Clinical presentation, etiology, and survival in adult acute encephalitis syndrome in rural Central India

Abstract

Background Acute encephalitis syndrome (AES) is a constellation of symptoms that includes fever and altered mental status. Most cases are attributed to viral encephalitis (VE), occurring either in outbreaks or sporadically. We conducted hospital-based surveillance for sporadic adult-AES in rural Central India in order to describe its incidence, spatial and temporal distribution, clinical profile, etiology and predictors of mortality. Methods All consecutive hospital admissions during the study period were screened to identify adult-AES cases and were followed until 30-days of hospitalization. We estimated incidence by administrative sub-division of residence and described the temporal distribution of cases. We performed viral diagnostic studies on cerebrospinal fluid (CSF) samples to determine the etiology of AES. The diagnostic tests included RT-PCR (for enteroviruses, HSV 1 and 2), conventional PCR (for flaviviruses), CSF IgM capture ELISA (for Japanese encephalitis virus, dengue, West Nile virus, Varicella zoster virus, measles, and mumps). We compared demographic and clinical variables across etiologic subtypes and estimated predictors of 30-day mortality. Results A total of 183 AES cases were identified between January and October 2007, representing 2.38% of all admissions. The incidence of adult AES in the administrative subdivisions closest to the hospital was 16 per 100,000. Of the 183 cases, a non-viral etiology was confirmed in 31 (16.9%) and the remaining 152 were considered as VE suspects. Of the VE suspects, we could confirm a viral etiology in 31 cases: 17 (11.2%) enterovirus; 8 (5.2%) flavivirus; 3 (1.9%) Varicella zoster; 1 (0.6%) herpesvirus; and 2 (1.3%) mixed etiology); the etiology remained unknown in remaining 121 (79.6%) cases. 53 (36%) of the AES patients died; the case fatality proportion was similar in patients with a confirmed and unknown viral etiology (45.1 and 33.6% respectively). A requirement for assisted ventilation significantly increased mortality (HR 2.14 (95% CI 1.0–4.77)), while a high Glasgow coma score (HR 0.76 (95% CI 0.69–0.83)), and longer duration of hospitalization (HR 0.88 (95% CI 0.83–0.94)) were protective. Conclusion This study is the first description of the etiology of adult-AES in India, and provides a framework for future surveillance programs in India.

Aetiologies of Central Nervous System infections in adults in Kathmandu, Nepal: A prospective hospital-based study

“…A provincial hospital based study done in Vietnam found enteroviruses in CSF by real-time RT-PCR in 10% of children and in 8% of adults with a CNS infection25. A recent hospital-based study in central India reported 11% of the adult patients with CNS infection had enteroviruses26. In our study, 13% (n = 12) of the patients with CNS infection had enteroviruses.…”

Encephalitic Arboviruses: Emergence, Clinical Presentation, and Neuropathogenesis

“…Additional encephalitic arboviruses that lead to neuroinvasive disease with neurocognitive sequelae in American patients include SLEV, LACV, EEEV, and Powassan virus, with total case numbers in the hundreds [94][95][96][97]. Finally, worldwide, encephalitic arboviruses, including JEVand RVFV, cause neurologic illness at the rate of 50 to 100,000 cases/year with neurocognitive sequelae in survivors [98][99][100]. There are currently no diagnostic or treatment modalities for cognitive sequelae in patients that recover from arbovirus encephalitides.…”

Non-Polio Enteroviruses, the Neglected and Emerging Human Pathogens:Are we Waiting for the Sizzling Enterovirus Volcano to Erupt?

“…Though these cases were originally presumed to be due to Japanese encephalitis virus, they turned out to be negative for JEV. A few investigations revealed enterovirus association with these encephalitis cases (Joshi et al, 2012;Joshi et al, 2013;Sapkal et al, 2009;Kumar et al, 2011;Kumar et al, 2012;Lewthwaite et al, 2010), but there is no consensus on the serotype/s associated with the disease. Similarly, a few epidemiological studies on aseptic meningitis and acute hemorrhagic conjunctivitis cases from different regions of the country have been reported (Gopalakrishna 2007; Kumar et al, 2013;Madhavan et al, 2000;Maitreyi et al, 1999;Satpathy et al, 1996;Shukla et al, 2010), but a detailed analysis needs to be carried out.…”

“…A major proportion of these cases appear to be of non-Japanese Encephalitis Virus etiology, and enteroviruses have been implicated (Kakkar et al, 2013;Kumar et al, 2011;Kumar et al, 2012;Fowlkes et al, 2008;Sapkal et al, 2009;Joshi et al, 2012;Joshi et al, 2013;Reingold et al, 2013) and there is a need for systematic detailed study of the disease (Kakkar et al, 2013). Though epidemics of hemorrhagic conjunctivitis and handfoot-and mouth disease associated with enterovirus infections are being reported in the news (Times of India 2013) frequently from different parts of the country, very few have been investigated (Deshpande et al, 2003;Gopalakrishna et al, 2007;Gopalakrishna et al, 2012;Maitreyi et al, 1999;Madhavan et al, 2000).…”