Cefotaxime-heparin lock prophylaxis against hemodialysis catheter-related sepsis among Staphylococcus aureus nasal carriers.

Staphylococcus aureus nasal carriers undergoing hemodialysis (HD) through tunneled cuffed catheters (TCCs) form a high-risk group for the development of catheter-related bloodstream infections (CRBSI) and ensuing morbidity. The efficacy of antibiotic-locks on the outcomes of TCCs among S. aureus nasal carriers has not been studied earlier. Persistent nasal carriage was defined by two or more positive cultures for methicillin-susceptible (MSSA) or methicillin-resistant (MRSA) S. aureus of five standardized nasal swabs taken from all the participants dialyzed at a large out-patient HD center affiliated to a tertiary care hospital. Of 218 participants, 82 S. aureus nasal carriers dialyzed through TCCs (n = 88) were identified through April 2005 to March 2006 and randomized to two groups. Group I comprised of 39 nasal carriers who had TCCs (n = 41) "locked" with cefotaxime/heparin while group II included 43 patients with TCCs (n = 47) filled with standard heparin. The CRBSI incidence and TCC survival at 365 days were statistically compared between the two groups. A significantly lower CRBSI incidence (1.47 vs. 3.44/1000 catheter-days, P <0.001) and higher infection-free TCC survival rates at 365 days (80.5 vs. 40.4%, P <0.0001) were observed in the cefotaxime group compared with the standard heparin group. However, no significant difference in MRSA-associated CRBSI incidence was observed between the two groups. Cefotaxime-heparin "locks" effectively reduced CRBSI-incidence associated with gram-positive cocci, including MSSA, among S. aureus nasal carriers. There remains a compelling requirement for antibiotic-locks effective against MRSA.

Emergence of nalidixic acid resistance in Shigella sonnei isolated from patients having acute diarrheal disease: report from eastern province of Saudi Arabia.

During the 5 years of the study period (October 1999-October 2003), 110 strains of Shigella were isolated from fecal samples of patients having acute diarrheal diseases. Shigella sonnei phase 1 was the most prevalent (88/110, 80.0%) serotype. Resistance to nalidixic acid was not encountered from 1999-2002. Nalidixic acid resistance was observed in 6/13 (46.1%) of the S. sonnei phase 1 strains isolated from April-August 2003. Minimum inhibitory concentration to nalidixic acid among these strains was 48-96 microg/ml. All the six nalidixic acid resistant strains of S. sonnei phase 1 had reduced susceptibility (MIC 0.25 microg/ml) to ciprofloxacin.

The impact of nasal carriage of methicillin-resistant and methicillin-susceptible Staphylococcus a ureus (MRSA & MSSA) on vascular access-related septicemia among patients with type-II diabetes on dialysis.

BACKGROUND: Fairly higher nasal carriage rates among type-II diabetics place them at a greater risk of endogenous Staphylococcus aureus linked vascular access-related septicemia (VRS) that is also dependent on the type of vascular access used for hemodialysis (HD). The prevalence of nasal carriage of methicillin susceptible and methicillin-resistant S. aureus (MSSA and MRSA) and its impact on VRS was determined in order to identify most vulnerable group and plan potential prophylactic strategies, accordingly. METHODS: Five standardized nasal swab cultures were performed in 208 patients enrolled for long-term HD through July 1996 to July 1999. Persistent nasal carriage was defined by two or more positive cultures for MSSA or MRSA. Peripheral blood cultures were collected on clinical suspicion of septicemia. RESULTS: The prevalence of type-II diabetes of 28.0% with 72.4% of nasal carriage rate and three folds higher S. aureus related VRS (RR-3.19, p<0.0001) than diabetic non-carriers on HD, was observed. Type-II diabetics also had higher MSSA and MRSA nasal carriage rates (53.4% and 19.0%) than non-diabetic nasal carriers (18.6 and 6.0%) yet, carried a comparable (RR-4.0 vs. 4.5) risk of VRS between MSSA and MRSA nasal carriers. Among diabetic type-II S. aureus nasal carriers, central venous catheters (CVCs) carried 35 and 38 times higher collective risk of developing MSSA and MRSA nasal carriage-related VRS respectively than Arterio-venous fistula (AVF). The AVF recorded the lowest risk of developing MSSA and MRSA nasal carriage-related VRS (0.013 and 0.010 episodes/patient-year) in both diabetic type-II MSSA and MRSA nasal carrier groups. CONCLUSIONS: Diabetic type-II S. aureus nasal carriers on HD through CVCs make an extremely high-risk group for MSSA and MRSA nasal carriage-related VRS. The incidence of S. aureus nasal carriage-related VRS could reasonably be reduced through a challenging obligation of optimizing AVF prevalence in this high-risk group, while limiting the use of CVCs, at the same time.

Outcome of dialysis access-related septicemia among diabetics following optimized AV-fistula placement.

BACKGROUND: AV fistula (AVF) is the safest of vascular accesses with lowest infection rates; yet only 23% patients used AVF during 1997 in USA. The lower prevalence of AVF among diabetics on hemodialysis (HD) places them at a higher risk of vascular-access-related septicemia (VRS) and ensuing mortality. In this study we assessed the outcome of VRS after maximizing the frequency of native AVF in this largest growing population on HD. METHODS: Study included 218 patients, 63 diabetics and 155 nondiabetics on HD, through July 1996 to July 2000 when National Kidney Foundation-Dialysis Outcome and Quality Initiative (NKF-DOQI) set goal was accomplished with overall 72% of functioning AVF (57.2% diabetics and 78.1% nondiabetics) through joint efforts of nephrologists and vascular surgeons. RESULTS: Overall, 10.6% patients per year developed VRS through 125 episodes, over 10,464 patient-months, recording 1.19 episodes per 100 patient-months. In the diabetic group, 13.87% patients per year had VRS during 44 episodes with 1.45 episodes per 100 patient-months while 1.08 episodes per 100 patient-months were recorded in nondiabetics with 9.35% per year having VRS during 81 episodes. Collectively, catheters recorded 1.5 folds higher VRS episodes in diabetic than in nondiabetic group. Mortality of 9.28% per year in diabetic group as compared to that of 6.45% per year in nondiabetic group [RR-1.436, 95% CI (0.778-2.651)] was observed, while overall mortality of 7.5% per year recorded is a good deal lower than 12-22% reported. CONCLUSION: The NKF-DOQI set aim of dialyzing over 50% patients through AVF is attainable in diabetics as well. Optimizing AVF is a viable approach to lessen VRS related mortality in diabetics on HD. Our continued dependence on vascular catheters is largely responsible for higher mortality in diabetics than nondiabetics on HD due to lack of cagily established pre-ESRD program for diabetics.

Nosocomial transmission of syphilis during haemodialysis in a developing country.

Patients with end-stage renal disease (n = 187) secondary to diverse aetiologies who underwent haemodialysis (HD) between November 1996 and November 2000 were routinely screened for syphilis using the rapid plasma reagin (RPR) test and confirmed by means of a microhemagglutination assay for Treponema pallidum. All the confirmed syphilis patients were asymptomatic and were diagnosed serologically. A true seroprevalence of 6.9% (13/187) and a biological false seropositivity of 4.2% (8/187) for syphilis were recorded. Most (11/13) of the true seropositive patients were aged between 51 and 80 y. Whilst 10/13 patients were true syphilis seropositive at the time of first HD, 3/13 patients became true seropositive an average of 12 months (range 10-14 months) after HD. Penicillin treatment was given to all 13 patients simultaneously only after the appearance of 3 new true syphilis seropositive cases. Complete seroreversion was observed in 4/10 patients in the pre-HD true syphilis seropositive group of presumptive transmitters who became RPR-negative, whereas the 3 new true seropositive cases showed a serial 4-fold decline in RPR titres 12 months after penicillin therapy, suggestive of an active disease with adequate therapeutic response. These results clearly indicate that latent syphilis is prevalent in long-term elderly HD patients. The true seroconversion of 3 new patients who had undergone HD for an average of 12 months is indicative of nosocomial transmission and the silently active nature of the disease, which necessitates regular monitoring of syphilis serology among HD patients.

Vascular access related septicemia in hemodialysis: a focus on bacterial flora and antibiotic access salvage.

A good vascular access is the lifeline of patients on long-term hemodialysis (HD) and anteriovenous fistula is considered the ideal access. Vascular access related septicemia (VARS) is the second most common cause of mortality among HD patients. Such infections could also lead to loss of vascular access unless specific measures are taken to preserve the accesses. The present study was designed to determine the incidence of septicemia, common bacterial flora involved, and impact of early, empirical antibiotic therapy on vascular access salvage among HD patients. This prospective study, involved 209 patients, undergoing long-term HD, from June 1996 to June 2000. A total of 85 (40.6%) developed VARS with predominance in females (63.7%), patients above 50 years of age (37.0%) and those having diabetes mellitus (25.1%). A total of 124 episodes of septicemia were recorded with an average of 1.23 episodes per 100 patient-months during the four year (10032 patient-months) study period. Peripheral blood samples for culture and sensitivity were collected and the patients were started empirically on amikacin-vancomycin combination which was modified after obtaining culture and sensitivity results. A cure was defined as 45 days symptom-free interval after antibiotic therapy was completed. Staphylococcus aureus was the commonest (29.0%) organism associated with VARS, followed by Pseudomonas aeruginosa (15.3%). The temporary vascular access group recorded maximum number of VARS episodes; [femoral catheter (FC) group, (43.5%), followed by subclavian (SC) group, (28.2%)] and the lowest (8.8%) was seen in the AVF group. Vascular access salvage rate of 48/85 (56.4%) and mortality of 22/85 (25.9%) was observed in the present study. Antibiotic access salvage with Amikacin-Vancomycin combination has an advantage of preserving vascular access sites in at least, 50% of cases.