Some of the final cases of the deadly Ebola virus could have been passed on through breast milk, new research suggests.
An analysis of the tail-end of the epidemic found that some of the last cases were transmitted through unconventional routes such as semen and breast milk.
An international team of researchers sequenced Ebola virus genomes in a temporary tent laboratory in Sierra Leone.
Researchers led by the University of Cambridge and Wellcome Trust Sanger Institute generated 554 complete Ebola genome sequences from samples of blood, cheek swabs, semen and breast milk.
These were collected between December 2014 and September 2015 from Ebola isolation and treatment centres in the north and west of the country.
The research, published in the journal Virus Evolution, describes a number of case studies.
These include a mother who may have transmitted Ebola to her baby via breastfeeding, and an Ebola survivor who passed on the virus sexually a month after being released from quarantine.
Dr Jeremy Farrar, director of the Wellcome Trust, said: "Close contact with an infected individual is still by far the most common way for Ebola to spread.
"But this study supports previous research suggesting that the virus can persist in bodily fluids for a long time after recovery.
"These unusual modes of transmission may have contributed to isolated flare-ups of infections towards the end of the epidemic.
"The success of this innovative project shows how important it is to carry out genome sequencing within the affected countries, and for the data to be shared in a rapid and open way as part of the epidemic response.
"Strengthening laboratory and surveillance facilities where they are currently lacking will also aid early detection, making the world better prepared for infectious disease outbreaks."
During the outbreak which swept Guinea, Liberia and Sierra Leone, more than 28,000 cases were reported including over 11,000 deaths.