Identifying Hemodialysis Patients With the Highest Risk of Staphylococcus aureus Endogenous Infection Through a Simple Nasal Sampling Algorithm

Abstract

In contrast to Staphylococcus aureus intermittent nasal carriers, persistent ones have the highest risk of infection. This study reports the usefulness of a simple nasal sampling algorithm to identify the S. aureus nasal carriage state of hemodialysis patients (HPs) and their subsequent risk of infection.From a cohort of 85 HPs, 76 were screened for S. aureus nasal carriage once a week during a 10-week period. The S. aureus nasal load was quantified by using either culture on chromogenic medium or fully automated real-time polymerase chain reaction assay. Molecular typing was used to compare strains from carriage and infection.The algorithm based on quantitative cultures was able to determine the status of S. aureus nasal carriage with a sensitivity of 95.8%, a specificity of 94.2%, a positive predictive value of 88.5%, and a negative predictive value of 98.0%. Of note, the determination of the S. aureus carriage state was obtained on the first nasal sample for all the 76 HPs, but 1 (98.7%). The algorithm based on quantitative polymerase chain reaction assay directly from the specimen yielded similar performances. During the 1-year follow-up after the last sampling episode, HPs classified as persistent nasal carriers with the algorithm were found to have a higher risk of S. aureus infection than those classified as nonpersistent carriers (P < 0.05), especially for infections of endogenous origin (P < 0.001).This simple algorithm is reliable for determining the S. aureus nasal carriage status in clinical practice and could contribute to characterize at an early stage of take-up patients with the highest risk of S. aureus infection.

Interplay of nasal and rectal carriage of Staphylococcus aureus in intensive care unit patients

“…In the present work, we did not investigate other reservoirs as the study was observational without additional sampling of the patients. Additionally, because of the high rate of patients exposed to antimicrobial drugs, the prevalence of S. aureus carriage was probably underestimated and not reliable to determine the S. aureus nasal carrier status, as described by our team [37,38] when we investigated the relationship between persistent and non-persistent carriers and the risk of developing a ICU-acquired S. aureus infection. However, this study is relevant in a population of ICU patients because of the frequent prescription of antibiotics in all ICUs.…”

Molecular Characterization of Staphylococcus aureus Isolates Obtained from Hemodialyzed Patients at the Hospital de Clínicas of Paraguay: A pilot study

“…This study portrayed a high prevalence of nasal S. aureus carriage compared with others studies 14,15 that showed between 5-13% of S. aureus carriage. 14,15 However, two studies demonstrated similar carriage rates of S. aureus in hemodialysis patients including Verhoeven et al (58%) 16 and Price et al (49%). 17 The risk of infections in nasal carriers of this microorganism is real and well defined.…”

Can bloodstream infection be predicted by nasal culture in hemodialysis patients?

“…Verhoeven and colleagues reported S. aureus in 18/76 hemodialysis patients (23.6%) during a one year follow-up, which is also close to the second nasal canal culture in the present study. They also proposed an algorithm for taking nasal luid culture once a week during a 10-week period based on quantitative polymerase chain reaction with a sensitivity, and speci ity of 95.8%, and 94.2%, respectively [12]. Therefore, it is necessary to pay great attention to nasal luid specimens in hemodialysis patients.…”

“…Moreover, persistent nasal colonization with resistant S. aureus is suggested as an important risk factor associated with increased all-cause mortality rate [11]. Thus, nasal colonization by S. aureus in hemodialysis patients is considered as a risk factor associated with bacteremia and general infection, especially for infections of endogenous origin [12] and its eradication may decrease the infection rate [13]. Moreover, coagulase-negative staphylococci and diphteroids may be positive in one-fourth of patients' nasal vestibules [14].…”