Human Rift Valley Fever Outbreak in Kabale district, 2016

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1 Public Health Fellowship Program Field Epidemiology Track Human Rift Valley Fever Outbreak in Kabale district, 2016 Dr. Henry Kyobe Bosa MBChB, MSc Cohort 2016

2 Notification of suspected VHF, Kabale District On 7 th March 2016 Ministry of Health was notified of suspected viral hemorrhagic fever case A middle-aged, male abattoir worker hospitalized at Kabale Regional Referral Hospital Confirmed Rift Valley Fever (RVFV) by RT-PCR at Uganda Virus Research Institute, Entebbe. 2

3 Epidemic prone zoonotic disease RVF primarily is a mosquito-borne animal disease with a potential to infect humans Majority of human infections occur due to direct or indirect contact with blood or organs of infected animals Number of human outbreaks in E. Africa: recent one in Kenya in 2007, 404 cases (118 deaths) in multiple provinces 3

4 **Distribution, magnitude of major human RVF in Africa Country Year Cases n Fatalities n Estimated impact, US$ (X10 6 ) Egypt , Mauritania Senegal Kenya , Somalia , Somalia , Kenya , South Africa **Nanyingi et el,

5 Severe forms of RVF may cause death or permanent impairment* Duration Outcome Mild 2-6 days Mild illness complete remission Progression to severe form(s) Severe (8-10%) Ocular 1-3 weeks after mild phase 50% permanent vision loss Encephalitis 1-4 weeks after mild phase Residual neurological deficit may persist Hemorrhagic 50% fatality 5 *CDC, Updated Nov 2013

6 First human RVF outbreak in 38 years Seven RVF cases reported near Uganda Virus Research Institute on outskirts of Entebbe in 1968; Lunyo Nakiwogo Bunono Henderson, B.E, et al: Annals of Trop Med & Parat,

7 Objectives of epidemiological investigation To characterize the extent of the outbreak To Control the outbreak To propose public health interventions 7

8 Case definitions A suspect RVF case was defined as acute onset of fever (>37.5 o C), negative malaria test In addition to least two of the following symptoms; headache, muscle or joint pain any gastrointestinal symptom Confirmed case - suspected case with laboratory confirmation by detection of RVF RT-PCR or serum IgM antibodies by ELISA 8

9 Case finding Through community interviews: in the affected communities abattoir workers Review of clinical records at health facilities in the areas of the confirmed cases 9

10 Results of case finding 18 suspect cases were line-listed from active case-finding Two non-fatal RVF confirmed cases by RT-PCR 10

11 Characteristics of line-listed cases, n=18 Mean age (years) 33 Sex (%, Male) 78 Dead (%) 17 Occupation (%) Farmer 22 Butcher 11 Student 11 Pork roaster 6 Business 6 11

12 Clinical characteristics, n=18 Symptom % Fever 80 Abdominal pain 75 Bleeding 75 Confusion 60 Joint pains 44.4 Hepatomegaly 11 Bloody diarrhea 11 Coma 11 Loss vision 10 Sensitivity to light 10 12

13 Suspected epi linkage of confirmed cases 13 Feb 1Attends various health case facilities between 13 to 25 K, 16yr, male, student, Kamuganguzi S/C 5 days 18 Feb KF, 48yr, male, butcher, Kabale central Within RVF incubation period: 2 to 7 days KRRH OPD 22 nd Feb Admitted 7 March and confirmed 11 March for RVF PCR Pos 13 13

14 Summary description of confirmed cases Case Date of onset Age Sex Occupation Transmission (Feb 2016) (Years) (Probable mode) No1 13th 16 Male Student Vector No2 18 th 42 Male Butcher Meat handling 14

15 Summary of epidemiolgical findings The two confirmed cases were epidemiologically linked in terms of time Limited evidence of widespread transmission among abattoir workers in the period 5 months prior to outbreak, multiple cow and goat abortions were reported in nearby farms 15

16 Suspected outbreak of abortions in animal populations before human cases abortion abortion abortion abortion abortion abortion Purchase and sale of healthy, sick and dead animals Oct Nov Dec Jan Feb March Feb 13: Case No 1 Feb 18, Case No 2 16

17 Conclusion These are the first cases of human RVF infections in Uganda since The human RVF infections may have been random spillover from missed RVF outbreak from livestock. 17

18 Recommendations Early detection is critical in control of RVF. RVF sentinel surveillance amongst abattoir workers for detection of RVF in humans in the area Strengthen RVF surveillance in animals in a One Health Approach 18

19 Public Health Fellowship Program Field Epidemiology Track ESD, MoH Kabale DHT, DVO KRRH UVRI CDC PHFP MAAIF South Western Acknowledgment