By Jeremy Bender from Business Insider

It’s an ironic global security threat, but facilities meant to prevent and cure disease have sometimes inadvertently aided in its spread.

For instance, the Centers for Disease Control (CDC) made headlines last month when an estimated 84 of its scientists were exposed to a live and potentially deadly strain of anthrax.

A second probe into the incident has discovered a number of additional lapses in the CDC’s handling of the situation, including the use of expired disinfectant, the transportation of dangerous materials in Ziploc bags, and the storage of anthrax in unlocked refrigerators in unrestricted hallways.

These lapses highlight the fact that even with labs with the highest level of precautions in place, human error can always lead to the unintentional spread of diseases. It’s a rare event, and the overwhelming majority of pathogens are responsibly stored. But there are a handful of examples throughout the past century of viruses inadvertently escaping from lab containment and entering the broader world.

The Bulletin of the Atomic Scientists recently compiled a report reviewing five such events.

The 1977 H1N1 human influenza pandemic

Due to lab mishandling, a strain of the H1N1 influenza managed to escaped from a Chinese facility that was likely trying to create a vaccine for the disease. The virus spread globally and had an infection rate of 20% to 70% among those exposed. Luckily, the strain of the virus caused only mild disease and few fatalities.

Smallpox outbreaks in Great Britain

From 1963 to 1978, there were three smallpox escapes from two different laboratories. All three were due to poor standards and bad practices within the labs. Three cases and at least 80 deaths were linked to the outbreaks.

The 1995 Venezuelan equine encephalitis (VEE) outbreak

In 1995, 10,000 people in Venezuela and 75,000 people in Colombia fell ill with a VEE strain that had escaped from a lab. The outbreak caused upwards of 311 deaths and 3,000 cases of neurological complications.

Various SARS outbreaks

Severe Acute Respiratory Syndrome (SARS) was a global epidemic in 2003 that caused 8,000 infections and 774 deaths across 29 countries. Since the original epidemic, there have been six escapes of the virus from laboratories — four in Beijing, and an additional one each in Singapore and Taiwan.

In all cases, the virus escaped due to negligence and human error. Fortunately, none of the escapes led to a renewed outbreak.

The 2007 Foot and Mouth (FMD) outbreak in the UK

FMD is a highly transmissible disease that infects cloven-hoofed animals. Outbreaks of the disease can cause billions of dollars in economic damage as millions of animals may need to be culled to limit the disease’s spread. In 2007, 278 animals in the UK became infected with FMD after the virus escaped from a biosafety lab four kilometers away. The outbreak required 1,578 animals to be culled and cost an estimated 200 million pounds.

IMAGE: An Anthrax sample in a petri dish Center for Disease Control

For more on this story go to: http://www.businessinsider.com/5-terrifying-times-pandemics-escaped-from-laboratories-2014-7#ixzz37vnEC2EN