Infectious Disease

Ferdinands, J.M., Gaglani, M., Martin, E.T., Monto, A.S., Middleton, D., Silveira, F., Talbot, H.K., Zimmerman, R. and Patel, M. (2021). “Waning vaccine effectiveness against influenza-associated hospitalizations among adults, 2015-2016 to 2018-2019, US Hospitalized Adult Influenza Vaccine Effectiveness Network.” Clin Infect Dis Jan 19;ciab045. [Epub ahead of print].

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We observed decreased effectiveness of influenza vaccine with increasing time since vaccination for prevention of influenza A(H3N2), influenza A(H1N1)pdm09, and influenza B(Yamagata)-associated hospitalizations among adults. Maximum VE was observed shortly after vaccination, followed by an absolute decline in VE of about 8 to 9% per month post-vaccination.

Pham, V., Nguyen, L., Hedin, R.J., Shaver, C., Hammonds, K.A.P. and Culp, W.C., Jr. (2021). “COVID-19: Anesthesia Machine Circuit Pressure During Use As An Improvised ICU Ventilator.” Anesth Analg Jan 12. [Epub ahead of print].

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BACKGROUND: Use of anesthesia machines as improvised ICU ventilators may occur in locations where waste anesthesia gas suction(WAGS) is unavailable. Anecdotal reports suggest as much as 18 cmH2O positive end-expiratory pressure(PEEP) being inadvertently applied under these circumstances, accompanied by inaccurate pressure readings by the anesthesia machine. We hypothesized that resistance within closed anesthetic gas scavenging systems(AGSS) disconnected from WAGS may inadvertently increase circuit pressures. METHODS: An anesthesia machine was connected to an anesthesia breathing circuit, a reference manometer, and a standard bag reservoir to simulate a lung. Ventilation was initiated as follows: Volume Control, TV 500 mL, respiratory rate 12, I:E 1:1.9, FiO2 1.0, fresh gas flow(FGF) rate 2.0 liters per minute(LPM), and PEEP 0 cmH2O. After engaging the ventilator, PEEP and peak inspiratory pressure(PIP) were measured by the reference manometer and the anesthesia machine display simultaneously. The process was repeated using prescribed PEEP levels of 5, 10, 15, and 20 cmH2O. Measurements were repeated with the WAGS disconnected and then were performed again at FGF of 4, 6, 8, 10, and 15 LPM. This process was completed on three anesthesia machines: Dräger Perseus A500, Dräger Apollo, and the GE Avance CS2. Simple linear regression was used to assess differences. RESULTS: Utilizing non-parametric Bland-Altman analysis, the reference and machine manometer measurements of PIP demonstrated median differences of -0.40 cmH2O (95%LOA: -1.00,0.55) for the Dräger Apollo, -0.40 cmH2O (95%LOA: -1.10, 0.41) for the Dräger Perseus, and 1.70 cmH2O (95%LOA: 0.80,3.00) for the GE Avance CS2. At FGF 2 LPM and PEEP 0 cmH2O with the WAGS disconnected, the Dräger Apollo had a difference in PEEP of 0.02 cmH2O (95%CI: -0.04,0.08; p=0.53); the Dräger Perseus A500, <0.0001 cmH2O (95%CI: -0.11 0.11; p=1.00); and the GE Avance CS2, 8.62 cmH2O (95%CI: 8.55,8.69; p<0.0001). After removing the hose connected to the AGSS and the visual indicator bag on the GE Avance CS2, the PEEP difference was 0.12 cmH2O (95%CI: 0.059,0.181; p=0.0002). CONCLUSIONS: Displayed airway pressure measurements are clinically accurate in the setting of disconnected WAGS. The Dräger Perseus A500 and Apollo with open scavenging systems do not deliver inadvertent CPAP with WAGS disconnected, but the GE Avance CS2 with a closed AGSS does. This increase in airway pressure can be mitigated by the manufacturer's recommended alterations. Anesthesiologists should be aware of the potential clinically important increases in pressure that may be inadvertently delivered on some anesthesia machines, should the WAGS not be properly connected.

Alsharidah, S., Ayed, M., Ameen, R.M., Alhuraish, F., Rouheldeen, N.A., Alshammari, F.R., Embaireeg, A., Almelahi, M., Adel, M., Dawoud, M.E., Aljasmi, M.A., Alshammari, N., Alsaeedi, A., Al-Adsani, W., Arian, H., Awad, H., Alenezi, H.A., Alzafiri, A., Gouda, E.F., Almehanna, M., Alqahtani, S., Alshammari, A. and Askar, M.Z. (2021). “COVID-19 convalescent plasma treatment of moderate and severe cases of SARS-CoV-2 infection: A multicenter interventional study.” Int J Infect Dis 103: 439-446.

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OBJECTIVE: To study the effectiveness of COVID-19 convalescent plasma (CCP) therapy for patients with moderate and severe COVID-19 disease. METHODS: This non-randomized prospective cohort study was conducted from May 21 to June 30, 2020, at four major tertiary hospitals in Kuwait. CCP was administered to 135 patients. The control group comprised 233 patients who received standard treatment. All patients (N = 368, median age 54 [range 15-82]) had laboratory-confirmed SARS-CoV-2 infection and either moderate or severe COVID-19 disease. RESULTS: CCP treatment was associated with a higher rate of clinical improvement in patients with moderate or severe disease. Among those with moderate COVID-19 disease, time to clinical improvement was 7 days in the CCP group, versus 8 days in the control group (p = 0·006). For severe COVID-19 disease, time to clinical improvement was 7 days in the CCP group, versus 15.5 days in the control group (p = 0·003). In the adjusted analysis, patients with moderate disease treated with CCP had a significantly lower 30-day mortality rate. Compared to the control group, oxygen saturation improved within 3 days of CCP transfusion, and lymphocyte counts improved from day 7 in patients with moderate COVID-19 disease and day 11 in patients with severe disease. C-reactive protein levels declined throughout the first 14 days after CCP transfusion. None of the CCP patients developed a serious transfusion reaction. CONCLUSIONS: The data show that administration of CCP is a safe treatment option for patients with COVID-19 disease with a favorable outcome in the rate of, and time to, clinical improvement.

Tenforde, M.W., Talbot, H.K., Trabue, C.H., Gaglani, M., McNeal, T.M., Monto, A.S., Martin, E.T., Zimmerman, R.K., Silveira, F., Middleton, D.B., Olson, S.M., Garten Kondor, R.J., Barnes, J.R., Ferdinands, J.M. and Patel, M.M. (2020). “Influenza vaccine effectiveness against hospitalization in the United States, 2019-2020.” J Infect Dis Dec 30;jiaa800. [Epub ahead of print].

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BACKGROUND: Influenza causes significant morbidity and mortality and stresses hospital resources during periods of increased circulation. We evaluated the effectiveness of the 2019-2020 influenza vaccine against influenza-associated hospitalizations in the United States. METHODS: We included adults hospitalized with acute respiratory illness at 14 hospitals and tested for influenza viruses by reserve transcription polymerase chain reaction. Vaccine effectiveness (VE) was estimated by comparing the odds of current-season influenza vaccination in test-positive influenza cases versus test-negative controls, adjusting for confounders. VE was stratified by age and major circulating influenza types along with A(H1N1)pdm09 genetic subgroups. RESULTS: 3116 participants were included, including 18% (553) influenza-positive cases. Median age was 63 years. Sixty-seven percent (2079) received vaccination. Overall adjusted VE against influenza viruses was 41% (95% confidence interval [CI]: 27-52). VE against A(H1N1)pdm09 viruses was 40% (95% CI: 24-53) and 33% against B viruses (95% CI: 0-56). Of the two major A(H1N1)pdm09 subgroups (representing 90% of sequenced H1N1 viruses), VE against one group (5A+187A,189E) was 59% (95% CI: 34-75) whereas no significant VE was observed against the other group (5A+156K) [-1%, 95% CI: -61-37]. CONCLUSIONS: In a primarily older population, influenza vaccination was associated with a 41% reduction in risk of hospitalized influenza illness.

Tenforde, M.W., Kondor, R.J.G., Chung, J.R., Zimmerman, R.K., Nowalk, M.P., Jackson, M.L., Jackson, L.A., Monto, A.S., Martin, E.T., Belongia, E.A., McLean, H.Q., Gaglani, M., Rao, A., Kim, S.S., Stark, T.J., Barnes, J.R., Wentworth, D., Patel, M.M. and Flannery, B. (2020). “Effect of antigenic drift on influenza vaccine effectiveness in the United States – 2019-2020.” Clin Infect Dis Dec 25;ciaa1884. [Epub ahead of print].

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BACKGROUND: At the start of the 2019-2020 influenza season, concern arose that circulating B/Victoria viruses of the globally emerging clade V1A.3 were antigenically drifted from the strain included in the vaccine. Intense B/Victoria activity was followed by circulation of genetically diverse A(H1N1)pdm09 viruses, that were also antigenically drifted. We measured vaccine effectiveness (VE) in the United States against illness from these emerging viruses. METHODS: We enrolled outpatients aged ≥6 months with acute respiratory illness at five sites. Respiratory specimens were tested for influenza by reverse-transcriptase polymerase chain reaction (RT-PCR). Using the test-negative design, we determined influenza VE by virus sub-type/lineage and genetic subclades by comparing odds of vaccination in influenza cases versus test-negative controls. RESULTS: Among 8,845 enrollees, 2,722 (31%) tested positive for influenza, including 1,209 (44%) for B/Victoria and 1,405 (51%) for A(H1N1)pdm09. Effectiveness against any influenza illness was 39% (95% confidence interval [CI]: 32-44), 45% (95%CI: 37-52) against B/Victoria and 30% (95%CI: 21-39) against A(H1N1)pdm09 associated illness. Vaccination offered no protection against A(H1N1)pdm09 viruses with antigenically drifted clade 6B.1A 183P-5A+156K HA genes (VE 7%; 95%CI: -14 to 23%) which predominated after January. CONCLUSIONS: Vaccination provided protection against influenza illness, mainly due to infections from B/Victoria viruses. Vaccine protection against illness from A(H1N1)pdm09 was lower than historically observed effectiveness of 40-60%, due to late-season vaccine mismatch following emergence of antigenically drifted viruses. The effect of drift on vaccine protection is not easy to predict and, even in drifted years, significant protection can be observed.