Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: Donnah on 29/09/2013 00:04:14
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If a person has shingles and the rash is present, is it just the blisters that are contagious, or can the virus also be passed by other methods (like sneezing)? Is there any danger to pregnant women if they come into contact with someone (not the blisters, just the person) that has shingles?
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I think it can be transmitted through sneezing .
Similar to influenza viruses spread way
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Hi Donnah
Shingles is a recurrence of VZV (varicella zoster virus) which, the first time you catch it, causes chickenpox and then lurks in your nervous system for the rest of your life. At times of low (cell mediated) immunity, the virus can recrudesce, exiting the nervous system to infect a patch of skin and produce a painful blistering rash. This is zoster. The blisters are crammed with millions of infectious viral particles and a patient with the rash is potentially infectious from the time the rash first appears until the blisters have all scabbed over and no new ones are appearing. A patient with zoster is NOT infectious viral the aerosol route, and if the rash is on a covered part of the body, the risk of transmission to a non-immune person is extremely low.
In contrast, a person with chicken pox (ie infected acutely with VZV for the first time) is highly infectious viral the aerosol route because the virus initially replicates in the throat and airways; patients shed the virus in airway secretions - and may therefore pass the virus to another person - for up to 2 days before the rash appears.
Individuals who have a history of chickenpox infection are not at risk from contact with cases of chickenpox or shingles.
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There is also a varicella (chickenpox) vaccine that is being administered to children in the USA, and presumably elsewhere too. However, the vaccine is apparently a live-attenuated virus, and should not be administered to pregnant women (although the effects of the vaccine on pregnant women and their babies is still being studied, and recommendations could change in the future).
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Thank you for the information, that's helpful.
Is it true that the chickenpox virus can also reactivate without any blisters, possibly causing nerve pain down the side of a leg?
The person I'm referring to had nerve pain down the right leg for about a year. The nerve pain cleared up, but then the right shoulder and chest area manifested pain and shingles rash almost immediately.
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Yes, we think that in some circumstances reactivations without clinical lesions may account for cases of nerve pain or paraesthesia (numbness and tingling) in certain dermatomes (skin patches supplied by certain nerves) over time.
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Thank you Chris, you're very good at explaining things.