Doctors have discovered their first lead in figuring out what is causing the deaths of an alarming amount of children in Cambodia. We alerted you to the story of the mystery illness that claimed the lives of at least 61 children in the country on Friday. Most were dying within 24 hours of entering the hospital with respiratory and neurological problems, while the rest were only lasting about three days. Medical experts couldn't figure out what the problem was, but it seemed to only affect children.

Now, doctors have discovered at least one disease plaguing the children, though there could be more. CNN reports the Institut Pasteur in Cambodia discovered 15 of 24 patients tested came back positive for Enterovirus Type 71, a strain of hand, foot and mouth disease that can cause severe neurological problems for children. Adults' more developed immune systems are usually able to fight it off, but a child's immune system is still vulnerable enough for the disease. 

But the EV71 diagnosis still doesn't answer for the respiratory problems bothering the children. A WHO official warned that more analysis is needed. "We have now to see what really is causing the deadly pulmonary complication and see if a toxic factor is playing a role too," explained Dr. Beat Richner, who works at the Kantha Bopha hospital where most of the patients have been treated. This Al-Jazeera report says Richner thinks bad prescriptions from local hospitals could be a factor. "All these children have encephalitis [inflammation of the brain] and in the later hours of their life they develop a severe pneumonia with a destruction of the alveoli in the lungs. That is the reason they die," Richner said.