Adult influenza A (H1N1) related encephalitis: A case report

Case Report IntroductIonInfluenza is an acute, usually self-limited, febrile illness caused by infection with influenza type A or B virus.While respiratory symptoms are the most common, myositis, rhabdomyolysis, myoglobinuria, myocarditis, pericarditis, and central nervous system (CNS) involvement have all been described with influenza virus infections.[1] Influenza related encephalitis/encephalopathy is more common is paediatric population, however neurological complications appears to have increased after 2009 pandemic.[2][3] Only eight cases with adult influenza A related-encephalopathy has been reported by Victoria Bangualid and Judith Berger.[4] CNS complications may manifest as encephalopathy, seizures, and Guillain-Barré Syndrome.[5][6][7][8] The diagnosis is difficult because there is no uniform clinical presentation; influenza virus is rarely detected in cerebrospinal fluid (CSF) and may no longer be detectable in respiratory samples when the patient presents with neurological symptoms.[9] We would like to report a patient with adult H1N1 influenza, who developed encephalitis. case reportA 76-year-old , an elderly female in her mid 70s, was admitted to our Intensive Care Unit with chief complaints of sore throat, sneezing, and fever for the last 7 days, along with oliguria during the last 3 days.She was initially treated at a district hospital with macrolides, antipyretics, and aminoglycosides.Oseltamivir 75 mg bd was initiated 1 day prior to admission.Her comorbidities included hypertension and rheumatoid arthritis.The patient was on tablet methotrexate which she had left 2 months prior to admission.Her chest radiograph was suggestive of right-sided pneumonia.On admission, she was conscious, alert, hypotensive, and maintaining saturation on room air.Her mean arterial pressure improved after fluid resuscitation.Her initial laboratory results showed thrombocytopenia (63,000/μl), a deranged renal profile (blood urea nitrogen -38 mg/dl, creatinine 2.1 mg/dl), and hyponatremia (124 mg/dl).Her total leukocyte count, liver functions, and coagulation profile were within normal limits.Chest X-ray showed bilateral homogenous opacities in all lung fields.Her antibiotic regimen was modified toThe year 2009-2010 saw H1N1 influenza outbreaks occurring in almost all countries of the world, causing the WHO to declare it a pandemic of an alert level of 6.In India, H1N1 influenza outbreaks were again reported in late 2014 and early 2015.Since then, sporadic cases of H1N1 influenza have been reported.H1N1 influenza usually presents itself with respiratory tract symptoms.In a minority of patients, abdominal symptoms may occur as well.Acute influenza-associated encephalopathy/encephalitis mostly occurs in the pediatric population, whereas in adults, it is a rare complication.The incidence of neurological complications appears to have increased after the 2009 H1N1 influenza A virus pandemic.We would like to draw attention to an adult patient case who initially presented with respiratory symptoms but then deteriorated and developed encephalitis, which is rarely reported.As per literature reviewed by Victoria Bangualid and Judith Berger on PubMed, only 21 cases of neurological complications were found in adult influenza A patients, out of whom 8 had encephalopathy.