The effects of el nino and la nina on africa's climate

La Niña, there is marginal rainfall and stronger winds in East Africa, while the El Niño warm phase leads to weak wind conditions with frequent rain. Moreover, during the coldest period of the last ice age about 18 000 to 21 000 years ago, East Africa's climate was relatively stable and dry. Hope this helps, good luck 

Both El Niño and La Niña are opposite effects of the same phenomenon: the ENSO (El Niño Southern Oscillation). Both are an oscillation in the temperatures between the atmosphere and the ocean of the eastern equatorial Pacific region, roughly between the International Dateline and 120 degrees west

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast.