The nations of sub-Saharan Africa are still perceived on average to have the world’s most corrupt governments, according to the latest index published by Transparency International (TI).

The Berlin-based organisation says in its annual report, released on Tuesday, that sub-Saharan Africa is the lowest-scoring region on its 2018 Corruption Perceptions Index.

The region “has failed to translate its anti-corruption commitments into any real progress”, the report says.

“A region with stark political and socio-economic contrasts and longstanding challenges, many of its countries struggle with ineffective institutions and weak democratic values, which threaten anti-corruption efforts.”

But it says five nations in which there are “promising political developments” are worth watching for prospects of improvement.

In Angola, which comes near the bottom of the index in 165th place, “new leadership… provides hope for anti-corruption reforms”.

Citizen engagement and official inquiries into corruption in South Africa, which occupies 73rd place in the world, “are positive steps.”

Transparency International also highlights, without further comment, Kenya and Nigeria (both in 144th place) as providing hope for improvement, as well as Botswana – already one of the African countries with the highest ranking on the index.

And it names Cote d’Ivoire (105th place) as one of the countries which has improved its position the most in the last seven years.

TI says the index draws on 13 surveys of business people and other expert assessments to measure perceived levels of public sector corruption in 180 countries and territories.

The five least corrupt governments in sub-Saharan Africa are perceived to be those of the Seychelles (28th in the world), Botswana (34th), Cape Verde (45th), Rwanda (48th) and Namibia (52nd).

Five sub-Saharan African countries are among the 10 perceived to have the world’s most corrupt public sectors: Somalia comes in at the bottom of the index (180th place), with South Sudan at 178th and Sudan, Guinea Bissau and Equatorial Guinea (all in 172nd place) doing only marginally better.

Commenting on the global picture, the report describes what it calls “a sadly familiar picture” in which “the vast majority of countries assessed have made little to no progress.” This threatens democracy, says Transparency International.

“Corruption chips away… to produce a vicious cycle, where corruption undermines democratic institutions and, in turn, weak institutions are less able to control corruption,” according to Patricia Moreira, managing director of Transparency International.

“With many democratic institutions under threat across the globe – often by leaders with authoritarian or populist tendencies – we need to do more to strengthen checks and balances and protect citizens’ rights.”