The Ebola epidemic in Africa, with 2 cases now reported in the US has brought a lot of attention on disease transmission. There have been several virus outbreaks in foreign countries that have posed threats to the US. The SARS breakout in 2002 and the China Avian Influenza (H7N9) Virus in 2013 are examples of this issue. There were only a handful of deaths in the US attributed to SARS and one known death from the Avian Flu. The biggest risk of spreading diseases across the ocean is people traveling from the infected area.
People are obviously the carriers of viruses from one country to another, but what about cargo? Is it possible that a virus or bacterial based diseases could spread from one continent to another by shipping product? Shipping food, animals and drugs definitely can spread disease, but these types of products are highly controlled and would not cause epidemics. One example is “mad cow” disease. Over the years, different countries have banned imported beef from other countries. The first country that was the object of the ban was Great Britain, where the European Union banned beef imported from Britain. In 2003, China and Korea banned beef imports from the US and Canada. “In June 11, 2014 – The USDA announces a recall of 4,000 pounds of beef; a spokesperson cites “an abundance of caution.” The meat comes out of the Fruitland American Meat processing plant in Jackson, Missouri.” Source: USDA News Release. In general the shipment of food products can cause disease by ingesting contaminated food. But this situation is different than a potential epidemic or pandemic as someone getting sick from containmenated food is not contagious.
What about simply spreading disease via shipping containers or other packaging materials?
In order for a disease such as a virus to spread from one country to another the virus would have to somehow get transferred onto the crate surface, survive through the trip, then someone at the receiving end would have to contact that surface and introduce it into their body via mouth, nose or eyes. This scenario is considered very unlikely for one reason: Most viruses and bacteria can only survive for a short period of time outside the human body. Generally, most viruses die in just a couple of hours. If there was fecal matter or pool of blood, the virus could survive much longer, but once the blood or feces are dry, the virus would not be able to survive. Since most cargo shipments can take days or even weeks, the likelihood of survival is null. There is a much higher likelihood of domestic shipments transferring viruses, but even in those cases, the odds are close to zero.
ISPM 15 deals with the transfer of invasive species in wooden containers. Specifically beetles that bore into wood have been transferred from Asia to North America. This issue has caused significant damage to forests, but beetles to do not transmit any disease to humans or other animals. ISPM 15 requires that wood packages be treated so that any containment of invasive insects is eliminated. Since ISPM 15 has been adapted worldwide, the transfer of invasive insects has significantly declined.
Mold and mildew can thrive in wood and can get transferred from one country to another. Certain types of molds can make human sick if they inhale a significant amount of mold spores. In order for this to occur, someone would have to be in a closed area with the contaminated crate for an extended period of time. This is a very unlikely scenario. Additionally the person getting sick from the mold would not be contagious so there would be no epidemic.
There is a much higher probability of spreading viruses via indirect contact from using an ATM machine, handling money or from door handles and tables in crowded areas where transfer can take place within minutes of surface contamination.