The UN World Health Organisation (WHO) has decried South Sudan's disease burden which it said is rising rapidly in the midst of a protracted conflict that is causing widespread displacement and a major food crisis, China's Xinhua news agency reported.

Evans Liyosi, WHO South Sudan Representative, said malaria infections are on the rise in the war-torn country, with more than 1.3 million people infected in 2017, and thousands others sick with measles and cholera.

"Disease is a leading cause of death in South Sudan today, and malaria is the number one killer," Liyosi said in a statement issued in Juba on Wednesday night.

Malaria season which is underway across much of sub-Saharan Africa exacts a particularly heavy toll in South Sudan and the country's entire population is at high risk of contracting the illness because of a fractured health system and challenges related to accessing the population due to insecurity.

According to WHO, an estimated 1.3 million people have fallen ill with malaria this year, while thousands are affected by cholera and measles, particularly along the Nile River and in camps for displaced people.

The deadly mosquito-borne disease accounts for 65 per cent of all illnesses reported in health facilities across the country. Every week it infects more than 77,500 people and kills nearly 220 -- most of them children under the age of five.

South Sudan has also recorded nearly 20,000 cases of cholera and more than one thousand victims of measles since January.

WHO and partners are working to provide critical health services to 2.7 million people targeted for health across the country, but the health response faces a staggering 84 per cent funding gap.

Across the country, malnutrition, severe pneumonia, malaria and perinatal complications remain the most common causes of death in children under five.

The UN health agency regularly deploys mobile medical teams to outbreak hot spots for diseases such as cholera and malaria to help respond to disease outbreaks.

The teams also train frontline health workers on malaria diagnosis and treatment to improve quality of care and access to treatment.

Oral cholera vaccination campaigns have vaccinated nearly one million people against cholera, stemming the spread of the disease in areas where the vaccine was deployed.

"Awareness raising interventions and cholera treatment facilities have also helped to contain the spread of the waterborne illness," WHO said. - BERNAMA