The Democratic Republic of the Congo has faced the deadly threat of Ebola 16 times since the virus was discovered there in 1976, with a 2018-20 outbreak killing almost 2,300 people. On Sunday, the World Health Organization declared the 17th outbreak to be a public health emergency of international concern. So far, 139 suspected deaths and almost 600 suspected cases of the haemorrhagic fever virus have been identified, nearly all in the DRC’s north-eastern provinces of Ituri and North Kivu, with two cases in Uganda of people who had travelled from the DRC.

There is also anxiety about neighbouring South Sudan. The WHO fears the disease has been spreading for a couple of months and, given the highly mobile population, warns that it could take months more to bring it under control. While it judges the risk of global spread to be low, it thinks the regional risk is high.

The Bundibugyo virus responsible for the DRC cases is believed to be less deadly than more common Ebola strains such as the one that killed 11,000 people in the 2014-16 west African outbreak. But one study suggested that it still kills around a third of those infected, and there are no licensed vaccines or approved treatments, though some are in the pipeline. Its rarity may also have contributed to how long it took to be detected, with authorities initially testing for other strains.

Yet human choices shape disease outbreaks as much as the characteristics of the pathogens themselves. The eastern DRC has endured years of armed conflict, with a surge over the last year. War makes it harder to reach communities, forces displaced people into often crowded and insanitary conditions, and reduces access to healthcare. Too often – including in Ituri – combatants attack health facilities. Beleaguered communities receiving minimal support distrust the authorities and those sent by them, including health workers. Overcoming that requires not only sensitivity to local beliefs, customs and concerns, but also a surge in provision, with medical teams providing routine healthcare and vaccinations to establish trust and facilitate the creation of Ebola treatment centres.

Medical workers in the region have expertise and experience – they don’t need international teams flying in, but adequate resources. Instead, the slashing of aid budgets by Donald Trump and leaders in the UK and elsewhere has had punitive effects. The International Rescue Committee says that it had to cut its health and outbreak preparedness areas in eastern DRC from five to two because of US cuts, affecting everything from disease surveillance to the provision of handwashing stations and latrines. It blames the funding reduction directly for the delayed detection of the virus. US criticism of the WHO’s response as “a little late” is rich from an administration that withdrew from it, taking away the body’s biggest pot of funding.

International governments are now offering emergency-response funding. While that is essential, keeping deadly diseases under control depends on consistent support for those on the frontline and for expertise and monitoring internationally. A Global Preparedness Monitoring Board report published on Monday warned that infectious disease outbreaks are becoming more common due to the climate crisis and war, while geopolitical fragmentation is weakening collective responses. The DRC’s outbreak should remind us all that our choices have long-term consequences.