The U.S. lost three points from its 2014 score. Despite gains in some countries, an annual index shows that 68 percent of the world's countries have "a serious corruption problem."
The U.S. and other countries have agreed to lift sanctions imposed on Iran over its nuclear program, but Washington still has other sanctions in place against Tehran.
On a trial basis, a British company is releasing genetically modified mosquitoes in Brazil to try to reduce the Aedes aegypti population — the species spreading Zika.
More than 23,000 have come so far, with California a top destination — especially the Los Angeles suburbs in the San Gabriel Valley. Many teens live with host families and attend private schools.
Iran's president is in Italy at the start of a Europe trip made possible by the lifting of sanctions following the implementation of the Iran nuclear deal. President Hassan Rouhani met with the Pope Tuesday before heading to France.
Authorities in Colombia, Ecuador, El Salvador and Jamaica are encouraging women to delay getting pregnant due to the spread of the mosquito-borne illness, Zika. The virus has been linked to brain damage in infants. Delaying pregnancy is a challenge for women in the region where rape is the cause of many pregnancies, and women have little access to contraception.
Despite the progress represented by the Iran nuclear deal, rising tensions between the U.S. and Russia, North Korea's nuclear tests and other conflicts mean the world is still close to catastrophe.