No abstract

Hendra virus (HeV) is lethal to humans and horses, and little is known about its epidemiology. Biosecurity restrictions impede advances, particularly on understanding pathways of transmission. Quantifying the environmental survival of HeV can be used for making decisions and to infer transmission pathways. We estimated HeV survival with a Weibull distribution and calculated parameters from data generated in laboratory experiments. HeV survival rates based on air temperatures 24 h after excretion ranged from 2 to 10 % in summer and from 12 to 33 % in winter. Simulated survival across the distribution of the black flying fox (Pteropus alecto), a key reservoir host, did not predict spillover events. Based on our analyses we concluded that the most likely pathways of transmission did not require long periods of virus survival and were likely to involve relatively direct contact with flying fox excreta shortly after excretion.

While the region is known for deep midlatitude cyclones, it is the accompanying fields of marine boundary layer (MBL) clouds that seem to be critical to understanding the radiative energy balance of this region (Bodas-Salcedo et al., 2012, 2014, 2016, 2019). Inspired by Trenberth and Fasullo (2010), who showed a high bias in surface-absorbed solar energy by models, studies have increasingly focused on the ubiquity of supercooled liquid water in SO clouds. Simulations of these clouds too aggressively reduce cloud cover through ice phase precipitation processes (Frey & Kay, 2017; Vergara-Temprado et al., 2018). Recent modeling studies have mitigated this bias through various means and have shown the climate system's sensitivity to these SO MBL clouds (Kay et al., 2016; Tan et al., 2016). How the properties of liquid phase clouds-especially supercooled liquid phase clouds-vary across the SO remains an important topic. While the meteorology of the SO is predictable, variations in factors that control the local and regional aerosol properties differ considerably from regions north of the Antarctic Circumpolar Current (ACC) to the marginal seas along the Antarctic (Armour et al., 2016; Fossum et al., 2018). While seasonally varying sea surface temperatures and sea ice contribute to the cloud variability (Huang et al., 2016), the Antarctic Circumpolar Current essentially divides the SO into lower latitude temperate and high latitude oceans. Especially in the high latitude SO, seasonal biological productivity results in

We have tested the in vitro susceptibility to the neuraminidase (NA) inhibitors of 96 highly pathogenic clade 2.1 A(H5N1) viruses from Indonesia, isolated between 2008 and 2011. HPAI virus samples obtained through the Influenza Virus Monitoring (IVM) surveillance program in Indonesia were tested for susceptibility to oseltamivir and zanamivir. The NAs of four viruses were identified as extreme outliers to oseltamivir, based on statistical analysis by box plots, with IC values ranging from 46 to 62 nM. The NAs of two of these viruses from Sumatra and Aceh, had an N294S substitution, while one virus from Sulawesi had an S246N NA substitution. The NAs of all four viruses showed a specific loss of slow binding to oseltamivir in an IC kinetics assay. As observed in our previous surveillance, there was only a minimal effect on the sensitivity to zanamivir or peramivir for these mutants or any of the other isolates tested. The continued circulation of subtype H5N1 viruses in avian species poses an on-going zoonotic threat. The fact that we continue to identify avian isolates with naturally occurring mutations conferring reduced oseltamivir susceptibility remains a concern, given oseltamivir will be a key antiviral in the event of a new pandemic emerging.