{"doi":"10.1016/j.lanwpc.2021.100380","title":"Understanding the etiology and epidemiology of meningitis and encephalitis: now and into the future","abstract":"Meningitis and encephalitis are important causes of morbidity and mortality worldwide. Meningitis is one of the four largest contributors of neurological disability-adjusted life years (DALY) globally.1Global, regional, and national burden of neurological disorders, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol. 2019; 18(5):459-480.Google Scholar In the U.S., from 2000-2010, there were approximately seven encephalitis hospitalizations per 100,000 population.2George BP Schneider EB Venkatesan A. Encephalitis hospitalization rates and inpatient mortality in the United States, 2000-2010.PLoS One. 2014; 9e104169Google Scholar The international consortium for encephalitis stated that specific etiologies are found in <50% of cases of encephalitis.3Venkatesan A Tunkel AR Bloch KC et al.Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium.Clin Infect Dis. 2013; 57: 1114-1128Google Scholar Although several studies have assessed the frequency of various pathogens in encephalitis in countries such as the USA, France, Australia and England, large-scale studies of this nature had previously not been carried out in Asian populations.4Stahl JP Mailles A. What is new about epidemiology of acute infectious encephalitis?.Curr Opin Neurol. 2014; 27: 337-341Google Scholar A review of the infectious causes of encephalitis, in 2016, found herpes simplex virus (HSV) to be the most frequently reported pathogen (in 65% of studies), followed by Varicella-zoster virus (VZV) and Enteroviruses, with important regional differences, such as the Japanese encephalitis virus (JEV) in Asia.5Boucher A Herrmann JL Morand P et al.Epidemiology of infectious encephalitis causes in 2016.Med Mal Infect. 2017; 47: 221-235Google Scholar 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.6Wang L-P Yuan Y Liu Y-L et al.Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study.The Lancet Regional Health - Western Pacific. 2022; 20100361Summary Full Text Full Text PDF Scopus (2) Google Scholar This large study, spanning a decade, is an important contribution towards understanding the etiology and epidemiology of meningitis and encephalitis. Wang et al6Wang L-P Yuan Y Liu Y-L et al.Etiological and epidemiological features of acute meningitis or encephalitis in China: a nationwide active surveillance study.The Lancet Regional Health - Western Pacific. 2022; 20100361Summary Full Text Full Text PDF Scopus (2) Google Scholar 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 most important one was age; enterovirus was more common in children (age <18 years), and HSV and JEV were more frequently detected in adults (age >18 years). For bacterial infections, Streptococcus pneumoniae was more common in children aged <5 years, Neisseria meningitidis in children between ages 5-18 years, and Staphylococcus Aureus in adults. The pathogen spectrum also showed geographical and seasonal variations. There were some differences in the pathogens detected in hospitalized patients versus outpatients. Additionally, population density and gross domestic product, which are often reflective of socioeconomic status, affected pathogen circulation. The authors also analyzed the year-to-year variation of detected pathogens, which showed, except for JEV, a decrease ","journal":"The Lancet Regional Health - Western Pacific","year":2022,"id":272387,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":11,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.809,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":231250,"name":"Eoin P. Flanagan","orcid":"0000-0002-6661-2910","position":1,"is_corresponding":false},{"id":761762,"name":"Vyanka Redenbaugh","orcid":"0000-0001-6400-7760","position":0,"is_corresponding":true}],"reference_count":10,"raw_metadata":null,"created_at":"2026-07-19T00:27:43.806977Z","pmid":"35112093","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}