No impact of early real-time PCR screening for respiratory viruses on length of stay and use of antibiotics in elderly patients hospitalized with symptoms of a respiratory tract infection in a single center in Norway.

We tested the hypothesis that the results of real-time polymerase chain reaction (PCR) analyses for respiratory viruses would reduce antibiotic treatment and length of stay in elderly patients hospitalized with respiratory infections. Within 24 h of hospital admission, a total of 922 patients aged ≥60 years were interviewed for symptoms of ongoing respiratory tract infection. Symptomatic patients were swabbed for oropharyngeal/nasopharyngeal presence of viral pathogens immediately by members of the study group. During a 2-month period, non-symptomatic volunteers among interviewed patients were swabbed as well (controls). Oropharyngeal/nasopharyngeal swabs were analyzed with real-time PCR for nine common respiratory viruses. A total of 147 out of 173 symptomatic patients and 56 non-symptomatic patients (controls) agreed to participate in the study. The patients were allocated to three cohorts: (1) symptomatic and PCR-positive (S/PCR+), (2) symptomatic and PCR-negative (S/PCR-), or (3) non-symptomatic and PCR-negative (control). There were no non-symptomatic patients with a positive PCR result. A non-significant difference in the frequency of empiric antibiotic administration was found when comparing the S/PCR+ to the S/PCR- cohort; 16/19 (84 %) vs. 99/128 (77 %) (χ(2) = 0.49). Antibiotic treatment was withdrawn in only two patients in the S/PCR+ cohort after receiving a positive viral diagnosis. The length of stay did not significantly differ between the S/PCR+ and the S/PCR- groups. We conclude that, at least in our general hospital setting, access to early viral diagnosis by real-time PCR had little impact on the antimicrobial treatment or length of hospitalization of elderly patients.

A comparison of nasopharyngeal and oropharyngeal swabbing for the detection of influenza virus by real-time PCR.

We tested the hypothesis that swabs from the nasopharynx carry a higher viral load than swabs from the oropharynx in patients with real-time polymerase chain reaction (PCR)-confirmed influenza infection. Using flocked swabs, oropharyngeal and nasopharyngeal samples were harvested from hospital-admitted influenza patients no later than 3 days after the initial detection of influenza virus. Comparison of cycle threshold (CT) values was performed to assess differences in viral load in the specimens. Seventeen patients were diagnosed with influenza B, 14 patients with influenza A(H1N1)pdm09, and one patient with influenza A(H3N2). Nasopharyngeal samples were positive at a lower CT value than the oropharyngeal samples [mean difference in CT 5.75, 95 % confidence interval (CI) 3.8-7.7, p < 0.01], suggesting that, on average, the calculated viral load of the nasopharyngeal samples was 54 times higher (95 % CI 13.7-210.8) than those of the oropharyngeal samples. The corresponding difference in the calculated viral load for influenza A(H1N1)pdm09 virus was 23 times (95 % CI 3.8-136.2, p < 0.01) and for influenza B virus, it was 80 times (95 % CI 9.3-694.6, p < 0.01). In patients with acute influenza, nasopharyngeal swabbing was clearly superior to oropharyngeal swabbing in terms of diagnostic yield by real-time PCR.

Swabbing for respiratory viral infections in older patients: a comparison of rayon and nylon flocked swabs.

The purpose of this study was to compare the sampling efficacy of rayon swabs and nylon flocked swabs, and of oropharyngeal and nasopharyngeal specimens for the detection of respiratory viruses in elderly patients. Samples were obtained from patients 60 years of age or above who were newly admitted to Sorlandet Hospital Arendal, Norway. The patients were interviewed for current symptoms of a respiratory tract infection. Using rayon swabs and nylon flocked swabs, comparable sets of mucosal samples were harvested from the nasopharynx and the oropharynx. The samples were analysed using real-time polymerase chain reaction (PCR) methods. A total of 223 patients (mean age 74.9 years, standard deviation [SD] 9.0 years) were swabbed and a virus was recovered from 11% of the symptomatic patients. Regardless of the sampling site, a calculated 4.8 times higher viral load (95% confidence interval [CI] 1.3-17, p = 0.017) was obtained using the nylon flocked swabs as compared to the rayon swabs. Also, regardless of the type of swab, a calculated 19 times higher viral load was found in the samples from the nasopharynx as compared to the oropharynx (95% CI 5.4-67.4, p < 0.001). When swabbing for respiratory viruses in elderly patients, nasopharyngeal rather than oropharyngeal samples should be obtained. Nylon flocked swabs appear to be more efficient than rayon swabs.

Transthoracic fine-needle aspiration in the aetiological diagnosis of community-acquired pneumonia.

To investigate the safety and practicability of conducting transthoracic fine-needle aspiration (TFNA) in a general hospital setting, we applied the TFNA procedure to 20 patients hospitalized with community-acquired pneumonia (CAP) within 36 h of admission. Also, a preliminary assessment was made of the potential value of adding TFNA to conventional methods of diagnostic microbiology. TFNA was easy to perform and caused little discomfort, and no serious adverse events were observed. In spite of ongoing antimicrobial treatment, a likely aetiological diagnosis was established for 14 of 20 (70%) of the patients. TFNA may provide important additional information on the aetiology of CAP.