A descriptive study on prevalence pattern of Japanese encephalitis in State of Manipur

Background and Objective

Japanese encephalitis (JE) surveillance is not well established in many countries, and laboratory confirmation is challenging, the true extent and prevalence of the virus and burden of disease are not well understood. It is estimated that 67,900 clinical cases of JE occur annually despite the widespread availability of vaccine, with approximately 13,600-20,400 deaths and an overall incidence rate of 1.8/100,000 in the 24 countries with JE risk. The present study aimed at determining the prevalence rate (PR) and distribution (time, place and person) of JE cases in Manipur. This descriptive study was conducted over 24-month period (2016-2017).

Materials and Methods

A total of 1770 cases of acute encephalitis syndrome tested for JE including 251 confirmed JE were diagnosed by IgM antibody-capture enzyme-linked immunosorbent assay.

Results

The JE cases were most commonly reported in the age group of >15 years. Most of JE prevalence was seen in rural distribution in our study. There is a strong seasonal pattern of JE occurrence in Manipur which peaked in July-August and declined by October each year, which corresponds to the monsoon season. The JE cases were reported in all the districts of the state expanding in the plains and hill regions.

Conclusions

The changing pattern of JE cases among different age groups was also observed in our study. The present study reveals the changing pattern of the prevalence of JE in the State of Manipur and initiated a systematic approach of JE surveillance also highlights the need for further expanding of surveillance across the state.

Epidemiology of central nervous system infectious diseases: a meta-analysis and systematic review with implications for neurosurgeons worldwide

OBJECTIVE

Central nervous system (CNS) infections cause significant morbidity and mortality and often require neurosurgical intervention for proper diagnosis and treatment. However, neither the international burden of CNS infection, nor the current capacity of the neurosurgical workforce to treat these diseases is well characterized. The objective of this study was to elucidate the global incidence of surgically relevant CNS infection, highlighting geographic areas for targeted improvement in neurosurgical capacity.

METHODS

A systematic literature review and meta-analysis were performed to capture studies published between 1990 and 2016. PubMed, EMBASE, and Cochrane databases were searched using variations of terms relating to CNS infection and epidemiology (incidence, prevalence, burden, case fatality, etc.). To deliver a geographic breakdown of disease, results were pooled using the random-effects model and stratified by WHO region and national income status for the different CNS infection types.

RESULTS

The search yielded 10,906 studies, 154 of which were used in the final qualitative analysis. A meta-analysis was performed to compute disease incidence by using data extracted from 71 of the 154 studies. The remaining 83 studies were excluded from the quantitative analysis because they did not report incidence. A total of 508,078 cases of CNS infections across all studies were included, with a total sample size of 130,681,681 individuals. Mean patient age was 35.8 years (range: newborn to 95 years), and the male/female ratio was 1:1.74. Among the 71 studies with incidence data, 39 were based in high-income countries, 25 in middle-income countries, and 7 in low-income countries. The pooled incidence of studied CNS infections was consistently highest in low-income countries, followed by middle- and then high-income countries. Regarding WHO regions, Africa had the highest pooled incidence of bacterial meningitis (65 cases/100,000 people), neurocysticercosis (650/100,000), and tuberculous spondylodiscitis (55/100,000), whereas Southeast Asia had the highest pooled incidence of intracranial abscess (49/100,000), and Europe had the highest pooled incidence of nontuberculous vertebral spondylodiscitis (5/100,000). Overall, few articles reported data on deaths associated with infection. The limited case fatality data revealed the highest case fatality for tuberculous meningitis/spondylodiscitis (21.1%) and the lowest for neurocysticercosis (5.5%). In all five disease categories, funnel plots assessing for publication bias were asymmetrical and suggested that the results may underestimate the incidence of disease.

CONCLUSIONS

This systematic review and meta-analysis approximates the global incidence of neurosurgically relevant infectious diseases. These results underscore the disproportionate burden of CNS infections in the developing world, where there is a tremendous demand to provide training and resources for high-quality neurosurgical care.

Aetiologies of central nervous system infections in adults in Kathmandu, Nepal: a prospective hospital-based study

We conducted a prospective hospital based study from February 2009-April 2011 to identify the possible pathogens of central nervous system (CNS) infections in adults admitted to a tertiary referral hospital (Patan Hospital) in Kathmandu, Nepal. The pathogens of CNS infections were confirmed in cerebrospinal fluid (CSF) using molecular diagnostics, culture (bacteria) and serology. 87 patients were recruited for the study and the etiological diagnosis was established in 38% (n = 33). The bacterial pathogens identified were Neisseria meningitidis (n = 6); Streptococcus pneumoniae (n = 5) and Staphylococcus aureus (n = 2) in 13/87(14%). Enteroviruses were found in 12/87 (13%); Herpes Simplex virus (HSV) in 2/87(2%). IgM against Japanese encephalitis virus (JEV) was detected in the CSF of 11/73 (15%) tested samples. This is the first prospective molecular and serology based CSF analysis in adults with CNS infections in Kathmandu, Nepal. JEV and enteroviruses were the most commonly detected pathogens in this setting.