Hantavirus and Ebola outbreaks carry with them familiar attendants in the US: extreme conspiracy theories about a planned pandemic, or “plandemic”, designed to upend midterms elections or push new vaccines or any one of a myriad of wild ideas.

Ebola, which the World Health Organization warned Friday is spreading rapidly in the Democratic Republic of the Congo and poses a “very high” risk at the national level. In the upside-down world of conspiracy theories it could be a bioweapon, a financial plot, or a scheme to extract national resources.

The Hantavirus outbreak, which began on a cruise ship in the South Atlantic, killing three passengers and causing at least 11 to test positive, carries its own set of baggage: passengers were crisis actors, or it was caused by Covid vaccines and Bill Gates, or perhaps it was an Israeli false flag operation and can be cured by the antiviral horse de-wormer ivermectin.

This is not new, though undoubtedly the ever-growing influence of social media and now AI slop, means that such ideas spread further and faster than ever before.

“This is very normal, and we should not be shocked that people are conspiracy theorizing,” said Dr Joseph Uscinski, an associate professor of political science at the University of Miami and author of a new book on the consequences of the Black Death that killed more than one third of Europeans in the 14th century.

“If people are paying attention to something, so are people who are conspiracy-minded, and they are going to interpret disease through that lens,” he adds. “Of course, there is going to be a conspiracy behind it and they’re going to blame people they already dislike.”

Uscinski points out that theories around hantavirus and Ebola are not much different than during Covid, Aids, or other virus outbreaks. During the previous Ebola outbreak in 2014, online posts – some picked up by Infowars’ Alex Jones – held that Ebola victims were returning as zombies. But that was during the fourth season of The Walking Dead.

“Whatever the disease, people are going to say there’s a conspiracy behind it, or that it’s not real and the vaccine is scam. It’s the same stuff done over and over,” Uscinski adds.

Currently such theories are especially strong on the right in the US.

On Jones’s network, one host, Harrison Smith, proposed: “If I was the bad guy, you know what I would do? I’d really release the hantavirus. I would really have an actually super deadly virus spreading from person to person, and then I would release a real vaccine.”

WHO’s chief scientist, Sylvie Briand, said on Friday that obeldesivir, an experimental Covid antiviral treatment developed by Gilead, could be used among Ebola contacts to prevent them ⁠from ​developing the disease.

The rightwing site Gateway Pundit, which included a “Contagion Emergency Kit”, suggested that hantavirus was “another plandemic” and a “transparent effort to terrorize Americans and swing the midterms against President Trump”.

Mikki Willis, who made the film Plandemic, about the conspiracy theory that the Covid pandemic was planned, said that “they are … gonna try this again” with hantavirus. According to the website Media Matters, which monitors the right wing in the US, numerous podcasters and social media figures have linked the twin viral outbreaks as a way of potentially disrupting the coming US midterm elections.

But claims that conspiracy theories are always rightwing are not entirely accurate. “When people conspiracy theorize they are almost always accusing a center of power, whether that’s pharmaceutical companies or the government,” Uscinski says.

Anti-fluoridation, a movement that opposes the addition of fluoride to public water supplies, exists in Portland, Oregon, and it does in Florida, but for different reasons: one group mainly thinks it’s a capitalist corporate plot; the other is anti-communist.

Same with vapor-trail conspiracies that started during the anti-Vietnam war protests. The Make America Healthy Again movement has also blended its political coloring from left and right.

“They can be political but not necessarily partisan – but they are always held by people who don’t trust the establishment,” Uscinski says. “Wherever you find conspiracy-minded people you’ll find conspiracies. The defining characteristic is not if they’re left or right, but that they’re raging conspiracy theorists.”

But, ironically for anti-government conspiracists, it is attacks on state power that are actually harming the response to the viruses.

US engagement in curbing the current Ebola outbreak is hampered by massive cuts to global public health efforts, including the dismantling of the US Agency for International Development (USAID) and research cuts at US health agencies, including the Centers for Disease Control and Prevention.

Last week, US secretary of state Marco Rubio and WHO chief Tedros Adhanom Ghebreyesus clashed on US international engagement after Rubio said the agency was a “little late” in identifying the Ebola outbreak in DRC.

Middle Ages historian Thomas Asbridge, author of The Black Death, argues that the response to hantavirus, Ebola, Covid and the 14th century plague share common characteristics.

Asbridge points out the Black Death came during financial and climate crises – the collapse of the Florentine gold-backed economy and the onset of the Little Ice Age.

“That is a quite similar context to what we have been experiencing in the early part of the 21st century,” he says, pointing to the economic financial crisis of 2008 and human contact with animals carrying zoonotic pathogens that jump across species.

So too does confusion over precisely how to respond – something not helped by hostility to government or confusion over officials sometimes mixed messaging. In response to identification of the Andes strain of hantavirus onboard MV Hondius, officials initially offered contradictory information about whether it was spread by rodent dropping or could by close human-to-human contact. During Covid, people were first advised to wash food, and there were questions over whether it was airborne and the distance it could travel, and how long you could be in a space with someone.

And amid the natural confusion of dealing with a virus, conspiracy theorists only add to the problem – which remains a very real one.

“We might be much slower to accept and respond appropriately to what’s required,” Asbridge says. “We’re absolutely right to be alarmed and cautious about Ebola and hantavirus. Hopefully we will be lucky this century.”