America continues to suffer from an "egg shortage", with the chain restaurant Denny's (DENN.US) implementing an additional charge for eggs.

US chain restaurant Dennis (DENN.US) said on Monday that, due to egg shortages in the US, the company will temporarily charge an additional fee for egg-containing meals. The company, based in South Carolina, said that the amount of the extra fee will vary at its approximately 1500 locations. In a statement, Dennis said, "Due to nationwide egg shortages and rising egg prices, some of our restaurants will need to temporarily charge an additional fee for each egg-containing meal. Due to the varying impact of egg shortages in different regions, the additional fee will be determined based on market conditions and restaurant circumstances." Dennis stated that, due to the "unstable" situation, it will not disclose specific regions or locations that will be charging the additional fee. Avian flu has led to the deaths of millions of hens, leading to egg shortages at grocery stores and restaurants across the US. Due to insufficient supply, wholesale egg prices have reached new highs. The US Department of Agriculture said last Friday that, due to the impact of avian flu, wholesale egg prices are "steadily rising, and at a high base," with supply "very tight and little chance of improvement in the short term." Last week, the price of white eggs rose to $8.07 per dozen, an increase of 33 cents, or 4.7%. Overall inventory decreased by 2%, with cage-free egg inventory down by 3.5% and nutritionally enhanced egg inventory down by 12.5%. Dennis is not the only restaurant passing on the increased costs to consumers. Earlier this month, Waffle House decided to charge a 50-cent additional fee for each egg. Meanwhile, chain grocery stores like Trader Joe's and Walmart Inc. (WMT.US) have also limited the number of eggs customers can purchase.