It sounds more like a viral encephalitis. It can be from toxins, but, are there blood samples to check for parasites, bacteria or virus.

Every tenth villager of Kazakhstan's Kalachi (click here) has unexpectedly fallen asleep in broad daylight – some unable to wake up for several days. Despite numerous attempts to find the cause of the inexplicable disorder, the Sleepy Hollow riddle remains unsolved.

Over 600 residents of Kalachi village in Kazakhstan's north may have never read Washington Irving's 'Legend of Sleepy Hollow,' or watched the popular American TV series or film – but they refer to their homeland as "Sleepy Hollow," as everyone there is scared of an indiscriminate illness that has no cure....

The children witnesses stated there was a mine with smoke coming from it and the wind was carrying the smoke toward them and then the wind changed. They then reported six of the children succumbed to sleep afterwards.

If there are airborne toxins then close the mine and seal it to prevent further problems.

...Symptoms (click here) that might require emergency treatment include loss of consciousness, seizures, muscle weakness, or sudden severe dementia....

The young child brought home from a visit to the doctor is reported to be acting strange. The child appears to be agitated. Brain damage of any kind can result in permanent changes in behavior. So, while the illness seems benign as it isn't causing death yet, there appears to be some long lasting symptoms that may even be permanent. The slightest encephalitis can't simply be disregarded as an inconvenience and the common cold.