Outcomes of West Nile encephalitis patients after 1 year of West Nile encephalitis outbreak in Kerala, India: A follow-up study

Abstract

We reported an acute encephalitis syndrome outbreak in Alappuzha district in Kerala, India during the year 2011. The etiology was confirmed to be West Nile virus lineage 1. Many encephalitis patients from this outbreak exhibited neurological sequelae post recovery. This study was aimed to assess the clinical outcomes of West Nile encephalitis confirmed case-patients after 1 year of acute illness. Forty West Nile virus confirmed encephalitis patients were selected from the 2011 outbreak was included in this study. Out of 40 cases, only 30 survived after 12 months. Among these 30 recovered case-patients, 27 (90%) consented for clinical follow-up and 23 (73.67%) of them consented for assessment of cognitive impairment and deposition of blood sample for antibody testing. The most common symptom observed in these patients was fatigue (25.93%). Other symptoms included dizziness (7.4%), decreased sense of hearing (7.4%) and decreased sense of smell (7.4%). Reduced power in limbs was found in 33.33% of the cases. Most of the patients (23.1%) were dependent on others for normal daily living activities. The patients also had probable risk of poor cognition (29.41%) and dementia (57.14%). None of the patients were positive for WNV specific IgM at 12 months post onset of disease. The study concluded that the long-term sequelae were noticed in WNV positive patients. Prevention effort should be focused on the elderly (≥60 years old) people who have a higher risk of severe sequelae. The state health authorities should create awareness among people in order to prevent the transmission of disease. J. Med. Virol. 88:1856-1861, 2016. © 2016 Wiley Periodicals, Inc.

Cochlear-Vestibular Impairment due to West Nile Virus Infection

“…Balance and gait abnormalities as a neurological manifestation of WNV infection have also been reported by other authors. 10,[17][18][19] The etiology of this deficit is still unclear, and may be multifactorial, possibly related to concurrent deficits in motor, neurosensory or vestibular function.…”

Long-term, West Nile virus-induced neurological changes: A comparison of patients and rodent models

“…Some concurrent diseases such as diabetes and hypertension have been associated with greater risk of sequelae ( Cook et al., 2010 ). Old age appears to increase the risk ( Murray et al., 2014 ; Patel et al., 2015 ; Balakrishnan et al., 2016 ), while younger age correlates with a greater chance of full recovery ( DeBiasi and Tyler, 2006 ). Gender appears to play a role as well: men are less likely to develop depression ( Nolan et al., 2012 ), and men tend to recover cognitive function faster than women ( Loeb et al., 2008 ).…”

A systematic study on the recent crisis in public health in Kerala

“…We can see that most of the diseases are highly communicable in the state of Kerala. These infections are mostly transmitted by mosquitoes 1,2,14,16,19,23,35,37 water 29,[32][33][34] , air 3,12,25,27 and direct and indirect contact 1,2,4,27,32-34 Figure 2. Many of the diseases are observed to occur in the rural areas and the poorer sections of the society who usually live in poor living conditions, don't have proper access to healthcare facilities and also lack the awareness of getting rid of these diseases 8,27,29,33,35 .…”

“…It is a zoonotic disease spread by mosquitoes of the genus Culex 18 . Prevalence of antibodies against Japanese encephalitis virus was found in people of the district of Alappuzha in Kerala 14 .…”

“…These viruses are transmitted to humans via mosquitoes of the genus Culex 13 . There had been many reported outbreaks of acute encephalitis reported in Alappuzha district of Kerala and upon subsequent serological tests, the prevalence of antibodies against West Nile virus was found in many of the people 14 . In 2011 there were reports of encephalitis outbreaks in Kerala attributed to the West Nile virus 15 .…”