It was not known whether the WHO figure included five Al Ain Rescue workers who had direct contact with Esporlas before his death and are in precautionary quarantine.
WHO said it had been informed of the 10 new cases by UAE health authorities.
However, in a statement released through the state news agency Wam, the Health Authority Abu Dhabi (Haad) said it had identified an additional three cases after screening healthcare workers in Al Ain.
Officials at Haad refused to comment on the discrepancy in the figures.
In its statement to Wam, Haad said the three new cases displayed no symptoms, but preventive measures had been taken to keep them in quarantine.
“From previous asymptomatic cases in the UAE, individuals tend to clear the virus themselves within 10-14 days, but are kept in isolation in hospital during this time,” the authority said.
Haad said there was no public-health concern and it was coordinating with the Ministry of Health and other authorities, taking measures recommended by WHO to screen anyone who had come in contact with a confirmed case.
WHO said it had been informed of the 10 new cases on Sunday and Monday but was not issuing any special recommendations.
“We would need more information to understand the background to the new cases,” said spokesman Gregory Hartl.
The new cases bring the global Mers total to 238 infected, with 92 deaths.
Dr Asiim Malik, a consultant and the head of infectious disease at Mafraq Hospital, said the new cases were no cause for concern.
“I think people probably get so scared,” he said. “When they see a cluster, they think it is an outbreak. But as long as people take good care of their hygiene and turn to advice from the proper authorities and the experts, I do not think anyone should panic.”
He said healthcare workers needed to strictly adhere to the health and safety guidelines and protocols already in place.
“We know that healthcare workers are on the front line for any kind of communicable disease,” he said. “If they want to mitigate that risk they must follow the guidelines. Those people who are treating or transporting patients … they have had the training.
“This has to be 100 per cent compliance for the health-care workers to protect themselves and to protect others, so that is what I am urging.”
Mers is still an emerging disease, said Dr Malik, and questions about it remain.
“This is a new disease,” he said. “We can only share what we know, we cannot tell people what we don’t know. Things are under control. For us, we work every day with these people so we are the front line. All we are trying to tell people is that it’s business as usual for us. Nothing has changed.”
Haad’s most recent statement repeated advice from earlier in the week on how to prevent the spread of respiratory illnesses. This includes washing hands in soapy water for 20 seconds, covering the mouth when coughing or sneezing, and avoiding close contact with anyone complaining of flu-like symptoms.
It said it was imperative to follow advice about the illness released by the Ministry of Health and other local health authorities.
The ministry has said no travel bans, port screenings or trade restrictions had been put in place as a result of Mers, but it was monitoring the situation closely to ensure the health and safety of all.
The virus emerged in Saudi Arabia in 2012 and cases of Mers have been confirmed in the UAE, Saudi Arabia, Qatar, Kuwait, Bahrain, Oman, Britain, France, Germany, Italy and Tunisia.
Travellers who have been to the Middle East who develop flu-like symptoms should be tested for the virus, WHO advises.