Sub-Saharan Africa economies are set to post a decline in growth in 2015, fuelled by falling oil and other commodity prices.

The advent of new types of conflict and the potential for disease epidemics also pose risks to the region’s growth prospects, according to the World Bank's bi-annual publication Africa's Pulse.

The bank projects the continent’s economic growth will slow down to 4 per cent in 2015 from 4.5 per cent in 2014. The forecast is below the 4.4 per cent average annual growth rate of the past two decades and well short of Africa’s peak growth rates of 6.4 per cent in 2002-2008.

Economic activity in the region is being impacted by the sharp drop in oil prices which fell a whopping 57 per cent between June 2014 and January 2015. The decline in crude prices between June 2014 and March 2015 still remains above 50 per cent.

Other commodity prices also weakened sharply. Between June 2014 and March 2015, the price of iron ore and copper dropped by 37 per cent and 13 per cent respectively. Similarly, the cost of rubber and cotton plunged by 24 per cent and 17 per cent respectively.

Africa’s oil exports, which accounted for nearly half of the region’s GDP in 2014, have been hard hit by weakening terms of trade, the report says.

Economies which are vulnerable to oil price changes depend heavily on oil for exports receipts and fiscal revenues. Oil accounts for around 90 per cent of the merchandise export in Angola, Chad, Equatorial Guinea and Nigeria.

“This is a challenging year for the continent. Declining oil prices, insurgent of conflicts such as the civil war in South Sudan and extremists (al-Shabaab) in Kenya and diseases such as Ebola in West Africa highlights the dangers the continent is facing amid a weakening economic system,” said Francisco Ferreira, the bank’s chief economist in charge of the African region.

Ebola-affected countries of Guinea, Liberia and Sierra Leone witnessed weaker growth as activity in mining, services and agriculture contracted. Economic activity, however, remained strong in Cote’ d'Ivoire, Mozambique and Tanzania.

According to the biannual report, growth in most emerging and frontier markets fell short of expectations in 2014 and forecasts for 2015 continue to be downgraded.

Lower commodity prices are expected to weigh heavily on exporters of these commodities, putting pressure on current account and fiscal balances. Countries that stand to lose the most are the less diversified oil exporters such as Angola and the Republic of Congo.

On the other hand net oil importers such as Kenya, Cote d’Ivoire and Senegal are set to witness modest gains from cheaper energy prices.

African economies continue to tap international bond markets to finance infrastructure projects with countries like Cote d’Ivoire returning to the market in February while Ethiopia had a debut issue in December 2014.

The bank notes that although debt burdens for these countries remain manageable, the debt-to gross domestic product (GDP) ratios for countries with increased bond market access have picked up in recently years, calling for extreme caution particularly due to uncertainty about future global conditions.