Mystery 'Disease X' probed after killing 79 people in Congo

Health officials in the Democratic Republic of the Congo expect to know within days the cause of an infectious disease outbreak termed 'Disease X' that's sickened hundreds of people and killed at least 79, since late October.

Almost 200 of the 376 afflicted with a flu-like illness are younger than five years, said Jean Kaseya, director of the Africa Centres for Disease Control and Prevention. Cases of fever, headache, cough, difficulty breathing, and anaemia were first reported on Oct. 24 in the Panzi health zone in the southwestern province of Kwango, with national authorities alerted on December 1.

"We have a delay of almost five to six weeks, and in five to six weeks so many things can happen,"  Kaseya said Thursday on a weekly call with reporters. "Ongoing testing will help us to understand what the issue is."

The disease emerged at a time of increased influenza circulation, and the culprit is likely to be airborne, said Dieudonne Muamba, director general of the National Public Health Institute. Patient specimens are being analyzed at a national lab in Kinshasa, some 500 kilometres (311 miles) from the outbreak zone.

Tests may be completed within 48 hours, with results released at the weekend, officials said.

The outbreak has renewed concerns about the emergence of a new pathogen with the potential to spread across the world just a few years after Covid-19 forced countries to shut down borders and brought economic and social activities to a standstill.

Earlier this year, the spread of a new strain of mpox prompted the World Health Organization to declare the disease a public health emergency of international concern, though the virus' spread out of Africa has remained sporadic.

Africa CDC is supporting Congolese officials with epidemiologists, laboratory scientists and infection prevention and control experts, Kaseya said, adding that the outbreak highlights challenges in detecting diseases across the sprawling nation, where numerous deadly outbreaks occur concurrently.

"This is why we are supporting the country to build strong capacity on surveillance,"  he said.

The WHO has also deployed experts, essential medicines, and diagnostic and sample collection kits to Kwango, helping authorities understand its modes of transmission, it said in a statement Friday. So far, the disease has been reported in seven of the 30 health zones in the remote province.

While a respiratory pathogen is being investigated as a possible cause, so are diseases such as malaria and measles, among others, the WHO said.

Health authorities in Hong Kong said late Thursday that they will tighten screenings at the airport for visitors arriving from Johannesburg and Addis Ababa, the two African transit hubs that could ferry travellers from the Democratic Republic of Congo. In Japan, the foreign ministry also advised people against unnecessary travel to the region affected by the outbreak.