A logo is pictured on the World Health Organization (WHO) headquarters in Geneva, Switzerland, November 22, 2017.
A logo is pictured on the World Health Organization (WHO) headquarters in Geneva, Switzerland, November 22, 2017. Reuters / DENIS BALIBOUSE

Outbreaks of endemic diseases such as monkeypox and lassa fever are becoming more persistent and frequent, the World Health Organization's (WHO) emergencies director, Mike Ryan, warned on Wednesday.

As climate change contributes to rapidly changing weather conditions like drought, animals and human are changing their behaviour, including food-seeking habits. As a result, "ecologic fragility" diseases that typically circulate in animals are increasingly jumping into humans, he said.

"Unfortunately, that ability to amplify that disease and move it on within our communities is increasing - so both disease emergence and disease amplification factors have increased."

For instance, there is an upward trend in cases of Lassa fever, an acute viral illness spread by rodents endemic to Africa, he said.

"We used to have three to five years between Ebola outbreaks at least, now it's lucky if we have three to five months," he added.

"So there's definitely ecological pressure in the system."

His commentary comes as cases of monkeypox continue to rise outside Africa, where the pathogen is endemic.

On Wednesday, the WHO said it had received reports of more than 550 confirmed cases of the viral disease from 30 countries outside of Africa since the first report in early May.

Meanwhile, although COVID-19 cases are declining globally, there are regions such as the Americas with concerning trends, WHO director-General Tedros Adhanom Ghebreyesus highlighted in a briefing on Wednesday.

The experience of COVID has triggered the WHO to kickstart a process to draft and negotiate an international treaty to strengthen pandemic prevention, preparedness and response.

Pandemics, like climate change, affect every citizen on the planet, said Ryan.

"We've seen the difficulties we faced in this pandemic - we may face a more severe pandemic in the future and we need to be a hell of a lot better prepared than we are now," said Ryan.

"We need to establish the playbook for how we're going to prepare and how we're going to respond together. That is not about sovereignty. That's about responsibility."