Oswaldo Cruz Foundation, Brazilian Ministry of Health, Brazil

Urban slum health, emerging infectious diseases

Oswaldo Cruz Foundation (Fiocruz), Brazilian Ministry of Health

The Oswaldo Cruz Foundation (Fiocruz) serves as the research branch of the Brazil Ministry of Health. Fiocruz and Yale University have long-standing research and training programs based the city of Salvador, which focus on health problems that have emerged due rapid urbanization and the growth of urban informal settlements. The site conducts research around infectious diseases such as leptospirosis (a rat-borne disease which is the cause of epidemics of pulmonary hemorrhage syndrome), bacterial meningitis, acute respiratory infections (e.g. COVID-19), vaccine preventable diseases and arboviruses. The site also provides research training opportunities in non-communicable diseases which affect informal settlements, such as hypertension, food insecurity and violence. A key feature of the site is a longitudinal community-based cohort of residents of the Pau da Lima favela that have been followed since 2003. Examples of projects that have been implemented include the following:

• Immunological drivers of SARS-CoV-2 endemicity. This ongoing study aims to identify the immunological features that contribute to this transition in an urban slum community in Brazil which experienced high SARS-CoV-2 infection rates (75%) early in the pandemic and received COVID-19 vaccination later in the pandemic. By identifying the immune drivers for the transition of SARS-CoV-2 endemicity, the researchers aims to generate key evidence to inform the development of novel vaccines (intranasal, multi-antigen) and new approaches to tracking SARS-CoV-2 infections in populations.
• Naturally acquired and vaccine-mediated immunity to leptospirosis. This study included 14,000 residents of Pau da Lima and focused on characterizing the natural history of leptospirosis and determining the effectiveness of improved sanitation and other community-based interventions in preventing this zoonotic disease. Objectives included determining whether naturally-acquired infection induces robust anti-Leptospira protein responses and whether these responses are correlates of immunity to reinfection, identifying the specific Leptospira proteins which elicit attenuated vaccine and naturally-acquired immunity, and if immunization with antigens confers cross-protective immunity.
• Natural history of Zika virus congenital infection. This project prospectively evaluated the role of an early immunologic response in protecting against congenital transmission of Zika virus and developing clinical disease in offspring.
• Health interventions to deliver improved sanitation interventions to prevent urban leptospirosis transmission. This ongoing quasi-experimental cluster trial evaluates the efficacy of sanitation strategies with and without community engagement to reduce the incidence of Leptospira infection in Salvador. Additionally, this project will elucidate the mechanism by which closing sewer interventions reduce direct human contact with sewage and environmental pathogen load in urban slums.
• Advanced pathogen detection in an urban ‘hot spot.’ Metagenomic next generation sequencing is being incorporated into clinical settings that serve a large urban region to detect and identify pathogens that are otherwise easy to miss, which would offer the opportunity to respond to outbreaks in Salvador before they become a global threat.