Bacteria & Viruses
Bacteria are simple single-celled, completely independent, organisms that are able to eat and reproduce on their own- they are sort of like fish swimming in the ocean of your body. Under the right conditions bacteria reproduce very quickly; one bacterium divides into two separate bacteria about every 20 or 30 minutes. At that rate, one bacterium can become millions in just a few hours.
Antibiotics are a class of drugs that treat bacterial infections by stopping growth of bacteria or killing the bacteria directly. Antibiotics generally work rapidly and you should feel some improvement within 24-48 hours.
A virus is a different breed altogether. A virus is not really alive and can infect a body years later. A virus particle is nothing but a piece of DNA (cell blueprint) in a protective coat. The virus comes in contact with a cell, attaches itself to the cell wall and injects its DNA into the cell. The DNA uses the machinery inside the living cell to reproduce new virus particles. Eventually the hijacked body cell dies and bursts, freeing the new virus particles; or the viral particles may bud off of the cell so it remains alive. In either case, the body cell is a factory for the virus and not an independent living organism.
Like antibiotics for bacteria, specific antivirals are used for specific viruses. Unlike antibiotics, antiviral drugs do not destroy their target virus but slow or stop their copying process. To be effective these medications must begin within 48 hours of symptoms otherwise too many viruses will have been made.
Examples of antiviral medications include acyclovir (brand name Zovirax) used to treat the herpes virus in “shingles” (chicken pox virus), and oseltamivir (brand name Tamiflu ®); or zanamivir (brand name Relenza ®) which may be given to prevent or treat influenza. Influenza antivirals have been found to be 70-90% effective against susceptible viruses. The influenza virus destroys the ability of the lung to clear bacteria and often the flu will result in a bacterial lung infection. If sputum colour changes from clear or white to yellow, green or brown it generally means there is a bacterial infection and antibiotics are necessary.
Just as bacteria can develop resistance to an antibiotic, viruses can become resistant to an antiviral. Be sure to ask your doctor when to expect results, and find out what you should do if you are not better.
