West nile virus infection: One-Year postkidney transplant

Abstract

West Nile virus (WNV) infections are a mosquito-borne virus of the Flaviviridae family. The clinical feature of the virus varies between individuals from being asymptomatic in most of the cases to severe central nervous system disease manifested as meningitis, encephalitis, and paralysis. Diabetic nephropathy patient with microvascular and macrovascular complications, who received a kidney transplant a year ago on immunosuppressive therapy, presented with a three-day history of upper respiratory tract infection and fever. He lived in an endemic area of brucella infection. He underwent a thorough and full evaluation with various laboratory and radiological evaluations. The patient was started empirically on ceftriaxone and acyclovir for a presumptive diagnosis of herpes encephalitis and covering also Listeria with ampicillin. The patient did not improve with the initial management, so a T2-weighted magnetic resonance imaging of the brain executed that showed nonspecific hyper-intensity in the left frontal area suggestive of microangiopathic changes. WNV-neutralizing antibodies were positive with a high titer >1:640, whereas WNV RNA was not detected in the plasma sample. In the serum sample, WNV IgM and IgG were both positive. WNV IgM antibodies were detected with 6.55 and 5.97 antibody index and were done by a semiquantitative ELISA. Furthermore, WNV-neutralizing antibodies were positive as well as with a titer of 1:80. As there is no specific antiviral treatment available, the patient management was supportive; reduction in immunosuppressive agents and the use of IV IgG. This is the first reported case of one-year post renal transplant who developed WNV encephalitis and neuropathy with significant response to immunoglobulin after 18 days of infections.