* Cause of three new Ebola cases unknown
* Liberia has been declared Ebola-free twice before
* Neighbours Guinea, Sierra Leone have no cases
By James Harding Giahyue
MONROVIA, Nov 22 Liberia has placed 153 people
under surveillance as it seeks to control a new Ebola outbreak
in the capital more than two months after the country was
declared free of the virus, health officials said.
Three Ebola cases emerged in Liberia on Friday. The first of
the new patients was a 15-year-old boy called Nathan Gbotoe from
Paynesville, a suburb east of the capital Monrovia. Two other
family members have since been confirmed as positive and they
are all hospitalised.
"We have three confirmed cases and have listed 153 contacts,
and we have labelled them as high, medium and low in terms of
the risk," Liberia's Chief Medical Officer Dr. Francis Kateh
told Reuters late on Saturday.
The West African country has suffered the highest death toll
in the worst known Ebola outbreak in history, losing more than
4,800 people. It has twice been declared Ebola-free by the World
Health Organization, once in May and again on Sept. 3, only for
new cases to emerge.
It is not known how Gbotoe was infected and Kateh did not
offer any explanation, saying that investigations were ongoing.
Cross-border transmission seems unlikely since neighbouring
Guinea has zero cases while Sierra Leone was declared Ebola-free
this month after 42 days without a case.
In the Duport Road neighbourhood of Paynesville, health
officials went from house to house on Saturday delivering food
and water to neighbours of the infected family, deemed at risk
of catching the disease.
Unlike in previous months, there were no barriers or
soldiers to enforce quarantines.
Neighbour Elizabeth Powell said she was more worried about
lost income than catching Ebola, which is transmitted through
the bodily fluids of the sick.
"I am worried about food and my business," she said. The
epidemic has crippled Liberia's economy and President Ellen
Johnson-Sirleaf says it will take two years to recover.
The previous resurgence of Ebola in Liberia is thought to
have been via sexual transmission since the virus can exist in
the semen of male survivors for at least nine months after
infection, much longer than its incubation period in blood.
It is also theoretically possible for an infected animal to
trigger a fresh chain of transmission. The index case in the
West African outbreak that has killed around 11,300 people was a
child believed to have been infected by a bat.
(Additional reporting and writing by Emma Farge; Editing by Ros