Ocular manifestation of Rift Valley Fever as observed in the 2006 epidemic in Kenya

Abstract

Introduction: Rift Valley fever (RVF)is a febrile viral zoonotic disease that affects ruminants primarily and humans as secondary host. It occurs in low rainfall plains after abnormally wet season and flooding which promotes mosquito breeding. Retinitis, macula oedema and transient non-granulommatous anterior uveitis are common ocular manifestation of the disease" 9, 10, 12, 18. This study aimed at finding the clinical picture during the 2006/2007 epidemic in Kenya. Objective: To establish the prevalence and pattern of ocular findings in people with Rift Valley Fever during the Kenyan epidemic . Methodology: All the forty seven (47)cases who tested positive to RVFvirus by peR or IgM antibodies in Baringo and Machakos districts were interviewed and ocular examination with a slit lamp done. A torch was used to assess pupillary reflexes. Binocular slit lamp fundoscopy with 90 dioptre loupe and or binocular indirect fundoscopy was then done with dilated pupil. The data was entered into and analyzed using the SPSSsoftware package version 12.0. Results: Of the forty seven cases seen 55.3% were males; majority of the males were herders (38.5%)and most females were domestic workers (57.1%). Initial symptoms were fever (91.5%), generalized weakness (91.5%), and headache (89.5%). Blurred vision was reported in 76.6% of the cases. The subjects gave history of mosquito bites (95.7%)and contact with animal tissues during cooking (53.2%), care of sick animals (80.9%), drinking unboiled milk (43.2%) and delivering aborting animals (36.2%). Ocular signs attributable to RVF were mainly retinal and occurred in 43.1% of the subjects. Macula oedema (33.7%), retinitis (22.1%) and retinal vasculitis were the most significant macular and paramacular findings in the eyes. Vision was affected significantly by their presence. Conclusion: There were retinal lesions in 43.1% of our cases that could be explained by RVFinfection. The retinal lesions look similar to those seen in acute posterior multifocal placoid pigmentary epitheliopathy (APMPPE).The findings of this survey may justify the involvement of health workers in the initial response to the epidemic. Recommendations: Eye workers need to be involved in early response to RVF epidemic, and long-term follow-up of cases that had ocular features of RVF to determine long-term sequelae and potential foveal involvement