The National Institute for Communicable Diseases (NICD) identified an outbreak of the Rift Valley Fever (RVF) on a farm bordering the Northern Cape last month. A total of 250 sheep deaths and abortions took place as a result of the outbreak and two of the farm workers were confirmed to be affected by RVF.
A further 8 cases were reported in June after locals in the area began experiencing symptoms of the disease. It is believed to be circulated by the mosquito population.
Another RVF outbreak was recorded this month in Kenya with 26 reported human cases and six deaths resulting from the fever. This is the first sign of the disease in Kenya since the 2006 to 2007 outbreak which claimed 234 lives. Following these occurrences the United Arab Emirates has banned the import of livestock from South Africa.
The last RVF outbreak that occurred in South Africa was recorded from 2010 to 2011. More than 14 000 livestock were infected over 8 provinces. including the Western Cape. A total of 278 people were also infected and 25 people died.
The majority of human cases occur due to contact with blood or organs of infected animals but can also occur from insect bites, most commonly mosquitos. Symptoms vary often and human cases can develop mild to severe forms of the disease.
Mild symptoms of Rift Valley fever include:
– Flu-like symptoms
– Muscle and joint pain
– Headaches and light sensitivity
– Reduced appetite and vomiting
Severe symptoms of Rift Valley fever include:
– Retinal lesions
– Blurred or decreased vision
– Intense headache
– Memory loss
– Liver impairment
– Internal hemorrhaging
NICD Senior Communications Manager, Sinenhlanhla Jimoh said that there was an isolated incident, in which one sheep on a on a single farm in Jacobsdal was infected.
“There have been no recorded cases of human-to-human transmission with Rift Valley fever. The isolated outbreak occurred shortly before the onset of winter which possibly contributed to the isolated nature of the outbreak – being a mosquito borne disease, the cold weather likely decreased mosquito numbers sufficiently to prevent a major epidemic. However, if farmers do not heed the advice from DAFF to vaccinate their animals (cattle and sheep) before the warmer rainy months, there is a possibility for more widespread cases in the coming summer.”
The NICD has asked all health care workers to be aware and vigilant when dealing with patients exhibiting signs of RVF and in such instances that patients do meet the definition that they submit specimens to the NICD-NHLS for laboratory testing.