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Hantavirus infections and small mammal diversity in Chile: No differences between protected and unprotected areas highlight the need for public health strategies
(Public Library of Science (PLoS), 2025-10-30)
Fernando Torres-Pérez
;
Nicolás Ferrada
;
Roxana Astudillo
;
Marcela Ferrés
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VIAL CLARO, PABLO AGUSTIN
<jats:sec id="sec001"> <jats:title>Background</jats:title> <jats:p> Zoonotic viruses, such as <jats:italic>Orthohantavirus andesense</jats:italic> (ANDV; the causative agent of hantavirus cardiopulmonary syndrome, HCPS), pose significant public health risks at the human-wildlife interface. Understanding their eco-epidemiological dynamics is critical for elucidating the interplay between reservoir hosts, environmental factors, and spillover to humans. In Chile, the long-tailed pygmy rice rat ( <jats:italic>Oligoryzomys longicaudatus</jats:italic> ) serves as the primary reservoir for ANDV. This study investigates whether protected areas (PA), which typically support higher biodiversity and stable ecosystems, exhibit lower ANDV seroprevalence compared to unprotected areas (UPA), where anthropogenic disturbances may alter host-pathogen dynamics. </jats:p> </jats:sec> <jats:sec id="sec002"> <jats:title>Methodology</jats:title> <jats:p>Between 2001–2008, we conducted small mammal sampling across 22 sites (11 PA and 11 UPA) in natural landscapes of Chile. Seroprevalence of ANDV was assessed via strip immunoassay, while small mammal diversity was evaluated using standardized trapping protocols and diversity indices. We used similarity percentage analysis to identify species contributing to community dissimilarities and applied Renyi diversity profiles to compare small mammal diversity between area types.</jats:p> </jats:sec> <jats:sec id="sec003"> <jats:title>Main Findings</jats:title> <jats:p> We captured 627 small mammals (PA: 331, 14 species; UPA: 296, 10 species) across 12,898 trap-nights. Seroprevalence in <jats:italic>O. longicaudatus</jats:italic> was identical in PA and UPA (9.5%). No significant differences were found in the relative abundance or seropositivity of <jats:italic>O. longicaudatus</jats:italic> between area types. Ecological indices (Shannon-Wiener, Simpson, richness, evenness) and community composition (ANOSIM) also showed no significant differences. Rényi profiles indicated marginally higher diversity in PA, driven by greater richness and evenness. </jats:p> </jats:sec> <jats:sec id="sec004"> <jats:title>Conclusions</jats:title> <jats:p>These findings suggest that ecological factors, such as habitat type, climatic conditions, and/or human behavior, may play a more critical role in shaping viral prevalence than protection status alone. The study underscores the necessity for consistent public health interventions to mitigate the risk of hantavirus cardiopulmonary syndrome across all environments, particularly in regions where human activities intersect with natural habitats.</jats:p> </jats:sec>
1
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SARS-CoV-2 infectivity and antigenic evasion: spotlight on isolated Omicron sub-lineages
(2024)
Aldo Barrera
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Constanza Martínez-Valdebenito
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Jenniffer Angulo
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Carlos Palma
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HORMAZABAL CASTILLO, JUAN PATRICIO
<jats:p>Since the SARS-CoV-2 outbreak in 2019, a diversity of viral genomic variants has emerged and spread globally due to increased transmissibility, pathogenicity, and immune evasion. By the first trimester of 2023 in Chile, as in most countries, BQ and XBB were the predominant circulating sub-lineages of Omicron. The molecular and antigenic characteristics of these variants have been mainly determined using non-authentic spike pseudoviruses, which is often described as a limitation. Additionally, few comparative studies using isolates from recent Omicron sub-lineages have been conducted. In this study, we isolated SARS-CoV-2 variants from clinical samples, including the ancestral B.1.1, Delta, Omicron BA.1, and sub-lineages of BA.2 and BA.5. We assessed their infectivity through cell culture infections and their antibody evasion using neutralization assays. We observed variations in viral plaque size, cell morphology, and cytotoxicity upon infection in Vero E6-TMPRSS2 cells for each variant compared to the ancestral B.1.1 virus. BA.2-derived sub-variants, such as XBB.1.5, showed attenuated viral replication, while BA.5-derived variants, such as BQ.1.1, exhibited replication rates similar to the ancestral SARS-CoV-2 virus. Similar trends were observed in intestinal Caco-2 cells, except for Delta. Antibody neutralization experiments using sera from individuals infected during the first COVID-19 wave (FWI) showed a consistent but moderate reduction in neutralization against Omicron sub-lineages. Interestingly, despite being less prevalent, BQ.1.1 showed a 6.1-fold greater escape from neutralization than XBB.1.5. Neutralization patterns were similar when tested against sera from individuals vaccinated with 3xBNT162b2 (PPP) or Coronavac-Coronavac-BNT162b2 (CCP) schedules. However, CCP sera showed 2.3-fold higher neutralization against XBB.1.5 than FWI and PPP sera. This study provides new insights into the differences between BA.2 and BA.5-derived variants, leading to their eventual outcompetition. Our analysis offers important evidence regarding the balance between infectivity and antigenic escape that drives the evolution of second-generation SARS-CoV-2 variants in the population.</jats:p>
5Scopus© Citations 3
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Viral shedding and viraemia of Andes virus during acute hantavirus infection: a prospective study
(2024)
Marcela Ferrés
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Constanza Martínez-Valdebenito
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Carolina Henriquez
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Claudia Marco
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Jenniffer Angulo
10Scopus© Citations 29
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Hantavirus in humans: a review of clinical aspects and management
(2023)
Pablo A Vial
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Marcela Ferrés
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VIAL COX, MARIA CECILIA
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Jonas Klingström
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Clas Ahlm
Scopus© Citations 77 79
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Prospective Evaluation of Household Contacts of Persons with Hantavirus Cardiopulmonary Syndrome in Chile
(2007)
Marcela Ferrés
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VIAL CLARO, PABLO AGUSTIN
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Claudia Marco
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Lia Yañez
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Paula Godoy
3Scopus© Citations 149
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Proteinuria in Hantavirus Cardiopulmonary Syndrome: A Frequent Finding Linked To Mortality
(2021)
LOPEZ HERNANDEZ, RENE RAMON
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Gregory Mertz
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GRAF SANTOS, JERÓNIMO
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Mauricio Espinoza
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Marcela Ferrés
27Scopus© Citations 4
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Mother-to-Child Transmission of Andes Virus through Breast Milk, Chile1
(2020)
Marcela Ferrés
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Constanza Martínez-Valdebenito
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Jenniffer Angulo
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Carolina Henríquez
;
Jorge Vera-Otárola
Scopus© Citations 17 4
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Person-to-Person Household and Nosocomial Transmission of Andes Hantavirus, Southern Chile, 2011
(2014)
Constanza Martinez-Valdebenito
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Mario Calvo
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VIAL COX, MARIA CECILIA
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Rita Mansilla
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Claudia Marco
22Scopus© Citations 90
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A Single-Nucleotide Polymorphism of αVβ3 Integrin Is Associated with the Andes Virus Infection Susceptibility
(2019)
Constanza Martínez-Valdebenito
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Jenniffer Angulo
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Nicole Le Corre
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Claudia Marco
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VIAL COX, MARIA CECILIA
<jats:p>The Andes Orthohantavirus (ANDV), which causes the hantavirus cardiopulmonary syndrome, enters cells via integrins, and a change from leucine to proline at residue 33 in the PSI domain (L33P), impairs ANDV recognition. We assessed the association between this human polymorphism and ANDV infection. We defined susceptible and protective genotypes as “TT” (coding leucine) and “CC” (coding proline), respectively. TT was present at a rate of 89.2% (66/74) among the first cohort of ANDV cases and at 60% (63/105) among exposed close-household contacts, who remained uninfected (p < 0.05). The protective genotype (CC) was absent in all 85 ANDV cases, in both cohorts, and was present at 11.4% of the exposed close-household contacts who remained uninfected. Logistic regression modeling for risk of infection had an OR of 6.2–12.6 (p < 0.05) in the presence of TT and well-known ANDV risk activities. Moreover, an OR of 7.3 was obtained when the TT condition was analyzed for two groups exposed to the same environmental risk. Host genetic background was found to have an important role in ANDV infection susceptibility, in the studied population.</jats:p>
Scopus© Citations 12 4
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Platelet Count in Patients with Mild Disease at Admission is Associated with Progression to Severe Hantavirus Cardiopulmonary Syndrome
(2019)
LOPEZ HERNANDEZ, RENE RAMON
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Mario Calvo
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VIAL COX, MARIA CECILIA
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Marcela Ferrés
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GRAF SANTOS, JERÓNIMO
<jats:p>Background: Hantavirus cardiopulmonary syndrome (HCPS) has a mortality up to 35–40% and its treatment is mainly supportive. A variable to predict progression from mild to severe disease is unavailable. This study was performed in patients with documented infection by Andes orthohantavirus, and the aim was to find a simple variable to predict progression to moderate/severe HCPS in patients with mild disease at admission. Methods: We performed a retrospective analysis of 175 patients between 2001 and 2018. Patients were categorized into mild, moderate, and severe disease according to organ failure and advanced support need at hospital admission (e.g., mechanical ventilation, vasopressors). Progression to moderate/severe disease was defined accordingly. Clinical and laboratory variables associated with progression were explored. Results: Forty patients with mild disease were identified; 14 of them progressed to moderate/severe disease. Only platelet count was different between those who progressed versus those that did not (37 (34–58) vs. 83 (64–177) K/mm3, p < 0.001). A ROC curve analysis showed an AUC = 0.889 (0.78–1.0) p < 0.001, with a platelet count greater than 115K /mm3 ruling out progression to moderate/severe disease. Conclusions: In patients with mild disease at presentation, platelet count could help to define priority of evacuation to tertiary care centers.</jats:p>
Scopus© Citations 10 4

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