title: Social contact patterns in Vietnam and implications for the control of infectious diseases.
abstract: BACKGROUND
  The spread of infectious diseases from person to person is determined by the frequency and nature of contacts between infected and susceptible members of the population. Although there is a long history of using mathematical models to understand these transmission dynamics, there are still remarkably little empirical data on contact behaviors with which to parameterize these models. Even starker is the almost complete absence of data from developing countries. We sought to address this knowledge gap by conducting a household based social contact diary in rural Vietnam.
  
  
  RESULTS
  A diary based survey of social contact patterns was conducted in a household-structured community cohort in North Vietnam in 2007. We used generalized estimating equations to model the number of contacts while taking into account the household sampling design, and used weighting to balance the household size and age distribution towards the Vietnamese population. We recorded 6675 contacts from 865 participants in 264 different households and found that mixing patterns were assortative by age but were more homogenous than observed in a recent European study. We also observed that physical contacts were more concentrated in the home setting in Vietnam than in Europe but the overall level of physical contact was lower. A model of individual versus household vaccination strategies revealed no difference between strategies in the impact on R(0).
  
  
  CONCLUSIONS
  This work is the first to estimate contact patterns relevant to the spread of infections transmitted from person to person by non-sexual routes in a developing country setting. The results show interesting similarities and differences from European data and demonstrate the importance of context specific data.
authors.affiliation: Oxford University Clinical Research Unit, Hanoi, Vietnam. peter.horby@gmail.com
authors.forename: Peter
authors.initials: P
authors.lastname: Horby
authors.forename: Quang Thai
authors.initials: QT
authors.lastname: Pham
authors.forename: Niel
authors.initials: N
authors.lastname: Hens
authors.forename: Thi Thu Yen
authors.initials: TT
authors.lastname: Nguyen
authors.forename: Quynh Mai
authors.initials: QM
authors.lastname: Le
authors.forename: Dinh Thoang
authors.initials: DT
authors.lastname: Dang
authors.forename: Manh Linh
authors.initials: ML
authors.lastname: Nguyen
authors.forename: Thu Huong
authors.initials: TH
authors.lastname: Nguyen
authors.forename: Neal
authors.initials: N
authors.lastname: Alexander
authors.forename: W John
authors.initials: WJ
authors.lastname: Edmunds
authors.forename: Nhu Duong
authors.initials: ND
authors.lastname: Tran
authors.forename: Annette
authors.initials: A
authors.lastname: Fox
authors.forename: Tran Hien
authors.initials: TH
authors.lastname: Nguyen
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D002648:Child; D002675:Child, Preschool; D003140:Communicable Disease Control / Q000379:methods*; D003141:Communicable Diseases / Q000635:transmission*; D003625:Data Collection; D005260:Female; D006798:Housing / Q000706:statistics & numerical data; D006801:Humans; D007114:Immunization; D007223:Infant; D007231:Infant, Newborn; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014744:Vietnam; D055815:Young Adult