Toxocara infection in the United States: the relevance of poverty, geography and demography as risk factors, and implications for estimating county prevalence
To estimate Toxocara infection rates by age, gender and ethnicity for US counties using data from the National Health and Nutrition Examination Survey (NHANES).
After initial analysis to account for missing data, a binary regression model is applied to obtain relative risks of Toxocara infection for 20,396 survey subjects. The regression incorporates interplay between demographic attributes (age, ethnicity and gender), family poverty and geographic context (region, metropolitan status). Prevalence estimates for counties are then made, distinguishing between subpopulations in poverty and not in poverty.
Even after allowing for elevated infection risk associated with poverty, seropositivity is elevated among Black non-Hispanics and other ethnic groups. There are also distinct effects of region. When regression results are translated into county prevalence estimates, the main influences on variation in county rates are percentages of non-Hispanic Blacks and county poverty.
For targeting prevention it is important to assess implications of national survey data for small area prevalence. Using data from NHANES, the study confirms that both individual level risk factors and geographic contextual factors affect chances of Toxocara infection.
KeywordsToxocara infection Poverty Ethnicity Geographic prevalence Bayesian
- Brooke J (1984) 6 Years of canine-waste law: all in all, a cleaner New York, Sect. I. New York Times 25 (16 June)Google Scholar
- Centre for Disease Control (2007) Documentation, codebook, and frequencies; surplus sera laboratory component: antibody to Toxocara larva migrans. NHANES III, Series 11 Data Files 26A. Available via http://www.cdc.gov/nchs/about/major/nhanes/archive_whatsnew.htm. Accessed 30 March 2010
- Graubard B, Korn E, Midthune D (1997) Testing goodness-of-fit for logistic regression with survey data. In: Proceedings of the section on survey research methods. American Statistical Association, Alexandria, pp 170–174Google Scholar
- Hotez P (2007) Neglected diseases and poverty in ‘‘the other America’’: the greatest health disparity in the United States? PLoS Negl Trop Dis 1(3):e149. doi: 10.1371/journal.pntd.0000149
- Hotez P (2008) Neglected infections of poverty in the United States of America. PLoS Negl Trop Dis 2(6):e256. doi: 10.1371/journal.pntd.0000256
- Hotez P, Wilkins P (2009) Toxocariasis: America’s most common neglected infection of poverty and a helminthiasis of global importance? PLoS Negl Trop Dis 3(3):e400. doi: 10.1371/journal.pntd.0000400
- Mizgajskaa H (2001) Eggs of Toxocara in the environment and their public health implications. J Helminthol 75:147–151Google Scholar
- Morenoff J, Lynch J (2004) What makes a place healthy? Neighborhood influences on racial/ethnic disparities in health over the life course. In: Anderson N, Bulatao R, Cohen B (eds) Critical perspectives on racial and ethnic differences in health in late life. National Academy Press, Washington, DC, pp 406–449Google Scholar
- Plaut M, Zimmerman E, Goldstein R (1996) Health hazards to humans associated with domesticated pets. Annu Rev Pub Health 17:221–215Google Scholar
- Tolan M, Laufer R (2009) Toxocariasis: an overview. eMedicine (Parasitology). Available via http://emedicine.medscape.com/article/999850-overview Accessed 30 March 2010
- United States Department of Agriculture (USDA) (2004) Rural poverty at a glance. Rural Development Research Report Number 100, USDA Economic Research Service, Washington, DCGoogle Scholar