title: Human H5N1 influenza infections in Cambodia 2005-2011: case series and cost-of-illness.
abstract: BACKGROUND
  Southeast Asia has been identified as a potential epicentre of emerging diseases with pandemic capacity, including highly pathogenic influenza. Cambodia in particular has the potential for high rates of avoidable deaths from pandemic influenza due to large gaps in health system resources. This study seeks to better understand the course and cost-of-illness for cases of highly pathogenic avian influenza in Cambodia.
  
  
  METHODS
  We studied the 18 laboratory-confirmed cases of avian influenza subtype H5N1 identified in Cambodia between January 2005 and August 2011. Medical records for all patients were reviewed to extract information on patient characteristics, travel to hospital, time to admission, diagnostic testing, treatment and disease outcomes. Further data related to costs was collected through interviews with key informants at district and provincial hospitals, the Ministry of Health and non-governmental organisations. An ingredient-based approach was used to estimate the total economic cost for each study patient. Costing was conducted from a societal perspective and included both financial and opportunity costs to the patient or carer. Sensitivity analysis was undertaken to evaluate potential change or variation in the cost-of-illness.
  
  
  RESULTS
  Of the 18 patients studied, 11 (61%) were under the age of 18 years. The majority of patients (16, 89%) died, eight (44%) within 24 hours of hospital admission. There was an average delay of seven days between symptom onset and hospitalisation with patients travelling an average of 148 kilometres (8-476 km) to the admitting hospital. Five patients were treated with oseltamivir of whom two received the recommended dose. For the 16 patients who received all their treatment in Cambodia the average per patient cost of H5N1 influenza illness was US$300 of which 85.0% comprised direct medical provider costs, including diagnostic testing (41.2%), pharmaceuticals (28.4%), hospitalisation (10.4%), oxygen (4.4%) and outpatient consultations (0.6%). Patient or family costs were US$45 per patient (15.0%) of total economic cost.
  
  
  CONCLUSIONS
  Cases of avian influenza in Cambodia were characterised by delays in hospitalisation, deficiencies in some aspects of treatment and a high fatality rate. The costs associated with medical care, particularly diagnostic testing and pharmaceutical therapy, were major contributors to the relatively high cost-of-illness.
authors.affiliation: Communicable Disease Policy Research Group, London School of Hygiene & Tropical Medicine, Faculty of Public Health, 9th Fl, Satharanasukwisit Building, 420/1 Rajvithi Road, Bangkok 10400 Thailand. karen@cdprg.org.
authors.forename: Karen
authors.initials: K
authors.lastname: Humphries-Waa
authors.forename: Tom
authors.initials: T
authors.lastname: Drake
authors.forename: Anthony
authors.initials: A
authors.lastname: Huszar
authors.forename: Marco
authors.initials: M
authors.lastname: Liverani
authors.forename: Khieu
authors.initials: K
authors.lastname: Borin
authors.forename: Sok
authors.initials: S
authors.lastname: Touch
authors.forename: Teng
authors.initials: T
authors.lastname: Srey
authors.forename: Richard
authors.initials: R
authors.lastname: Coker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002160:Cambodia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D017281:Cost of Illness; D005260:Female; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007223:Infant; D053124:Influenza A Virus, H5N1 Subtype; D007251:Influenza, Human / Q000191:economics / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged