Ebola có thể đã lây lan ra ngoài châu Phi. Các cơ quan y tế đang phản ứng như thế nào?

The latest Ebola outbreak is showing no signs of slowing.

On April 24, the first suspected case of the rare Bundibugyo strain of Ebola was detected in the Democratic Republic of the Congo (DRC) . On May 17, the World Health Organisation declared the outbreak a “Public Health Emergency of International Concern”.

The current Ebola outbreak is the third-largest in world history, with 906 suspected cases and 223 deaths in the DRC alone as of 27 May.

And it may have spread to other continents. Health authorities are now investigating a suspected case in Italy, and two possible cases in Brazil. All three are believed to be travellers returning from either the DRC or Uganda. One American man who tested positive for Ebola is currently being treated in Germany.

As concerns grow, the Coalition for Epidemic Preparedness Innovations has committed more than A$86 million in funding to fast-track the development of three potential vaccines, targeting the Bundibugyo strain.

But in the meantime, could this outbreak spread further? And how concerned should we be?

A deadly virus

Ebola is a rare but potentially fatal virus that mainly spreads through direct contact with the bodily fluids – such as blood, faeces and vomit – of an infected person.

Early symptoms of Ebola include sore throat, headaches, fever, fatigue and body pain. Severe Ebola cases can cause skin rashes, shortness of breath, vomiting, diarrhoea, abdominal pain and seizures.

Ebola was first identified in humans in 1976. Since then, there have been more than 40 outbreaks around the world, with the majority occurring in African countries.

The current outbreak is the third ever to be caused by the rare Bundibugyo strain. The majority of past outbreaks were driven by the more deadly Zaire strain, which kills up to 90% of people compared to up to 34% for Bundibugyo.

What is driving this latest outbreak?

The factors driving this latest outbreak also contributed to the devastating West African outbreak of 2014-16, where more than 11,000 people died.

In both outbreaks, the virus had been circulating for months before an outbreak was declared, and initial cases had non-specific symptoms.

Both outbreaks also rapidly spread in urban areas. Transmission in health-care settings is another common factor.

Political instability and social unrest also contributed to both outbreaks. Most recently in the DRC, crowds have set fire to hospital tents, prompting some patients to flee isolation wards.

And certain cultural practices – including traditional burial rituals that often involve handling dead bodies – may have accelerated the spread of both outbreaks.

How it crossed continents

Similar to the West African outbreak, this latest Ebola outbreak has spread to other continents through travel.

Nine cases and one death have already been reported in Uganda, which shares a border with the DRC.

An American man who tested positive for Ebola while working in the DRC, is in a stable condition after being treated in Germany.

In Italy, authorities are monitoring a traveller who recently returned from the DRC to the city of Cagliari.

According to some reports, Brazilian authorities are investigating two suspected Ebola cases. They are believed to be two travellers, one who returned from the DRC to São Paulo and the other from Uganda to Rio de Janeiro.

Importantly, both suspected cases have been diagnosed with other illnesses. The São Paulo patient presented with fever and was later diagnosed with severe meningitis. The Rio de Janeiro patient tested positive for malaria after developing a cough, chills and diarrhoea, but has since tested negative for Ebola.

So for now, no Ebola cases have been confirmed in Brazil. But these suspected cases have prompted the country to activate its Ebola safety protocols, including patient isolation, laboratory testing, and epidemiological investigations.

Meanwhile, several countries have imposed travel restrictions to prevent Ebola from reaching their shores.

Both the United States and Canada are temporarily restricting entry for travellers from the DRC, Uganda and South Sudan. The US and other countries such as India and Mexico are also strengthening public health screening and disease monitoring measures, particularly at airports. Some countries have mandated a 21-day quarantine period for their citizens returning from the DRC.

Could it spread further, including to Australia?

At this stage, the risk of Ebola reaching Australia is very low.

Australia has not put in place any travel or quarantine requirements for affected countries, but federal health minister Mark Butler says authorities are still monitoring the outbreak “very closely”.

Based on lessons from past outbreaks, there are three main ways the current Central African outbreak could play out.

Without effective control measures, cases may surge in the coming months. Some models suggest that by mid-May, up to 1,000 cases had already occurred in the DRC, compared to official figures of about 900 cases. So the actual number of Ebola cases may be much higher than authorities realise.

In a more favorable scenario, a strengthened public health response could bring this latest outbreak under control. This would be possible with continued support from the international community, the rapid development of vaccines and community engagement.

However, the most realistic outcome is cases will continue to rise before authorities successfully contain the current outbreak.

Nevertheless, the international community responded much more swiftly to this outbreak, particularly compared to the devastating 2014-16 West African outbreak. That alone may protect us from an outbreak of the same catastrophic scale and cost.

Holly Seale receives funding from the National Health and Medical Research Council and NSW Health. She has previously received funding from Pfizer to present at international conferences.

Abrar Ahmad Chughtai and Md Saiful Islam do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.