At least two US states have reported outbreaks of child pneumonia cases amid fears around a similar illness that is spreading in China and Europe.

The Warren County Health District in Ohio recorded an ‘extremely high number of pediatric pneumonia cases’ since August. The number, 142, is above the county average and meets the department’s definition of an outbreak.

‘We do not think this is a novel/new respiratory disease but rather a large uptick in the number of pneumonia cases normally seen at one time,’ stated the health district on Wednesday.

The outbreak in Ohio comes as some parts of China have seen a surge in pneumonia cases in children. The mysterious illness has jammed hospitals and resulted in long wait times for patients to be seen.

The World Health Organization (WHO) has requested from China ‘additional  epidemiologic and clinical information, as well as laboratory results’ around the cases, the Wall Street Journal reported.