He will urge fellow world leaders to "wake up" to the threat posed by such diseases at the G7 summit in Germany.
The UK will "lead the way" with a team of "disease detectives" on permanent standby to fly anywhere in the world to identify new infections, he will say.
He will also warn each fresh disease risks being harder to contain.
Last year's outbreak of Ebola in west Africa infected 27,000 people and killed 11,130 in Sierra Leone, Liberia and Guinea.
The World Health Organization (WHO) was widely judged to have been ill-equipped when Ebola first hit.
At the annual G7 meeting in the Bavarian Alps, German Chancellor Angela Merkel is expected to call for a shake-up of the organisation and the way it responds to pandemics.
Mr Cameron will also announce Â£20m of government money for a new vaccine research network to bring together pharmaceutical companies, academics and disease experts to focus on the most serious global health threats.
"The recent Ebola outbreak was a shocking reminder of the threat we all face from a disease outbreak," said Mr Cameron.
"Despite the high number of deaths and devastation to the region, we got on the right side of it this time, thanks to the tireless efforts of local and international health workers.
"But the reality is that we will face an outbreak like Ebola again and that virus could be more aggressive and more difficult to contain.
"It is time to wake up to that threat."
He said a "reservist force" would also be created including hundreds of doctors, nurses and public health experts ready for call-up if the outbreak was not contained at an early stage.
The meeting of world leaders is expected to be dominated by the Ukraine crisis, amid fears Russian President Vladimir Putin is deliberately building up further military pressure in eastern Ukraine.
Mr Cameron is expected to join forces with US President Barack Obama to press for sanctions on Russia to be extended.
Current EU sanctions are due to expire at the end of July.
Greece's debt crisis and how to tackle global warming are also likely to be on the agenda.
On Saturday, Mr Cameron called for a global crackdown on the "cancer" of corruption in the wake of Fifa bribery allegations.
Mr Cameron is expected to have a bi-lateral meeting with Mr Obama later.
Prime Minister David Cameron is to unveil plans for a rapid reaction force of UK medical experts to respond to future pandemics like Ebola.