The Almeirim City Council in collaboration with the Agrupamento dos Centros de Saúde da Lezíria and the Instituto Gulbenkian de Ciência carried out a serological study on covid-19 to determine whether the population had been exposed to the virus.

In total, 553 people were tested: 270 people (1.16% of the population) a random sample of the population, which belongs to 121 households (0.99% of the households listed in the municipality of Almeirim), 200 first-line health professionals fighting the virus and 83 cases of infected people or with confirmed case contacts.

The serological study carried out between May 23 and July 4 showed that 3.88% of the people tested were in contact with the new coronavirus, although the majority had only mild symptoms. In other words, the study revealed an appreciable number of cases of asymptomatic infection that would otherwise not be detected. Of the sample of health professionals tested, only 1% had antibodies to the SARS-COV-2 virus. This low number of positive tests in a population with a higher risk of exposure, suggests that the implementation of personal protection measures was successful.

The results reinforce the importance of conducting serological studies to define precise measures to contain and respond to the pandemic.

The serological tests used in this study were developed by the consortium led by the Instituto Gulbenkian de Ciência, serology4COVID, which brought together 4 more Portuguese biomedical institutes in the area of Oeiras and Lisbon (ITQB NOVA – Instituto de Tecnologia Química e Biológica António Xavier da Universidade Nova de Lisboa, iBET – Instituto de Biologia Experimental e Tecnológica,  iMM – Instituto de Medicina Molecular João Lobo Antunes e o CEDOC-NMS, Centro de Estudos de Doenças Crónicas da NOVA Medical School da Universidade Nova de Lisboa) and which had the financial support of the Municipality of Oeiras, the Calouste Gulbenkian Foundation and the Sociedade Francisco Manuel dos Santos.