Performance assessment of 11 commercial serological tests for SARS-CoV-2 on hospitalised COVID-19 patients.

BACKGROUND: Commercial availability of serological tests to evaluate immunoglobulins (Ig) targeting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has grown exponentially since the start of the coronavirus disease 2019 (COVID-19) outbreak. Thorough validation of these tests is important before use as epidemiological tools to infer seroprevalence in specific populations and as diagnostic tools to complement molecular approaches (e.g., quantitative reverse transcription-polymerase chain reaction). METHODS: Commercial serological tests from 11 suppliers were assayed side-by-side using 126 samples from SARS-CoV-2-infected inpatients and 36 from healthy and HIV-infected individuals. RESULTS: The majority of the tests assayed have >95% specificity. For the sensitivity calculation, samples were stratified by days since symptoms onset; sensitivity peaks at 16-21 days for IgM and IgA (maximum 91.2%, Euroimmun) and, dependant on the test, at 16-21 or >21 days for IgG (maximum 94.1%, Snibe). Data from semiquantitative tests show that patients with a severe clinical presentation have lower levels of Ig targeting SARS-CoV-2 at <10 days since symptoms onset and higher levels at >21 days, compared to patients with a non-severe presentation. CONCLUSIONS: This study highlights the heterogeneity of sensitivity and generally high specificity of the serological tests and establishes a basis for their usefulness to complement diagnostic techniques and population seroprevalence studies.

An epidemiological study determining blood pressure in a Portuguese cohort: the Guimarães/Vizela study.

Surveying the evolution of blood pressure (BP) levels and hypertension (HTN) prevalence is important. A stringent strategy was utilized in a population cohort study. The BP was measured at two visits at least 3 months apart, and the results were analyzed using the following two methods: the Surveillance method (three BP measurements were performed in one visit, and the results were compared with those published previously for the identical method) and the Clinical method (three measurements per visit for two visits, and the concordant results in both visits were used to determine the BP classification). A total of 2542 subjects completed the evaluation. Using the Clinical method, an average systolic/diastolic BP value of 129.8/76.8 mm Hg was obtained, and the prevalence of HTN was 31.6%. Of the hypertensive patients, 74.3% were aware of his/her condition; 69.1% were treated and 40.8% of those treated had adequate BP control. A total of 24.7% of subjects changed his/her BP classification between visits, and 13.7% misreported HTN. Using the Surveillance method, we determined that the average global SBP has been maintained, with HTN prevalence increasing in this region, drifting from reported trends nationally and worldwide. There has been improvement in the proportion of treated and controlled subjects; however, the Surveillance method overestimated the HTN prevalence and underestimated the proportion of treated and controlled subjects. The BP levels were higher than observed worldwide in high-cardiovascular (CV) risk countries as well as higher than the minimum risk exposure level for developing CV disease.

Requirements for authorisation of internal dosimetry services.

In order to ensure that a facility is in compliance with the occupational exposure requirements established by regulatory authorities, the measurements and dose assessments specified in the individual monitoring programme need to be reliable. There are two important questions that shall be addressed here: one is how the licensed facilities can demonstrate to their workers and regulatory bodies compliance with the regulatory limits and the reliability of the results of the individual monitoring programmes; the other concerns the mechanisms used to demonstrate to a facility in another country the reliability of the measurement results of an individual monitoring bioassay programme. The accreditation of the bioassay laboratory, according to ISO/IEC 17025, shall be the basic requirement for obtaining the authorisation granted by the national regulatory authority. For the second question, such confidence can be achieved through International Laboratory Accreditation Cooperation (ILAC).

Latin american and Caribbean intercomparison of radiation protection area monitoring instruments.

In December 2000 the International Atomic Energy Agency sponsored an intercomparison of radiation protection area monitoring instruments which was held at the Instituto de Radioproteção e Dosimetria--IRD/CNEN, Rio de Janeiro. Brazil. This intercomparison exercise was aimed at evaluating the ability of some Latin American and Caribbean countries to perform calibrations or such instruments, or have them properly performed by a third party. Nine countries participated in the exercise with 13 portable gamma dose rate monitors. The quantity of interest for the intercomparison was the ambient dose equivalent, H*(10), although some instruments were not designed or calibrated in this quantity. Results were converted to H*(10), whenever necessary. according to the information supplied by each participant. All results for the quantity of interest agree well within 10% of the reference values and the quoted uncertainties.

Monitorizaçäo individual em geometrias complexas de exposiçäo a fótons / Individual monitoring in complex geometry of photon exposure

A razão (dose efetiva, E/Dose equivalente pessoal, Hp (10) foi calculada para diversos cenários de exposição a campos paralelos de fótons. São apontados algumas situações onde o número de monitores e a localização do mesmo sobre o corpo do trabalhador devem ser objeto de análise para que a dose efetiva não seja subestimada.

Considerations related to the decontamination of houses in Goiânia: limitations and implications.

We are considering some aspects related to the decontamination activities of about 50 houses affected by 137Cs in Goiânia. We describe the way these contaminations occurred, the instruments used, and the procedures. We also discuss the dose limits established for decontamination and the consequences resulting from this action. We call attention to the importance of not only the technical aspects in such activities but also the psychosocial implications resulting from them.