The first reported human Rift Valley Fever outbreak in Uganda, 2016

Abstract

Introduction : on 8 March 2016, the Ministry of Health received a report of a suspected case of viral hemorrhagic fever (VHF) in Kabale Regional Referral Hospital. By 15th March, there were two laboratory confirmed cases of Rift Valley Fever (RVF). We conducted the investigation to assess the scope of the outbreak, identify its source and risk factors in order to inform public health interventions for controlling the outbreak. Methods : a suspected case was defined as acute onset of fever (> 37.5°C), negative malaria test, and at least two of the following three symptoms: Headache, Muscle or joint pain and any gastroenteritis symptom (nausea, vomiting, abdominal pain, and diarrhea). A Probable Case was any person meeting the suspect case definition with deranged liver functions tests plus at least one of the following; bleeding symptoms, such as: bleeding from the nose, vomiting blood, coughing out blood (without history of TB), blood in stool, blood in urine; sudden change in vision, jaundice, any unexplained death. A confirmed case was a suspected or probable case that is laboratory confirmed by detection of RVF nucleic acid by reverse-transcriptase polymerase chain reaction (RT-PCR) or demonstration of serum IgM or IgG antibodies by ELISA. We found cases by going to the affected communities and health facilities in the catchment areas where the confirmed cases came from. Results : the investigation revealed 2 confirmed cases. In-depth interviews revealed that the symptom onset for the primary case was February 13th while onset date for the secondary case was February 18th. A review of the records in the health centers in the vicinity of the area where the primary case originated also did not reveal any increase in febrile illnesses. Prior to symptom onset of the primary case, one farmer reported 3 successive goat abortions every month from October 2015 to December 2015. In February 2015, one farmer also reported 3 cow abortions within the same week. Conclusion : There appears to be an outbreak among the livestock however there is no increase in febrile illnesses in the community. Health education should be done in the community to promote use of mosquito nets and protection of abattoir workers. The ministry of Agriculture, Animal Industries and Fisheries (MAAIF) should work with the Ministry of Health to assess the existence of the virus among the animals and mosquitoes. MAAIF should also ensure enforcement of the laws prohibiting the sale and consumption of sick or dead animals. All animals in the area should be vaccinated against RVF and health workers should be sensitized to consider RVF as a differential diagnosis in non-malaria febrile illness.