NICD Special Communique-January 2011
Three new laboratory-confirmed human cases of Rift Valley fever (RVF) virus infection have been identified. All three cases are farmers/farm workers who had direct contact with animal tissues and body fluids when slaughtering/skinning livestock during late January 2011. All three cases presented with flu-like illness to their local healthcare practitioners. RVF was included in the differential diagnosis based on their occupational risk, and specimens were submitted to the NICD-NHLS for testing. The Special Pathogens Unit confirmed RVF virus infection by RT-PCR. All three patients are reportedly recovering, although one patient had developed hepatitis during the course of his illness.
These are the first laboratory-confirmed human RVF cases since mid-September 2010. During 2010, a total of 238 confirmed human RVF cases was reported following a widespread outbreak affecting 8 of the 9 provinces (i.e. all except for KwaZulu-Natal Province). During 2011 to date, the Department of Agriculture, Forestry and Fisheries has confirmed two isolated animal RVF outbreaks in Western Cape Province and one in Eastern Cape Province, with another suspected outbreak in Gauteng Province. Further animal RVF outbreaks in previously affected areas are possible following the heavy rainfall experienced throughout large parts of the country during recent months.
We have revised and updated the Healthcare Workers Handbook on RVF. The 2011 handbook (see attached or download from the NICD website – nicd.ac.za) provides healthcare workers (HCW) with a synopsis of RVF, details the clinical features and complications of disease, explains the case definition and criteria for laboratory testing, provides guidance as to specimen collection and referral for testing, advises on management and infection prevention and control issues, and gives advice as to prevention of this disease in humans. Please specifically note the following important amendments to the previous version:
The case definition and criteria for laboratory testing for a suspected RVF case has been revised.
The RVF suspected case investigation form (see pg 6 of the guideline) has been updated. HCW are requested to complete this new form and submit it together with specimens when RVF testing is requested.
The NICD-NHLS Hotline does NOT need to be contacted routinely for every case of suspected RVF. However, in the case of severely ill hospitalised patients where clinical advice is sought, or for whom laboratory testing needs to be prioritised and expedited, please call the NICD-NHLS Hotline (082-883-9920) which is a 24-hour service for HCW countrywide. Please note that the NICD-NHLS Hotline is not a service for the general public, who should contact the Department of Health Hotline (086-136-4232) for any queries.
One of the most critical roles HCW play in the prevention of human RVF infections is by promoting and strengthening public health education and risk reduction. Messages to the community, especially within affected areas should focus on:
Avoiding high-risk animal husbandry procedures and slaughtering practices through the use of gloves and other protective clothing, especially when handling sick animals.
Avoiding the unsafe consumption of fresh blood, raw (unpasteurised or uncooked) milk or animal tissue. In outbreak regions, all animal products (blood, meat and milk) should be thoroughly cooked before eating. Slaughtering of sick animals for consumption should be discouraged during outbreaks.
Personal and community protection against mosquito bites through the use of insect repellents (containing 30-50% DEET), insecticide-treated bed nets, and wearing of light-coloured clothing.
Source: Outbreak Response and Special Pathogens Units, NICD-NHLS; Departments of Health, and Agriculture, Forestry and Fisheries.
The National Institute for Communicable Diseases (NICD), a division of the National Health Laboratory Service,