Outbreak Response Unit, National Institute for Communicable Diseases (NICD) of the National Health Laboratory Service (NHLS), Sandringham, Johannesburg.
S Afr Med J. 2011 Apr;101(4):263-6. doi: 10.7196/samj.4544.
During 2008, Rift Valley fever (RVF) virus re-emerged in South Africa as focal outbreaks in several provinces.
To investigate an outbreak affecting cattle farmers and farm workers, and the staff and students of a veterinary school, assess the prevalence of infection during the outbreak, document the clinical presentation of cases, and identify potential risk factors.
We conducted a cross-sectional serological survey of exposed veterinarians and farmers, who were examined to determine the presence of current or recent illness. Blood specimens were collected for virus isolation, nucleic acid detection and serology. A subset was interviewed using a standardised questionnaire to obtain data on recent exposures and risk factors for infection.
Of 53 participants potentially exposed to infected domestic ruminants, 15% had evidence of recent infection and 4% evidence of past exposure to the RVF virus. The prevalence of acute infection was 21% in veterinarians compared with 9% in farmers and farm workers. After a mean incubation period of 4.3 days, the most frequent symptoms experienced included myalgia (100%), headache (88%) and malaise (75%). No asymptomatic cases were identified. Transmission, by direct contact with infected animals was the major risk factor in these professional groups. Performing animal autopsies was significantly associated with acute infection (risk ratio 16.3, 95% confidence interval 2.3 - 114.2).
Increased risks associated with veterinary practices highlight a need for the use of personal protective equipment, and identify veterinarians as a primary target group for future vaccination.
2008 年，裂谷热（RVF）病毒在南非重新出现，多个省份出现局部暴发。
调查一起影响牛场主和农场工人以及兽医学校教职员工和学生的暴发疫情，评估暴发期间的感染流行率，记录病例的临床表现，并确定潜在的危险因素。
我们对接触过受感染的家养反刍动物的兽医和农民进行了横断面血清学调查，检查他们是否存在现症或近期疾病。采集血液样本进行病毒分离、核酸检测和血清学检测。采用标准问卷对一部分人进行访谈，以获取近期暴露和感染危险因素的数据。
在 53 名可能接触过受感染的家养反刍动物的参与者中，15%有近期感染的证据，4%有过去感染 RVF 病毒的证据。兽医急性感染的患病率为 21%，而农民和农场工人为 9%。平均潜伏期为 4.3 天后，最常见的症状包括肌痛（100%）、头痛（88%）和不适（75%）。未发现无症状病例。这些职业群体中，与受感染动物的直接接触是主要的传播途径。进行动物剖检与急性感染显著相关（风险比 16.3，95%置信区间 2.3-114.2）。
与兽医实践相关的风险增加突显了使用个人防护设备的必要性，并确定兽医是未来疫苗接种的主要目标人群。
