Nigeria’s first confirmed Ebola patient in more than a decade is believed to have contracted the virus while travelling in Uganda, although health authorities are yet to establish the source of her infection.

According to a report by Reuters, the Swiss Federal Department of Foreign Affairs told the newspaper in an emailed statement on Thursday that the patient, a Ugandan-born woman married to a Swiss diplomat based in Abuja, has been receiving treatment at a private clinic in the Nigerian capital for about a week.

According to Reuters, the statement said the woman was believed to have contracted the virus during a visit to Uganda about two weeks earlier. Her husband, who travelled with her, is in isolation but has not developed symptoms.

However, the World Health Organisation (WHO) and the Africa Centres for Disease Control and Prevention (Africa CDC) said they had not received verified information that the woman travelled to the Democratic Republic of the Congo (DRC), where the current Ebola outbreak began.

Conflicting travel accounts

According to Reuters, Ugandan authorities had earlier said the woman travelled to eastern DRC before transiting through Uganda.

However, Africa CDC official Wessam Mankoula said on Thursday that there was no validated information confirming that the patient had travelled to the DRC.

Mr Mankoula said Nigeria and Uganda were exchanging information to reconstruct her travel history and identify the possible source of infection.

WHO representative to Nigeria Pavel Ursu said the information received by the agency indicated that the woman had been in Uganda from 16 September and returned to Abuja on 3 October.

The WHO official said the information available to the agency did not establish that she had travelled outside Uganda.

Patrick Otim, a WHO emergency response manager, also said the source of the infection remained unknown as investigators worked to establish the patient’s movements before she became ill.

One area of investigation is the health facilities the woman visited in Abuja after developing symptoms and before she was hospitalised, including the possibility of exposure to other people during that period, he said.

Meanwhile, the Ugandan government said that the country had no active Ebola cases.

Uganda recorded 20 Ebola cases between May and June, most of them linked to infections imported from the DRC. The WHO declared the country’s outbreak over in August after 42 days without a new confirmed case.

Nigeria’s response

The uncertainty surrounding the woman’s travel history comes as Nigeria works to prevent further transmission following confirmation of the imported infection on 20 October.

As PREMIUM TIMES reported, the patient is a 42-year-old woman who lives in Abuja and recently travelled to Uganda. She developed symptoms on 6 October, three days after returning to Nigeria, and initially sought treatment at a private hospital, believing she had malaria.

She later visited another private hospital, where she was admitted on 11 October after her condition failed to improve. Her infection was subsequently confirmed through laboratory testing.

PREMIUM TIMES also reported that health authorities had identified 44 people who might have been exposed to the patient, including healthcare workers, patients, caregivers and travel contacts.

The government has begun contact tracing and is working with international partners to establish the woman’s movements and identify anyone who may have been exposed.

The WHO has urged Nigerians to remain calm, explaining that one confirmed imported case does not, by itself, mean the country is experiencing an Ebola ‘outbreak’. The agency is supporting Nigeria with case investigation, laboratory testing, contact tracing and infection prevention measures.

Regional outbreak

Nigeria’s case comes amid an Ebola outbreak that was declared in the DRC in May and has spread to other African countries, raising concerns about cross-border transmission.

The outbreak is caused by the Bundibugyo virus, a species of Ebola virus for which there is currently no licensed vaccine.

Kenya has also reported cases linked to the movement of the virus across borders, adding to concerns about the challenges of tracing infections among international travellers.

Ebola spreads through direct contact with the blood or other bodily fluids of an infected person, or with contaminated materials. Symptoms may include fever, headache, weakness, vomiting and diarrhoea.

According to a BBC report, French health authorities said it was an “exceptional case in a severely immunocompromised patient” and there was currently no risk to the public.

Shav is a disease that primarily affects cattle and can be spread by infected midges. Cases have also occurred in sheep, goats, alpacas and horses, but infections in people were previously unheard of.

The World Health Organisation (WHO) and European Centre for Disease Prevention and Control (ECDC) said they were monitoring the situation, with French officials still investigating how the virus had spread to a human.

In a post on his official X account, WHO Director-General, Tedros Ghebreyesus, said the agency was working with French authorities to establish the source of the infection, possible routes of transmission and any potential public health risks.

Mr Ghebreyesus said the French patient was in an area where the Shamonda virus was circulating in animals and where Culicoides midges were also present.

“WHO is in contact with French authorities who are collecting information to better understand the source of infection in the first human patient, possible routes of transmission and any potential risk to public health,” he said.

What is Shamonda virus?

Shamonda virus primarily affects animals, particularly cattle, and spreads between animals through the bites of infected Culicoides midges, small biting insects. It has also been detected in sheep, goats and horses.

The virus was first identified in Nigeria in the 1960s and has circulated in parts of Africa and Asia for decades without any previously documented human infection.

French authorities believe the patient may have contracted the virus through a midge bite in eastern France, where infections had been detected in animals during the spring and summer.

The patient was receiving treatment for a ‘serious’ illness at a hospital in Lyon when he/she developed neurological complications that preliminary findings suggested were very likely linked to the virus.

Investigations are continuing to determine how the infection occurred and whether the virus contributed to the patient’s death.

Emerging disease concerns

The development comes amid international attention to other infectious disease threats this year, including hantavirus and Ebola.

Hantavirus is a group of viruses primarily transmitted to humans through contact with infected rodents or their urine, droppings and saliva. Depending on the strain, infection can cause severe respiratory illness or affect the kidneys.

In May, a cluster of hantavirus infections linked to a cruise ship prompted an international response after three people died among 13 reported cases. The outbreak was declared over in July.

Ebola, meanwhile, causes a severe illness that can include fever, vomiting, diarrhoea and, in some cases, internal or external bleeding. The disease spreads through direct contact with the blood or other bodily fluids of infected people and contaminated materials.

Nigeria confirmed an imported case of Ebola caused by the Bundibugyo virus in the Federal Capital Territory on 20 October, following an outbreak that began in the Democratic Republic of the Congo (DRC) and spread to other countries.

The WHO has said the Shamonda virus case appears isolated based on current evidence, although investigations into how the patient became infected and the potential public health implications are continuing.