A British healthcare worker with Ebola is being evacuated from the Democratic Republic of the Congo to the UK for medical treatment, it has been confirmed.

“A British citizen currently in the DR Congo has tested positive for Ebola,” a spokesperson for the UK government said in a statement on Wednesday. “The UK has well-established procedures for dealing with cases like this, and those processes have been activated … The risk to the UK public from Ebola remains low.”

The patient, whose identity is unknown, is in a stable condition and is expected to arrive in the UK on Wednesday or Thursday before being transferred in a specialist ambulance to a “high consequence” infectious disease unit, according to an official document seen by Reuters.

A humanitarian organisation sent the worker to DR Congo to help in the response to the outbreak, which is the second largest on record. It is the first case involving a British national contracting Ebola in the current outbreak.

The Royal Free hospital in London has a high-level isolation unit for infectious diseases such as Ebola; other centres are in Newcastle and Liverpool.

Ebola is a highly contagious, severe and often fatal illness. It is spread through direct contact with body fluids such as the blood or vomit of infected people, or dead bodies.

The current outbreak, declared on 15 May by DR Congo’s health ministry, has surpassed 10,000 cases, and 5,000 deaths. It is the 17th in DR Congo since Ebola was identified, was caused by the Bundibugyo virus, and has become the largest and deadliest in the country’s history. The Bundibugyo virus has no approved treatment, though vaccine trials are under way.

Since the outbreak started, it has spread to Kenya and Uganda in east Africa, while last month Nigeria confirmed a case in the capital, Abuja, after a woman who arrived from Uganda tested positive for the virus. She, along with a close contact, were evacuated to Switzerland for treatment.

In an interview with the Guardian last month, Dr Jean Kaseya, the director general of the Africa Centres for Disease Control and Prevention (CDC), said the “unprecedented” spread of the Ebola outbreak meant it could reach the UK and other countries.

“We want all countries to know that they are not safe if they don’t take appropriate measures,” he said. “Each country, not only in the African region, but all continents, must now increase the preparedness level and the possibility for treatment.

“It is the first time three African regions have been affected [by Ebola]. The geographic extension of this outbreak is unprecedented.”

British health authorities say the risk ⁠to the wider public from imported Ebola cases remains low and the NHS has procedures in place to manage suspected and confirmed infections.

There have only been four confirmed cases recorded in Britain since 1976, ‌according to the UK Health Security Agency.