Nairobi ( CNN ) -- Kenya Airways will suspend flight operations to Liberia and Sierra Leone , the latest airline to curb flights because of the ongoing Ebola outbreak in West Africa . The suspension is temporary , and the airline will continue operating flights to Nigeria and Ghana , Kenya Airways said . The Kenyan government announced other restrictions , saying it is temporarily suspending entry into Kenya of passengers who have passed through Sierra Leone , Guinea and Liberia . Health professionals and Kenyan citizens returning home from those countries will be the exceptions , but will have to undergo extensive screening and close monitoring , said James Macharia , Cabinet secretary of the Kenya Ministry of Health . The measures come as the World Health Organization warned this week that the magnitude of the Ebola crisis in West Africa is `` vastly '' underestimated . Ebola has infected at least 2,127 people in Nigeria , Guinea , Liberia and Sierra Leone since the outbreak began this year . Of the victims , 1,145 have died as of Wednesday , according to the WHO . `` The outbreak is expected to continue for some time , '' the WHO said in a statement this week . `` Staff at the outbreak sites see evidence that the numbers of reported cases and deaths vastly underestimate the magnitude of the outbreak . '' Though the United Nations agency did not provide an estimate of unreported cases , it said it 's teaming up with the affected countries to gather more intelligence from the ground . It 's also working with other agencies , including the World Food Program , to feed about 1 million people quarantined in villages in Guinea , Liberia and Sierra Leone . As experts scramble to contain the outbreak , health officials are considering the use of experimental treatments and vaccines , since no there is no proven cure for the deadly virus . Ebola spreads through contact with organs and bodily fluids such as blood , saliva , urine and other secretions of infected people . It causes viral hemorrhagic fever , which affects multiple organ systems . Early symptoms include sudden onset of fever , weakness , muscle pain , headaches and a sore throat . They later progress to vomiting , diarrhea , impaired kidney and liver function , and sometimes internal and external bleeding . WHO : Evidence shows Ebola crisis 'vastly ' underestimated . 9 things to know about the Ebola virus . Report : Ebola outbreak probably started with 2-year-old . CNN 's Michael Martinez contributed to this report .
Kenya Airways temporarily suspends flights to Liberia and Sierra Leone . Sierra Leone also temporary denies entry by passengers from Liberia , Sierra Leone , Sierra Leone . Health professionals and Kenyan citizens are exempt from temporary ban . But the health workers and citizens will have to undergo extensive screening .