virology blog
About viruses and viral disease
The TWiVites discuss Zika virus seroprevalence in wild monkeys, Zika virus mRNA vaccines, and a gamete fusion protein inherited from viruses.
You can find TWiV #432 at microbe.tv/twiv, or listen below.
Click arrow to play
Download TWiV 432 (65 MB .mp3, 108 min)
Subscribe (free): iTunes, RSS, email
Become a patron of TWiV!
On episode #173 of the podcast This Week in Virology, the TWiVites discuss seroevidence for human infection with avian influenza H5N1, and the discovery of a new influenza virus in Guatemalan bats.
You can find TWiV #173 at www.microbe.tv/twiv.
Hosts: Vincent Racaniello, Dick Despommier, Alan Dove, and Rich ConditOn episode #41 of the podcast “This Week in Virology”, Vincent, Dick, Alan and Rich Condit chat about infectious salmon anemia virus, virus-resistant grapevines, virulence of pandemic H1N1 influenza virus, origin of 1918 influenza virus, holy water ban to halt influenza, frequency of human WU and KI polyomavirus infection, rabies in China, and host species of sin nombre virus.
[powerpress url=”http://traffic.libsyn.com/twiv/TWiV041.mp3″]
Click the arrow above to play, or right-click to download TWiV #41 (51 MB .mp3, 73 minutes)
Subscribe to TWiV in iTunes, by the RSS feed, or by email
Links for this episode:
Wal-Mart stops buying Chile salmon on virus outbreak
Virus-resistant grapevines
Virulence of H1N1 pandemic influenza virus in animal models
Did 1918 influenza virus originate in birds or not?
Holy water ban to halt swine flu
Frequent Human Infection with WU and KI Polyomaviruses
Rabies in China
Increased Host Species Diversity and Decreased Prevalence of Sin Nombre Virus
Fast, cheap PCR for crime scenes (thanks Jim!)
Weekly Science Picks
Alan For Love of Insects by Thomas Eisner
Rich Making of the Atomic Bomb by Richard Rhodes
Dick Origin of Species by Charles Darwin
Vincent Gallileoscope (thanks Zach!)
Send your virology questions and comments (email or mp3 file) to twiv@microbe.tv or leave voicemail at Skype: twivpodcast
While immunosuppressive therapy can ameliorate a variety of diseases, one unfortunate side effect of the treatment is that it may lead to pathogenic infections by viruses which would otherwise be benign. An example is the brain infection PML which occurs when immunosuppression leads to replication of the polyomavirus JC. How many polyomaviruses do we have to worry about, and how frequently do they infect humans?
There are five known human polyomaviruses: JC and BK, both isolated in 1971, and the more recently discovered KIV, WUV, and MCV (Merkel cell polyomavirus). The percentage of the human population that is infected with these viruses has been addressed by determining whether antibodies directed against the viral capsid protein VP1 are present in sera.
A total of 1501 serum specimens from healthy blood donors were examined. The presence of antibody to the viruses – known as seroprevalence – was 82% for BKV, 39% for JCV, 15% for LPV, 55% for KIV, 69% for WUV, and 25 and 42% for two different MCV strains. The sampling error is plus or minus 1%. Seroprevalence of these viruses was also examined in samples from 721 children, and the results were similar to those obtained with adult sera. From this information the authors conclude that polyomavirus infection of humans probably occurs during childhood.
The authors also determined the level of antibodies to a monkey polyomavirus, SV40. This virus was introduced into millions of people as a contaminant of early preparations of inactivated and infectious poliovirus vaccines. Whether or not the virus causes tumors in humans is a matter of scientific and legal controversy. Only 2% of the specimens were positive for antibodies to SV40. The low seroprevalence of antibodies to SV40 suggest that this virus does not circulate extensively among humans.
Given the high seroprevalence of polyomaviruses in humans, it is not surprising that they are significant pathogens in immunosuppressed populations. An important question is why these viruses can peacefully co-exist in many humans without causing disease. Are human polyomaviruses simply passengers, or do they benefit us in some unknown way?
Kean, J., Rao, S., Wang, M., & Garcea, R. (2009). Seroepidemiology of Human Polyomaviruses PLoS Pathogens, 5 (3) DOI: 10.1371/journal.ppat.1000363