Health officials in Liberia have confirmed two more cases of Ebola, bringing the new outbreak to five infections.  It’s distressing news for a country that had been declared Ebola-free two months ago, after losing more than 4,800 of its people to the killer virus.

The latest patients are a boy and a girl from the same Nedowein community where the first victim of the new outbreak, a 17-year old boy, died of the disease on 28 June.  They were brought to a treatment center near Monrovia, where the other two patients are also isolated.  In addition, officials say 120 people have been quarantined, and 14 who are considered active “high risk” contacts are being monitored.

Doctors are racing to find out how the dead teen was infected.  Tests showed that the boy’s strain of Ebola did not match those still circulating in the outbreaks in Sierra Leone and Guinea.  He had to have gotten it in Liberia, but probably not from the local environment.  Ebola degrades quickly outside the human body.

But inside is another story.  Even after a patient is cured, the Ebola virus might hang on for weeks in the inner eye, placenta, or sexual organs.  The final fatality of Liberia’s original outbreak apparently caught it by having sex with her boyfriend, who survived Ebola months before.

More than 11,260 people died in the West African Ebola Outbreak.