Maine health officials reported Thursday that four more people have been stricken with lung illness related to e-cigarette use, giving the state five cases amid the national alarm about the growing health emergency that had claimed 18 lives as of Tuesday.

Gov. Janet Mills has directed the Maine Center for Disease Control and Prevention to work with the Maine Attorney General’s Office to increase compliance checks on e-cigarette products to prevent sales to youths.

Maine Sen. Rebecca Millett, D-Cape Elizabeth, on Thursday morning called on the Mills administration to immediately ban flavored vaping products, which have been criticized for being targeted to young people, even though it’s illegal for those under 21 to purchase e-cigarettes in Maine. New York, Rhode Island and Michigan have announced bans on flavored e-cigarettes, while Massachusetts has imposed a four-month moratorium on the sale of all vaping products.

“That would be a good first step,” Millett said of a flavorings ban. “Banning flavorings would be helpful because it gets at the issue of marketing to youth, but it doesn’t answer the central question of the safety of these products. We are at a crisis point.”

Mills’ spokeswoman, Lindsay Crete, said in a statement that the governor “has requested the Maine CDC explore all options to curb the use of e-cigarette products to the extent necessary to protect the health and well-being of Maine people, especially our youth. Whether it is appropriate to ban all of these devices or to issue a warning that people should avoid using certain additives is an important distinction that is being considered.”

Robert Long, Maine CDC spokesman, said in response to a question about a ban on flavored vape products that agency officials are “reviewing all options and have not ruled out anything.”

Millett says she will introduce a bill in January that would ban the sale of vaping products in Maine until the U.S. Food and Drug Administration can determine whether they are safe.

“We need to hit the pause button until we know what these products are doing to people’s lungs,” said Millett, who added that the most effective response would be from the federal government rather than from the states. “The U.S. Food and Drug Administration needs to do its job and take action. This is not just a Maine issue. This is a national issue.”

Five Mainers – four adults and one youth – have been diagnosed with lung illness after using e-cigarette products, the Maine CDC said.

Similar cases have been reported in 47 other states and one U.S. territory. The U.S. Centers for Disease Control and Prevention reports that through Oct. 1 there had been 18 deaths in 10 states and more than 1,080 lung injuries attributed to vaping.

The FDA is looking at tightening regulations, and there could be an upcoming federal ban on flavored products. Popular flavorings include cinnamon, vanilla and fruit flavors. The FDA announced on Sept. 11 that it would consider banning new flavored e-cigarette products from entering the market, but details were not announced. Federal officials said more action may be taken.

“We must act swiftly against flavored e-cigarette products that are especially attractive to children,” acting FDA Commissioner Dr. Ned Sharpless said in a statement Sept. 11.

No deaths have been reported in Maine. The cases in Maine were reported between the second week of August and the end of September and involve patients who exhibited symptoms similar to those identified in other states, the Maine CDC said.

Symptoms include coughing, shortness of breath, chest pain, fever and fatigue.

The Maine patients reported a history of using e-cigarette products or smoking materials containing tetrahydrocannibinol, or THC, the active ingredient in cannabis. Other patients reported using THC and nicotine, while a third group reported using only e-cigarettes that contain nicotine, the Maine CDC said.

The Maine CDC did not yet have more specific information on the products that were being used, such as whether they were black market products or purchased from a legal vendor, said Long, the agency spokesman.

“Our first priority is the health of the affected individuals,” Long said in an emailed response to questions. “We are still reviewing the cases to determine details about the factors and products involved, including where the patients acquired the products and whether the products were altered after acquisition. There is no single, potentially causative factor present in all of the cases, which is also the situation nationally.”

Vaping had been viewed by many users as a safer alternative to smoking, although research on the products is in the early stages.

The U.S. CDC reported on Thursday that researchers are investigating the current outbreak, but much is unknown.

“The specific chemical exposure (or exposures) causing this outbreak is unknown at this time,” a U.S. CDC update said.

Doctors, mostly from the Mayo Clinic in Rochester, Minnesota, evaluated lung biopsies from 17 patients who had experienced lung injuries from vaping, according to a letter published on Wednesday in the New England Journal of Medicine.

All of the biopsies showed “patterns of acute lung injury” according to the letter, which also pointed out that much more research on vaping needs to be conducted. Seventy percent of the lung injuries involved people who had ingested THC in vaping products, and the remaining 30 percent were nicotine-only products.

The surge of vaping-related illnesses has intensified concerns about a dramatic increase in use of e-cigarettes among school-aged children, and the absence of regulation and knowledge about the short- and long-term health effects.

“Maine has been a leader in addressing public health risks associated with tobacco use and vaping,” said Dr. Nirav Shah, director of the Maine CDC. “Regardless of whether you are using e-cigarettes for tobacco, cannabis or flavoring, you are inhaling something that could harm your lungs. And we must remember that smoking regular combustible cigarettes remains the leading preventable cause of death in the United States.”

Maine passed a law this year that taxes e-cigarettes the same as combustible tobacco products, as well as a law sponsored by Millett that prohibits vaping on all Maine school grounds.

Maine also requires people to be at least 21 to purchase vaping and tobacco products.

“As a tobacco 21 state and with robust youth prevention and compliance measures in place, Maine is already committed to protecting our residents from the harmful effects of e-cigarettes,” Jeanne Lambrew, Maine’s health and human services director, said in a statement. “But we must do all we can to keep these products out of the hands of Maine youth, as well as discourage use among adults.”