There’s some good news from the Ebola front.

Experts say the deadly virus has had little impact on U.S. shipping — so far.

The U.S. Coast Guard has tightened port of entry requirements for ships coming from affected areas in West Africa: Liberia, Guinea and Sierra Leone. But few vessels calling at U.S. ports actually come from those countries.

The majority of  U.S.-bound ships sailing from the affected areas are bulk carriers from Guinea; only a few come from Sierra Leone or Liberia. Of the 34,600 ships calling at U.S. ports in 2014, only 50 came from the three main affected countries, according to an analysis by IHS, the Colorado-based market research and consulting firm.

Although there are currently no U.S. quarantines or restrictions on international ocean-going trade, the maritime industry is being cautious. Last month members of the longshoremen’s union in Baltimore delayed loading cargo on a ship heading to West Africa, apparently concerned about Ebola. The ship was later cleared by the Coast Guard.

Shipping associations have issued guidelines and Maersk recently assured customers that there is no record of an Ebola virus being transmitted through international shipping.

But things could really get ramped up should the disease spread to larger maritime countries in West Africa, most notably Nigeria, according to IHS Maritime and Trade Analyst Gary Li.

Nigeria is the single largest maritime trader in the region with 102 ships calling at U.S. ports this year, including product tankers, crude oil tankers and container ships.

Nigeria has been declared “Ebola free” at the moment, but Li says if the disease takes hold there, trade from West Africa could be severely affected and the Coast Guard will struggle under the burden of expanded inspections.

Definitely something worth keeping an eye on.

Pamela Glass is the Washington, D.C., correspondent for WorkBoat. She reports on the decisions and deliberations of congressional committees and federal agencies that affect the maritime industry, including the Coast Guard, U.S. Maritime Administration and U.S. Army Corps of Engineers. Prior to coming to WorkBoat, she covered coastal, oceans and maritime industry news for 15 years for newspapers in coastal areas of Massachusetts and Michigan for Ottaway News Service, a division of the Dow Jones Company. She began her newspaper career at the New Bedford (Mass.) Standard-Times. A native of Massachusetts, she is a 1978 graduate of Wesleyan University (Conn.). She currently resides in Potomac, Md.