Polymerase Chain Reaction

Rickettsial Disease Diagnostic Testing and Interpretation

Author/s: 
Centers for Disease Control and Prevention

This video provides information on rickettsial disease diagnostic methods for healthcare providers, including what tests are available and when it is most appropriate to collect samples. This video focuses on the use of polymerase chain reaction (or PCR) tests, and the indirect immunofluorescence antibody (IFA) assay for rickettsial disease diagnosis.

Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study

Author/s: 
Chen, N, Zhou, M, Dong, X, Qu, J, Gong, F, Han, Y, Qiu, Y, Wang, J, Liu, Y, Wei, Y, Xia, J, Yu, T, Zhang, X, Zhang, L

BACKGROUND:

In December, 2019, a pneumonia associated with the 2019 novel coronavirus (2019-nCoV) emerged in Wuhan, China. We aimed to further clarify the epidemiological and clinical characteristics of 2019-nCoV pneumonia.

METHODS:

In this retrospective, single-centre study, we included all confirmed cases of 2019-nCoV in Wuhan Jinyintan Hospital from Jan 1 to Jan 20, 2020. Cases were confirmed by real-time RT-PCR and were analysed for epidemiological, demographic, clinical, and radiological features and laboratory data. Outcomes were followed up until Jan 25, 2020.

FINDINGS:

Of the 99 patients with 2019-nCoV pneumonia, 49 (49%) had a history of exposure to the Huanan seafood market. The average age of the patients was 55·5 years (SD 13·1), including 67 men and 32 women. 2019-nCoV was detected in all patients by real-time RT-PCR. 50 (51%) patients had chronic diseases. Patients had clinical manifestations of fever (82 [83%] patients), cough (81 [82%] patients), shortness of breath (31 [31%] patients), muscle ache (11 [11%] patients), confusion (nine [9%] patients), headache (eight [8%] patients), sore throat (five [5%] patients), rhinorrhoea (four [4%] patients), chest pain (two [2%] patients), diarrhoea (two [2%] patients), and nausea and vomiting (one [1%] patient). According to imaging examination, 74 (75%) patients showed bilateral pneumonia, 14 (14%) patients showed multiple mottling and ground-glass opacity, and one (1%) patient had pneumothorax. 17 (17%) patients developed acute respiratory distress syndrome and, among them, 11 (11%) patients worsened in a short period of time and died of multiple organ failure.

INTERPRETATION:

The 2019-nCoV infection was of clustering onset, is more likely to affect older males with comorbidities, and can result in severe and even fatal respiratory diseases such as acute respiratory distress syndrome. In general, characteristics of patients who died were in line with the MuLBSTA score, an early warning model for predicting mortality in viral pneumonia. Further investigation is needed to explore the applicability of the MuLBSTA score in predicting the risk of mortality in 2019-nCoV infection.

FUNDING:

National Key R&D Program of China.

Oseltamivir plus usual care versus usual care for influenza-like illness in primary care: an open-label, pragmatic, randomised controlled trial

Author/s: 
Butler, CC, van der Velden, AW, Bongard, E, Saville, BR, Holmes, J, Coenen, S, Cook, J, Francis, NA, Lewis, RJ, Godycki-Cwirko, M, Llor, C, Chlabicz, S, Lionis, C, Seifert, B, Sundvall, PD, Colliers, A, Aabenhus, R, Bjerrum, L, Jonassen Harbin, N, Lindbæk M, Glinz, D, Bucher, HC, Kovacs, B, Radzeviciene Jurgute, R, Touboul Lundgren, P, Little, P, Murphy, AW, De Sutter, A, Openshaw, P, de Jong, MD, Connor, JT, Matheeussen, V, Ieven, M, Goossens, H, Verheij, TJ

BACKGROUND:

Antivirals are infrequently prescribed in European primary care for influenza-like illness, mostly because of perceived ineffectiveness in real world primary care and because individuals who will especially benefit have not been identified in independent trials. We aimed to determine whether adding antiviral treatment to usual primary care for patients with influenza-like illness reduces time to recovery overall and in key subgroups.

METHODS:

We did an open-label, pragmatic, adaptive, randomised controlled trial of adding oseltamivir to usual care in patients aged 1 year and older presenting with influenza-like illness in primary care. The primary endpoint was time to recovery, defined as return to usual activities, with fever, headache, and muscle ache minor or absent. The trial was designed and powered to assess oseltamivir benefit overall and in 36 prespecified subgroups defined by age, comorbidity, previous symptom duration, and symptom severity, using a Bayesian piece-wise exponential primary analysis model. The trial is registered with the ISRCTN Registry, number ISRCTN 27908921.

FINDINGS:

Between Jan 15, 2016, and April 12, 2018, we recruited 3266 participants in 15 European countries during three seasonal influenza seasons, allocated 1629 to usual care plus oseltamivir and 1637 to usual care, and ascertained the primary outcome in 1533 (94%) and 1526 (93%). 1590 (52%) of 3059 participants had PCR-confirmed influenza infection. Time to recovery was shorter in participants randomly assigned to oseltamivir (hazard ratio 1·29, 95% Bayesian credible interval [BCrI] 1·20-1·39) overall and in 30 of the 36 prespecified subgroups, with estimated hazard ratios ranging from 1·13 to 1·72. The estimated absolute mean benefit from oseltamivir was 1·02 days (95% [BCrI] 0·74-1·31) overall, and in the prespecified subgroups, ranged from 0·70 (95% BCrI 0·30-1·20) in patients younger than 12 years, with less severe symptoms, no comorbidities, and shorter previous illness duration to 3·20 (95% BCrI 1·00-5·50) in patients aged 65 years or older who had more severe illness, comorbidities, and longer previous illness duration. Regarding harms, an increased burden of vomiting or nausea was observed in the oseltamivir group.

INTERPRETATION:

Primary care patients with influenza-like illness treated with oseltamivir recovered one day sooner on average than those managed by usual care alone. Older, sicker patients with comorbidities and longer previous symptom duration recovered 2-3 days sooner.

FUNDING:

European Commission's Seventh Framework Programme.

Practice Transformation Under the University of Colorado's Primary Care Redesign Model

Author/s: 
Smith, P.C., Lyon, C., English, A.F., Conry, C.

PURPOSE:

We compared the transformation experience of 2 family medicine practices that implemented the Primary Care Redesign (PCR) team-based model to improve access, quality, and experience without increasing cost. The University of Colorado's A.F. Williams Family Medicine clinic (pilot practice) implemented the model in February 2015, and a smaller, community-based practice (wave 2 practice) did so 2 years later, in February 2017.

METHODS:

The PCR model increased the ratio of medical assistants to clinicians from about 1:2 to 2.5:1 while expanding the role of the medical assistants, through enhanced rooming procedures, in-room support (eg, scribing), postclinician wrap-up, and in-basket assistance. We assessed access, clinical quality metrics, staffing costs, and clinician and staff experience and burnout for at least 7 months before and 42 months after the intervention.

RESULTS:

In the pilot practice, compared with preimplementation, there were improvements in total appointments and rates of hypertension control, colorectal cancer screening, and most diabetic quality metrics. In the wave 2 practice, total appointments increased slightly when clinicians were added pre-PCR and then increased substantially after implementation; initially variable hypertension control improved rapidly after implementation. The wave 2 practice's colorectal cancer screening improved gradually, then accelerated postimplementation, while diabetic metrics initially remained stable or declined, then improved postimplementation. New patient appointments began to increase for both practices in late 2015, but grew faster in the pilot practice under PCR. Over time, all experiential domains improved for clinicians; most remained stable for staff. Clinician burnout was reduced by at least one-half in both practices except during low staffing periods, which also adversely affected staff. After a ramp-up period, the number of staff hours per visit remained stable.

CONCLUSIONS:

The PCR model is associated with simultaneous improvements in quality, access, and clinician experience, as well as reductions in burnout, while maintaining staffing costs.

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