Institutional outbreaks of influenza-like illnesses in the state of São Paulo: an analysis of the epidemiological profile during the COVID-19 pandemic.

OBJECTIVES: This study aimed to spatiotemporally analyze the profile of influenza-like illness (ILI) outbreaks in the state of São Paulo, Brazil, between 2020 and 2022. STUDY DESIGN: This was a cross-sectional retrospective study. METHODS: Outbreaks of ILI with final diagnoses of COVID-19, influenza, or other respiratory viruses (ORVs) recorded between January 2020 and November 2022, obtained from the Notifiable Diseases Information System (SINAN NET) Outbreak module, were analyzed. Kernel density estimates and Getis-Ord Gi∗ statistics were performed to identify spatial clusters. RESULTS: A total of 13,314 ILI outbreaks were identified, involving 130,568 cases and 2649 deaths. Of these, 104,399 (80%) were confirmed as COVID-19, 15,861 (12%) were confirmed as ORV, and 10,308 (8%) were confirmed as influenza. The year 2021 had the highest number of outbreaks and cases. Schools recorded the most outbreaks and cases, followed by long-term care facilities for older adults (LTCs). The highest average number of cases per outbreak and the highest attack rates occurred at social gatherings and prisons. Prisoners were three times more likely to contract COVID-19 during outbreaks than people in other institutions. The highest hospitalization and mortality rates for all virus types occurred in the LTC group. The occurrence and intensity of outbreaks were highly heterogeneous among the different institutions after the introduction of new SARS-CoV-2 variants in the state. CONCLUSIONS: ILI outbreaks were not randomly distributed; they clustered in specific areas. Transmissibility varied among different institutions with different responses to the COVID-19 pandemic. These results can be used as a basis for prioritizing actions and allocating resources during future pandemics.

Eco-morphological attributes and feeding habits in coexisting characins.

The head morphology and feeding habits of pairs of characin species (family Characidae) that coexist in four different coastal rainforest streams were analysed. Coexisting species differed in size, but were very similar in eco-morphological attributes. Gut analyses revealed differences in feeding preferences for each coexisting species, indicating resource partitioning. A pattern of organization in species pairs that was repeated in the four studied streams was noticed. The pattern consisted of one slightly larger species with a feeding preference for items of allochthonous origin and another smaller species with a preference for autochthonous items. The hypothesis that small morphological differences enable the current coexistence of those species pairs was proposed. Furthermore, the results show ecological equivalence among different species in the studied streams.