The deadliest outbreak of the Ebola virus in seven years has killed 70 people and infected as many as 111 in Guinea, causing neighboring Senegal to close its border with the country. Senegal’s Ministry of Interior has ordered all movements of people through the southern boundary to Guinea suspended indefinitely to prevent the spread of the disease, according to a statement published today by the state-run press agency, APS.Most of the cases detected in Guinea since January have been in the towns of Guekedou, Macenta, Kissidougou and Dabola, the country’s Health Ministry said in an e-mailed statement yesterday. There has been one death among eight cases of the infectious disease in the capital, Conakry, it said. It marks the deadliest outbreak since 2007, when 187 people died of Ebola in the Democratic Republic of Congo, according to the World Health Organization’s website. The Economic Community of West African States, a regional body known as Ecowas, expressed “deep concern” over the outbreak yesterday and called for international help to thwart the “serious threat” it poses to regional security. The transmission to Conakry, a city of 1.6 million people, represents a “new dynamic” in the outbreak, though the situation remains “extremely fluid,” Gregory Hartl, a WHO spokesman, said yesterday.