NEW YORK — A surge of orders for gear to protect against Ebola is leading to backlogs through January for some U.S. customers, as demand expands beyond hospitals to firefighters and others, manufacturers and health care workers said.

Requests for bodily fluid-resistant gowns, shoe covers and face shields have jumped since the first case of the virus was diagnosed in the United States in late September and as Ebola has ravaged three West African countries..

The shortage has forced firefighters to improvise when dealing with a potential Ebola patient by using existing, standard gear, putting them further at risk, officials said.

In the fight against the outbreak at its West African source, doctors and nurses have not seen gear shortages, according to officials with the World Health Organization, Doctors Without Borders and the U.S. Centers for Disease Control and Prevention. But word of the exceptionally high demand has prompted concern that future orders might not be filled, officials said.

While manufacturers such as DuPont and Lakeland Industries Inc. have increased production capacity, some are unable to keep up.

DuPont has more than tripled its production, first to address the “unprecedented level of demand” in Liberia, Sierra Leone and Guinea, DuPont spokeswoman Sandra James said by email. The Wilmington, Delaware-based company has also received orders from other countries, particularly the United States, she said.

“Even with the significant capacity increases we have already made, demand is now exceeding our supply,” she said.

DuPont is prioritizing orders for people in direct contact with patients in West Africa.

Most orders are from the WHO, Doctors Without Borders and the CDC, for health care workers on the ground in West Africa, said James, who would not give specific numbers.

The disease has killed more than 4,800 people, all but a handful in West Africa, since it emerged in March.

Lakeland Industries is on track to double its production by January to meet Ebola-related orders of about 1 million protective suits, plus hoods, foot coverings and gloves, the New York area-based company said. Company spokesman Jordan Darrow would not comment on any backlog.

In the United States, only four people had been diagnosed with Ebola beginning on Sept. 30 and one has died. But there have been dozens of scares, and firefighters, paramedics and other first responders must prepare for each case as if it were real.

Ebola can only be caught via the bodily fluids of someone with its symptoms. The virus — which can cause fever, vomiting, diarrhea and bleeding — is not airborne.

The International Association of Fire Fighters lobbying group has asked President Barack Obama to allocate more money for fire departments to train and equip first responders and to urge manufacturers to increase production of the gear.

Fire departments nationwide are ordering enough gear for all staff who could be exposed to Ebola instead of keeping a few suits available, said association official Patrick Morrison.

While they wait for orders to be filled, first responders are using existing equipment, including standard suits and gloves. But they worry that, unlike gear designed for Ebola, it may not protect them. The gear on hand also cannot be disinfected and reused, raising costs, Morrison said in a phone interview.

Orders for protective gear have also surged on eBay, likely including purchases from fearful, ordinary consumers, according to Aron Hsiao, a consultant at e-commerce market trend analyst Terapeak. Before Ebola arrived on U.S. soil, gear sales on eBay totaled less than $50,000 per month. The figure has since climbed to $250,000 a month.