The means of transport that can be used to get to Madagascar from Europe and the United States are restricted to planes since the regular sea links have been discontinued. Here are the Websites of some airline companies to which you can buy a ticket or reserve a seat for the island:
: http://www.airmadagascar.com
On all airlines serving Madagascar there are low and high season rates. Low season is from January to the end of June, and mid September to mid December.