Joao Almeida Santos

Scopus Publications

Influenza vaccine effectiveness from nine studies during drifted A(H3N2) subclade K predominance, Europe, September 2025 to January 2026
Heloise Lucaccioni, Diogo FP Marques, Freja Kirsebom, Hanne-Dorthe Emborg, Mark Hamilton, Heather Whitaker, Amanda Bolt Botnen, Magda Bucholc, Francisco Pozo, Nick Andrews, Ramona Trebbien, Safraj Shahul Hameed, Karina Lauenborg Møller, Mark G O’Doherty, Jamie Lopez-Bernal, Kirsty Morrison, Simon Cottrell, Suzanne Wilton, Angela MC Rose, Esther Kissling, and
Eurosurveillance, 2026
The European 2025/26 influenza season is dominated by the influenza A(H3N2) virus, with most sequenced viruses belonging to subclade K, genetically drifted from the vaccine virus, raising concerns around vaccine effectiveness (VE). Despite this, VE estimates from nine European studies (19 countries) indicate all-age influenza A VE of 25–45% for outpatient and hospital settings combined, similar to other seasons, with highest estimates among children (47–72%). Vaccination should be encouraged and complemented by other infection prevention and control measures.
Vaccine effectiveness against medically attended, laboratory-confirmed influenza in the I-MOVE primary care network in Europe, VEBIS project, 2024/25
Héloïse Lucaccioni, Francisco Pozo, Gloria Pérez-Gimeno, Ralf Dürrwald, Marina Uras, Lisa Domegan, Beatrix Oroszi, Adam Meijer, Camino Trobajo-Sanmartín, Dorina Ujvari, Ana Paula Rodrigues, Ivan Mlinarić, Mihaela Lazar, Eva Rivas Wagner, Annika Erdwiens, Vincent Enouf, Adele McKenna, Gergő Túri, Marit de Lange, Iván Martínez-Baz, Neus Latorre-Margalef, Raquel Guiomar, Sanja Kurečić Filipovic, Sorin Dinu, Olatz Mokoroa, Kristin Tolksdorf, Shirley Masse, Charlene Bennett, Katalin Kristóf, Mariette Hooiveld, Jesús Castilla, João Santos, Vesna Višekruna Vučina, Rodica Popescu, Sabrina Bacci, Marlena Kaczmarek, Esther Kissling
Expert Review of Vaccines, 2026
BACKGROUND: We conducted a multicenter test-negative study to estimate vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in primary care, Europe, 2024/25. RESEARCH DESIGN AND METHODS: Specimens were collected from patients with acute respiratory infection. All or a random sample of viruses were sequenced. VE was (1-odds ratio) × 100, adjusted for confounders. RESULTS: We included 7275 cases and 17,516 controls (weeks 40-2024-18-2025). The overall VE was 46% (95% CI: 40-52), lowest in adults ≥65 years at 28% (95% CI: 12-42). VE against influenza A(H1N1)pdm09 was 30% (95% CI: 19-40); ranging 16-34% by age and vaccination target group. Most (88%) circulating clades were 5a.2a, distinct from the vaccine clade. VE was 28% (95% CI: 7-45) against 5a.2a (C.1.9), and 6% (95% CI: -62-45) against the vaccine-matched clade 5a.2a.1 (D). VE against influenza A(H3N2) was 38% (95% CI: 26-49); ranging 20-66% by age and target group. Circulating viruses belonged to the vaccine clade 2a.3a.1, with 88% subclade (J.2). VE against influenza B was 76% (95% CI: 69-81); ranging 70-80% by age and target group; all viruses belonged to the vaccine clade V1A.3a.2, with diverse subclades. CONCLUSIONS: Influenza vaccination protected approximately one in two vaccinated individuals against medically attended infection in primary care in Europe, 2024/25, varying by (sub)type and age.
Hybrid, infection- and vaccination-induced protection against laboratory- confirmed SARS-CoV-2 infection in a European multi-centre prospective cohort of healthcare workers, 2021–2024
Madelyn Rojas-Castro, Ranya Mulchandani, Kim Brolin, Zvjezdana Lovrić Makarić, Anneli Uusküla, Colm Bergin, Catherine Fleming, Paolo Bonfanti, Rita Murri, Viesturs Zvirbulis, Dace Zavadska, Konstanty Szuldrzynski, Vânia Gaio, Corneliu Petru Popescu, Mihai Craiu, Raluca-Maria Hrișcă, Maria Cisneros, Miriam Latorre-Millán, Goranka Petrović, Liss Lohur, Jonathan McGrath, Lauren Ferguson, Anna Spolti, Katleen De Gaetano Donati, Ilze Abolina, Dagne Gravele, Ausenda Machado, Simin Aysel Florescu, Mihaela Lazar, Pilar Subirats, Laura Clusa, Gordan Sarajlić, Jacklyn Sui, Claire Kenny, Rosaria Santangelo, Dainis Krievins, Elza Anna Barzdina, Camila Valadas Henriques, Alma Gabriela Kosa, Săftica-Mariana Pohrib, Victor Daniel Miron, Carmen Muñoz-Almagro, Ana Maria Milagro, Sabrina Bacci, Camelia Savulescu, , Hanna Sepp, Lisa Domegan, Joan O’Donell, Maeve Kernan, Anne Moriarty, Conor Moran, Giulia De Angelis, Giulia Menchinelli, Cinzia Recine, Silvia Zelli, Benedetta Falasca, Silvia Lamonica, Zrinka Bošnjak, Ana Budimir, Tvrtko Žarko, Božena Rašić, Marko Ćurković, Porin Makarić, Senka Repovečki, Kornelija Petir, Irena Tabain, Tatjana Vilibić Čavlek, Janis Meisters, Laura Zemite, Hilda Darta Snipe, Estere Ergle, Ana Palmira Amaral, João Almeida Santos, Daniela Dias, Licínia Gomes, Miguel Lança, Henrique Carvalho, Jose Alves, Daniel R. Codreanu, Alexandru Marin, Amaresh Pérez-Arguello, Iolanda Jordan, Juan Jose Garcia-Garcia, Antonio Rezusta López, Alexander Isaias Tristancho Baró, Ignacio Ezpeleta Ascaso, Sandra Dueñas Jollard, Noelia Terren Marco, Tamara Valero Vicente, Nieves Felisa Martínez Cameo, Yolanda Gracia Grataloup, David Martínez Mateos, Beatriz Gilaberte Angós, Diego Ortega Larrea, María Pilar Abad Alejaldre, Cristina Carrasco Carbó, Carmen Martínez Giménez, Maria Gemma Martínez Andrés, Bruno del Moral Redolat, Ana Maria Sabio Blasco, Raquel Guiomar, Aryse Melo, Francisco Pozo, Iris Ganser, Cristina López, Albert Prats, Antony Nardone
BMC Medicine, 2025
BACKGROUND: Healthcare workers (HCWs) face high occupational exposure to SARS-CoV-2 and are a priority group for vaccination. Both natural infection and vaccination-individually or combined as hybrid immunity-confer protection against SARS-CoV-2 infection. This study aimed to evaluate the protection conferred by hybrid, infection-induced, and booster vaccine-induced immunity against laboratory-confirmed SARS-CoV-2 infections in HCWs during the circulation of three pandemic and one post-pandemic Omicron sublineages. METHODS: We conducted a prospective cohort study of HCWs from 18 hospitals across nine European countries. Participants underwent RT-PCR testing at enrolment and during weekly or fortnightly follow-ups. The study period was divided based on dominant Omicron sublineage circulation: BA.1/2 (Dec 16, 2021-Jun 1, 2022), BA.4/5/BQ.1 (Jun 2-Dec 31, 2022), BA.2/XBB (Jan 1-May 2, 2023), and post-pandemic XBB.1.5/BA.2.86 (Sep 1, 2023-May 21, 2024). Participants were classified into four groups: hybrid (prior infection and recent booster vaccination 7-179 days), infection-induced (prior infection, no recent vaccination), vaccine-induced immunity (recent booster vaccination, no prior infection), and a reference group (no prior infection, no recent booster vaccination). Adjusted hazard ratios (aHRs) for infection were estimated using Cox regression, adjusting for hospital, age, sex, chronic condition, and patient-facing role. RESULTS: A total of 3 133 HCWs were included: 2572 (82%) female, 1734 (55%) aged 40-59, and 563 (29%) with ≥ 1 chronic condition. Hybrid immunity showed significant protection during BA.1/2 (aHR = 0.37, 95%CI 0.21-0.63), BA.4/5/BQ.1 (aHR = 0.36, 95%CI 0.22-0.58), and XBB.1.5/BA.2.86 (aHR = 0.53, 95%CI 0.37-0.74) periods. Infection-induced immunity was protective across all periods, most during BA.1/2 (aHR = 0.26, 95%CI 0.12-0.53), and least during BA.2/XBB (aHR = 0.66, 95%CI 0.36-1.22). Vaccine-induced immunity alone offered limited protection during BA.1/2 (aHR = 0.72, 95%CI 0.49-1.06) and BA.4/5/BQ.1 (aHR = 0.77, 95%CI 0.50-1.19), with wide confidence intervals suggesting low statistical significance. CONCLUSIONS: Hybrid and infection-induced immunity groups were more protected against infection caused by earlier Omicron sub-lineages and more protected than vaccination alone, which had no significant protective effect. These findings highlight the need for adaptive public health strategies, including timely vaccine updates and understanding of prior SARS-CoV-2 infection to inform COVID-19 vaccination policies for HCWs in the post-pandemic era.
A protocol for high-dose quadrivalent influenza vaccine effectiveness in the community and long-term care facilities using electronic health records
Patrícia Soares, Verónica Gómez, Vânia Gaio, João Almeida Santos, Ana Paula Rodrigues, Ausenda Machado
Plos One, 2025
Since the 2022–2023 season in Portugal, a high-dose quadrivalent influenza vaccine is freely available for individuals living in long-term care facilities (LTCF). In 2024–2025, vaccination was extended to community-dwelling individuals aged ≥85 years. Given the scarcity of reported high-dose influenza vaccine effectiveness (IVE) estimates for this population, this study aims to estimate the high-dose relative and absolute IVE. A retrospective cohort study using data from electronic health records databases (EHR) will be implemented, using two cohorts, one of individuals vaccinated with influenza vaccine (to estimate relative IVE) and another of individuals eligible for the high-dose quadrivalent influenza vaccine (to estimate absolute IVE). We will consider two subgroups for both cohorts: individuals living in LTCF and community-dwelling individuals aged ≥85. We will use a fixed cohort approach, defining the eligible population by age at the vaccination campaign(s) start and living status. The outcomes are based on the primary cause of hospital admission. The reference population database will be defined by linking EHR on vaccination, comorbidities, and hospitalisations using a unique identifier through a deterministic data linkage procedure, and influenza vaccination status will be assessed retrospectively. We will use Cox proportional hazards regression models to estimate the hazard ratio (HR), considering as event the first hospitalisation due to influenza-like-illness and as exposure the vaccination status. IVE will be estimated as one minus the confounder-adjusted HR of vaccinated with the high-dose quadrivalent influenza vaccine vs vaccinated with standard dose (to estimate relative IVE) or unvaccinated (to estimate absolute IVE). While challenges such as EHR constraints and potential reporting bias pose limitations, using routinely collected data has successfully estimated COVID-19 VE and enables precise monitoring of VE with higher representativeness. The results of this study will inform the Health Ministry on the future influenza vaccine programme in Portugal.
An Overview of Monkeypox Virus Detection in Different Clinical Samples and Analysis of Temporal Viral Load Dynamics
Rita Cordeiro, Ana Pelerito, Isabel Lopes de Carvalho, Sílvia Lopo, Raquel Neves, Raquel Rocha, Paula Palminha, Nuno Verdasca, Cláudia Palhinhas, Maria José Borrego, Carla Manita, Idalina Ferreira, Célia Bettencourt, Patrícia Vieira, Sónia Silva, Ivone Água‐Doce, Carla Roque, Dora Cordeiro, Greice Brondani, João Almeida Santos, Susana Martins, Irene Rodrigues, Carlos Ribeiro, Maria Sofia Núncio, João Paulo Gomes, Fernando da Conceição Batista
Journal of Medical Virology, 2024
Mpox is a zoonotic disease caused by the Monkeypox virus (MPXV), and since May 2022, tens of thousands of cases have been reported in non‐endemic countries. We aimed to evaluate the suitability of different sample types for mpox diagnostic and assess the temporal dynamics of viral load. We evaluated 1914 samples from 953 laboratory‐confirmed cases. The positivity rate was higher for lesion (91.3%) and rectal swabs (86.1%) when compared with oropharyngeal swabs (69.5%) and urines (41.2%), indicating higher viral loads for the former. Supporting this, lesion and rectal swabs showed lower median PCR Ct values (Ct = 23 and Ct = 24), compared to oropharyngeal swabs and urines (Ct = 31). Stable MPXV loads were observed in swabs from lesions up to 30 days after symptoms onset, contrasting with a considerable decrease in viral load in rectal and oropharyngeal swabs. Overall, these results point to lesion swabs as the most suitable samples for detecting MPXV in the 2022–2023 multicountry outbreak and show comparable accuracy to rectal swabs up to 8 days after symptoms onset. These findings, together with the observation that about 5% of patients were diagnosed through oropharyngeal swabs while having negative lesions, suggest that multisite testing should be performed to increase diagnostic sensitivity.
Orogenital and anal infection by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and other sexually transmitted infections in men who have sex with men in Lisbon
Corrado Minetti, Miguel Rocha, Luís Miguel Duque, Paula Meireles, Cristina Correia, Dora Cordeiro, Inês João, Carla Manita, Sofia Soeiro, João Almeida Santos, Rita Matos, Catarina Almeida, Helena Cortes Martins, Elsa Vinagre, Sílvia Lopo, Maria José Borrego
International Journal of STD and AIDS, 2024
Background Men who have sex with men (MSM) are at risk for sexually transmitted infections (STIs), but more data on extragenital carriage are needed. Aim We assessed the genital and extragenital prevalence of bacterial and other STIs in MSM in a Lisbon sexual health clinic. Methods We screened oral, anal, and urine samples of MSM visiting the GAT-CheckpointLX clinic June 2017-December 2021 for Chlamydia trachomatis (including lymphogranuloma venereum, LGV), Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and U. parvum. Ano-oro-genital lesions were tested for LGV, Treponema pallidum, and Herpes Simplex Virus. Blood was tested for HIV and T. pallidum antibodies. Results N. gonorrhoeae was found in 16.6% of the MSM followed by C. trachomatis (13.2%), M. genitalium (10.3%) and T. vaginalis (0.2%). The most frequent occurrence was anorectal ( C. trachomatis, M. genitalium) and oral ( N. gonorrhoeae). We found high carriage of U. urealyticum (36.1%) and M. hominis (22.1%). LGV was detected in 21.8% of chlamydia-positive anorectal swabs. Syphilis was detected in 22.6% of tested MSM, while 13.8% had HIV. Gonorrhoea and chlamydia were significantly more prevalent in MSM with concomitant HIV or syphilis. Conclusion The substantial extragenital prevalence of bacterial STIs in MSM, and HIV and syphilis coinfections, suggest screening has value in identifying hidden carriage and in contributing for providing better care.
Seroprevalence of Specific SARS-CoV-2 Antibodies during Omicron BA.5 Wave, Portugal, April-June 2022
Irina Kislaya, Aryse Melo, Marta Barreto, Camila Henriques, Carlos Aniceto, Carla Manita, Sara Ramalhete, João Almeida Santos, Sofia Soeiro, Ana Paula Rodrigues, and
Emerging Infectious Diseases, 2023
After the rapid spread of SARS-CoV-2 BA.5 Omicron lineage in Portugal, we developed a seroepidemiologic survey based on a sample of 3,825 residents. Results indicated that from April 27 through June 8, 2022, the estimated seroprevalence of SARS-CoV-2 nucleocapsid or spike IgG was 95.8%, which indicates a high level of protection.
Tuberculin skin test and interferon-γ release assays: Can they agree?
João Almeida Santos, Raquel Duarte, Carla Nunes
Clinical Respiratory Journal, 2023
IntroductionThe diagnosis of latent tuberculosis infection (LTBI) relies largely on the tuberculin skin test (TST) or, more recently, on interferon‐gamma release assays (IGRA). Knowledge regarding these tests is essential to improve their usefulness in combating the tuberculosis epidemic.ObjectivesTo characterize the agreement between the IGRA and TST tests by determining the kappa coefficient (K) and agreement rate between these two tests in patients with active tuberculosis (TB).MethodsRetrospective cohort study conducted with data from active TB patients notified in the Portuguese Tuberculosis Surveillance System (SVIG‐TB), from 2008 to 2015. TST results were interpreted using a 5 mm (TST‐5 mm) and 10 mm (TST‐10 mm) cutoff. Kappa coefficient and agreement rate were calculated in order to evaluate the agreement between IGRA and TST (both cutoffs) test results.ResultsA total of 727 patients with results for both tests were included in the study, of which 3.4% (n = 25) had HIV infection, 5.6% (n = 41) diabetes, 5.0% (n = 36) oncological diseases and 4.4% (n = 32) inflammatory diseases.Of the 727 patients, 16.5% (n = 120) presented different outcomes between IGRA and TST‐5 mm, and 20.5% (n = 149) presented different outcomes between IGRA and TST‐10 mm. Kappa coefficient between IGRA and TST‐5 mm was 0.402 (p < 0.001) with an agreement rate of 83.5%. Between IGRA and TST‐10 mm, the kappa coefficient was 0.351 (p < 0.001), with an agreement rate of 79.5%. Patients with HIV infection, diabetes, oncologic diseases and inflammatory diseases presented a substantial agreement between IGRA and TST‐5 mm, while inflammatory diseases was the only variable that presented a substantial agreement between IGRA and TST‐10 mm.ConclusionAs both tests can present false‐negative results, the low level of agreement between the tests can potentially help identify more cases of LTBI if the two tests are used in parallel, with infections not detected by IGRA possibly being detected by the TST and vice versa.
SARS-CoV-2 Seroprevalence following a Large-Scale Vaccination Campaign in Portugal: Results of the National Serological Survey, September - November 2021
Irina Kislaya, Paulo Gonçalves, Sara Ramalhete, Marta Barreto, Ana Rita Torres, Vânia Gaio, Verónica Gómez, Carla Manita, João Almeida Santos, Sofia Soeiro, Rita De Sousa, Aryse Melo, Camila Henriques, Raquel Guiomar, Ana Paula Rodrigues, On Behalf of ISNCOVID-19 Group
Acta Medica Portuguesa, 2023
Introduction: Following a COVID-19 mass vaccination campaign, it is important to evaluate the population level of SARS-CoV-2 antibodies. The aim of this study was to estimate the seroprevalence rate of SARS-CoV-2 specific antibodies acquired due to infection or vaccination in the Portuguese population.Material and Methods: The National Serological Survey (third wave – ISN3COVID-19) is a cross-sectional nationwide epidemiological study developed on a sample of 4545 Portuguese residents aged one year or older, between the 28th September 2021 and the 19th November 2021. The SARS-CoV-2 anti-nucleoprotein and anti-spike IgG antibody levels were determined in serum samples using Abbott Chemiluminescent Microparticle Immunoassays. Seroprevalence estimates were stratified by age group, sex, administrative region and self-reported chronic conditions. Medians and respective 95% confidence intervals were used to describe the distribution of SARS-CoV-2 specific antibodies in specific population subgroups.Results: The total seroprevalence rate of SARS-CoV-2 was 86.4% (95% CI: 85.2% to 87.6%). A higher seroprevalence rate was estimated for women (88.3%), 50 to 59 years-old (96.5%) and in those with two or more self-reported chronic conditions (90.8%). A higher IgG (anti-Spike) concentration was observed in individuals vaccinated with the booster dose (median = 1 2601.3 AU/mL; 95% CI: 4127.5 to 19 089.1).Conclusion: There was a significant increase in SARS-CoV-2 seroprevalence following the mass vaccination campaign in Portugal. It is important to continue to monitor the distribution of specific SARS-COV-2 antibody at the population level to further inform public health policies.
SARS-CoV-2 seroprevalence in Portugal following the third epidemic wave: results of the second National Serological Survey (ISN2COVID-19)
Irina Kislaya, Paulo Gonçalves, Verónica Gómez, Vânia Gaio, Rita Roquette, Marta Barreto, Mafalda Sousa-Uva, Ana Rita Torres, Joana Santos, Rita Matos, Carla Manita, João Almeida Santos, Sofia Soeiro, Rita de Sousa, Inês Costa, Nuno Verdasca, Raquel Guiomar, Ana Paula Rodrigues, and
Infectious Diseases, 2022
BACKGROUND: Integrated approaches to surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection are important for public health actions. The 2nd National Serological Survey (ISN2COVID-19) aimed to characterize the extent of SARS-CoV-2 infection and vaccine-induced response in the Portuguese population following the third epidemic wave and the launch of the vaccination campaign. METHODS: A cross-sectional study was performed using data on 8463 Portuguese 1-79 years of age, collected in February and March, 2021. SARS-CoV-2 IgM and IgG (anti-nucleoprotein and anti-spike) antibodies were determined in serum samples using Abbott Architect chemiluminescent microparticle assays. Post-infection and vaccine-induced seroprevalence with 95% confidence intervals (95%CI) were estimated in the overall sample and stratified by population characteristics. RESULTS: The estimated seroprevalence was 15.5% (95%CI:14.6-16.5%), of which 13.5% (95%CI: 12.6-14.4%) was attributable to natural infection and 2.0% (95%CI:1.7-2.4%) to vaccination. The lowest seroprevelence was observed in persons aged 70-79 years (8.9% 95%CI:6.8-11.6), while seroprevalence in children (14.3%; 95%CI:11.5-17.6%) and adolescents (12.9%; 95%CI:10.5-15.7%) was similar to that of persons aged between 20 and 69 years. Of seropositive individuals, 22.6% (95%CI:19.7-25.9%) did not report any symptoms in 6 months prior to interview. Of persons with completed vaccination (2-doses), 98.6% (95%CI: 93.0-99.7%) had specific IgG (anti-S) antibodies. CONCLUSIONS: After the third epidemic wave, the post-infection SARS-CoV-2 seroprevalence was 1.7 times higher than the cumulative incidence based on PCR-testing, but was higher (2.7 times) in children may be due to the high proportion of asymptomatic and mild infections.
Patient and healthcare delays in critical and non-critical pulmonary tuberculosis incidence areas in Portugal: are there differences?
J. Almeida Santos, P. Soares, A. Leite, R. Duarte, C. Nunes
Public Health, 2021
Delayed diagnosis of active pulmonary tuberculosis - potential risk factors for patient and healthcare delays in Portugal
João Almeida Santos, Andreia Leite, Patrícia Soares, Raquel Duarte, Carla Nunes
BMC Public Health, 2021
Space-Time clustering and temporal trends of hospitalizations due to pulmonary tuberculosis: Potential strategy for assessing health care policies
João Almeida Santos, Danielle T Santos, Ricardo A Arcencio, Carla Nunes
European Journal of Public Health, 2021
Seroprevalence of SARS-CoV-2 infection in Portugal in May-July 2020: Results of the first national serological survey (ISNCOVID-19)
Irina Kislaya, Paulo Gonçalves, Marta Barreto, Rita De Sousa, Ana Cristina Garcia, Rita Matos, Raquel Guiomar, Ana Paula Rodrigues, On behalf of ISNCOVID-19 Group
Acta Medica Portuguesa, 2021
Host factors associated to false negative and indeterminate results in an interferon‐γ release assay in patients with active tuberculosis
J.A. Santos, R. Duarte, C. Nunes
Pulmonology, 2020
Tuberculin skin test and predictive host factors for false-negative results in patients with pulmonary and extrapulmonary tuberculosis
João Almeida Santos, Raquel Duarte, Carla Nunes
Clinical Respiratory Journal, 2020
Human brucellosis in Portugal—Retrospective analysis of suspected clinical cases of infection from 2009 to 2016
Ana Pelerito, Rita Cordeiro, Rita Matos, Maria Augusta Santos, Sofia Soeiro, João Santos, Carla Manita, Carla Rio, M. Santo, Eleonora Paixão, Alexandra Nunes, Sofia Núncio
Plos One, 2017

MOST CITED SCHOLAR PUBLICATIONS

Delayed diagnosis of active pulmonary tuberculosis - potential risk factors for patient and healthcare delays in Portugal
JA Santos, A Leite, P Soares, R Duarte, C Nunes
BMC Public Health 21 (1), 1-13 , 2021
2021
Citations: 61
Seroprevalence of SARS-CoV-2 infection in Portugal in May-July 2020: results of the first national serological survey (ISNCOVID-19)
I Kislaya, P Gonçalves, M Barreto, R De Sousa, AC Garcia, R Matos, ...
Acta medica portuguesa 34 (2), 87-94 , 2021
2021
Citations: 50
Interim 2024/25 influenza vaccine effectiveness: eight European studies, September 2024 to January 2025
AMC Rose, H Lucaccioni, K Marsh, F Kirsebom, H Whitaker, HD Emborg, ...
Eurosurveillance 30 (7), 2500102 , 2025
2025
Citations: 41
Host factors associated to false negative and indeterminate results in an interferon‐γ release assay in patients with active tuberculosis
JA Santos, R Duarte, C Nunes
Pulmonology 26 (6), 353-362 , 2020
2020
Citations: 38
Human brucellosis in Portugal - Retrospective analysis of suspected clinical cases of infection from 2009 to 2016
A Pelerito, R Cordeiro, R Matos, MA Santos, S Soeiro, J Santos, C Manita, ...
PLoS One 12 (7), e0179667 , 2017
2017
Citations: 26
SARS-CoV-2 seroprevalence in Portugal following the third epidemic wave: results of the second National Serological Survey (ISN2COVID-19)
I Kislaya, P Gonçalves, V Gómez, V Gaio, R Roquette, M Barreto, ...
Infectious Diseases 54 (6), 418-424 , 2022
2022
Citations: 20
Tuberculin skin test and predictive host factors for false‐negative results in patients with pulmonary and extrapulmonary tuberculosis
J Almeida Santos, R Duarte, C Nunes
The clinical respiratory journal 14 (6), 541-548 , 2020
2020
Citations: 18
An Overview of Monkeypox Virus Detection in Different Clinical Samples and Analysis of Temporal Viral Load Dynamics
R Cordeiro, A Pelerito, IL de Carvalho, S Lopo, R Neves, R Rocha, ...
Journal of Medical Virology 96 (12), e70104 , 2024
2024
Citations: 12
Tuberculin skin test and interferon‐γ release assays: Can they agree?
J Almeida Santos, R Duarte, C Nunes
The Clinical Respiratory Journal 17 (2), 109-114 , 2023
2023
Citations: 11
SARS-CoV-2 Seroprevalence Following a Large-Scale Vaccination Campaign in Portugal: Results of the National Serological Survey, September-November 2021
I Kislaya, P Gonçalves, S Ramalhete, M Barreto, AR Torres, V Gaio, ...
Acta Médica Portuguesa 36 (1), 5-14 , 2023
2023
Citations: 11
Patient and healthcare delays in critical and non-critical pulmonary tuberculosis incidence areas in Portugal: Are there differences?
JA Santos, P Soares, A Leite, R Duarte, C Nunes
Public Health, 41-47 , 2021
2021
Citations: 11
COVID‐19 Vaccine Effectiveness Against Medically Attended Symptomatic SARS‐CoV‐2 Infection Among Target Groups in Europe, October 2024–January 2025, VEBIS Primary Care Network
C Laniece Delaunay, N Verdasca, S Monge, L Domegan, N Sève, S Buda, ...
Influenza and Other Respiratory Viruses 19 (5), e70120 , 2025
2025
Citations: 10
Seroprevalence of Specific SARS-CoV-2 Antibodies during Omicron BA. 5 Wave, Portugal, April–June 2022.
I Kislaya, A Melo, M Barreto, C Henriques, C Aniceto, C Manita, ...
Emerging Infectious Diseases 29 (3) , 2023
2023
Citations: 8
Orogenital and anal infection by Chlamydia trachomatis , Neisseria gonorrhoeae , Mycoplasma genitalium , and other sexually transmitted infections in men who …
C Minetti, M Rocha, LM Duque, P Meireles, C Correia, D Cordeiro, I João, ...
International journal of STD & AIDS 35 (5), 379-388 , 2024
2024
Citations: 7
Anti-HAV IgG seroprevalence in Lisbon region residents: Preliminary results from the National Serological Survey 2015–2016
H Cortes-Martins, R Matos, S Moura, L Almeida, S Ferreira, C Manita, ...
Journal of Clinical Virology, S79-S80 , 2016
2016
Citations: 7
Diagnóstico da infeção por vírus da hepatite E no INSA, 2000-2012
C Ferreira, J Almeida Santos, T Lourenço, B C, M Rita, H Martins
Boletim Epidemiológico Observações 2 (5), 27-28 , 2013
2013
Citations: 7
Salmonella enterica: serotipos menos frequentes com importância em patologia humana, caraterizados no INSA entre 2002-2013
L Silveira, A Marques, J Santos, C Furtado, J Machado
Boletim Epidemiológico Observacões 3, 44-47 , 2014
2014
Citations: 6
Influenza vaccine effectiveness from nine studies during drifted A (H3N2) subclade K predominance, Europe, September 2025 to January 2026
H Lucaccioni, DFP Marques, F Kirsebom, HD Emborg, M Hamilton, ...
Eurosurveillance 31 (7), 2600109 , 2026
2026
Citations: 5
Training on the impact of climate change on public health: reflections and lessons learnt
S Viegas, JA Santos, A Kazmierczak, R Assunção, C Viegas, C Martins
Portuguese Journal of Public Health 41 (3), 230-234 , 2023
2023
Citations: 5
Space–time clustering and temporal trends of hospitalizations due to pulmonary tuberculosis: potential strategy for assessing health care policies
JA Santos, DT Santos, RA Arcencio, C Nunes
European Journal of Public Health 31 (1), 57-62 , 2021
2021
Citations: 5

Joao Almeida Santos

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Scopus Publications

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MOST CITED SCHOLAR PUBLICATIONS