High anti-SARS-CoV-2 antibody seroconversion rates before the second wave in Manaus, Brazil, and the protective effect of social behaviour measures: results from the prospective DETECTCoV-19 cohort

Background: The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil. Methods: A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms. Findings: 2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52–14·79) overall and 6·78% (5·61–8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54–61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21–1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09–1·45]), relaxation of physical distancing (1·31 [1·05–1·64]), and having flu-like symptoms (1·79 [1·23–2·59]) or a COVID-19 diagnosis (3·57 [2·27–5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56–0·97]). Interpretation: An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures. Funding: Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO.World Health OrganizationRevisión por pare

Cytokine profile associated with chronic and acute human schistosomiasis mansoni

The production and regulation of interleukin (IL) IL-13, IL-4 and interferon-gamma (IFN-³) was evaluated in 43 schistosomiasis patients with different clinical forms. Whole-blood cultures cytokine production in response to soluble egg antigen (SEA), soluble worm adult preparation (SWAP), mitogens, neutralizing antibodies or recombinant IL-13 were measured by ELISA. After SWAP stimulation, chronic patients, particularly hepatointestinals, produced higher levels of IL-4 in comparison with acute patients, suggesting the presence of a type 2 cytokine profile in these patients. Following SEA and SWAP stimulation, hepatosplenic (HS) patients showed increased levels of IFN-³ when compared with acute patients, indicating that HS disease in humans is associated with a type 1 cytokine response. The mechanisms of immune regulation are apparently different between the clinical stages of the disease, some of which are antigen-specific

EFEITO DA INVERS\uc3O NO TRATAMENTO DE MOIR\uf5ES SUBMETIDOS AO M\uc9TODO DE SUBSTITUI\uc7\uc3O DA SEIVA

This work aimed to evaluate the effect of inversion of Prosopis juliflora and Leucaena leucocephala fence posts, in distribution, penetration and retention of copper chrome borate (CCB) solution applied by sap displacement method. The Prosopis juliflora was collected in Brazilian Agricultural Research Company (EMBRAPA) and the Leucaena leucocephala at the Federal University of Campina Grande in Patos, Para\uedba state, Brazil. Trees with DAP from 5.0 to 10.0 cm were employed. Disks of 2.0 cm of thickness were retired on the top and on the base of pieces. The external disks were then discarded and the intern ones were employed to determine the wood characteristics, being the round pieces with 2.0 m. A solution of 2% of active ingredients of CCB was used to treated woods. A total of 10 pieces of each species were treated, and five of them remained in the solution for 8 days and the five ones had their tops inverted after the sixth day of treatment. The pieces were seasoned; disks of 2.0 cm of thickness were taken in 5 positions along of pieces and the analyses for determination of copper and boron penetration took place. The values of wood characteristics indicated that the pieces were homogeneous. The absorption of the solution was of 19.9 liters (Prosopis juliflora) and of 17.0 liters (Leucaena leucocephala). The nominal retentions of CCB were 7.72 and 5.34 kg active ingredients (a.i.)/m3, respectively. In general, the inversion of the pieces in the preservative solution is recommended, by providing a better distribution, penetration and retention of CCB on treated pieces.O objetivo da pesquisa foi avaliar o efeito da invers\ue3o de moir\uf5es de algaroba ( Prosopis juliflora ) e de leucena ( Leucaena leucocephala ), na solu\ue7\ue3o preservativa, na distribui\ue7\ue3o, penetra\ue7\ue3o e reten\ue7\ue3o do borato de cobre cromatado (CCB) aplicado pelo m\ue9todo de substitui\ue7\ue3o da seiva. A algaroba foi coletada na Empresa Brasileira de Pesquisa Agropecu\ue1ria (EMBRAPA) e a leucena no Campus da Universidade Federal de Campina Grande, em Patos - PB. Foram colhidas \ue1rvores com DAP entre 6,0 a 12,0 cm. Retiraram-se dois discos de 2,0 cm de espessura no topo e base das pe\ue7as. Os discos externos foram descartados e os internos empregados nas determina\ue7\uf5es das caracter\uedsticas das madeiras, ficando as pe\ue7as com 2,0 m. Empregouse uma solu\ue7\ue3o de 2% de ingredientes ativos de CCB. Foram tratadas 10 pe\ue7as de cada esp\ue9cie, tendo cinco delas permanecido dispostas na solu\ue7\ue3o durante 8 dias e cinco tiveram seus topos invertidos ap\uf3s o sexto dia de tratamento. As pe\ue7as foram secas ao ar, retiraram-se discos de 2,0 cm de espessura para a determina\ue7\ue3o da penetra\ue7\ue3o (cinco posi\ue7\uf5es nas pe\ue7as) e para a reten\ue7\ue3o do CCB (tr\ueas posi\ue7\uf5es). Os valores das caracter\uedsticas das madeiras indicaram que as pe\ue7as eram homog\ueaneas. A absor\ue7\ue3o da solu\ue7\ue3o foi de 19,9 litros (algaroba) e de 17,0 litros (leucena), acarretando em uma reten\ue7\ue3o nominal de CCB de 7,72 e 5,34 kg de ingredientes ativos (i.a.)/m3, respectivamente. De maneira geral, a invers\ue3o das pe\ue7as na solu\ue7\ue3o preservativa \ue9 recomend\ue1vel, por proporcionar uma melhor distribui\ue7\ue3o, penetra\ue7\ue3o e reten\ue7\ue3o do CCB ao longo da pe\ue7a tratada

SELECTABLE PERMUTATION ENCODER/DECODER FOR A QPSK MODEM

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaAn artifact of QPSK modems is ambiguity of the recovered data. There are four variations of the output data for a given input data stream. All are equally probable. To resolve this ambiguity, the QPSK data streams can be differentially encoded before modulation and differentially decoded after demodulation. The encoder maps each input data pair to a phase angle change of the QPSK carrier. In the demodulator, the inverse is performed - each phase change of the input QPSK carrier is mapped to an output data pair. This paper discusses a very simple and unique differential encoder/decoder that handles all possible data pair/phase change permutations.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

SHORT COMMUNICATION - Preliminary Results on the Effects of CD40/CD40L Interactions and SAC-induction on IFN-g Expression in Human Schistosomiasis

In this communication the authors analyzed the pattern of expression of IFN-γ as a surrogate type 1 response in different clinical forms of schistosomiasis in response to stimulation involving T-cell dependent and T-cell independent pathways, to investigate which pathways were functional in human schistosomiasis, and to further characterize the nature of Th1 response impairment in this parasitic disease

Enhanced Interleukin-12 and CD40 Ligand Activities but Reduced Staphylococcus aureus Cowan 1-Induced Responses Suggest a Generalized and Progressively Impaired Type 1 Cytokine Pattern for Human Schistosomiasis

Whole-blood-cell cultures from schistosomiasis patients were stimulated with a variety of T-cell-dependent and T-cell-independent stimuli to determine whether the defect in type 1 cytokine expression observed following helminth infection is associated with alterations in interleukin-12 (IL-12) or CD40 ligand (CD40L) responsiveness. Cultures from uninfected individuals produced abundant gamma interferon in response to Staphylococcus aureus Cowan 1 (SAC), while patients with intestinal and hepatosplenic disease displayed intermediate and weak responses, respectively. Importantly, the decrease in type 1 cytokine expression was not attributed to defects in IL-12- or CD40L-induced activity. Indeed, schistosomiasis patients displayed heightened responses and even produced more biologically active IL-12 when stimulated with SAC and CD40L than did uninfected controls. Finally, additional studies suggested only a partial role for IL-10, since intestinal patients were the only group that overproduced this downregulatory cytokine. Together, these studies demonstrate that the type 1 deficiency in chronic hepatosplenic schistosomiasis is not related to specific defects in IL-12, IL-10, or CD40L activity, although changes in the functional status of antigen-presenting cells appear to be involved

Preliminar evaluation of cytokines in the hepatitis C-schistosomiasis co-infection

Evaluation of hepatic fibrosis is usually performed by histopathological examination of biopsies. However, this is an invasive and potentially dangerous procedure. Several studies have proposed serum biological markers of hepatic fibrosis. This communication evaluates the use of serum cytokines as markers of hepatic fibrosis in hepatitis C, schistosomiasis, and co-infection

SHORT COMMUNICATION - Preliminary Results on the Effects of CD40/CD40L Interactions and SAC-induction on IFN-g Expression in Human Schistosomiasis

In this communication the authors analyzed the pattern of expression of IFN-γ as a surrogate type 1 response in different clinical forms of schistosomiasis in response to stimulation involving T-cell dependent and T-cell independent pathways, to investigate which pathways were functional in human schistosomiasis, and to further characterize the nature of Th1 response impairment in this parasitic disease

Studies on the production and regulation of interleukin, IL-13, IL-4 and interferon-g in human Schistosomiasis mansoni

The production and regulation of interleukin (IL) IL-13, IL-4 and Interferon-γ was evaluated in different clinical forms of human schistosomiasis. The mechanisms of immune regulation are apparently different in the various clinical stages of the disease, some of them being antigen specific

Studies on the production and regulation of interleukin, IL-13, IL-4 and interferon-g in human Schistosomiasis mansoni

The production and regulation of interleukin (IL) IL-13, IL-4 and interferon-gamma was evaluated in different clinical forms of human schistosomiasis. The mechanisms of immune regulation are apparently different in the various clinical stages of the disease, some of them being antigen specific