title: Comparison of the clinical presentations of Naegleria fowleri primary amoebic meningoencephalitis with pneumococcal meningitis: a case-control study.
abstract: BACKGROUND
  Primary amoebic meningoencephalitis (PAM) is a rare but fatal infection caused by Naegleria fowleri. The infection is acquired by deep nasal irrigation with infected water. Patients present with signs and symptoms similar to pneumococcal meningitis, leading to delayed diagnosis and treatment and hence high mortality.
  
  
  METHODS
  We conducted a case-control study comparing culture proven cases of PAM with pneumococcal meningitis presenting to our center between April 2008 and September 2014. Only patients with blood and/or cerebrospinal fluid cultures positive for Streptococcus pneumoniae during the same time period were included for comparison.
  
  
  RESULTS
  There were 19 cases of PAM and pneumococcal meningitis, each. When comparing PAM with pneumococcal meningitis, patients with PAM were more likely to be male (89.5 vs. 36.8 %), younger (mean age: 30 vs. 59 years), present with seizures (42.1 vs. 5.3 %). Both groups of patients presented with similar vital signs and there were no remarkable differences on physical examinations, Glasgow Coma Scale scores, laboratory and radiological investigations and cerebrospinal fluid parameters. PAM was also more likely to present if the city's average maximum temperature was higher in the previous week (mean: 34.6 vs. 30 °C). There was history of fresh water contact in only one patient. On multivariate analysis, PAM was more likely if patients presented when the city's average maximum temperature was high, being young males.
  
  
  CONCLUSIONS
  PAM and pneumococcal meningitis remain virtually indistinguishable; however, these predictive features should be validated in a prospective study and may lead to a viable algorithm for early management of these patients.
authors.affiliation: Medical Graduate, Aga Khan University, Karachi, Pakistan.
authors.forename: Mohammad Faizan
authors.initials: MF
authors.lastname: Zahid
authors.affiliation: Medical College, Aga Khan University, Karachi, Pakistan.
authors.forename: Muhammad Hamza
authors.initials: MH
authors.lastname: Saad Shaukat
authors.affiliation: Department of Medicine, Aga Khan University, Karachi, Pakistan.
authors.forename: Bilal
authors.initials: B
authors.lastname: Ahmed
authors.affiliation: Section of Microbiology, Department of Pathology and Laboratory Medicine, Aga Khan University, Karachi, Pakistan.
authors.forename: Mohammad Asim
authors.initials: MA
authors.lastname: Beg
authors.affiliation: Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan.
authors.forename: Muhammad Masood
authors.initials: MM
authors.lastname: Kadir
authors.affiliation: Section of Infectious Diseases, Department of Medicine, Aga Khan University, Karachi, Pakistan. faisal.mahmood@aku.edu.
authors.forename: Syed Faisal
authors.initials: SF
authors.lastname: Mahmood
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D020808:Central Nervous System Protozoal Infections / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008586:Meningitis, Pneumococcal / Q000175:diagnosis* / Q000453:epidemiology*; D008875:Middle Aged; D016848:Naegleria fowleri; D012189:Retrospective Studies; D055815:Young Adult
keywords: Acute bacterial meningitis; Clinical presentation; Naegleria fowleri; Primary amoebic meningoencephalitis; Streptococcus pneumoniae