites. Of the 891 patients (23.1 percent of the 3864 who completed the study) who had S. aureus in their anterior nares, 444 received mupirocin and 447 received placebo. Among the patients with nasal carriage of S. aureus, 4.0 percent of those who received mupirocin had nosocomial S. aureus infections, as compared with 7.7 percent of those who received placebo (odds ratio for infection, 0.49; 95 percent confidence interval, 0.25 to 0.92; P=0.02).Prophylactic intranasal application of mupirocin did not significantly reduce the rate of S. aureus surgical-site infections overall, but it did significantly decrease the rate of all nosocomial S. aureus infections among the patients who were S. aureus carriers.

A 27-year-old man presented to the emergency department with a 5-day history of fevers. Test your diagnostic and therapeutic skills at NEJM.org.

Infection with Bacillus anthracis, commonly known as anthrax, has reemerged as a weapon of bioterrorism. This review article revisits and updates our 1999 review of anthrax and contains practical information for the physician faced with a possible case of this dangerous infection.

Background Group B streptococcal infections are a leading cause of neonatal mortality, and they also affect pregnant women and the elderly. Many cases of the disease in newborns can be prevented by the administration of prophylactic intrapartum antibiotics. In the 1990s, prevention efforts increased. In 1996, consensus guidelines recommended use of either a risk-based or a screening-based approach to identify candidates for intrapartum antibiotics. To assess the effects of the preventive efforts, we analyzed trends in the incidence of group B streptococcal disease from 1993 to 1998. Methods Active, population-based surveillance was conducted in selected counties of eight states. A case was defined by the isolation of group B streptococci from a normally sterile site. Census and live-birth data were used to calculate the race-specific incidence of disease; national projections were adjusted for race. Results Disease in infants less than seven days old accounted for 20 percent of all 7867 group B streptococcal infections. The incidence of early-onset neonatal infections decreased by 65 percent, from 1.7 per 1000 live births in 1993 to 0.6 per 1000 in 1998. The excess incidence of early-onset disease in black infants, as compared with white infants, decreased by 75 percent. Projecting our findings to the entire United States, we estimate that 3900 early-onset infections and 200 neonatal deaths were prevented in 1998 by the use of intrapartum antibiotics. Among pregnant girls and women, the incidence of invasive group B streptococcal disease declined by 21 percent. The incidence among nonpregnant adults did not decline. Conclusions Over a six-year period, there has been a substantial decline in the incidence of group B streptococcal disease in newborns, including a major reduction in the excess incidence of these infections in black infants. These improvements coincide with the efforts to prevent perinatal disease by the wider use of prophylactic intrapartum antibiotics.

Background In patients with persistent fever and neutropenia, amphotericin B is administered empirically for the early treatment and prevention of clinically occult invasive fungal infections. However, breakthrough fungal infections can develop despite treatment, and amphotericin B has substantial toxicity. Methods We conducted a randomized, double-blind, multicenter trial comparing liposomal amphotericin B with conventional amphotericin B as empirical antifungal therapy. Results The mean duration of therapy was 10.8 days for liposomal amphotericin B (343 patients) and 10.3 days for conventional amphotericin B (344 patients). The composite rates of successful treatment were similar (50 percent for liposomal amphotericin B and 49 percent for conventional amphotericin B) and were independent of the use of antifungal prophylaxis or colony-stimulating factors. The outcomes were similar with liposomal amphotericin B and conventional amphotericin B with respect to survival (93 percent and 90 percent, respectively), resolution of fever (58 percent and 58 percent), and discontinuation of the study drug because of toxic effects or lack of efficacy (14 percent and 19 percent). There were fewer proved breakthrough fungal infections among patients treated with liposomal amphotericin B (11 patients [3.2 percent]) than among those treated with conventional amphotericin B (27 patients [7.8 percent], P=0.009). With the liposomal preparation significantly fewer patients had infusion-related fever (17 percent vs. 44 percent), chills or rigors (18 percent vs. 54 percent), and other reactions, including hypotension, hypertension, and hypoxia. Nephrotoxic effects (defined by a serum creatinine level two times the upper limit of normal) were significantly less frequent among patients treated with liposomal amphotericin B (19 percent) than among those treated with conventional amphotericin B (34 percent, P Conclusions Liposomal amphotericin B is as effective as conventional amphotericin B for empirical antifungal therapy in patients with fever and neutropenia, and it is associated with fewer breakthrough fungal infections, less infusion-related toxicity, and less nephrotoxicity.

Nosocomial pneumonia is a leading cause of death from hospital-acquired infections, with an associated crude mortality rate of approximately 30 percent.1 Ventilator-associated pneumonia refers specifically to nosocomial bacterial pneumonia that has developed in patients who are receiving mechanical ventilation. Ventilator-associated pneumonia that occurs within 48 to 72 hours after tracheal intubation is usually termed early-onset pneumonia; it often results from aspiration, which complicates the intubation process.2 Ventilator-associated pneumonia that occurs after this period is considered late-onset pneumonia. Early-onset ventilator-associated pneumonia is most often due to antibiotic-sensitive bacteria (e.g., oxacillin-sensitive Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae), whereas late-onset . . .

In this issue of the Journal, Itani and colleagues1 describe a study in which 1002 patients were randomly assigned to receive either ertapenem or cefotetan in a single dose before elective colorectal surgery. Many experienced surgeons and hospital epidemiologists will probably be surprised that the overall rate of failure in the modified intention-to-treat analysis was approximately 40% for patients receiving ertapenem and 50% for those receiving cefotetan. A possible explanation for these high failure rates is that the authors of the study, unlike those of most previous trials, included unexplained use of postoperative antibiotics and anastomotic leaks in their definition . . .

Each year in the United States, more than 12 million traumatic wounds are treated in emergency departments.1 When nonemergency or elective incisions are included, approximately 90 million skin-suturing procedures are performed each year.2 Traumatic lacerations occur most often in young men, typically on the face, scalp, and hands.3 More than 50 percent of all lacerations are caused by blunt injury that produces shear forces, and most others by sharp objects, such as metal, glass, and wood.3,4 Only a minority of wounds are caused by mammalian or nonmammalian bites.3 The ultimate goals of wound management are to avoid infection and . . .

Improved management of infectious complications of cancer has contributed substantially to the success of care over the past several decades. In the 1960s it became clear that neutropenia was highl...

Vesicoureteral reflux, the retrograde flow of bladder urine into the ureter, is common in young children with urinary tract infections and is associated with renal scarring. Reflux is generally discovered when a voiding cystourethrogram is obtained after a urinary tract infection and is categorized as grade I (retrograde flow of urine into the ureter alone) to grade V (massive reflux into a distorted ureter and calyceal system). After an observational study by Edwards et al.1 showed that vesicoureteral reflux improved or resolved with long-term, low-dose antibiotic treatment to prevent infection, such treatment gained popularity. Nearly four decades later, we still . . .

Randomized, controlled trials have shown that prophylactic antibiotics are effective in preventing surgical-wound infections. However, it is uncertain how the timing of antibiotic administration affects the risk of surgical-wound infection in actual clinical practice.We prospectively monitored the timing of antibiotic prophylaxis and studied the occurrence of surgical-wound infections in 2847 patients undergoing elective clean or "clean-contaminated" surgical procedures at a large community hospital. The administration of antibiotics 2 to 24 hours before the surgical incision was defined as early; that during the 2 hours before the incision, as preoperative; that during the 3 hours after the incision, as perioperative; and that more than 3 but less than 24 hours after the incision, as postoperative.Of the 1708 patients who received the prophylactic antibiotics preoperatively, 10 (0.6 percent) subsequently had surgical-wound infections. Of the 282 patients who received the antibiotics perioperatively, 4 (1.4 percent) had such infections (P = 0.12; relative risk as compared with the preoperatively treated group, 2.4; 95 percent confidence interval, 0.9 to 7.9). Of 488 patients who received the antibiotics postoperatively, 16 (3.3 percent) had wound infections (P less than 0.0001; relative risk, 5.8; 95 percent confidence interval, 2.6 to 12.3). Finally, of 369 patients who had antibiotics administered early, 14 (3.8 percent) had wound infections (P less than 0.0001; relative risk, 6.7; 95 percent confidence interval, 2.9 to 14.7). Stepwise logistic-regression analysis confirmed that the administration of antibiotics in the preoperative period was associated with the lowest risk of surgical-wound infection.We conclude that in surgical practice there is considerable variation in the timing of prophylactic administration of antibiotics and that administration in the two hours before surgery reduces the risk of wound infection.