An Economic and Social Analysis of La Crosse Encephalitis in North Carolina
Utz, John Todd. An economic and social analysis of La Crosse encephalitis in North Carolina. (Under the direction of Charles S. Apperson)
La Crosse encephalitis (LACE), a viral illness vectored by mosquitoes, is endemic in western North Carolina. Clinical manifestations of La Crosse (LAC) virus infection range from mild fever to aseptic meningitis or frank encephalitis. Due to non-specific or sub-clinical symptoms and the absence of an accurate, timely diagnostic tool, the true incidence of LAC virus infection is unknown for the endemic foci of the illness. To estimate the socioeconomic burden of LACE in North Carolina, interviews of serologically confirmed LACE patients or the parent(s)/guardian(s) of the case patients were conducted. The estimated burden of LACE was divided into three categories: direct medical costs; indirect medical costs; and social costs. Direct medical cost is the dollar value associated with medical treatment and rehabilitation for LACE. Indirect medical costs refer to any lost income and/or expense required that is not involved in treatment or rehabilitation of a person with LACE. Social costs were measured with Disability Adjusted Life Years (DALYs) and the Impact of La Crosse Encephalitis Scale (ILCES). DALYs are a non-monetary estimate of productive life years lost due to an illness or health event, while ILCES scores measure the affect of LACE on the overall emotional and social well being of the case patient and family. Participants exhibited three severities of LACE: frank encephalitis with no sequelae (n = 4); frank encephalitis with limited sequelae (n = 16); and frank encephalitis with lifetime sequelae (n = 5). The total cumulative time of study, date of onset of LACE to date of interview, for all case patients within the three disease severity classes was 100.59 life years.
The total direct and indirect medical costs associated with LACE for 100.59 life years of the 25 patients with frank encephalitis was $794,303, ranging from $7,521 - 175,586 for individual case patients. On average, the direct and indirect medical costs of a single case of LACE were $32,974 (± SD = 34,793, n = 25). The projected cost of a case of LACE with lifetime neurological sequelae ranged from $48,775 to $3,224,831 (n = 5), depending on severity of sequelae. Quantitative and qualitative measures of the socioeconomic burden of LACE are included in the analyses to create an estimate addressing both the economic and social impacts of LACE on the family. For the 25 LACE patients, 55.19 of 100.59 life years (54.83%) were impaired to some degree. Along with impaired life years, approximately 13.00 DALYs were accumulated for the 25 patients over 100.59 life years of study. ILCES scores demonstrate the majority of the social burden is borne by patients with lifetime, neurological sequelae (n = 5). Projected DALY estimates for individual patients with lifetime neurological sequelae ranged from 12.90 ? 72.37 DALYs, depending on DALY type and estimated life expectancy used. The socioeconomic burden resulting from LACE is substantial, which highlights the importance of the illness in western North Carolina, as well as the need for active surveillance and prevention programs for the vector/virus complex.
Advisor:Charles S. Apperson; V. Kerry Smith; J. Newt MacCormack; D. Wes Watson
School:North Carolina State University
School Location:USA - North Carolina
Source Type:Master's Thesis
Date of Publication:11/04/2002