Hong Kong has stepped up precautions over the Ebola outbreak in the Democratic Republic of Congo (DRC) and Uganda, as the World Health Organization (WHO) declared the epidemic “a public health emergency of international concern.”

The WHO said on Sunday that there had been 246 suspected cases and 80 suspected deaths in the DRC as of Saturday, in addition to a handful of apparent cases in Uganda.

The outbreak was caused by the Bundibugyo virus disease, and there is currently no vaccine.

There are no confirmed cases in Hong Kong, but the Centre for Health Protection (CHP) has enacted a series of precautionary measures, according to a government press release on Sunday.

Although there are no direct flights from the affected areas, “the CHP will strengthen health screening for passengers arriving on flights from Africa at the airport… Suspected cases will be immediately referred to public hospitals for isolation and treatment.”

It will also bolster public awareness and health education efforts, and provide airlines, doctors and hospitals with updated information.

The CHP advises against visiting affected regions.

Highly lethal

Ebola is transmitted to humans through close contact with the blood, secretions, organs, or other bodily fluids of infected animals.

The virus is highly lethal and causes haemorrhagic fever, systemic inflammation, and multi-organ failure. The case fatality rates from past outbreaks range from 25 to 90 per cent, according to the WHO – the average is 50 per cent.

Meanwhile, Médecins Sans Frontières (MSF) is preparing a large-scale response to the outbreak, the humanitarian charity said in a press release on Sunday.

“The number of cases and deaths we are seeing in such a short timeframe, combined with the spread across several health zones and now across the border, is extremely concerning,” said MSF Emergency Programme Manager Trish Newport. “In Ituri, many people already struggle to access healthcare and live with ongoing insecurity, making rapid action critical to prevent the outbreak from escalating further.”

The NGO is mobilising more teams comprising medical, logistical, and support staff experienced in responding to viral haemorrhagic fever outbreaks, it said.

An infectious disease specialist has called on Hong Kong authorities to step up rodent checks, despite confirmation that no residents from the city were on board the hantavirus-hit cruise ship in the Atlantic Ocean.

Speaking on an RTHK programme on Friday, physician and infectious disease specialist Dr Joseph Tsang said the Agriculture, Fisheries and Conservation Department (AFCD) should conduct regular monitoring of rats.

“The AFCD should conduct regular monitoring to test whether rats in the environment carry viruses,” he said.

The Centre for Health Protection (CHP) previously issued a statement on Thursday, saying there were no Hong Kong residents on the hantavirus-stricken cruise ship, which carried 147 passengers and crew members.

The CHP also said that, as of Wednesday, no infections had been reported in Hong Kong.

According to the World Health Organization (WHO), as of Thursday, there were eight reported cases linked to the MV Hondius, including three deaths. Five of the eight cases have been confirmed as hantavirus.

‘Cannot let our guard down’

Hantavirus is primarily transmitted through direct contact with the faeces, saliva or urine of infected rodents, or by inhaling aerosolised particles of their waste, according to the CHP. Human-to-human transmission is relatively rare, and there is currently no vaccine to prevent infection.

The risk to global health posed by the cruise ship incident is low, the CHP added, citing the WHO.

Tsang said that, despite the low risk, he still urged cleaners to be aware of the dangers.

“I wouldn’t say the risk of infection in Hong Kong is especially high, but we cannot let our guard down,” the physician said.

“Hantavirus is usually concentrated in places with more rats, such as refuse collection points, rear stairwells, or the back alleys of restaurants. Sanitation workers should take particular care.”

Dengue fever poses a “moderate” risk to Hong Kong, a health official has said after the city recorded its first local case of the infection this year.

Albert Au, head of the Centre for Health Protection (CHP), said in an RTHK radio programme on Wednesday that rising temperatures and the imminent rainy season made environments more favourable for mosquito breeding.

“The infection rate for mosquito-borne diseases in Southeast Asia and neighbouring regions remains high,” Au said in Cantonese. “So we think the risk of an outbreak cannot be neglected.”

Hong Kong is investigating a local case of dengue fever after a 21-year-old man, who had not travelled outside the city lately, tested positive for the dengue virus.

According to a government statement on Tuesday, the man developed symptoms including fever and a rash last week, and is currently in stable condition in hospital.

He told authorities he had recently been bitten by mosquitoes near a construction site in Penny’s Bay on Lantau, where he works.

Environmental inspections showed there were “multiple sites conducive to mosquito breeding” there, including drainage channels with weeds and leaves, as well as stagnant water, the statement read.

The man lives at Tai Wo Estate in Tai Po. The CHP has set up a consultation booth at the estate to provide health assessments and dengue fever antibody tests for people with symptoms.

12 imported cases this year

So far, 12 other cases of dengue fever have been recorded this year, all of them imported.

Dengue fever, a viral infection transmitted to humans through mosquito bites, is most commonly recorded in warmer climates, according to the World Health Organization (WHO).

Most people experience mild or no symptoms, although severe cases – often caused by multiple infections – can lead to death.

Au said there might have been undiagnosed imported cases of dengue fever in the community that transmitted the virus locally. However, authorities have not found epidemiological links between the man’s case and other previously recorded imported cases.

In 2025, the city recorded 59 cases of dengue fever, all imported. In 2024, there were 161 cases, five of which were local.

According to the government statement, the 21-year-old’s household contacts and workers at the construction site are so far asymptomatic.

Members of the public are advised to inspect their homes and prevent water accumulation to remove potential mosquito breeding grounds.