U.S. oil futures dropped on Friday, reversing sharp overnight gains as reports of a new case of Ebola in the U.S. weighed on risk sentiment. On the New York Mercantile Exchange, crude oil for delivery in December traded at $81.37 a barrel during European early afternoon trade, down 0.72$ or 0.88%. Prices jumped 1.57$ or 1.95% on Thursday to settle at $82.09. Futures were likely to find support at $80.05 a barrel, Thursday’s low and resistance at $83.15, the high from October 22. Oil prices weakened after The New York Times reported earlier Friday that a doctor in New York City, identified as Craig Spencer, tested positive for the Ebola virus after returning from treating patients in West Africa. The first confirmed case in America’s largest city sparked fresh concerns over the spread of the virus, weighing heavily on risk-related assets. Crude futures has strengthened on Thursday after Saudi Arabia said it cut crude oil production by about 328,000 barrels in September to a total of 9.36 million barrels. Concerns over weakening global demand combined with indications that the Organization of the Petroleum Exporting Countries will not cut output to support oil markets have weighed on prices in recent weeks. OPEC oil output hit a two-year high of 31 million barrels per day in September, led by higher production from Iraq and Libya. Some market analysts believe that only a cut in production by the oil cartel will halt the decline in prices. Oil ministers from the 12-member group are scheduled to meet in Vienna on November 27 to consider whether to adjust their production target for early 2015. Elsewhere, on the ICE Futures Exchange in London, Brent oil for December delivery dropped 0.70$, or 0.81%, to hit $86.13 a barrel. The spread between the Brent and the WTI crude contracts stood at $4.76.