Rapid evolution of A(H5N1) influenza viruses after intercontinental spread to North America

Highly pathogenic avian influenza A(H5N1) viruses of clade 2.3.4.4b underwent an explosive geographic expansion in 2021 among wild birds and domestic poultry across Asia, Europe, and Africa. By the end of 2021, 2.3.4.4b viruses were detected in North America, signifying further intercontinental spread. Here we show that the western movement of clade 2.3.4.4b was quickly followed by reassortment with viruses circulating in wild birds in North America, resulting in the acquisition of different combinations of ribonucleoprotein genes. These reassortant A(H5N1) viruses are genotypically and phenotypically diverse, with many causing severe disease with dramatic neurologic involvement in mammals. The proclivity of the current A(H5N1) 2.3.4.4b virus lineage to reassort and target the central nervous system warrants concerted planning to combat the spread and evolution of the virus within the continent and to mitigate the impact of a potential influenza pandemic that could originate from similar A(H5N1) reassortants

A novel model of lethal Hendra virus infection in African green monkeys and the effectiveness of ribavirin treatment

The henipaviruses, Hendra virus (HeV) and Nipah virus (NiV), are emerging zoonotic paramyxoviruses that can cause severe and often lethal neurologic and/or respiratory disease in a wide variety of mammalian hosts, including humans. There are presently no licensed vaccines or treatment options approved for human or veterinarian use. Guinea pigs, hamsters, cats, and ferrets, have been evaluated as animal models of human HeV infection, but studies in nonhuman primates (NHP) have not been reported, and the development and approval of any vaccine or antiviral for human use will likely require efficacy studies in an NHP model. Here, we examined the pathogenesis of HeV in the African green monkey (AGM) following intratracheal inoculation. Exposure of AGMs to HeV produced a uniformly lethal infection, and the observed clinical signs and pathology were highly consistent with HeV-mediated disease seen in humans. Ribavirin has been used to treat patients infected with either HeV or NiV; however, its utility in improving outcome remains, at best, uncertain. We examined the antiviral effect of ribavirin in a cohort of nine AGMs before or after exposure to HeV. Ribavirin treatment delayed disease onset by 1 to 2 days, with no significant benefit for disease progression and outcome. Together our findings introduce a new disease model of acute HeV infection suitable for testing antiviral strategies and also demonstrate that, while ribavirin may have some antiviral activity against the henipaviruses, its use as an effective standalone therapy for HeV infection is questionable. Copyrigh

Comparative Pathogenesis of Three Human and Zoonotic SARS-CoV Strains in Cynomolgus Macaques

The severe acute respiratory syndrome (SARS) epidemic was characterized by increased pathogenicity in the elderly due to an early exacerbated innate host response. SARS-CoV is a zoonotic pathogen that entered the human population through an intermediate host like the palm civet. To prevent future introductions of zoonotic SARS-CoV strains and subsequent transmission into the human population, heterologous disease models are needed to test the efficacy of vaccines and therapeutics against both late human and zoonotic isolates. Here we show that both human and zoonotic SARS-CoV strains can infect cynomolgus macaques and resulted in radiological as well as histopathological changes similar to those seen in mild human cases. Viral replication was higher in animals infected with a late human phase isolate compared to a zoonotic isolate. While there were significant differences in the number of host genes differentially regulated during the host responses between the three SARS-CoV strains, the top pathways and functions were similar and only apparent early during infection with the majority of genes associated with interferon signaling pathways. This study characterizes critical disease models in the evaluation and licensure of therapeutic strategies against SARS-CoV for human use

Search for the retroviral origin of a novel murine spontaneous lymphoma

It is known that many types of leukemias and lymphomas are of viral origin. A new strain of immunologically deficient mice, the BALB/c x C57B1/6 beige nude mice, has been observed to develop spontaneous lymphomas of unknown origin at a high frequency. It is possible the tumors originate from a retroviral infection, which we attempted to show by detection of viral reverse transcriptase (RT) activity. We measured the (RT) activity in the supernatants of cocultures from the spleen and lymph node tissues of the beige nude animals by two methods, tritiated thymidine triphosphate incorporation in a standard RT assay, and the commercially available RT-DetectTM (DuPont) method. Of all supernatants tested, none showed a significant amount of RT activity compared with a cell line that was known to be actively producing the retrovirus MuLV. Upon electron microscopic analysis of the tumor-like cells grown in coculture, no viral particles were observed. Flow cytometric analysis of the tumor-like cells showed two general phenotypes; one predominately of a helper T cell type, and the other of a less differentiated immature thymocyte type.Thesis (M.S.)Department of Biolog

Identifying risk factors for compassion fatigue in psychologists in Aotearoa, New Zealand

Psychologists work extensively with people experiencing personal and mental health difficulties, providing psychological support and therapeutic interventions. While past research has established that psychologists are at risk of secondary traumatic stress and burnout (together comprising Compassion Fatigue), little is known about the professional and personal circumstances that mitigate their risk. The current study surveyed mental health symptoms and professional quality of life among 149 registered psychologists in Aotearoa, New Zealand (4.1% of the workforce). A broad range of experiences were considered, including psychologists’ symptoms of stress, anxiety, depression, Burnout, Secondary Traumatic Stress, Compassion Satisfaction and resilience, along with contextual factors including caseload, professional support, and personal circumstances, in the second year of the pandemic. LASSO regression was used to identify variables that predicted Compassion Fatigue and Compassion Satisfaction. Although psychologists find their work rewarding and satisfying, our results indicate a high rate of psychological distress and risk of compassion fatigue in our cohort of psychologists, partly associated with increased stress from COVID-19. This study identifies risk factors including COVID related stress, working with clients at risk, and symptoms of stress and anxiety, accounting for 59% of the variance in compassion fatigue. Additional informal supervision support, resilience and increased employer support were predictive of increased Compassion Satisfaction. It is imperative to focus on professional support, personal well-being and manageable caseloads, to ensure a future sustainable psychology workforce