The wealth of the U.S. is contrasted with the poverty of developing countries.

Literal

America's richness [topic-は] developing-countries' poverty [with-と] comparison-contrast done-is.

比較対照される is the passive of 比較対照する (to compare and contrast) — 'is contrasted.' 発展途上国 is 'developing nations.' A formal, analytical sentence typical of social science writing.