virology blog
About viruses and viral disease
By David Tuller, DrPH
While some medical professionals argue that prolonged non-specific symptoms after acute COVID-19 are psychogenic and that “Long COVID” as a presumed clinical entity was concocted by a cabal of queers and feminists, others are getting on with efforts to disseminate more appropriate information to their colleagues. These efforts often involve drawing parallels with the pathophysiology of ME/CFS.
On episode #362 of the science show This Week in Virology, the virus virtuosos, with their usual verve, illuminate a new method to identify all the viral nucleic acids in a sample, and regulation of viral gene expression by codon usage.
You can find TWiV #362 at www.microbe.tv/twiv.
Hosts: Vincent Racaniello, Dickson Despommier, Rich Condit, and Alan Dove
The complete TWiVome deconstructs the movie Contagion.
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Click the arrow above to play, or right-click to download TWiV 167 (53 MB .mp3, 88 Â minutes).
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Dickson – Guinea Pig Doctors by Jon Franklin
Rich – Learn to appreciate technology and Everythings amazing and nobodys happy (YouTube)
Alan – JD Hooker slide collection
Vincent – iTunes U app and iBooks Author
Listener Pick of the Week
Judi – Makers of Many Things by Eva March Tappan
Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv, or call them in to 908-312-0760. You can also post articles that you would like us to discuss at microbeworld.org and tag them with twiv.
Contagion is the name of a new action-thriller movie about a global outbreak of a deadly viral disease. The trailer is now available. From the website:
Synopsis
“Contagion” follows the rapid progress of a lethal airborne virus that kills within days. As the fast-moving epidemic grows, the worldwide medical community races to find a cure and control the panic that spreads faster than the virus itself. At the same time, ordinary people struggle to survive in a society coming apart.
I hope they get the science right. We’ll see when it opens on 9 September 2011.
Global fish farming may be the solution to the impending collapse of the commercial fishing industry, but penned fish are susceptible to infectious diseases. Infection with salmon infectious anemia virus, an orthomyxovirus, lead Wal-Mart to stop buying farmed salmon from Chile, the world’s second largest producer of the fish. As a consequence Chilean farmed salmon are being immunized to prevent infection. Heart and skeletal muscle inflammation (HSMI) is another disease of farmed salmon, first detected in Norway – the world’s largest supplier of the fish – in 1999. The results of deep sequencing suggest that HSMI is caused by a novel piscine reovirus.
HSMI was transmitted to salmon by inoculation with tissue extracts of diseased fish or by co-habitation. RNA was extracted from the heart and subjected to high throughput sequence analysis, which revealed the presence of a novel member of the reovirus family. These are are non-enveloped, icosahedral viruses with 10-12 segments of double-stranded RNA that infect a variety of hosts, including humans: rotaviruses are important agents of gastroenteritis.
The presence of piscine reovirus in salmon with HSMI was examined by polymerase chain reaction assays. Included were heart and kidney samples from 29 salmon from three different outbreaks of HSMI, and from 10 healthy fish. All but one of the diseased fish, and none of the healthy fish, contained PRV nucleic acid. To determine the prevalence of PRV in healthy salmon, samples were collected from 9 different Norwegian coastal waters. Sixteen of 66 (24.2%) of these fish were positive for PRV.
Is heart and skeletal muscle inflammation of salmon caused by piscine reovirus? It’s possible, but further work is needed to prove causality, as the authors write:
Formal implication of PRV in HSMI will require isolation in cell culture and fulfillment of Koch’s postulates, or prevention or modification of disease through use of specific drugs or vaccines.
It’s important to identify the etiologic agent of HSMI because it is a threat to both farmed and wild salmon. Farmed fish are kept in pens in the open ocean, facilitating spread of infectious diseases to wild fish. Knowledge of the causative agent will permit preventive measures such as immunization.
Palacios G, Lovoll M, Tengs T, Hornig M, Hutchison S, Hui J, Kongtorp RT, Savji N, Bussetti AV, Solovyov A, Kristoffersen AB, Celone C, Street C, Trifonov V, Hirschberg DL, Rabadan R, Egholm M, Rimstad E, & Lipkin WI (2010). Heart and skeletal muscle inflammation of farmed salmon is associated with infection with a novel reovirus. PloS one, 5 (7) PMID: 20634888