Most cases of RVF resolve spontaneously and completely. However, sometimes fatigue and weakness persist for weeks or months.
Overall case fatality rates for patients with uncomplicated Rift Valley fever virus infection varies between epidemics; however, it is usually around 1%. For people who develop the haemorraghic form the case fatality is much higher at approximately 50%.[11]World Health Organization. Rift Valley fever. Feb 2018 [internet publication].
http://www.who.int/mediacentre/factsheets/fs207/en
Ocular complications can resolve spontaneously and completely within 10 to 12 weeks with no sequelae.[1]National Institute for Communicable Diseases. Healthcare workers guidelines on Rift Valley fever (RVF). Jan 2021 [internet publication].
https://www.nicd.ac.za/wp-content/uploads/2021/02/Rift-Valley-Fever-2021-Guidelines-for-Health-Care-Workers_110321.pdf
[2]Jankovic J, Mazziotta J, Pomeroy S, et al. Bradley and Daroff's neurology in clinical practice, 2-volume set. 8th ed. Elsevier. 2021.[12]Centers for Disease Control and Prevention. Rift Valley fever. Jun 2023 [internet publication].
https://www.cdc.gov/vhf/rvf
[51]Al-Hazmi A, Al-Rajhi AA, Abboud EB, et al. Ocular complications of Rift Valley fever outbreak in Saudi Arabia. Ophthalmology. 2005 Feb;112(2):313-8.
http://www.ncbi.nlm.nih.gov/pubmed/15691569?tool=bestpractice.com
Ocular complications resulting from lesions in the macula can result in permanent vision loss and ocular damage in approximately 70% of patients.[1]National Institute for Communicable Diseases. Healthcare workers guidelines on Rift Valley fever (RVF). Jan 2021 [internet publication].
https://www.nicd.ac.za/wp-content/uploads/2021/02/Rift-Valley-Fever-2021-Guidelines-for-Health-Care-Workers_110321.pdf
[32]LaBeaud AD, Muchiri EM, Ndzovu M, et al. Interepidemic Rift Valley fever virus seropositivity, northeastern Kenya. Emerg Infect Dis. 2008 Aug;14(8):1240-6.
https://wwwnc.cdc.gov/eid/article/14/8/08-0082_article
http://www.ncbi.nlm.nih.gov/pubmed/18680647?tool=bestpractice.com
[35]LaBeaud AD, Muiruri S, Sutherland LJ, et al. Postepidemic analysis of Rift Valley fever virus transmission in northeastern Kenya: a village cohort study. PLoS Negl Trop Dis. 2011;5:e1265.
http://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0001265
http://www.ncbi.nlm.nih.gov/pubmed/21858236?tool=bestpractice.com
[53]Newman-Garhardt S, Muiruri S, Muchiri E, et al. Potential for autoimmune pathogenesis of Rift Valley fever virus retinitis. Am J Trop Med Hyg. 2013;89:495-7.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3771287
http://www.ncbi.nlm.nih.gov/pubmed/23918215?tool=bestpractice.com
Neurological complications are associated with severe disease and may materialise up to 60 days after initial symptom onset. The spectrum of neurological complications extends from mild (intense headaches, disorientation) to severe (coma, memory loss). Residual neurological deficit and sequelae are common with severe complications. Supportive care can improve prognosis.[1]National Institute for Communicable Diseases. Healthcare workers guidelines on Rift Valley fever (RVF). Jan 2021 [internet publication].
https://www.nicd.ac.za/wp-content/uploads/2021/02/Rift-Valley-Fever-2021-Guidelines-for-Health-Care-Workers_110321.pdf
[2]Jankovic J, Mazziotta J, Pomeroy S, et al. Bradley and Daroff's neurology in clinical practice, 2-volume set. 8th ed. Elsevier. 2021.[12]Centers for Disease Control and Prevention. Rift Valley fever. Jun 2023 [internet publication].
https://www.cdc.gov/vhf/rvf
[50]World Organisation for Animal Health. Rift Valley fever animal disease information. 2018 [internet publication].
https://www.woah.org/en/disease/rift-valley-fever