Health checks have begun at a major US airport following an outbreak of the highly infectious Ebola virus in parts of Africa.

The US Centres for Disease Control and Prevention (CDC) commenced screening selected travellers at Chicago’s O’Hare International Airport on Wednesday, May 20 as health authorities tackle the outbreak.

The move follows the CDC’s announcement just days earlier that any US passport holder who has travelled to the Democratic Republic of Congo, Uganda or South Sudan within the previous three weeks will be prohibited from entering the country. The restriction will remain in place for at least 30 days, according to an order issued by the CDC on Monday.

Ebola is a highly infectious illness transmitted through contact with bodily fluids. It often causes fatal haemorrhagic fever, rapid multi-organ failure and internal or external bleeding.

“Ebola is one of the most infectious diseases out there. I’m not an alarmist, but I’m very concerned,” said CEO of Wellness Equity Alliance, Dr Tyler Evans.

Ebola cases continue to proliferate across parts of East and Central Africa, with the World Health Organization (WHO) having declared the outbreak a public health emergency of international concern.

At least six Americans are reported to have been exposed to Ebola.

An American doctor who contracted Ebola in the DRC has been transported to Germany for treatment, accompanied by his wife and four children, as the WHO warned of the “scale and speed” of the outbreak. Federal health authorities have confirmed that the screening procedures at the busy O’Hare airport are designed to stop the virus from reaching the US.

Individuals who have visited Uganda, the DRC or South Sudan within the previous 21 days are being refused entry unless they hold US citizenship or permanent residency. Returning citizens and permanent residents arriving from those nations must undergo enhanced screening protocols at the airport.

Officials are monitoring travellers’ temperatures, asking about possible exposure and gathering contact-tracing details.

Anyone displaying symptoms or running a fever will be escorted to a quarantine facility at the airport for further assessment.

If given the all-clear, the traveller will receive a care kit containing guidance to check their temperature twice daily for the following three weeks.

Read More: Ebola outbreak: Major airport begins screening arrivals as experts ‘very concerned’