Fish with lesions caused by Epizootic Ulcerative Syndrome

Juba, 07 January 2022 -- The Food and Agriculture Organization of the United Nations (FAO) in South Sudan and the Ministry of Livestock and Fisheries have confirmed the presence of Epizootic Ulcerative Syndrome among fish in Northern Bahr el Ghazal. The diagnosis comes after testing of samples at the Central Veterinary Diagnostic Laboratory in Juba.

The disease outbreak was first reported to FAO on 13 December 2021, and FAO responded by dispatching a fisheries expert to Aweil on 16 December 2021 to facilitate an investigation in collaboration with the national Ministry of Livestock and Fisheries and the state-level Ministry of Animal Resources and Tourism.

FAO provided vehicles to support missions to the two locations of Nyamlel and Aroyo to take samples of diseased fish. Samples were brought back to Juba on 23 December 2021 and subsequently tested positive for Epizootic Ulcerative Syndrome (EUS).

A fungal disease associated with flooding 

 EUS is a seasonal water mould, an external parasite caused by fungus. The infection is caused by an oomycete fungi known as Aphanomyces invadans or A. piscicida. First reported in 1971, EUS has been found to affect both wild and farmed fish. In this particular outbreak, the disease is affecting Clarias gariepinus, a scaleless fish commonly known as African catfish.

The timing of this disease outbreak may be related to flooding in the affected areas. Rivers swelled beyond their banks and submerged areas which are not normally covered by water. As the flooding receded, the waters carried pathogens back into the rivers, affecting the fish.

FAO applauds the Governor of Northern Bahr Ghazal state for having implemented a fishing ban as soon as the disease was identified, thus limiting the spread of the disease.

As the mould has a limited lifespan (approximately 20 days) which has now elapsed, the Minister of Livestock and Fisheries, Onyoti Adigo Nyikwec has now ordered the fishing ban to be lifted.

Working with government to combat future outbreaks

Moving forward, it is essential to equip fishing experts across the country to quickly address any future disease outbreaks. As such, FAO is planning, in collaboration with the national and state governments, to conduct workshops for state fisheries officials to provide guidance on identification, reporting and response to fish disease outbreaks.

“FAO stands firm to support and facilitate the government in addressing issues pertaining to health and livelihood of the communities. Our team of fisheries experts will provide clarification on issues that needs attention” said Mary Lero, Assistant FAO Representative (Programmes).

Fisherfolk in Northern Bahr el Ghazal are advised to continue to monitor the health of their catches. While EUS does not itself make affected fish dangerous to eat, secondary bacterial infections may render the fish dangerous to human health. Therefore, it is NOT ADVISABLE to eat any fish with signs of this disease.

Fish with visible lesions should be burned or disposed of by burying in a deep hole far from any water source. Do not return affected fish to the water source.