Bacterial meningitis: Aetiology, risk factors, disease trends and severe sequelae during 50 years in Sweden

Abstract

Background Bacterial meningitis (BM) is a rare but severe infection. Few population‐based studies have characterised BM episodes and sequelae over long periods. Methods This was a population‐based observational cohort study with national coverage, using data on aetiological pathogens, sex, premorbid conditions, steroid pretreatment, severe sequelae and birth, death and diagnosis dates collected from 10,339 patients with BM reported to the National Board of Health and Welfare in Sweden between 1964 and 2014. Results During the 50‐year study period, the incidence of BM decreased in young children, but not in the elderly. The most common cause of BM was pneumococci (34%), followed by Haemophilus influenzae (26%), and meningococci (18%), mainly community acquired. Premorbid conditions were found in 20%. After the H. influenzae type b vaccine was introduced in 1993, the BM incidence decreased by 36%. Following pneumococcal conjugated vaccine introduction in 2009, the incidence and 30‐day mortality from pneumococcal meningitis decreased by 64% and 100%, respectively, in previously healthy children, and the 30‐day mortality decreased by 64% among comorbid adults. The BM incidence in immunosuppressed patients increased by 3% annually post vaccine introduction. The 30‐day mortality was 3% in children and 14% in adults, and the rate of severe sequelae was 44%. On average, patients lost 11 years of healthy life due to BM. Conclusion The introduction of conjugated vaccines into the childhood vaccination program has reduced the incidence of BM in young children, but not in adults. Post vaccine introduction, patients present with more premorbid conditions and other bacterial causes of BM, emphasising the need for a correct diagnosis when treating these infections.

Diagnosis of Neurological Infections in Pediatric Patients from Cell-Free DNA Specimens by Using Metagenomic Next-Generation Sequencing

“…Consistently, we found that infants had the highest abundance of pathogenic species and rates of meningitis secondary to H. influenzae , and S. pneumoniae was highest among children <5 years of age ( 49 – 51 ). Meanwhile, S. pneumoniae was the main causative pathogen identified in all three age categories, and H. influenzae was only identified in infants and preschool children, which was in accordance with a previous Chinese report from Yunnan ( 52 ) and other studies from Sweden ( 53 ), Brazil ( 54 ), and England and Wales ( 55 ) but differed from data collected in mainland China ( 56 ). Most children and adolescents with viral CNS infections can recover completely in ~7 to 10 days without specific treatments ( 9 ).…”

Klebsiella pneumoniae sepsis complicated with central nervous system involvement: A case series

“…Klebsiella pneumoniae rarely causes community‐acquired CNS infections in most countries, including Japan. 1 , 2 , 3 , 4 , 5 Meningitis due to gram‐negative bacilli, including K. pneumoniae , is uncommon, with only a few cases having been described in a multicenter survey and in a hospital‐based survey undertaken in Japan. 4 , 5 This trend is similar in the United States 1 and in Europe 2 , 3 whereas, in Taiwan, the incidence of community‐acquired bacterial meningitis due to K. pneumoniae has been reported to be high.…”

“… 1 , 2 , 3 , 4 , 5 Meningitis due to gram‐negative bacilli, including K. pneumoniae , is uncommon, with only a few cases having been described in a multicenter survey and in a hospital‐based survey undertaken in Japan. 4 , 5 This trend is similar in the United States 1 and in Europe 2 , 3 whereas, in Taiwan, the incidence of community‐acquired bacterial meningitis due to K. pneumoniae has been reported to be high. 8 , 9 This epidemiological difference may be related to the accumulation of cases of hypervirulent K. pneumoniae ( hvKp ) in certain Asian countries.…”

“…Klebsiella pneumoniae rarely causes community‐acquired CNS infections in most countries, including Japan 1–5 . Meningitis due to gram‐negative bacilli, including K. pneumoniae , is uncommon, with only a few cases having been described in a multicenter survey and in a hospital‐based survey undertaken in Japan 4,5 .…”

“…Klebsiella pneumoniae ( K. pneumoniae ) causes nosocomial and community‐acquired infections of the urinary and biliary tracts and pneumonia. Community‐acquired central nervous system (CNS) infections with K. pneumoniae are rare among adults in most countries, 1 , 2 , 3 , 4 , 5 including Japan. 4 , 5 Invasive liver abscess syndrome (ILAS) due to K. pneumoniae is known to cause CNS metastatic complications, resulting in high morbidity and mortality rates.…”