H1N1 Encephalitis ‘Sans’ Flu – A Case Report

Year 2021, , 166 - 169, 15.09.2021

Anup Halappanavar Subrat Kumar Nanda Faiz Mh Ahmad R Srınath

https://doi.org/10.5799/jmid.993996

Abstract

Influenza H1N1 infection is a viral infection with a seasonal preponderance, usually presents with flu-like symptoms, and rarely has extra-respiratory manifestations. It has taken a pandemic form on few occasions in the past. Involvement of the Central Nervous System (CNS), though rare, is described.
We describe a 42-year immunocompromised woman who presented with an acute febrile rapidly progressive encephalopathic illness without the usual flu-like symptoms. Instead, she had widespread Magnetic Resonance Imaging (MRI) brain changes resulting in a fatal outcome. Such an encephalitic presentation of H1N1 infection without respiratory involvement has never been reported. J Microbiol Infect Dis 2021; 11(3):166-169.

Keywords

H1N1 Infection, Encephalitis, Magnetic Resonance Imaging

References

• 1. Rothberg MB, Haessler SD. Complications of seasonal and pandemic influenza. Crit Care Med 2010; 38(4 Suppl): e91–97.
• 2. Prerna A, Lim, JY, Tan NW, et al. Neurology of the H1N1 pandemic in Singapore: a nationwide case series of children and adults. J Neurovirol 2015; 21(5):491-499.
• 3. Togashi T, Matsuzono Y, Narita M, et al. Influenza-associated acute encephalopathy in Japanese children in 1994-2002. Virus Res 2004; 103:75–78.
• 4. Studahl M. Influenza virus and CNS manifestations. J Clin Virol 2003; 28:225–232.
• 5. Toovey S. Influenza-associated central nervous system dysfunction: a literature review. Travel Med Infect Dis 2008; 6:114–124.
• 6. Bengualid V and Berger J. Neurologic complications of acute influenza in adults: Case report and review of the literature. J Neurosci Clin Res 2017; 2:1.
• 7. Devinder M, Arun K, Pratibha V, et al. Indian J Crit Care Med 2018; 22(5): 384–387. 8. Kimura S, Ohtuki N, Nezu A, Tanaka M, Takeshita S. Clinical and radiological variability of influenza-related encephalopathy or encephalitis. Acta Paediatr Jpn 1998; 40:264–270.
• 9. Takanashi J, Barkovich AJ, Yamaguchi K, et al. Influenza-associated encephalitis/encephalopathy with a reversible lesion in the splenium of the corpus callosum: a case report and literature review. Am J Neuroradiol 2004; 25:798–802.
• 10. Lyon JB, Remigio C, Milligan T, et al. Acute necrotizing encephalopathy in a child with H1N1 influenza infection. Pediatr Radiol 2010; 40:200–205.