Bunyaviruses

00:01 The bunyaviridae.

00:04 The bunyaviridae are mid-sized, enveloped viruses which have a helical capsid.

00:09 They also have a linear single-stranded, negative-sense segmented RNA genome, and so they must carry an RNA- dependent RNA polymerase.

00:18 And you could see images of the bunyaviridae on the scanning electron micrograph in front of you.

00:27 The representative species that we'll talk about are the encephalitis viruses, especially the California encephalitis virus.

00:34 And then hemorrhagic fever viruses, including hantavirus, and similarly, the sandfly/rift valley fever virus, and the Crimean-Congo hemorrhagic fever virus.

00:45 Because these all manifest in a similar fashion, today we will just discuss, of those, the hantavirus.

00:52 So, the bunyaviridae primarily are arboviruses, meaning that they are transmitted through the bite of a biting insect, especially mosquitoes, but sometimes, fleas, flies, or ticks.

01:07 The exception, of course, is the hantavirus that is transmitted by rodents, including this cute little one in front of you on the image.

01:15 The pathogenesis of the bunyaviridae starts with primary infection, regardless of whether it is via the bite of a biting insect, or via the stool or urine of a infecting rodent.

01:29 After primary infection occurs with the inoculation, then flu-like symptoms develop, and again, this is a very typical pattern with many of the viruses we talk about.

01:39 The primary processes: fever, malaise, anorexia, some vomiting, diarrhea, general sense of poor being.

01:49 And then there is a secondary viremia after that primary infection, and while the symptoms are ongoing, and target organs are affected depending on the virus and depending on the virus' tropism.

02:02 And some of the target organs are displayed here, but especially the central nervous system, especially for the encephalitis viruses, liver, lungs, endothelium with vascular infection, especially with the hantavirus.