Property and casualty insurer Ace Ltd. said it may exclude Ebola coverage from some of its policies.

The Swiss company said that it is making the decision on a “case by case” basis for new and renewal policies under its global casualty unit, which offers coverage for U.S.-based companies and organizations that travel or have operations outside the U.S.

Ace said in a statement that it is evaluating the risk for clients that might travel to or operate in select African countries with higher exposure to the Ebola virus. It did not specify how many policies this might affect and declined to say if it has put an exclusions of this sort in place yet.

The company appears to be one of the first insurers to disclose that it is making modifications specific to Ebola, but that doesn’t mean it is the only one.

Insurers are constantly reevaluating the risks to their business, said Robert Hartwig, president of the Insurance Information Institute.

This could include incorporating the threat from earthquakes, political tensions or public health risks such as Ebola.