There is no outbreak of yellow fever in Kenya despite detecting symptoms of the virus from two people who had travelled from Angola, a senior government official said on Friday.

Cabinet Secretary for Health Dr. Cleopa Mailu said there has not been any local transmission of the virus due to quick intervention by health officials after a confirmation of the two cases of yellow fever in two people who came for a visit from their work station in Angola in early March.

"By the time the two people arrived in Kenya they were already beyond transmission phase as per the world Health Organization (WHO) definition," Mailu said in a statement issued in Nairobi.

The East African nation has instituted a raft of measures in all points of entry for visitors from Angola who do not have valid yellow fever vaccination certificate.

The health ministry said travelers from Angola, the epicenter of an ongoing large Yellow Fever Virus outbreak, must have been vaccinated ten days before travel.

The ministry said travellers from Angola who are not Kenyan citizens or residents and do not have valid yellow fever vaccination certificates will be denied entry into the country.

Mailu observed that the two cases were travel related and to date no Kenyan has been infected as was earlier thought.

"We wish to reassure the general public and foreigners that all parts of Kenya are safe to travel to and there is no cause for alarm," he added.

Mailu took issue with a poster issued by Ugandan ministry of health that indicates that Kenya, alongside Angola and the Democratic Republic Congo (DRC) are currently facing yellow fever outbreak.

He noted that the poster is not true reflection of the situation in the country and that already the government of Kenya has taken up the matter with the Ugandan authorities on the basis of the allegation.

According to Mailu, an outbreak in Kenya is unlikely since the Ministry of Health personnel are on high alert at all points of entry. It is now two weeks since the last case was reported by the government.

Kenya is classified as a low risk country for yellow fever infection with the last outbreak having occurred in 1992.

The UN World Health Organization (WHO) said on Friday the outbreak of yellow fever has killed at least 146 people in Angola since December and most of the deaths have been in the bustling capital of Luanda.

The yellow fever virus is transmitted when a mosquito bites an infected monkey and then bites a human being.

Once contracted, the virus incubates in the body for three to six days followed by illness whose symptoms include fever, muscle pain with prominent backache, headache, shivers, loss of appetite and nausea or vomiting.

In severe cases patients develop jaundice and bleeding. Health officials said vaccination is the single most important measure for preventing yellow fever.