Testing efforts for SARS-CoV-2 have been burdened by the scarcity of testing materials and personal protective equipment for health care workers. The simple and painless process of saliva collection allows for widespread testing, but enthusiasm is hampered by variable performance compared to nasopharyngeal swab (NPS) samples. We prospectively collected paired NPS and saliva samples from a total of 300 unique adult and pediatric patients. SARS-CoV-2 RNA was detected in 32.2% (97/300) of the individuals using the TaqPath COVID-19 Combo Kit (Thermo Fisher). Performance of saliva and NPS were compared against the total number of positives regardless of specimen type. The overall concordance for saliva and NPS was 91.0% (273/300) and 94.7% (284/300), respectively. The positive percent agreement (PPA) for saliva and NPS was 81.4% (79/97) and 89.7% (87/97), respectively. Saliva detected 10 positive cases that were negative by NPS. In symptomatic and asymptomatic pediatric patients not previously diagnosed with COVID-19, the performances of saliva and NPS were comparable (PPA: 82.4% vs 85.3%). The overall PPA for adults were 83.3% and 90.7% for saliva and NPS, respectively, with saliva detecting 4 cases less than NPS. However, saliva performance in symptomatic adults was identical to NPS (PPA of 93.8%). With lower cost and self-collection capabilities, saliva can be an appropriate alternative sample choice to NPS for detection of SARS-CoV-2 in children and adults.
Testing efforts for SARS-CoV-2 have been burdened by the scarcity of testing materials and personal protective equipment for healthcare workers. The simple and painless process of saliva collection allows for widespread testing, but enthusiasm is hampered by variable performance compared to nasopharyngeal swab (NPS) samples. We prospectively collected paired NPS and saliva samples from a total of 300 unique adult and pediatric patients. SARS-CoV-2 RNA was detected in 32.2% (97/300) of the individuals using the TaqPath COVID-19 Combo Kit (Thermo Fisher). Performance of saliva and NPS were compared against the total number of positives regardless of specimen type. The overall concordance for saliva and NPS was 91.0% (273/300) and 94.7% (284/300), respectively. The positive percent agreement (PPA) for saliva and NPS was 81.4% (79/97) and 89.7% (87/97), respectively. Saliva detected 10 positive cases that were negative by NPS. In symptomatic and asymptomatic pediatric patients not previously diagnosed with COVID-19, the performances of saliva and NPS were comparable (PPA: 82.4% vs 85.3%). The overall PPA for adults were 83.3% and 90.7% for saliva and NPS, respectively, with saliva detecting 4 cases less than NPS. However, saliva performance in symptomatic adults was identical to NPS (PPA of 93.8%). With lower cost and self-collection capabilities, saliva can be an appropriate alternative sample choice to NPS for detection of SARS-CoV-2 in children and adults.
HPeV infections of the central nervous system occurred mainly in young infants and were more commonly associated with neurologic symptoms at presentation, despite the fact that CSF findings were within the normal range in the vast majority of these cases. HPeV should be included in the differential diagnosis of young children with central nervous system symptoms and sepsis-like illness, even in the presence of normal CSF parameters.
The in vitro susceptibility of group D streptococci (enterococci) to ampicillin was studied comparing the results obtained in Mueller-Hinton broth (MHB) with those obtained in normal human serum (NHS). The rate of enterococcal killing was consistently faster in NHS than in MHB at equivalent ampicillin concentrations. Whereas an increasing media pH appeared to decrease the susceptibility of enterococci to ampicillin by determinations of the minimum bactericidal concentration (MBC) of ampicillin, an opposite increase in susceptibility was observed when the rate of bactericidal activity was studied. This difference may be explainable by the instability of ampicillin at higher pH values. In both MHB and NHS a paradoxical decrease in the rate and extent of enterococcal killing occurred as the ampicillin concentration was increased above the minimally effective concentration. These results demonstrate the inadequacies of the MBC test system and the need for standardizing test media used for determining the susceptibility of enterococci to ampicillin.Group D streptococci (enterococci) are frequently cultured from patients with pyelonephritis or endocarditis. Since enterococci are relatively resistant to antibiotics, the standard regimen used to treat severe enterococcal infections is a combination of penicillin and aminoglycoside (16). Adverse side effects associated with aminoglycoside antibiotics are frequent enough to make it desirable to find an equally effective, less toxic regimen. Previous reports suggest that in vitro the enterococcus is quite susceptible to ampicillin alone (3,20,26,28,29,32). However, single drug therapy of enterococcal endocarditis with ampicillin has given conflicting results (2, 12, 24). The controversy raised by these studies promoted the present evaluation of the in vitro susceptibility of the enterococcus to ampicillin. It was postulated that previous studies might have been in error because of the dissimilarity of standard laboratory culture media and body fluids. For example, the calcium and magnesium concentrations of laboratory culture media are much different than the serum concentrations of these cations. The significant effect of the media calcium and magnesium concentration on the susceptibility of Pseudomonas aeruginosa to gentamicin is well documented (10,11,25,35). For these reasons, susceptibility testing of enterococci to ampicillin was performed in both broth culture media and normal human serum. Since previous reports have described an effect of culture pH on ampicillin activity against the enterococcus, the effect of varying the culture media pH was also studied (33).MATERIALS AND METHODS MHB and NHS. A single lot number of MuellerHinton broth (MHB) was used throughout these studies (Difco Laboratories). Normal human serum (NHS) was obtained aseptically from three healthy donors and stored in small aliquots at -70 C until used. Serum complement was inactivated by heating at 56 C for 30 min. No variation in results was observed with different sera. For this reason, we arb...
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