A second American citizen has been infected with the Ebola virus amid a severe outbreak of the disease in the Democratic Republic of Congo, according to US health authorities.

The Centers for Disease Control and Prevention, headquartered in Atlanta, announced on Friday that an American citizen working for a humanitarian organisation in the Democratic Republic of Congo had contracted the infection. It was not immediately clear whether the infected person was a man or a woman.

Medical tests confirmed that the individual was infected with the Budibugyo strain, which is currently spreading rapidly in the region. The CDC is supporting contact-tracing efforts and risk assessments to prevent further infections, in cooperation with the relief organisation, Congolese health authorities, and other partners.

Ebola is a life-threatening viral disease transmitted through direct physical contact and exposure to bodily fluids.

According to the Congolese government, 1,830 cases have been laboratory-confirmed since the latest wave of the outbreak began in May. A total of 648 deaths from the disease have also been confirmed.