title: Incidence and seasonality of hypothermia among newborns in southern Nepal.
abstract: OBJECTIVE
  To quantify incidence, age distribution, and seasonality of neonatal hypothermia among a large population cohort.
  
  
  METHODS
  Longitudinal cohort study.
  
  
  METHODS
  Sarlahi, Nepal.
  
  
  METHODS
  A total of 23 240 newborns born between September 2, 2002, and February 1, 2006. Main Exposures Community-based workers recorded axillary temperature on days 1 through 4, 6, 8, 10, 12, 14, 21, and 28 (213 636 total measurements).
  
  
  METHODS
  Regression smoothing was used to describe axillary temperature patterns during the newborn period. Hypothermia incidence in the first day, week, and month were estimated using standard cutoffs. Ambient temperatures allowed comparison of mild hypothermia (36.0 degrees C to <36.5 degrees C) and moderate or severe hypothermia (<36.0 degrees C) incidence over mean ambient temperature quintiles.
  
  
  RESULTS
  Measurements lower than 36.5 degrees C were observed in 21 459 babies (92.3%); half (48.6%) had moderate or severe hypothermia, and risk peaked in the first 24 to 72 hours of life. Risk of moderate or severe hypothermia increased by 41.3% (95% confidence interval, 40.0%-42.7%) for every 5 degrees C decrease in average ambient temperature. Relative to the highest quintile, risk was 4.03 (95% confidence interval, 3.77-4.30) times higher among babies exposed to the lowest quintile of average ambient temperature. In the hot season, one-fifth of the babies (18.2%) were observed below the moderate hypothermia cutoff.
  
  
  CONCLUSIONS
  Mild or moderate hypothermia was nearly universal, with substantially higher risk in the cold season. However, incidence in the hot season was also high; thus, year-round thermal care promotion is required. Research on community, household, and caretaker practices associated with hypothermia can guide behavioral interventions to reduce risk.
authors.affiliation: International Center for Advancing Neonatal Health, Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, 615 N Wolfe St, Ste E8646, Baltimore, MD 21205,USA. lmullany@jhsph.edu
authors.forename: Luke C
authors.initials: LC
authors.lastname: Mullany
authors.forename: Joanne
authors.initials: J
authors.lastname: Katz
authors.forename: Subarna K
authors.initials: SK
authors.lastname: Khatry
authors.forename: Steven C
authors.initials: SC
authors.lastname: Leclerq
authors.forename: Gary L
authors.initials: GL
authors.lastname: Darmstadt
authors.forename: James M
authors.initials: JM
authors.lastname: Tielsch
mesh_terms: D017677:Age Distribution; D005260:Female; D006801:Humans; D007035:Hypothermia / Q000453:epidemiology*; D015994:Incidence; D007231:Infant, Newborn; D008297:Male; D009390:Nepal / Q000453:epidemiology; D012424:Rural Population / Q000706:statistics & numerical data; D012621:Seasons