Browsing by Author "Gonzalez, Maria Antonieta"

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    Exposure Practices to Animal-Origin Influenza A Virus at the Animal-Human Interface in Poultry and Swine Backyard Farms
    (2024) Baumberger, Cecilia; Anriquez, Gustavo; Galdames, Pablo; Palma, Tamara; Gonzalez, Maria Antonieta; Orozco, Katherinne; Oyarzun, Cristobal; Rojas, Camila; Marambio, Victor; Ruiz, Soledad; Di Pillo, Francisca; Schultz-Cherry, Stacey; Jimenez-Bluhm, Pedro; Rushton, Jonathan; Hamilton-West, Christopher
    Aim: Backyard production systems (BPS) represent an interface of contact between people, domestic and wild animals. Studies conducted in Chile during the last decade have provided extensive evidence of influenza A virus (IAV) circulation in backyard poultry and swine. The aim of this study was to investigate exposure practices of humans to animal-origin IAV within backyards. Methods and Results: Backyard farmers and household members of a total of 101 BPS in the proximity of wetlands located throughout Chile were interviewed between 2021 and 2022. Data were collected on the nature of human-animal contacts through participation in productive activities conducted within backyards, which was used to estimate participants' exposure risk to animal-origin IAV. Additionally, RT-qPCR and serologic IAV active surveillance was carried out in backyard animals. Multilinear regression was used to identify factors associated with exposure risk. Overall, IAV prevalence was 10.1% (95% CI: 4.7%-15.5%) and seroprevalence was 43.5% (95% CI: 29.7%-54.2%), both at the BPS level. Of 180 interviewees, 86% reported par-ticipating regularly in poultry or swine exposure activities within the backyard. A greater participation of male participants was observed when evaluating swine exposure activities, while female participation was greater for some activities related to poultry handling. Handwashing was a very extended hygiene practice; however, the use of personal protective equipment was uncom-mon. Different factors related to participants, households and backyards were associated with an increased exposure risk of participants to animal-origin IAV: (i) older age, (ii) less years of education, (iii) no off-farm work, (iv) greater backyard production value and (v) greater household consumption of backyard products.
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    Remote Sensing and Ecological Variables Related to Influenza A Prevalence and Subtype Diversity in Wild Birds in the Lluta Wetland of Northern Chile
    (2023) Ruiz, Soledad; Galdames, Pablo; Baumberger, Cecilia; Gonzalez, Maria Antonieta; Rojas, Camila; Oyarzun, Cristobal; Orozco, Katherinne; Mattar, Cristian; Freiden, Pamela; Sharp, Bridgette; Schultz-Cherry, Stacey; Hamilton-West, Christopher; Jimenez-Bluhm, Pedro
    The Lluta River is the northernmost coastal wetland in Chile, representing a unique ecosystem and an important source of water in the extremely arid Atacama Desert. During peak season, the wetland is home to more than 150 species of wild birds and is the first stopover point for many migratory species that arrive in the country along the Pacific migratory route, thereby representing a priority site for avian influenza virus (AIV) surveillance in Chile. The aim of this study was to determine the prevalence of influenza A virus (IAV) in the Lluta River wetland, identify subtype diversity, and evaluate ecological and environmental factors that drive the prevalence at the study site. The wetland was studied and sampled from September 2015 to October 2020. In each visit, fresh fecal samples of wild birds were collected for IAV detection by real-time RT-PCR. Furthermore, a count of wild birds present at the site was performed and environmental variables, such as temperature, rainfall, vegetation coverage (Normalized Difference Vegetation Index-NDVI), and water body size were determined. A generalized linear mixed model (GLMM) was built to assess the association between AIV prevalence and explanatory variables. Influenza positive samples were sequenced, and the host species was determined by barcoding. Of the 4349 samples screened during the study period, overall prevalence in the wetland was 2.07% (95% CI: 1.68 to 2.55) and monthly prevalence of AIV ranged widely from 0% to 8.6%. Several hemagglutinin (HA) and neuraminidase (NA) subtypes were identified, and 10 viruses were isolated and sequenced, including low pathogenic H5, H7, and H9 strains. In addition, several reservoir species were recognized (both migratory and resident birds), including the newly identified host Chilean flamingo (Phoenicopterus chilensis). Regarding environmental variables, prevalence of AIV was positively associated with NDVI (OR = 3.65, p < 0.05) and with the abundance of migratory birds (OR = 3.57, p < 0.05). These results emphasize the importance of the Lluta wetland as a gateway to Chile for viruses that come from the Northern Hemisphere and contribute to the understanding of AIV ecological drivers.