Early Infection Rate Research Articles

An obturator or "lateral" bypass in infected vascular prostheses in the groin?

The infection of the previously implanted vascular graft at the groin, is associated with great mortality and morbidity rate [1]. The authors present a retrospective study in which they analyzed management of infected vascular prostheses at the groin, using obturator bypass in 26 cases, and "lateral" bypass in 15 cases. The indications for obturator bypass reconstructions included: 20 infections of aorto-femoral grafts, two infected pseudoaneurysms in the groin after PTA of the superficial femoral artery, and 4 infections of iliac-femoral grafts. The indications for lateral bypass reconstructions were: infections after aorto-femoral reconstructions--8 cases; infection after femoro-popliteal reconstructions--4 cases; infection after iliac-femoral reconstruction--2 patients, and one infected pseudoaneurysm in the groin after PTA of the superficial femoral artery. In 3 subjects obturator bypass was performed using extraperitoneal approach, while in other 23 patients transperitoneal approach was done by donor's artery. The obturator bypass was performed using a PTFE graft in 3 cases, and Dacron graft in 23. The donor's artery used for obturator bypass was a noninfected proximal part of aortofemoral graft in 20 cases, and iliac artery in 6 patients. The superficial femoral artery was recipient artery for obturator bypass in 3 cases, deep femoral artery in one case, and above the knee popliteal artery in 22 cases (Figure 1). In two patients transperitoneal approach to donors artery for "lateral" bypass has been used, and in 13 cases extraperitoneal. The proximal noninfected part of aorto femoral graft was used as a donor's artery for lateral bypass in 8 patients, while common iliac artery in 7 subjects. In 5 cases reconstructions were performed using PTFE grafts, in 3 using autologous saphenous vein grafts, and in 7 using Dacron grafts. The recipient artery for "lateral" bypass was deep femoral in 8 cases, superficial femoral in three patients and above the knee popliteal artery in 4 subjects. After both types of reconstruction, extirpation of infected grafts from the groin was performed (Figure 2). The control examination was performed using physical and Doppler ultrasonographic examinations, one, 3, 6, 12 months, and then every year after the operation. In cases with suspected graft infection or thrombosis, control angiography was also performed. One intraoperative perforation of the urinary bladder has been done accidentally during obturator bypass reconstruction. The mean follow-up period for patients with obturator bypasses was 2.3 years, while 2.1 years for patients with "lateral" bypasses. Comparing with "lateral" bypass, obturator bypass showed statistically significant lower (p < 0.05) 30-day mortality and early graft infection rate, as well as statistically significant better early and total limb salvage rate. There were no statistically significant differences (p > 0.05) between obturator and "lateral" bypass procedures, having in mind, late graft infection rate, as well as early and late graft patency (Figures 3 and 4). In cases with infected vascular prostheses in the groin, the authors recommend obturator bypass comparing with "lateral" bypass.

Infection in Total Knee Replacement

Six thousand four hundred eighty-nine knee replacements were done in 6120 patients at the authors' institution between 1993 and 1999. Operations were done in a theater with vertical laminar flow and with the surgical team using body exhaust suits. Of these knee replacements, 116 knees became infected and 113 were available for followup. One hundred of the infections occurred in patients undergoing primary knee replacement, whereas the remaining infections occurred in patients undergoing revision knee replacement. Ninety-seven of these knees (86%) had deep periprosthetic infections and the remaining 16 knees had superficial wound infections. One third of the deep infections occurred within the first 3 months after surgery and the remaining 2/3 occurred after 3 months. The overall early deep infection rate for patients undergoing a primary knee replacement was 0.39%, whereas the rate for patients undergoing a revision knee replacement was 0.97%. A cohort of noninfected knee replacements from patients matched for gender, age, and month of surgery was used as a control group. Those comorbidities that were statistically significant in increasing the risk of infection were prior open surgical procedures, immunosuppressive therapy, poor nutrition, hypokalemia, diabetes mellitus, obesity, and a history of smoking. Patients undergoing revision procedures had a statistically higher risk of infection than did patients undergoing primary surgeries. If the surgery took longer than 2.5 hours, the risk of infection was increased significantly. There was no change in the infection rate when the perioperative antibiotic prophylaxis was decreased from 48 to 24 hours after surgery. The predominant infectious organisms were gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus Group B). Twenty percent of the knees that were infected clinically had no organisms that could be identified. In each case, the patient had been treated empirically at another institution with antibiotics before a culture of the joint was obtained.

Antibiotic Prophylaxis in Clean Surgery: Vascular Surgery

The commonest and most dangerous infective complication in vascular surgery is prosthetic graft infection. Despite the use of routine systemic antibiotic prophylaxis, graft infection occurs after 3-5% of all prosthetic vascular reconstructions. Infection is associated with a high rate of major morbidity and mortality, with significant time and cost implications. Management can be difficult and the outcome is often disappointing.Data from Italian Registry of Prosthetic Graft Infections show that the commonest site of infection is the aorto-femoral district and that involved bacteria are usually Gram-positive in early and low-grade infections and Gram-negative in late and high-grade infections. Results are poor, with a mortality rate of 15% for elective surgery and of 60% for emergency interventions.We report the results of a multicenter randomized controlled trial of rifampicin-bonded Dacron grafts in aorto-femoral surgery, in which our Department was involved. Data demonstrate a reduction in total early wound and graft infection rates, and 2-year results show a small, non-significant reduction in graft infection (1.7% in study group, 2.3% in control group). The same results were obtained in two other multicenter trials.

Cereal/legume rotation effects on cereal growth in Sudano-Sahelian West Africa: soil mineral nitrogen, mycorrhizae and nematodes.

Yield increases of cereals following legumes in rotation have been previously reported for West Africa, but little progress has been made to explain the mechanisms involved. At four sites in Niger and Burkina Faso, field trials with pearl millet (Pennisetum glaucum (L.) R. Br.), cowpea (Vigna unguiculata (L.) Walp), sorghum (Sorghum bicolor (L.) Moench) and groundnut (Arachis hypogaea L.) were conducted from 1996 to 1998 to investigate the role of soil mineral nitrogen (Nmin), native arbuscular mycorrhizae (AM) and nematodes in cereal/legume rotations. Grain and total dry matter yields of cereals at harvest were increased by legume/cereal rotations at all sites. Soil Nmin levels in the topsoil were consistently higher in cereal plots previously sown with legumes (rotation cereals) compared with plots under continuous cereal cultivation. However, these rotation effects on Nmin were much larger with groundnut than with cowpea. Roots of rotation cereals also had higher early AM infection rates compared to continuous cereals. The dominant plant-parasitic nematodes found in all experiment fields were Helicotylenchus sp., Rotylenchus sp. and Pratylenchus sp. In sorghum/groundnut cropping systems, nematode densities were consistently lower in rotation sorghum compared to continuous sorghum. Continuous groundnut had the lowest nematode densities indicating that groundnut was a poor host for the three nematode groups. In millet/cowpea cropping systems with inherently high nematode densities, crop rotations barely affected nematode densities indicating that both crops were good hosts. These results suggest that on the nutrient poor Sudano-Sahelian soils of our study, total dry matter increases of rotation cereals compared with continuous cereals can be explained by higher Nmin and AM infection levels early in the season. The site-specific magnitude of these effects may be related to the efficiency of the legume species to suppress nematode populations and increase plant available N through N2-fixation.

Methicillin-resistant staphylococci in clean surgery. Is there a role for prophylaxis?

The incidence of infection in clean surgery (i.e. surgery with no major contamination of the operative site) should be less than 2%, although the incidence of postoperative infections can be higher in patients with various risk factors (namely insertion of foreign bodies, a compromised immune status or prolonged duration of surgery). Although antibiotic prophylaxis has been shown to reduce the incidence of postoperative infections in clean surgery, there is still no consensus regarding its use in this area. However, for clean surgical procedures that involve implantation of foreign material, grafts or prosthetic devices, prophylaxis is well accepted and justifiable, since this practice is indicated when the benefits exceed the expected risks. Staphylococcus aureus and coagulase-negative staphylococci are responsible for 70 to 90% of wound infections in this type of surgery. First and second generation cephalosporins are considered the drugs of choice for surgical prophylaxis. Cefazolin and other cephalosporins have good tissue penetration but poor coverage against methicillin-resistant staphylococci. The frequency with which methicillin-resistant staphylococci have been recovered in nosocomial infections has increased steadily during recent years. This provides a rationale for the use of alternative antibiotics, such as the glycopeptides (vancomycin and teicoplanin), for prophylaxis in clean surgery in hospitals where the prevalence of methicillin-resistant staphylococci is high. The effectiveness and tolerability of teicoplanin as prophylaxis for orthopaedic surgery involving joint replacement were analysed in 4 randomised controlled trials. Two compared teicoplanin with cefamandole, while the others compared teicoplanin with either cefuroxime or cefazolin. The overall early wound infection rates (within 3 months) in these studies were 1.1% for teicoplanin and 1.7% for the comparator cephalosporin. The overall late infection rate was 0.2% for both treatment groups. Adverse events were attributed to the drug in 1% of patients in both treatment groups. Therefore, on the basis of these trials, single dose teicoplanin is as efficacious and as well tolerated as multiple dose cephalosporin regimens for prophylaxis in prosthetic joint surgery.

Management of Postoperative Wound Infection in Posterior Spinal Fusion with Instrumentation

Successful treatment of an infection depends first on prompt diagnosis. Management of postoperative wound infections after spinal fusion with instrumentation often presents therapeutic difficulties. This study reviews a total of 28 wound infections. An infection rate of early infection with 3.6% and late infection with 1.9% was noted. The treatment of wound infection depends on the appearance of infection. In early wound infection, it is not always necessary to remove the instrumentation, if a successful suction-irrigation system was inserted. In late wound infection, we removed the hardware in all cases. No evidence of pyogenic infection was presented. Additionally, intravenous antibiotics were used after the antibiogram.

Intrapartum antibiotics for group B streptococcal colonisation.

Group B streptococcal infection is common in pregnant women without causing harm. However it is also a significant cause of neonatal morbidity and mortality. The objective of this review was to assess the effects of intrapartum administration of antibiotics to women on infant colonization with group B streptococcus, early onset neonatal group B streptococcus sepsis and neonatal death from infection. The Cochrane Pregnancy and Childbirth Group trials register was searched. Controlled trials of pregnant women colonized with group B streptococcus comparing intrapartum antibiotic administration with no treatment, and providing data on infant colonization with group B streptococcus and/or neonatal infection. Eligibility and trial quality assessment were done by one reviewer. Five trials were included. Overall quality was poor, with potential selection bias in all the identified studies. Intrapartum antibiotic treatment reduced the rate of infant colonization (odds ratio 0.10, 95% confidence interval 0.07 to 0.14) and early onset neonatal infection with group B streptococcus (odds ratio 0.17, 95% confidence interval 0.07 to 0. 39). A difference in neonatal mortality was not seen (odds ratio 0. 12, 95% confidence interval 0.01 to 2.00). Intrapartum antibiotic treatment of women colonized with group B streptococcus appears to reduce neonatal infection. Effective strategies to detect maternal colonization with group B streptococcus and better data on maternal risk factors for neonatal group B streptococcus infection in different populations are required.

Prospective controlled trial of selective parenteral and enteral antimicrobial regimen in fulminant liver failure

To compare the efficacy of a selective parenteral and enteral antimicrobial regimen in patients with fulminant liver failure, we classified 104 patients on reaching grade II encephalopathy as infected or non-infected. Patients who were infected were randomly assigned to receive IV cefuroxime (group 1) or selective parenteral and enteral antimicrobial regimen (group 2). Noninfected patients were randomly selected to receive either selective parenteral and enteral antimicrobial regimen (group 3) or no initial antimicrobials until clinically indicated (group 4). The four groups were comparable regarding age, sex, cause of disease, coma grade, international normalization ratio, presence of kidney failure and indicators of poor prognosis on admission to the study. Clinical parameters such as white cell count, temperature or changes in the chest radiograph, which were used to stratify patients into those infected or not, were not good predictors of infection because early infection rates were similar in the two groups. Three patients died within 24 hr and were excluded from the analysis. We found 42 microbiologically confirmed infections: group 1, 6 of 21; group 2, 8 of 21; group 3, 9 of 28; and group 4, 19 of 31. A reduction in infection was seen between groups 3 and 4 (p < 0.05). Patients receiving the selective parenteral and enteral antimicrobial regimen (groups 2 and 3) had fewer infections than the control group (group 4) (p < 0.005). Groups receiving early antimicrobial therapy (groups 1, 2 and 3) had a lower incidence of infection compared with group 4 (p < 0.0005). Overall, 55.5% survived, with no significant difference between the four groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Differential effect of risk factors on early and late wound infections in patients undergoing herniorrhaphies.

In a prospective follow-up of 2846 patients who underwent hernia repair in 22 general surgery departments in Israel, factors affecting early or late infections were explored. Risk factors included inherent patient characteristics such as old age, ethnic group, and type of hernia prior to the surgery. Patient management factors included duration of the operation, use of urinary catheters, and use of drains. Of the 12 variables studied, only three had a constant effect during the entire 30-day follow-up. The other factors affected the occurrence of either early or late infections, but not both. For example, patients undergoing long operations, or from ethnic minorities, had a high rate of early infection, while those with special wound treatment (such as evacuation of hematomas) had high rates of late infection. It is postulated that factors present at the time of the operative incision tend to "cause" early infections, while factors that accumulate over time, or develop after leaving the operating theater, tend to affect late infections.

CSF drainage in patients with posterior fossa tumours.

The management of hydrocephalus secondary to a posterior fossa tumour is controversial. We audited recent practice with a retrospective analysis of 287 consecutive patients undergoing posterior fossa exploration for tumour. 85 shunts and 112 external ventricular drains (EVD) were placed. The overall CNS infection rate in the series was 6%. There was a significantly higher (p less than 0.01) infection rate in patients who had a drainage procedure, and a trend towards higher infection rates in patients with two drainage procedures. Early infection rates with EVDs and shunts were the same (7%). One third of patients with hydrocephalus had pre-operative drainage, a third had per-operative drainage but only a quarter required a permanent shunt. The majority of patients will not require a permanent shunt and where temporary CSF diversion is required EVD is reasonable.

The timing of flap coverage, bone-grafting, and intramedullary nailing in patients who have a fracture of the tibial shaft with extensive soft-tissue injury.

The cases of forty-three patients who had a Type-IIIB open fracture of the tibial shaft were reviewed to determine the effect of treatment of the soft-tissue injury on the rate of major complications. An infection developed in two of the eleven patients who had had early muscle-flap coverage compared with ten of the nineteen who had been managed by open care of the wound and nine of the thirteen who had had later flap coverage. Patients who had had bone-grafting after complete re-epithelialization of the wound, regardless of the method of closure, had a lower rate of early infection (none of sixteen compared with four of fifteen) and an earlier average time to union (fifty-four compared with sixty-three weeks) than those in whom the wound was not completely closed or was draining at the time of bone-grafting. Delayed intramedullary nailing with reaming was associated with a high rate of infection (nine of nineteen patients), regardless of the condition of the soft tissue at the time of nailing. In our opinion, adequate débridement and early assessment of the soft-tissue defect are necessary so that appropriate soft-tissue coverage can be provided within the first one to two weeks. When the soft-tissue portion of the injury is addressed promptly and definitively and then allowed to heal completely, secondary osseous reconstruction may proceed with fewer complications.

Cefuroxime in total joint arthroplasty: Intravenous or in bone cement

A prospective randomized clinical trial was performed in two centers to compare the effect of systemic cefuroxime and cefuroxime in bone cement in the prophylaxis of infection after total joint arthroplasty. In two comparable groups comprising 200 and 201 patients, there was no statistically significant difference in the incidence of superficial wound infection. The early deep infection rate was 1%, with no difference detected between the group that received antibiotic in bone cement and the group that received systemic antibiotic. There were no late deep infections. It is concluded that cefuroxime given systemically or in bone cement is an effective antibiotic in the prophylaxis of infection after total joint arthroplasty.

The cubic growth of AIDS cases: general dependence on early infection rates and distribution of times to appearance of clinical symptoms.

An observed cubic dependence on time of the cumulative growth in numbers of AIDS patients is shown to be the leading term of a power series in general. The cubic leading term follows from a nearly model-independent description of the rate of HIV infection, provided only that there is a distribution of incubation times to the appearance of clinically diagnosed AIDS symptoms with a finite initial derivative, that none of those infected exhibit immediate indications of illness, and that the epidemic begins with a finite initial rate of infection.

Early Infection and Competition for Nodulation of Soybean by Bradyrhizobium japonicum 123 and 138

Interactions of soybean with Bradyrhizobium japonicum 123 (serogroup 123) and 138 (serogroup c1) were used to examine the relationship between early infection rates, competition for nodulation, and patterns of nodule occupancy. Both strains formed more infections in autoclaved soil (sterile soil) than in untreated soil (unsterile soil). Inoculation did not increase numbers of infection threads in unsterile soil-grown plants, where infection of proximal portions of primary roots was complete by 5 days after planting. Both strains infected and nodulated at similar rates in sterile soil. Nodules were always clustered on the upper root system, regardless of inoculation and soil treatment. Sixty-seven percent of the nodules of uninoculated plants grown in unsterile soil were occupied by rhizobia belonging to serogroups other than 123 or c1. Inoculation with strain 123 or 138 increased occupancy by that strain at the expense of residency by other rhizobia. Eighty-three percent of all nodules on plants dually inoculated with both strains in sterile soil contained strain 138. The corresponding value for plants inoculated in unsterile soil was 31%. Neither inoculum strain dominated occupancy of first-formed nodules in unsterile soil. It appears that north central Missouri soil may not have populations of highly competitive serogroup 123 and that early infection and nodulation rates do not contribute to the competitive success of strain 138.

Acute and definitive management of traumatic osteocutaneous defects of the lower extremity.

Twenty-two lower extremity osteocutaneous defects resulting from high-energy trauma were managed from the onset of injury to rehabilitation by a collaborative effort between orthopedic and plastic surgeons. Emergency debridement of devitalized soft tissue and bone, external fracture stabilization, and serial debridements prepared the wound for closure with predominantly free-muscle transfers performed an average of 17 days (range 3 to 43 days) after injury. Cancellous or vascularized fibula grafting, depending on defect size, was performed an average of 9 weeks (range 6 to 16 weeks) after muscle flap closure. In this group of patients, whose average injury severity score was 18 (range 9 to 45) and whose average segmental bone defect was 8 cm (range 3 to 18 cm), the average time after injury to full weight bearing was 61 weeks (range 39 to 120 weeks). The early infection rate was 14 percent. Two extremities were amputated. There have been no chronic infections. Follow-up has ranged from 9 to 34 months.

Difficulties and complications of the Ender method of treatment of trochanteric fractures of the femur

The advantages of the Ender technique over the other methods of treatment of trochanteric fractures of the femur have been emphasized by several authors but the difficulties and complications of the method have perhaps not been sufficiently highlighted. With this imbalance in mind, 60 patients treated by the Ender method have been reviewed with particular emphasis on the problems encountered during treatment. The follow-up period ranges from 6 to 28 months. The main technical difficulties were experienced during the reduction and nailing of the comminuted and displaced fracture. The main postoperative complications were the cutting out of the nails from the head and neck fragment with weight bearing, backing down of the nails at the knee, and external rotation deformity. The early mortality, infection, delayed union and non-union rates were low.

Bacteria in Hip SurgeryA Study of Routine Aerobic and Anaerobic Cultivation from Skin and Closed Suction Wound Drains

One hundred and seven patients with closed suction wound drains after hip surgery were investigated with regard to bacteria in the drain. In one-third of the cases bacterial contamination of the wound was found. In more than half the total number of cases the bacteria in the wound were not identical with those found on the skin, either pre- or post-operatively. Anaerobe bacteria occurred only in one case. Penicillin administration considerably reduced the frequency of positive cultures. These findings support the prophylactic use of antibiotics in the prevention of late infections in endoprosthesis operations even when the early infection rate is satisfactorily low.

Age and Asian influenza, 1957.

<h3>Background</h3> Recent upsurge of new HIV infections among men who have sex with men (MSM) is a major concern in China. Paucity of national-level information regarding the burden and predictors of this progressive epidemic of new infections called for a multi-centric, timely and comprehensive investigation. <h3>Methods</h3> Mixed methods were used to recruit MSM (MSM) from seven cities in China between 2012 and 2013. Early and established HIV infections were estimated by Western Blot and BED HIV-1 capture enzyme immunoassay. Syphilis and herpes simplex virus-2 (HSV-2) were also tested. <h3>Results</h3> A total of 4496 eligible MSM were recruited. The majority was aged ≤35 years (77·5%), migrants (60·3%), never married (69·8%), and played receptive role in anal sex (70·5%). The HIV prevalence was 9·9%, and 41·9% were recently infected, with HIV incidence of 8·9/100 Person-Years (95% CI: 7·6–10·2). The prevalence of history HSV-2 and syphilis were 12·5% and 8·5%, respectively. Early HIV infection was associated with having multiple male partners (aOR = 1·4, 95% CI 1·1–1·9), recreational drug use (aOR = 2·2, 95% CI 1·6–3·0), anal bleeding (aOR = 2·1, 95% CI 1·4–3·0), circumcision experience (aOR = 2·0, 95% CI 1·3–3·1), syphilis infection (aOR = 2·8, 95% CI 1·9–4·3) and history HSV-2 infection (aOR = 2·3, 95% CI 1·5–3·3). <h3>Conclusion</h3> High rate of early HIV infection is potentially resulting in progressive deterioration of the overall HIV epidemic among MSM in China. Targeted interventions to address high-risk MSM including those having multiple partners, history of recreational drug use and syphilis or HSV-2 infection seemed to be the need of the hour.