A microscopic image of the Marburg virus.
CNN  — 

Cameroonian authorities detected two suspected cases of Marburg disease on Monday in Olamze, a commune on the border with Equatorial Guinea, the public health delegate for the region, Robert Mathurin Bidjang, said on Tuesday.

Equatorial Guinea officially declared its first outbreak of the Marburg virus, an illness similar to Ebola, on Monday.

Neighboring Cameroon had restricted movement along the border to avoid contagion following reports of an unknown, deadly hemorrhagic fever in Equatorial Guinea last week.

“On the 13th of February, we had two suspected cases. These are two 16-year-old children, a boy and a girl, who have no previous travel history to the affected areas in Equatorial Guinea,” Bidjang said at a meeting in Cameroon’s capital Yaounde.

Forty-two people who came into contact with the two children have been identified and contact tracing was ongoing, he added.

The World Health Organization (WHO) said earlier on Tuesday that it was increasing its epidemiological surveillance in Equatorial Guinea.

The small Central African country has so far reported nine deaths as well as 16 suspected cases of Marburg virus disease, with symptoms including fever, fatigue, and blood-stained vomit and diarrhea, according to the WHO.

“Surveillance in the field has been intensified,” said George Ameh, WHO’s country representative in Equatorial Guinea.

“Contact tracing, as you know, is a cornerstone of the response. We have…redeployed the COVID-19 teams that were there for contact tracing and quickly retrofitted them to really help us out.”

Equatorial Guinea quarantined more than 200 people and restricted movement last week in its Kie-Ntem province, where the hemorrhagic fever was first detected.

Marburg virus is a highly infectious disease that can have a fatality rate of up to 88%, according to the WHO. There are no vaccines or antiviral treatments approved to treat it.

“We’re working on a 30-day response plan where we should be able to quantify what are the exact measures and quantify what are the exact needs,” Ameh said.

He added that the country’s authorities had not reported any new suspected cases in the last 48 hours.