Considering the current gastro pandemic caused a particular strain of Norovirus, known as “Sydney 2012”, (nicknamed in the British Press as “Chunder from Down Under”) I thought I’d share some facts about the virus with you. And, yes, I promise you, sick facts ARE interesting 🙂
How much of the virus do you need to get sick?
The amount of virus needed to infect you is miniscule. You need a mere 10-100 virus particles to get sick, and bear in mind that in each ml of vomit there can be a million virus particles!
What are my chances of getting sick if I come into contact with it?
At least 50% of those exposed to the virus will get sick. Who’s feeling lucky?
But we can kill it, right?
Yep but it’s not as straightforward as you may think. This virus is pretty environmentally stable. It can still live when it’s all dried up, it can still be alive when heated (up to 60 degrees), and it can still infect you after being frozen. To top it all off, the persistent thing can still survive in some levels of chlorinated water. AND you’ll love this (not): There is evidence of people getting sick with Norovirus over 13 days after a gastro outbreak has occurred (if you want to know more…I’ll tell you: Hint, it was from a carpet!).
Is it easily passed around by hands?
Yes. If the virus is put on to your fingers, you could touch up to 7 surfaces, (one after the other) passing the virus on to each surface. And wait, it gets better: 14 people can then get contaminated after they then touch just one of those infected surfaces.
It’s pretty clear now how easily this strain of gastro can tear its way through families, schools, day-care centres and nursing homes, isn’t it?
Once I’ve had it, does that mean I’m protected from getting it again?
I wish! But no. Unlike Rotavirus, which the immune system is much better at recognising second time round, Norovirus behaves a little like the Cold virus. By that I mean it mutates all the time, changing shapes so that our immune systems don’t recognise it. This means we can get sick from it repeatedly.
More Coming Soon on: Gastro; Symptoms, Treatment and Prevention
The Research Base:
Barker J, Vipondb I, Bloomfiled S (2004) Effects of cleaning and disinfection in reducing the spread of Norovirus contamination via environmental surfaces Journal of Hospital Infection 58, 42–49
Chessbrough J, Barkiss-Jones L, Brown D (1997) Possible prolonged environmental survival of small round structured viruses. Journal Hospital Infections 35:325—326
Lopman B, Reacher M, Vipond I, Sarangi J, Brown D(2004) Clinical Manifestation of Norovirus Gastroenteritis in Health Care Settings Clinical Infectious Diseases 39:318–24
Murata T, Katsushima N, Mizuta K, Muraki Y, Hongo S, Matsuzaki Y (2007)Prolonged Norovirus Shedding in Infants 6 Months of Age With Gastroenteritis The Pediatric Infectious Disease Journal 26:1 pp46-49
Nygard K, Torven M, Ancker C, Knauth S, Hedlund K, Giesecke J, Andersson Y, Svensson L (2003) Emerging Genotype (GGIIb) of Norovirus in Drinking Water, Sweden Emerging Infectious Diseases 9(12): 1548–1552.
Simon A, Schildgen O, Binger A, Hasan C, Bode U, Buderus S, Engelhart S, Fleischhack G (2006) Norovirus outbreak in a pediatric oncology unit Scandinavian Journal of Gastroenterology 41: 693-699