When an epidemic becomes a pandemic – Shelby Sun

A few months ago, a hospital surveyor asked me. “As an infection control practitioner, what would keep you awake at night?”

“Outbreaks of staph infections and hospital acquired infections are a concern,” I said. “But, we can manage them. I worry about a global flu pandemic.”

Each year, during the winter season we have a seasonal flu epidemic. Certain strains of the existing flu viruses circulate within the country and cause illnesses. The flu vaccine is prepared in advance to combat the predicted circulating strains. The vaccine along with medications such as amantadine, rimantadine, zanamavir (relenza) and oseltamivir (tamiflu) keep the seasonal epidemic from causing significant illnesses and deaths.

Yet, every so often, the human flu virus mutates significantly and a new flu virus emerges. This is called an “antigenic shift.” This new virus leads to a pandemic rather than an epidemic because humans have no prior immunity against the new virus strain. Often this antigenic shift occurs when the flu viruses from animals combine with human flu viruses.

Presently, the avian flu virus poses the threat of causing a pandemic if it mutates to become a human flu virus. The avian influenza virus is mostly isolated from birds – though several human cases have been reported. The bird flu virus is generally not contagious from human to human – though few cases have been reported. Antiviral medicines such as relenza and ostalmavir may treat the bird flu – though no human studies have been conducted.

According to the Centers for Disease Control, a pandemic could have disastrous effects. Deaths could range from 90,000 to 200,000 with over 15% to 35% of the population effected causing economic impact ranging from $70 to $165 billion.

This is a scenario that will keep anyone awake. However, global preparedness with surveillance, containment, and treatments can stop a pandemic. Just as human intervention stopped the SARS virus in its tracks, global preparedness can prevent the next pandemic.