Cysticercosis in the United States: A Nationwide Hospitalization Study Assessing Burden of Disease, Fatality Risk Factors and Economic Impact of Infection
Background: Cysticercosis, an infection caused by the larval stage of the pork tapeworm Taenia solium, has become increasingly important both in the United States and globally in recent decades. Neurocysticercosis is one of the most common parasitic diseases of the human nervous system and a leading cause of acquired epilepsy worldwide. Despite its potential impact, there is a lack of comprehensive information on cysticercosis infection in the US. This study was designed to estimate the impact of cysticercosis nationwide, in terms of the number of people hospitalized and the economic burden of hospitalizations, as well as explore potential risk factors for cysticercosis in-hospital fatality. Methods: The Nationwide Inpatient Sample (NIS), representing a 20% sample of annual hospital discharge records in the US, was used for analysis from 1998-2009. National estimates of cysticercosis-related hospitalizations and rates, patient and hospital stay characteristics, and hospitalization-related charges were calculated using NIS sample weights and US Census Bureau data. Risk factors for fatality were evaluated using bivariate and multivariate logistic regression. Results: There were 28,565 cysticercosis-related hospitalizations nationwide estimated during the study period, representing a hospitalization rate of 8.16 per million population. The highest proportion of cases were reported in males, Hispanic populations, hospitals in the West and among patients aged 18-44, consistent with previous studies. There were 364 total in-hospital deaths estimated, representing an overall case-fatality rate of 1.28% and a nationwide in-hospital mortality rate of 0.1 deaths per million population. National estimates of associated charges among cysticercosis-related hospitalizations amounted to approximately $996 million. Male sex, hospital location in the West, shunting procedures and diagnoses of obstructive hydrocephalus were associated with in-hospital fatality in bivariate regression analysis (OR: 1.18, 2.36, 1.79 and 2.85 respectively). Discussion: National estimates of cases, deaths and associated charges reinforce the importance of cysticercosis in the US. Despite improvements in management strategies, the burden of cysticercosis-related hospitalizations remains substantial, indicating the need for significant progress towards reducing infection nationwide. Increased surveillance and identification of cases can serve to better define the burden of disease, potentially allowing for targeted prevention and control campaigns in populations at greatest risk.