China has ordered that travellers entering the country from Sudan must be screened for the yellow fever virus.
The move, made this month, came after the North African nation suffered an outbreak of the virus in October.
The epidemic is said to be the world's largest for 20 years and to date has killed 171 people out of a total of 849 who contracted the illness in 35 districts in Darfur, according to the World Health Organisation (WHO).
On Saturday 25 January the WHO will be rolling out the third phase of a vaccination campaign in Darfur, having already initiated campaigns last November and in the first week of January.
The third round of vaccinations will be administered to approximately two million people.
The first and second phase beginning in November and December were given to 2.2 million and 1.1 million people respectively.
The Sudanese outbreak comes just after the WHO underwent a mass-vaccination campaign in Ghana and Cameroon against yellow fever.
The immunisations carried out between 2011 and 2012 covered some 8.7 million people in the two countries.
According to the WHO there are an estimated 200,000 cases with 30,000 people dying from yellow fever worldwide.