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Alfredo Mayor

Bio: Alfredo Mayor is an academic researcher from University of Barcelona. The author has contributed to research in topics: Plasmodium falciparum & Malaria. The author has an hindex of 35, co-authored 150 publications receiving 3948 citations. Previous affiliations of Alfredo Mayor include International Military Sports Council & Carlos III Health Institute.


Papers
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Journal ArticleDOI
TL;DR: A relatively low seroprevalence of antibodies among HCW at the peak of the COVID-19 epidemic in Spain is reported, which calls for active periodic rRT-PCR testing in hospital settings.
Abstract: Health care workers (HCW) are a high-risk population to acquire SARS-CoV-2 infection from patients or other fellow HCW. This study aims at estimating the seroprevalence against SARS-CoV-2 in a random sample of HCW from a large hospital in Spain. Of the 578 participants recruited from 28 March to 9 April 2020, 54 (9.3%, 95% CI: 7.1-12.0) were seropositive for IgM and/or IgG and/or IgA against SARS-CoV-2. The cumulative prevalence of SARS-CoV-2 infection (presence of antibodies or past or current positive rRT-PCR) was 11.2% (65/578, 95% CI: 8.8-14.1). Among those with evidence of past or current infection, 40.0% (26/65) had not been previously diagnosed with COVID-19. Here we report a relatively low seroprevalence of antibodies among HCW at the peak of the COVID-19 epidemic in Spain. A large proportion of HCW with past or present infection had not been previously diagnosed with COVID-19, which calls for active periodic rRT-PCR testing in hospital settings.

330 citations

Journal ArticleDOI
TL;DR: This Series paper summarises recent progress and highlights unresolved issues related to the burden of malaria in pregnancy and suggests pregnant women could be used to monitor malaria transmission.
Abstract: Over the past 10 years, knowledge of the burden, economic costs, and consequences of malaria in pregnancy has improved, and the prevalence of malaria caused by Plasmodium falciparum has declined substantially in some geographical areas. In particular, studies outside of Africa have increased the evidence base of Plasmodium vivax in pregnancy. Rapid diagnostic tests have been poor at detecting malaria in pregnant women, while PCR has shown a high prevalence of low density infection, the clinical importance of which is unknown. Erythrocytes infected with P falciparum that express the surface protein VAR2CSA accumulate in the placenta, and VAR2CSA is an important target of protective immunity. Clinical trials for a VAR2CSA vaccine are ongoing, but sequence variation needs to be carefully studied. Health system and household costs still limit access to prevention and treatment services. Within the context of malaria elimination, pregnant women could be used to monitor malaria transmission. This Series paper summarises recent progress and highlights unresolved issues related to the burden of malaria in pregnancy.

193 citations

Journal ArticleDOI
09 Apr 2008-PLOS ONE
TL;DR: Two-dose SP was associated with a reduction in some indicators, but these were not translated to significant improvement in other maternal or birth outcomes, and ITNs should be part of the ANC package in sub-Saharan Africa.
Abstract: Current recommendations to prevent malaria in African pregnant women rely on insecticide treated nets (ITNs) and intermittent preventive treatment (IPTp). However there is no information on the safety and efficacy of their combined use. 1030 pregnant Mozambican women of all gravidities received a long-lasting ITN during antenatal clinic (ANC) visits and irrespective of HIV status were enrolled in a randomised double blind placebo-controlled trial to assess the safety and efficacy of 2-dose sulphadoxine-pyrimethamine (SP). The main outcome was the reduction in low birth weight. Two-dose SP was safe and well tolerated but was not associated with reductions in anaemia prevalence at delivery (RR 0.92 [95% CI 0.79-1.08]) low birth weight (RR 0.99 [95% CI 0.70-1.39]) or overall placental infection (p = 0.964). However the SP group showed a 40% reduction (95% CI 7.40-61.20]; p = 0.020) in the incidence of clinical malaria during pregnancy and reductions in the prevalence of peripheral parasitaemia (7.10% vs 15.15%) (p less than 0.001) and of actively infected placentas (7.04% vs 13.60%) (p = 0.002). There was a reduction in severe anaemia at delivery of borderline statistical significance (p = 0.055). These effects were not modified by gravidity or HIV status. Reported ITNs use was more than 90% in both groups. Two-dose SP was associated with a reduction in some indicators but these were not translated to significant improvement in other maternal or birth outcomes. The use of ITNs during pregnancy may reduce the need to administer IPTp. ITNs should be part of the ANC package in sub-Saharan Africa. (authors)

160 citations

Journal ArticleDOI
13 Feb 2014-Blood
TL;DR: The high prevalence and abundance of early sexual stages in bone marrow, as well as the relationship between hematological disturbances and gametocyte development in this tissue, are highlighted.

147 citations

Journal ArticleDOI
TL;DR: In this tertiary hospital in Mozambique, infectious diseases accounted for at least half of all maternal deaths, even though effective treatment is available for the four leading causes, HIV/AIDS, pyogenic bronchopneumonia, severe malaria, and pyogenic meningitis.
Abstract: Background Maternal mortality is a major health problem concentrated in resource-poor regions. Accurate data on its causes using rigorous methods is lacking, but is essential to guide policymakers and health professionals to reduce this intolerable burden. The aim of this study was to accurately describe the causes of maternal death in order to contribute to its reduction, in one of the regions of the world with the highest maternal mortality ratios.

136 citations


Cited by
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Journal ArticleDOI
Marina Pollán1, Beatriz Pérez-Gómez1, Roberto Pastor-Barriuso1, Jesús Oteo1, Miguel A. Hernán2, Miguel A. Hernán3, Mayte Pérez-Olmeda1, Jose L Sanmartín, Aurora Fernández-García4, Aurora Fernández-García1, Israel Cruz1, Nerea Fernández de Larrea1, Marta Molina, Francisco Rodríguez-Cabrera1, Mariano Martín, Paloma Merino-Amador4, Jose León Paniagua1, Juan F Muñoz-Montalvo, Faustino Blanco, Raquel Yotti1, Rodrigo Gutiérrez Fernández, Saturnino Mezcua Navarro, Matías Salinero Hernández, Manuel Cuenca-Estrella, Pablo Fernández-Navarro, Ana Avellón, Giovanni Fedele, Jesús Oteo Iglesias, María Teresa Pérez Olmeda, Maria Elena Martinez, Francisco D. Rodríguez-Cabrera1, Susana Padrones Fernández, José Manuel Rumbao Aguirre, José M. Navarro Marí, Begoña Palop Borrás, Ana Belén Pérez Jiménez, Manuel Rodríguez-Iglesias, Ana María Calvo Gascón, María Luz Lou Alcaine, Ignacio Donate Suárez, Oscar Suárez Álvarez, Mercedes Rodríguez Pérez, Margarita Cases Sanchís, Carlos Javier Villafáfila Gomila, Lluis Carbo Saladrigas, Adoración Hurtado Fernández, Antonio Oliver, Elías Castro Feliciano, María Noemí González Quintana, José María Barrasa Fernández, María Araceli Hernández Betancor, Melisa Hernández Febles, Leopoldo Martín Martín, Luis-Mariano López López, Teresa Ugarte Miota, Inés De Benito Población, María Sagrario Celada Pérez, María Natalia Vallés Fernández, Tomás Maté Enríquez, Miguel Villa Arranz, Marta Domínguez-Gil González, Isabel Fernández-Natal, Gregoria Megías Lobón, Juan Luis Muñoz Bellido, Pilar Ciruela, Ariadna Mas i Casals, Maria Doladé Botías, M. Angeles Marcos Maeso, Dúnia Pérez del Campo, Antonio Félix de Castro, Ramón Limón Ramírez, Maria Francisca Elías Retamosa, Manuela Rubio González, María Sinda Blanco Lobeiras, Alberto Fuentes Losada, Antonio Aguilera, Germán Bou, Yolanda Caro, Noemí Marauri, Luis Miguel Soria Blanco, Isabel González, Montserrat Hernández Pascual, Roberto Alonso Fernández, Natalia Cabrera Castro, Aurora Tomás Lizcano, Cristóbal Ramírez Almagro, M. Hernández, Nieves Ascunce Elizaga, María Ederra Sanz, Carmen Ezpeleta Baquedano, Ana Bustinduy Bascaran, Susana Iglesias Tamayo, Luis Elorduy Otazua, Rebeca Benarroch Benarroch, Jesús Lopera Flores, Antonia Vázquez de la Villa 
TL;DR: In this paper, a nationwide population-based study aims to estimate the seroprevalence of SARS-CoV-2 infection in Spain at national and regional level.

1,435 citations

Journal ArticleDOI
TL;DR: The challenge for the next decade is to build the global epidemiological infrastructure required for statistically robust genomewide association analysis, as a way of discovering novel mechanisms of protective immunity that can be used in the development of an effective malaria vaccine.
Abstract: Malaria is a major killer of children worldwide and the strongest known force for evolutionary selection in the recent history of the human genome. The past decade has seen growing evidence of ethnic differences in susceptibility to malaria and of the diverse genetic adaptations to malaria that have arisen in different populations: epidemiological confirmation of the hypotheses that G6PD deficiency, α + thalassemia, and hemoglobin C protect against malaria mortality; the application of novel haplotype-based techniques demonstrating that malaria-protective genes have been subject to recent positive selection; the first genetic linkage maps of resistance to malaria in experimental murine models; and a growing number of reported associations with resistance and susceptibility to human malaria, particularly in genes involved in immunity, inflammation, and cell adhesion. The challenge for the next decade is to build the global epidemiological infrastructure required for statistically robust genomewide association analysis, as a way of discovering novel mechanisms of protective immunity that can be used in the development of an effective malaria vaccine.

1,002 citations

Journal ArticleDOI
TL;DR: The various features of drug resistance in Plasmodium falciparum, including its determinants, current status in diverse geographical areas, molecular markers, and their implications are described.
Abstract: Since the first reports of chloroquine-resistant falciparum malaria in southeast Asia and South America almost half a century ago, drug-resistant malaria has posed a major problem in malaria control. By the late 1980s, resistance to sulfadoxine-pyrimethamine and to mefloquine was also prevalent on the Thai-Cambodian and Thai-Myanmar (Thai-Burmese) borders, rendering them established multidrug-resistant (MDR) areas. Chloroquine resistance spread across Africa during the 1980s, and severe resistance is especially found in east Africa. As a result, more than ten African countries have switched their first-line drug to sulfadoxine-pyrimethamine. Of great concern is the fact that the efficacy of this drug in Africa is progressively deteriorating, especially in foci in east Africa, which are classified as emerging MDR areas. Urgent efforts are needed to lengthen the lifespan of sulfadoxine-pyrimethamine and to identify effective, affordable, alternative antimalarial regimens. Molecular markers for antimalarial resistance have been identified, including pfcrt polymorphisms associated with chloroquine resistance and dhfr and dhps polymorphisms associated with sulfadoxine-pyrimethamine resistance. Polymorphisms in pfmdr1 may also be associated with resistance to chloroquine, mefloquine, quinine, and artemisinin. Use of such genetic information for the early detection of resistance foci and future monitoring of drug-resistant malaria is a potentially useful epidemiological tool, in conjunction with the conventional in-vivo and in-vitro drug-sensitivity assessments. This review describes the various features of drug resistance in Plasmodium falciparum, including its determinants, current status in diverse geographical areas, molecular markers, and their implications.

819 citations

Journal ArticleDOI
TL;DR: This current edition of this reference work is written by six major contributors and contains either rewritten or new chapters, including one 29-page chapter entitled "Ophthalmology in the Tropics" by F. C. Rodger, MD.
Abstract: The first edition of this reference work was published in 1898, and the last update was published in 1972. This current edition is written by six major contributors and contains either rewritten or new chapters, including one 29-page chapter entitled "Ophthalmology in the Tropics" by F. C. Rodger, MD. Not only is this material valuable to physicians in endemic areas, but it is also important for travelers to the tropics who may return home with these diseases. Most of the chapters discuss the following aspects of tropical disease: cause, transmission, immunology, epidemiology, geographical distribution, pathologic condition, clinical findings, and diagnosis (including laboratory findings, treatment, and prevention). Beside chapters on infections, there are chapters on disorders due to heat, nutritional diseases, and venoms and poisons, and appendices on protozoology, helminthology, entomology, and clinical pathologic conditions. Excellent illustrations of end-stage pathologic conditions are disconcerting. Ophthalmologists would be most interested in the discussion

781 citations

18 Aug 2020
TL;DR: The majority of the Spanish population is seronegative to SARS-CoV-2 infection, even in hotspot areas, and results emphasise the need for maintaining public health measures to avoid a new epidemic wave.

749 citations