More than 6,240 people in West Africa have been infected in the worst Ebola outbreak in history. The World Health Organization (WHO) has warned that, without drastic measures to halt the disease's spread, that number may rise to 20,000 infections by the beginning of November.

Ramon Martinez, a health metrics advisor to the WHO's Regional Office for the Americas, dug into WHO data to produce a series of interactive graphs forecasting the rate at which Ebola could possibly spread. The graphs were developed using a forecasting model called exponential smoothing and published on Martinez' blog Health Intelligence. They show a week-by-week forecast of the possible number of cases in the three worst-affected countries: Guinea, Liberia and Sierra Leone.

Martinez told The WorldPost that such forecasts are important as they help health services to "prepare for what is coming." Already, the Ebola outbreak has overwhelmed national health services in West Africa, and the United Nations has appealed for more international aid to stem the crisis.

Overall, Martinez predicts the number of Ebola cases will surpass 20,000 by Nov. 2, a similar projection to that of the WHO. He does expect the number of cases in Liberia to rise more dramatically than WHO Ebola researchers foresee. Some of the variances are due to using different forecasting models, Martinez explained.