Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study

Abstract

Background Acute meningitis or encephalitis (AME) results from a neurological infection causing high case fatality and severe sequelae. AME lacked comprehensive surveillance in China.Methods Nation-wide surveillance of all-age patients with AME syndromes was conducted in 144 sentinel hospitals of 29 provinces in China. Eleven AME-causative viral and bacterial pathogens were tested with multiple diagnostic methods.Findings Between 2009 and 2018, 20,454 AME patients were recruited for tests. Based on 9,079 patients with allfour-virus tested, 28.43% (95% CI: 27.50%-29.36%) of them had at least one virus-positive detection. Enterovirus was the most frequently determined virus in children <18 years, herpes simplex virus and Japanese encephalitis virus were the most frequently determined in 18À59 and ≥60 years age groups, respectively. Based on 6,802 patients with all-seven-bacteria tested, 4.43% (95% CI: 3.94%-4.91%) had at least one bacteria-positive detection, Streptococcus pneumoniae and Neisseria meningitidis were the leading bacterium in children aged <5 years and 5À17 years, respectively. Staphylococcus aureus was the most frequently detected in adults aged 18À59 and ≥60 years. The pathogen spectrum also differed statistically significantly between northern and southern China. Joinpoint analysis revealed age-specific positive rates, with enterovirus, herpes simplex virus and mumps virus peaking at 3À6 years old, while Japanese encephalitis virus peaked in the ≥60 years old. As age increased, the positive rate for

Understanding the etiology and epidemiology of meningitis and encephalitis: now and into the future

“…On joinpoint analysis, the authors found an increasing turnpoint at 25 years of age for JEV, hence, they advocated for a booster vaccine for this at the age of 25. 6 Similarly, a previous study showed the benefit of meningitis B vaccinations in preventing Neisseria meningitidis infections, demonstrating the key role of vaccinations in meningitis infection prevention. 7 …”

“…In The Lancet Regional Health – Western Pacific , Wang and colleagues report the results of a nationwide surveillance study across China, looking for viral and bacterial pathogens in patients with acute meningitis or encephalitis. 6 This large study, spanning a decade, is an important contribution towards understanding the etiology and epidemiology of meningitis and encephalitis.…”

“…Wang et al 6 studied 11 different bacterial and viral etiologies (enterovirus, HSV, JEV, Mumps virus, Neisseria meningitidis, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae type b, Escherichia coli, Mycobacterium tuberculosis, and Streptococcus suis) and assessed their relative frequencies, demographics, and time trends. They identified certain factors that were predictive of the type of pathogen detected.…”

“…The authors also analyzed the year-to-year variation of detected pathogens, which showed, except for JEV, a decrease in the number of infections with viruses. 6 …”

“…It is notable that an infectious cause was identified in only 30% of patients in this study. 6 This could be due to a limitation of the study being that many pathogens that may cause meningitis or encephalitis were not assessed for (e.g., bacteria: listeria monocytogenes, leptospirosis; fungi: cryptococcus neoformans; viruses: human immunodeficiency virus and VZV). Moreover, novel techniques such as metagenomic next generation sequencing, by assessing for a wide range of etiologies in an unbiased manner, may allow identification of infectious agents not initially considered on the differential diagnosis.…”