Diseases which could "shatter" civilisation if they were to begin spreading have been identified in a new report.
The 16 illnesses have emerged in countries across the world and have the potential to trigger a new pandemic, it has been claimed.
While some are well known to those in the West, such as E. coli and HIV, others are less known but just as deadly, with one causing bleeding from orifices and another brain swelling.
The diseases have been highlighted in a report published by the Coalition for Epidemic Preparedness Innovations (CEPI), an organisation founded by the Bill and Melinda Gates Foundation, the Wellcome Trust, and several nations.
The document warns: "Covid-19 is just one of many diseases with pandemic potential.
"More than 1.6 million yet to be discovered viral species from these virus families are thought to exist in mammal and bird hosts.
"And any of these could be the next Covid, or worse."
Highlighted in the report are coronaviruses other than Covid-19, which could rip through the world's populations with even deadlier consequences.
It warns: "The emergence of a coronavirus combining the transmissibility of Covid-19 with the lethality of SARS or MERS would be civilisation-shattering."
Other diseases could make a deadly comeback, according to CEPI, such as HIV and Ebola in Africa.
One of the conditions on the list shares similar qualities to the Bubonic Plague, which was passed to humans from the fleas on rats.
Lassa fever is passed from rodents to rats and can result in facial swelling, bleeding from the mouth, nose, eyes and vagina, and seizures in severe cases.
Last year the condition, which leads to a quarter of surviving patients temporarily losing their hearing, claimed 144 lives in Nigeria and has a fatality rate of about 1 in 100.
Currently there is no known cure or vaccine, with isolating patients, staying away from rodent droppings and getting a cat the best hope people have.
Another lesser known disease, Cryptosporidiosis, has already had a minor outbreak in the UK.
The diarrhoea disease, which is caused by microscopic parasites, lives in the intestines of humans and animals but can survive outside the body for long periods of time, including in swimming pools and hot tubs.
A cluster of cases of the disease, which can be particularly harmful to children, was seen in the West Midlands in 2016.
If it is left untreated in patients with weakened immune systems it can become chronic and even fatal.
Another disease to watch out for is Nipah, which is bat-borne and has had outbreaks in South-East and South Asia.
The neurological disease causes severe brain swelling, seizures and vomiting and has a fatality rate as high as 70%.
Other fatal diseases include Whitewater Arroyo virus which was thought not to be able to pass to humans until it killed three women in Calfornia, including a 14-year-old girl.
