Liberian chief medical officer Bernice Dahn has put herself under quarantine for 21 days, after one of her assistants died from the deadly Ebola virus.
Deputy Health Minister Bernice Dahn said she had no symptoms but wanted to take every precaution.
The World Health Organization (WHO) says more than 3,000 people have died from Ebola in West Africa.
Liberia has been the worst hit by the disease, accounting for 1,830 deaths – 150 in the last two days alone.
Health workers have been particularly vulnerable to the virus, which is spread by the infected bodily fluids of patients.
Health organizations recommend isolating people for at least 21 days, which is the maximum incubation period for the virus.
Bernice Dahn said she had not come into contact with any other infected people, apart from the office assistant who died this week, but wanted to take every precaution.
She has also instructed her staff to stay at home for the same time period.
The WHO highlighted the risk of infection for health workers trying to stem the outbreak in its latest report released on September 26.
The report said 375 workers are known to have been infected, and that 211 have so far died from the virus in Guinea, Liberia, Nigeria and Sierra Leone.
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