Cysticercosis-Related Deaths, California

Frank J. Sorvillo; Lawrence Portigal; Christopher DeGiorgio; Lisa Smith; Stephen H. Waterman; George W. Berlin; Lawrence R. Ash


Emerging Infectious Diseases. 2004;10(3) 

In This Article

Abstract and Introduction

Cysticercosis is an increasingly important disease in the United States, but information on the occurrence of related deaths is limited. We examined data from California death certificates for the 12-year period 1989-2000. A total of 124 cysticercosis deaths were identified, representing a crude 12-year death rate of 3.9 per million population (95% confidence interval [CI] 3.2 to 4.6). Eighty-two (66%) of the case-patients were male; 42 (34%) were female. The median age at death was 34.5 years (range 7-81 years). Most patients (107, 86.3%) were foreign-born, and 90 (72.6%) had emigrated from Mexico. Seventeen (13.7%) deaths occurred in U.S.-born residents. Cysticercosis death rates were higher in Latino residents of California (13.0/106) than in other racial/ethnic groups (0.4/106), in males (5.2/10 6) than in females (2.7/106), and in persons >14 years of age (5.0/106). Cysticercosis is a preventable cause of premature death, particularly among young Latino persons in California and may be a more common cause of death in the United States than previously recognized.

Cysticercosis, an infection caused by the larval form of the pork tapeworm, Taenia solium, is recognized as an increasingly important cause of severe neurologic disease in the United States.[1,2,3] In the typical transmission cycle, eggs from the adult tapeworm are shed in the feces of a human carrier and subsequently ingested by pigs, the usual intermediate host.[4] Larvae emerge from the eggs, penetrate the intestinal mucosa and disseminate through the bloodstream to various tissues where the larval stage or cysticercus develops. The cycle is completed when humans, the only naturally infected definitive host, consume raw or undercooked pork containing cysticerci, which attach to the small bowel and develop into adult tapeworms, thereby completing the cycle. However, humans may also become infected with the larval stage when eggs, which are directly infectious, are ingested, typically through contaminated food or water. Neurocysticercosis, the most severe form of the disease, occurs when larvae invade tissue of the central nervous system. While cysticercosis in the United States principally affects immigrants from cysticercosis-endemic areas of Latin America, it has been increasingly recognized in U.S.-born residents as well.[5,6,7]

Despite the growing importance of cysticercosis, surveillance systems for cysticercosis have rarely been implemented,[6,8] and the true impact of the disease in the United States is largely unknown. Although several case series have been published,[1,2,9,10,11] these have been facility-based efforts and, consequently, may not provide an accurate measure of either the incidence or severity of the disease. Such facility-based reports have suggested that deaths from cysticercosis in the United States are uncommon. Although population-based data would provide a more accurate assessment of cysticercosis death rates, such data are scarce. To measure cysticercosis-related death rates in California, we reviewed state mortality records for the 12-year period 1989-2000.