RESUMEN
Swallows (Hirundinidae) are a globally distributed family of passerine birds that exhibit remarkable similarity in body shape but tremendous variation in plumage, sociality, nesting behavior, and migratory strategies. As a result, swallow species have become models for empirical behavioral ecology and evolutionary studies, and variation across the Hirundinidae presents an excellent opportunity for comparative analyses of trait evolution. Exploiting this potential requires a comprehensive and well-resolved phylogenetic tree of the family. To address this need, we estimated swallow phylogeny using genetic data from thousands of ultraconserved element (UCE) loci sampled from nearly all recognized swallow species. Maximum likelihood, coalescent-based, and Bayesian approaches yielded a well-resolved phylogenetic tree to the generic level, with minor disagreement among inferences at the species level, which likely reflect ongoing population genetic processes. The UCE data were particularly useful in helping to resolve deep nodes, which previously confounded phylogenetic reconstruction efforts. Divergence time estimates from the improved swallow tree support a Miocene origin of the family, roughly 13 million years ago, with subsequent diversification of major groups in the late Miocene and Pliocene. Our estimates of historical biogeography support the hypothesis that swallows originated in the Afrotropics and have subsequently expanded across the globe, with major in situ diversification in Africa and a secondary major radiation following colonization of the Neotropics. Initial examination of nesting and sociality indicates that the origin of mud nesting - a relatively rare nest construction phenotype in birds - was a major innovation coincident with the origin of a clade giving rise to over 40% of extant swallow diversity. In contrast, transitions between social and solitary nesting appear less important for explaining patterns of diversification among swallows.
Asunto(s)
Teorema de Bayes , Filogenia , Filogeografía , Golondrinas , Animales , Golondrinas/genética , Golondrinas/clasificación , Funciones de Verosimilitud , Modelos Genéticos , Análisis de Secuencia de ADN , Evolución MolecularRESUMEN
BACKGROUND: Following the outbreak of the COVID-19 pandemic, several clinical trials have evaluated postexposure prophylaxis (PEP) among close contacts of an index individual with a confirmed SARS-CoV-2 infection. Because index individuals do not directly inform the efficacy of prevention interventions, they are seldom enrolled in COVID-19 PEP studies. However, adjusting for prognostic covariates such as an index individual's COVID-19 illness and risk behaviors can increase precision in PEP efficacy estimates, so approaches to accurately collecting this information about the index individual are needed. This analysis aimed to assess whether surveying household contacts captures the same information as surveying the index individual directly. METHODS: REGN 2069/CoVPN 3502, a randomized controlled trial of COVID-19 PEP, enrolled household contacts of SARS-CoV-2 index individuals. CoVPN 3502-01 retrospectively enrolled and surveyed the index individuals. We compared responses to seven similar questions about the index individuals' transmission cofactors that were asked in both studies. We estimated the percent concordance between index individuals and their household contacts on each question, with 50% concordance considered equivalent to random chance. RESULTS: Concordance between index individuals and contacts was high on the most objective questions, approximately 97% (95% CI: 90-99%) for index individual age group and 96% (88-98%) for hospitalization. Concordance was moderate for symptoms, approximately 85% (75-91%). Concordance on questions related to the index individual's behavior was only slightly better or no better than random: approximately 62% (51-72%) for whether they received COVID-19 treatment, 68% (57-77%) for sharing a bedroom, 70% (59-79%) for sharing a common room, and 49% (39-60%) for mask wearing at home. However, while contacts were surveyed within 96 h of the index individual testing positive for SARS-CoV-2, the median time to enrollment in CoVPN 3502-01 was 240 days, which may have caused recall bias in our results. CONCLUSIONS: Our results suggest a need to survey index individuals directly in order to accurately capture their transmission cofactors, rather than relying on their household contacts to report on their behavior. The lag in enrolling participants into CoVPN 3502-01 also highlights the importance of timely enrollment to minimize recall bias.
Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Tratamiento Farmacológico de COVID-19 , Pandemias/prevención & control , Estudios Retrospectivos , SARS-CoV-2 , AutoinformeRESUMEN
Doxycycline postexposure prophylaxis (doxy-PEP) reduces sexually transmitted infections (STIs) in men who have sex with men (MSM) and transgender women (TGW). In a clinical trial of doxy-PEP, we sought to assess acceptability, impact, and meaning of doxy-PEP use among MSM/TGW. We conducted semistructured, in-depth 1:1 interviews with MSM and TGW enrolled in the intervention arm of the Doxy-PEP study. We queried motivations for and meaning of use, attitudes, beliefs, adherence, effect on sexual behaviors, and partner, community, and structural factors related to use. We coded interview transcripts into content areas, followed by thematic analysis. We interviewed 44 participants (median age 38), 2% were TGW, 17% Black, 61% White, 30% Hispanic, and 45% persons with HIV. We identified three overarching themes. First, participants found doxy-PEP acceptable, and believed it was effective based on their history of STIs, easy to adhere to, and acceptable to sex partners. Second, doxy-PEP benefited their quality of life and mental health, offering "peace of mind" by reducing their anxiety about acquisition or unwitting transmission of STIs. Participants reported feeling more "in control" of preventing STIs, and positive about supporting their personal, partner, and community health. Third, impact on sexual behavior was variable, with most reporting no change or a brief initial change. Participants in a multi-site clinical trial of doxycycline for STI prevention perceived it to be efficacious, and that it provided quality-of-life benefits, including reduced anxiety and sense of control over sexual health. Doxy-PEP had limited impact on sexual behavior. Clinicaltrials.gov: NCT03980223.