title: Estimating the Burden of Snakebite on Public Hospitals in KwaZulu Natal, South Africa.
abstract: OBJECTIVE
  We propose a formula as a means to estimate the number and incidence of snakebites treated per annum in KwaZulu Natal (KZN), South Africa.
  
  
  METHODS
  Using an unvalidated formula that includes an antivenom ratio, we crudely estimated the total number of snakebite presentations in KZN. Using antivenom supply data from the central pharmacy, we stratified a sample of 6 hospitals that were surveyed to establish an antivenom ratio, that is, the total number of patients receiving antivenom to the total number of snakebite presentations at hospitals. The antivenom ratio and the average number of antivenom vials for treated snakebites were incorporated into a formula to crudely estimate the number of snakebite presentations. This was then applied to all public hospitals and districts in the region.
  
  
  RESULTS
  Seventy-eight percent of public hospitals were included. The mean antivenom ratio derived from the sample hospitals indicated that 12% (95% CI, 10-14%) of snakebite presentations received antivenom. We estimated an annual total of 1680 (95% CI, 1193-2357) snakebite presentations to hospitals. Two thirds of cases (1109 of 1680) were in the low-lying subtropical coastal region. Few cases were in the higher, cooler regions of KZN (87 of 1680) or the metropolitan city of Durban (93 of 1680). The overall incidence for KZN was 16/100,000. The estimated cost of snakebite in KZN was between $1,156,930 and $2,827,848.
  
  
  CONCLUSIONS
  We propose an alternative method to estimate the annual number of snakebite presentations to hospitals.
authors.affiliation: Nelson Mandela School of Clinical Medicine (Drs Wood and Hift); Ngwelezane Hospital (Dr Wood), KwaZulu Natal, South Africa. Electronic address: darrylrwood@yahoo.co.uk.
authors.forename: Wood
authors.initials: W
authors.lastname: Darryl
authors.affiliation: School of Public Health (Dr Sartorius), University of KwaZulu Natal.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sartorius
authors.affiliation: Nelson Mandela School of Clinical Medicine (Drs Wood and Hift).
authors.forename: Richard
authors.initials: R
authors.lastname: Hift
mesh_terms: D000997:Antivenins / Q000627:therapeutic use*; D006779:Hospitals, Public / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D012909:Snake Bites / Q000453:epidemiology* / Q000209:etiology; D013019:South Africa / Q000453:epidemiology
chemical_list: D000997:Antivenins
keywords: KwaZulu Natal; South Africa; antivenom; antivenom ratio; costs; distribution; incidence; mortality; snakebite