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A parcel has been delivered and contaminated by a person who has the flu.

For how long would the parcel be an effective disease vector?

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    $\begingroup$ Is spraying it with a 10% solution of bleach, letting that sit for 10 minutes really not an option? $\endgroup$ – swbarnes2 Oct 22 '18 at 22:34
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    $\begingroup$ Are we talking about actual influenza here? Most people, when they say “I have the flu” mean “I have a moderately serious cold”. The symptoms are somewhat similar but the pathogens causing it, as well as the severity of the disease, are completely different. $\endgroup$ – Konrad Rudolph Oct 23 '18 at 14:16
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    $\begingroup$ @swbarnes2 Rubbing alcohol or hydrogen peroxide also make good disinfectants, if bleach is not readily available. $\endgroup$ – Mason Wheeler Oct 23 '18 at 15:25
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    $\begingroup$ Worth noting, you can avoid this kind of concern in the future by getting your flu shot. $\endgroup$ – Maxander Oct 23 '18 at 17:36
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    $\begingroup$ Thing to note: postal packages might also have been contaminated several times due to being handled by infected or contamintated postal workers, or by being in contact with other infected packages, etc... And not only by flu, but other infections too. Actually, chances that any package you receive is sterile is practically nonexistent. So just practice good hygiene always (wash your hands, do not put them in mouth/nose/eyes etc) $\endgroup$ – Matija Nalis Oct 23 '18 at 21:00
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How long should I wait before handling the parcel to avoid contracting the virus?

If you use gloves, or don't touch your face and just wash your hands after opening, you don't have to wait at all. If you don't use gloves or want to pick your nose, rub your eyes, or fiddle with your beard while opening the package, wait 24 hours if the package is nonporous, and 2 hours if it is not. Generally, whether contaminated or not, don't lick, eat, inhale, or rub your eyes with the package :)

Influenza and similar respiratory viruses are transmitted by large droplets, aerosols, and fomites. Your package is a fomite, an object that can be contaminated and transmit disease. There is some debate about what mode of transmission is most significant for influenza, but fomites definitely do transmit influenza and similar viruses. In a study of homes and daycare centers with children who had an active influenza infection, 59% of home objects that were tested were positive for influenza. It's reasonably likely that your package was, at least at some point, contaminated.

@LDiago's answer is useful here, but deserves some clarification. The UK National Health Services information cited in that answer comes from this seminal study. I'm not entirely happy with the wording on the NHS website, though. Virus survives on nonporous surfaces for 24-48 hours. Virus is transferred from nonporous surfaces to hands in detectable amounts for 24 hours. If your package is paper, the relevant test is transfer from cloth or paper. Virus survives for 8-12 hours, and is measurably transferred to hands after 15 minutes to 2 hours. In any case, virus transferred to hands from a fomite survives for only 5 minutes.

Infection from fomites, however, requires virus to be transferred from the fomite to (typically) the hand, and then from the hand to respiratory tract epithelium. Inoculation of nasal passageways is sufficient for infection in laboratory conditions. Conjunctival and oral inoculation may also play a role. You can read more about this in Cecil Medicine Ch. 372 and Murray Medical Microbiology Ch 59.

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    $\begingroup$ i am sorry. I agree with you. I didnt checked the relevence of this study.... So thank you for your answer :) $\endgroup$ – L.Diago Oct 23 '18 at 6:59
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    $\begingroup$ +1 for the excellent advice of not inhaling mail order parcels! $\endgroup$ – Janus Bahs Jacquet Oct 23 '18 at 14:20
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    $\begingroup$ "wait 24 hours if the package is nonporous, and 2 hours if it is not." - dang, that double negative is really tripping me up. So, you mean, "wait 2 hours if the package is porous, and 24 hours if it is not"? $\endgroup$ – MrWhite Oct 23 '18 at 22:58
  • $\begingroup$ @cell0 I rolled this back because the appropriate usage here is "Virus survives", not "the virus", and "the relevant test is transfer", not "transferred". The test isn't transferred, the test is transfer (of virus). I appreciate your editing efforts. Please try to evaluate whether you've changed the meaning of a phrase by editing it, though. $\endgroup$ – De Novo Mar 13 '19 at 3:15
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From the UK National Health Service:

Flu viruses capable of being transferred to hands and causing an infection can survive on hard surfaces for 24 hours. Infectious flu viruses can survive on tissues for only 15 minutes.

Like cold viruses, infectious flu viruses survive for much shorter periods on the hands. After 5 minutes the amount of flu virus on hands falls to low levels.

Flu viruses can also survive as droplets in the air for several hours; low temperatures increase their survival in the air.

Parainfluenza virus, which causes croup in children, can survive for up to 10 hours on hard surfaces and up to 4 hours on soft surfaces.

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    $\begingroup$ Any idea why the virus can survive 24 hours on hard surfaces, but only 15 minutes on a tissue? $\endgroup$ – RockPaperLizard Oct 22 '18 at 22:47
  • $\begingroup$ How does the tissue kill the virus in 15 minutes? It doesn't have anything that can break down the virus afaik. $\endgroup$ – Nelson Oct 23 '18 at 1:04
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    $\begingroup$ @Nelson, dehydration. Most viruses (and bacteria) are quite susceptible to being dried out. $\endgroup$ – Mark Oct 23 '18 at 1:22

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