How long can an asymptomatic individual carry a virus?

Virii are all different.

Will the virus die out after a while?

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.
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Is it on a floppy disc or a CD?

:silly:

life and not show symptoms until your immune system is compromised.
L-lysine is supposed to be good to fight viruses.
I think the same may be true of the virus which is the cause of "Shingles" which is the same as the chicken pox virus:varicella-zoster virus. If you had chicken-pox as a child, or are exposed to it as an adult, you can develop "shingles" as an adult.
# Varicella: the primary infection that causes chickenpox.

# Herpes zoster: the reactivation of the virus that causes shingles

...to my own chagrin. The chicken pox virus resides in a dormant state at the base of the spine, but with certain triggers (especially stress), can flare up as herpes zoster (shingles), which truly SUCKS. Fortunately, Famvir (an expensive but potent anti-viral) can knowck it back effectively if it's administered early on.

I say this based on personal experience... especially tha "truly SUCKS" part.


:scared:

For some viruses, like Ebola, the prodromal stage (where the person is infected and contagious but not yet sick) is very, very short. In the case of HIV, it can be up to 15 years.

Google the specific virus.

But does the individual always eventually get sick?

I do not know whether you are trying to distinguish between a virus and bacteria. In any event, Typhoid Mary carried and spread Typhoid throughout her life even though she never had symptoms. I don't know whether typhoid is caused by a virus or bacteria.

Interim Recommendations: Infection Control Precautions for Influenza A (H5N1)

Infection control precautions for H5N1 remain unchanged from the CDC interim recommendations issued on February 3, 2004. All patients who present to a health-care setting with fever and respiratory symptoms should be managed according to recommendations for Respiratory Hygiene and Cough Etiquette and questioned regarding their recent travel history. Isolation precautions identical to those recommended for SARS should be implemented for all hospitalized patients diagnosed with or under evaluation for influenza A (H5N1) as follows:

* Standard Precautions
o Pay careful attention to hand hygiene before and after all patient contact
* Contact Precautions
o Use gloves and gown for all patient contact
* Eye protection
o Wear when within 3 feet of the patient
* Airborne Precautions
o Place the patient in an airborne isolation room (i.e., monitored negative air pressure in relation to the surrounding areas with 6 to 12 air changes per hour).
o Use a fit-tested respirator, at least as protective as a NIOSH-approved N-95 filtering facepiece respirator, when entering the room.

For additional information regarding these and other health-care isolation precautions, see the Guidelines for Isolation Precautions in Hospitals. These precautions should be continued for 14 days after onset of symptoms until an alternative diagnosis is established or until diagnostic test results indicate that the patient is not infected with influenza A virus (see Laboratory Testing Procedures below). Patients managed as outpatients or hospitalized patients discharged before 14 days should be isolated in the home setting on the basis of principles outlined for the home isolation of SARS patients (see www.cdc.gov/ncidod/sars/guidance/i/pdf/i.pdf).
Additional Avian Influenza A (H5N1) Information

* For information about reported outbreaks of avian influenza A (H5N1) among poultry, see the website of the World Organization of Animal Health (OIE).
* For information about human influenza A (H5N1) cases, see the WHO website.
* For clinical information about human influenza A (H5N1) cases, see:
o CDC. Cases of influenza A (H5N1) - Thailand, 2004. MMWR 2004;53:100-103.
o Hien TT, Liem AT, Dung NT, et al. Avian influenza A (H5N1) in 10 patients in Vietnam . New England Journal of Medicine 2004;350:1179-1188.
* For information about travel and avian H5N1 influenza, see the CDC Travelers’ Health website.
* For general information about influenza, see the CDC Influenza website.

http://www.cdc.gov/flu/avian/professional/han020405.htm