Technical performance of a lateral flow immunoassay for detection of anti-SARS-CoV-2 IgG in the outpatient follow-up of non-severe cases and at different times after vaccination: comparison with enzyme and chemiluminescent immunoassays.

This study assessed the technical performance of a rapid lateral flow immunochromatographic assay (LFIA) for the detection of anti-SARS-CoV-2 IgG and compared LFIA results with chemiluminescent immunoassay (CLIA) results and an in-house enzyme immunoassay (EIA). To this end, a total of 216 whole blood or serum samples from three groups were analyzed: the first group was composed of 68 true negative cases corresponding to blood bank donors, healthy young volunteers, and eight pediatric patients diagnosed with other coronavirus infections. The serum samples from these participants were obtained and stored in a pre-COVID-19 period, thus they were not expected to have COVID-19. In the second group of true positive cases, we chose to replace natural cases of COVID-19 by 96 participants who were expected to have produced anti-SARS-CoV-2 IgG antibodies 30-60 days after the vaccine booster dose. The serum samples were collected on the same day that LFIA were tested either by EIA or CLIA. The third study group was composed of 52 participants (12 adults and 40 children) who did or did not have anti-SARS-CoV-2 IgG antibodies due to specific clinical scenarios. The 12 adults had been vaccinated more than seven months before LFIA testing, and the 40 children had non-severe COVID-19 diagnosed using RT-PCR during the acute phase of infection. They were referred for outpatient follow-up and during this period the serum samples were collected and tested by CLIA and LFIA. All tests were performed by the same healthcare operator and there was no variation of LFIA results when tests were performed on finger prick whole blood or serum samples, so that results were grouped for analysis. LFIA's sensitivity in detecting anti-SARS-CoV-2 IgG antibodies was 90%, specificity 97.6%, efficiency 93%, PPV 98.3%, NPV 86.6%, and likelihood ratio for a positive or a negative result were 37.5 and 0.01 respectively. There was a good agreement (Kappa index of 0.677) between LFIA results and serological (EIA or CLIA) results. In conclusion, LFIA analyzed in this study showed a good technical performance and agreement with reference serological assays (EIA or CLIA), therefore it can be recommended for use in the outpatient follow-up of non-severe cases of COVID-19 and to assess anti-SARS-CoV-2 IgG antibody production induced by vaccination and the antibodies decrease over time. However, LFIAs should be confirmed by using reference serological assays whenever possible.

Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital.

OBJECTIVES: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19). METHODS: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed. RESULTS: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for >12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11% versus 0%, p=0.030), lymphopenia (42% versus 18%, p=0.020), C-reactive protein level of >30 mg/L (35% versus 0%, p=0.0001), and D-dimer level of >1000 ng/mL (43% versus 6%, p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11% versus 2%, p=0.178) and cardiac alterations on echocardiogram (33% versus 22%, p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100] versus 81 [34-100], p=0.012), and school score (60 [15-100] versus 70 [15-95], p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls. CONCLUSIONS: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19.

Use of lung ultrasound in neonates during the COVID-19 pandemic

In the current pandemic, caused by infection with severe acute respiratory syndrome coronavirus 2, ultrasound has played a fundamental role in patients who develop the resulting disease, designated coronavirus disease 2019 (COVID-19). In this study we present ultrasound images of the lungs of neonates with a suspected or confirmed diagnosis of COVID-19, distinguishing between the changes related to COVID-19 and those unrelated to the disease. Ultrasound examinations were performed by a pediatric sonographer. A total of 27 neonates were evaluated. Among those who presented no respiratory symptoms, some tested negative for COVID-19 and others tested positive. All of those who were pulmonary symptomatic, negative for COVID-19 presented transient tachypnea of the newborn and respiratory distress syndrome. Lung ultrasound images obtained in COVID-19-negative neonates showed, in some cases, a normal pattern (with A lines, few B lines, a thin, linear pleural line, and no pleural effusion), whereas in others showed coalescent B lines and areas of opacity. In two of the COVID-19-positive neonates, lung ultrasound examination showed several coalescent B lines, pleural thickening, and areas of opacity. Lung ultrasound in the neonatal period appears to be applicable within the context of the current pandemic, allowing efficient evaluation of COVID-19-related changes in neonates, as well as of pathologies inherent to the neonatal period. Resumo Na pandemia atual causada pelo SARS-CoV-19, a ultrassonografia (US) tem apresentado papel fundamental nos pacientes com COVID-19. Neste trabalho são mostradas imagens ultrassonográficas de recém-nascidos (RNs) suspeitos ou positivos para COVID-19 e alterações pulmonares não relacionadas a essa doença. As imagens ultrassonográficas foram obtidas por médico especialista em US pediátrica. Foram avaliados 27 RNs, sendo incluídos RNs assintomáticos da parte respiratória, COVID negativos e positivos, e RNs sintomáticos para a parte respiratória, COVID-negativos, observados na taquipneia transitória do recém-nascido ou na síndrome do desconforto respiratório. As imagens ultrassonográficas dos RNs negativos para COVID-19 mostraram tanto o padrão normal (presença de linhas A, poucas linhas B, linha pleural fina e linear, ausência de efusão pleural) quanto a presença de linhas B coalescentes e áreas de condensação pulmonar. Destaca-se a presença de dois RNs COVID-19 positivos apresentando múltiplas linhas B coalescentes, espessamento pleural e com áreas de condensação. Com este trabalho, os autores procuram demonstrar a aplicabilidade da US pulmonar dentro do contexto da pandemia da COVID-19, incluindo as doenças inerentes ao período neonatal.

Use of lung ultrasound in neonates during the COVID-19 pandemic.

In the current pandemic, caused by infection with severe acute respiratory syndrome coronavirus 2, ultrasound has played a fundamental role in patients who develop the resulting disease, designated coronavirus disease 2019 (COVID-19). In this study we present ultrasound images of the lungs of neonates with a suspected or confirmed diagnosis of COVID-19, distinguishing between the changes related to COVID-19 and those unrelated to the disease. Ultrasound examinations were performed by a pediatric sonographer. A total of 27 neonates were evaluated. Among those who presented no respiratory symptoms, some tested negative for COVID-19 and others tested positive. All of those who were pulmonary symptomatic, negative for COVID-19 presented transient tachypnea of the newborn and respiratory distress syndrome. Lung ultrasound images obtained in COVID-19-negative neonates showed, in some cases, a normal pattern (with A lines, few B lines, a thin, linear pleural line, and no pleural effusion), whereas in others showed coalescent B lines and areas of opacity. In two of the COVID-19-positive neonates, lung ultrasound examination showed several coalescent B lines, pleural thickening, and areas of opacity. Lung ultrasound in the neonatal period appears to be applicable within the context of the current pandemic, allowing efficient evaluation of COVID-19-related changes in neonates, as well as of pathologies inherent to the neonatal period.

Na pandemia atual causada pelo SARS-CoV-19, a ultrassonografia (US) tem apresentado papel fundamental nos pacientes com COVID-19. Neste trabalho são mostradas imagens ultrassonográficas de recém-nascidos (RNs) suspeitos ou positivos para COVID-19 e alterações pulmonares não relacionadas a essa doença. As imagens ultrassonográficas foram obtidas por médico especialista em US pediátrica. Foram avaliados 27 RNs, sendo incluídos RNs assintomáticos da parte respiratória, COVID negativos e positivos, e RNs sintomáticos para a parte respiratória, COVID-negativos, observados na taquipneia transitória do recém-nascido ou na síndrome do desconforto respiratório. As imagens ultrassonográficas dos RNs negativos para COVID-19 mostraram tanto o padrão normal (presença de linhas A, poucas linhas B, linha pleural fina e linear, ausência de efusão pleural) quanto a presença de linhas B coalescentes e áreas de condensação pulmonar. Destaca-se a presença de dois RNs COVID-19 positivos apresentando múltiplas linhas B coalescentes, espessamento pleural e com áreas de condensação. Com este trabalho, os autores procuram demonstrar a aplicabilidade da US pulmonar dentro do contexto da pandemia da COVID-19, incluindo as doenças inerentes ao período neonatal.