medRxiv preprint doi: https://doi.org/10.1101/2020.10.22.20216010; this version posted October 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . Fernando de Noronha: how an island controlled the community transmission of COVID-19 in Brazil Authors: Mozart Júlio Tabosa Sales1; Ligia Regina Franco Sansigolo Kerr2; Regina Vianna Brizolara3; Ivana Cristina de Holanda Cunha Barreto4; Rosa Lívia Freitas de Almeida5; Paulo Savio Angeiras de Goes6; Luiz Odorico Monteiro de Andrade2,4; Leuridan Cavalcante Torres1; Flávia Kelly Alvarenga Pinto3; Francisco Marto Leal Pinheiro Júnior2; Rebeca Valentim Leite6; Aline Priscila Rego de Carvalho7; Amanda Carolina Felix Cavalcanti de Abreu7; Rebecca Lucena Theophilo1,4; Fernando Rodrigues Magalhães8; Susane Lindinalva da Silva6; Carl Kendall2,9 Affiliations: 1 Instituto de Medicina Integral Professor Fernando Figueira 2 Universidade Federal do Ceará 3 Ministério da Saúde, Brasil 4 Fundação Oswaldo Cruz/Ceará 5 Universidade de Fortaleza 6 Universidade Federal de Pernambuco/Faculdade de Medicina de Olinda 7 Secretaria Estadual de Saúde de Pernambuco 8 Autarquia Territorial Distrito Estadual de Fernando de Noronha, Pernambuco 9 Tulane School of Public Health and Tropical Medicine Corresponding author: Ligia Regina Franco Sansigolo Kerr Universidade Federal do Ceará Programa de Pós-Graduação em Saúde Pública - Faculdade de Medicina Departamento de Saúde Comunitária R: Prof Costa Mendes, 1608 - 5º andar - Rodolfo Teófilo - CEP: 60.430-140 - Fortaleza - CE - Brasil Fone: +55-85-3366-9045 E-mail: [email protected] NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice. 1 medRxiv preprint doi: https://doi.org/10.1101/2020.10.22.20216010; this version posted October 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . Abstract Introduction: Fernando Noronha (FNA) is a small Brazilian archipelago in the Atlantic, part of the state of Pernambuco that COVID-19 has decimated. Anticipating the worst from the pandemic, Island and state authorities implemented a series of public health actions to contain the epidemic. This paper, reporting the results of the first wave of a cohort study, documents the measures and their effects through a cohort study. Methods: Measures were documented at the time of implementation. A random sample of 904 residents were selected from the health register, interviewed and tested for COVID-19 (RT-PCR and serology). The survey explored socioeconomic variables and adherence to prevention behaviors. Results: Flights were reduced from 38 to once a week, FNA was closed to tourism, schools were closed, and testing and tracing contacts was mandated along with social distancing and use of masks. A household lockdown was briefly imposed for residents. A prevalence of 5.1% was found, and a total of 158 cases of COVID-19 was estimated, although only 28 had been reported in routine surveillance. Half of the population reported food insecurity and applied for government COVID-19 benefits. Adherence to control measures was high, except for intrahousehold mask use with family and friends. Conclusion: Despite high levels of COVID-19 in Pernambuco, continued exposure through the provision of essential services from the mainland, and lack of direction from national authorities, FNA was able to implement a series of prevention measures unique in Brazil that contained the epidemic on the island. 2 medRxiv preprint doi: https://doi.org/10.1101/2020.10.22.20216010; this version posted October 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . Introduction Islands have been a fascination for epidemiologists1. The promise of island epidemiology is that transmission can be more closely monitored, and therefore the dynamics of transmission and the effect of interventions can be more effectively explored. This is especially critical in Brazil, until recently, the country with the second largest number of COVID-19 cases in the world2. Fernando de Noronha Archipelago (FNA) are 21 islands about 350 kilometers off Brazil's northeast coast. The official population of the islands is about 3000, all living on the main island that covers 17 km2. The total territory of the archipelago is 26 km2 3. FNA is managed by an administrator-general appointed by the Pernambuco state government. Most of FNA was declared a National Park in 1988. In 2001, UNESCO declared FNA a World Heritage Site, boosting tourism, the main economic activity of the island4. In 1942, the United States Army Air Force built an airport on the island to support the Allied campaign in Africa. At the end of the war FNA was returned to Brazil. Fernando de Noronha Airport is served by daily flights from Recife and Natal. In January and February 2020, Fernando de Noronha received 38 weekly flights, carrying an average of 452 passengers per day. Between April and June, frequency dropped to one per week, carrying an average of 4 passengers per day 5. Pernambuco is especially hard-hit by COVID-19, registering 132,152 cases (1382.8 cases/100,000 inhabitants) and 7,702 deaths (80.6 deaths/100,000 inhabitants) by September 6. FNA initiated prevention activities in the first half of March 2020, before the first official COVID-19 case was reported in the state. These included imposing a lockdown, promoting physical distancing and providing emergency assistance to the neediest families; enhancing testing for Sars-Cov-2, including monitoring of arriving travelers, restricting access to the island and the initiation of the cohort study described here to estimate the incidence and prevalence of Covid-19. In spite of special attention, before the beginning of this study at the end of May, 2020, there were 28 confirmed cases of COVID-19 reported in the archipelago 7 2020b. In addition to conventional measures the Government of Pernambuco and local authorities implemented a series of prevention measures unique in Brazil, such as active case detection and contact tracing, and movement regulation for all islanders. The potential to control the pandemic on this island, and better understand the uptake and effectiveness of control measures motivated our team to focus on Fernando de Noronha. The objective of this article is to discuss these control activities and report the results of the first round of the cohort study. Methodology Study design and location We implemented the study in FNA in two ways: 1) documenting pandemic-related events and documents, including epidemiological bulletins; and 2) a prospective cohort study. First we reviewed data extracted from the following sources: 1) demographic and socioeconomic data from the Brazilian Institute of Geography and Statistics 8; 2) state and district decrees and 3 medRxiv preprint doi: https://doi.org/10.1101/2020.10.22.20216010; this version posted October 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license . ordinances; 3) number of cases and deaths from COVID-19 reported by the Pernambuco State Health Department; 4) flights and passengers from the National Aviation Agency 5; and 5) information provided by local authorities and residents. The data were systematized as per the Center for Disaster Studies, FIOCRUZ 9. The second method is a cohort study including questionnaires and biological testing that began on May 22, 2020 and will be repeated at 60, 120, 180 and 360 days from baseline. Sample population and size All individuals residing on the island of any age were eligible to be included in the study. Names and addresses were drawn at random from a current list of all residents. Residents were excluded if not found at home after a second visit and replaced with another randomly selected. The project was described, voluntary participation emphasized, and the Informed Consent Form presented. In the case of minors (<18), parent or guardian provided consent. Ethical review complied with Resolution No. 466/2012 of the National Health Council and was approved by the National Research Commission (Project CONEPE #4.284.892). While the official population of FNA is 3,061 (IBGE, 2019), local authorities maintain an updated resident health register totaling 4122. Using 4122, a 95% CI, and an acceptable error of 1%, we calculated a sample size of 811. Estimating a loss to follow up of 10%, a final sample of 892 was chosen. Until April 28, 2020, only 28 confirmed cases of COVID-19 had been notified in FNA 7. A national survey estimated that for each COVID-19 case in Brazil, there would be about 15 undiagnosed cases 10. However, the situation of the AFN is unique, given exclusion of visitors since March 20. Thus, we estimate that there are about 4 unknown cases for each known case (112 cases), yielding an incidence of 2.7%. Data collection Participants were interviewed with appropriate hygiene measures to record: 1) demographic characteristics; 2) socioeconomic status (SES) and housing conditions, 3) clinical, epidemiological and health services variables; 4) measures adopted to prevent COVID-19; 5) mental health; and 6) food insecurity. To measure SES we used the Brazilian Economic Classification Criteria (BC).