title: Date palm sap linked to Nipah virus outbreak in Bangladesh, 2008.
abstract: BACKGROUND
  We investigated a cluster of patients with encephalitis in the Manikgonj and Rajbari Districts of Bangladesh in February 2008 to determine the etiology and risk factors for disease.
  
  
  METHODS
  We classified persons as confirmed Nipah cases by the presence of immunoglobulin M antibodies against Nipah virus (NiV), or by the presence of NiV RNA or by isolation of NiV from cerebrospinal fluid or throat swabs who had onset of symptoms between February 6 and March 10, 2008. We classified persons as probable cases if they reported fever with convulsions or altered mental status, who resided in the outbreak areas during that period, and who died before serum samples were collected. For the case-control study, we compared both confirmed and probable Nipah case-patients to controls, who were free from illness during the reference period. We used motion-sensor-infrared cameras to observe bat's contact of date palm sap.
  
  
  RESULTS
  We identified four confirmed and six probable case-patients, nine (90%) of whom died. The median age of the cases was 10 years; eight were males. The outbreak occurred simultaneously in two communities that were 44 km apart and separated by a river. Drinking raw date palm sap 2-12 days before illness onset was the only risk factor most strongly associated with the illness (adjusted odds ratio 25, 95% confidence intervals 3.3-∞, p<0.001). Case-patients reported no history of physical contact with bats, though community members often reported seeing bats. Infrared camera photographs showed that Pteropus bats frequently visited date palm trees in those communities where sap was collected for human consumption.
  
  
  CONCLUSIONS
  This is the second Nipah outbreak in Bangladesh where date palm sap has been implicated as the vehicle of transmission. Fresh date palm sap should not be drunk, unless effective steps have been taken to prevent bat access to the sap during collection.
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh. aziz.rahman@adelaide.edu.au
authors.forename: Muhammad Aziz
authors.initials: MA
authors.lastname: Rahman
authors.forename: Mohammad Jahangir
authors.initials: MJ
authors.lastname: Hossain
authors.forename: Sharmin
authors.initials: S
authors.lastname: Sultana
authors.forename: Nusrat
authors.initials: N
authors.lastname: Homaira
authors.forename: Salah Uddin
authors.initials: SU
authors.lastname: Khan
authors.forename: Mahmudur
authors.initials: M
authors.lastname: Rahman
authors.forename: Emily S
authors.initials: ES
authors.lastname: Gurley
authors.forename: Pierre E
authors.initials: PE
authors.lastname: Rollin
authors.forename: Michael K
authors.initials: MK
authors.lastname: Lo
authors.forename: James A
authors.initials: JA
authors.lastname: Comer
authors.forename: Luis
authors.initials: L
authors.lastname: Lowe
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rota
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Ksiazek
authors.forename: Eben
authors.initials: E
authors.lastname: Kenah
authors.forename: Yushuf
authors.initials: Y
authors.lastname: Sharker
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Luby
mesh_terms: D000293:Adolescent; D000328:Adult; D028023:Arecaceae; D001459:Bangladesh / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D018792:Encephalitis, Viral / Q000453:epidemiology / Q000821:virology*; D005260:Female; D005516:Food Microbiology; D045464:Henipavirus Infections / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D045405:Nipah Virus; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult