vCJD Cases Reported in the US

Four cases of vCJD have been reported from the United States. By convention, variant CJD cases are ascribed to the country of initial symptom onset, regardless of where the exposure occurred. There is strong evidence that suggests that two of the four cases were exposed to the BSE agent in the United Kingdom and that the third was exposed while living in Saudi Arabia. The specific overseas country where the fourth patient’s infection occurred is less clear.

The first patient was born in the United Kingdom in the late 1970’s and lived there until a move to Florida in 1992. The patient had onset of symptoms in November 2001 and died in June of 2004. The patient never donated or received blood, plasma, or organs, never received human growth hormone, nor did the patient ever have major surgery other than having wisdom teeth extracted in 2001. Additionally, there was no family history of CJD.

The second patient resided in Texas during 2001-2005. Symptoms began in early 2005 while the patient was in Texas. He then returned to the United Kingdom, where his illness progressed, and a diagnosis of variant CJD was made. The diagnosis was confirmed neuropathologically at the time of the patient’s death. While living in the United States, the patient had no history of hospitalization, of having invasive medical procedures, or of donation or receipt of blood and blood products. The patient almost certainly acquired the disease in the United Kingdom. He was born in the United Kingdom and lived there throughout the defined period of risk (1980-1996) for human exposure to the agent of bovine spongiform encephalopathy (BSE, commonly known as “mad cow” disease). His stay in the United States was too brief relative to what is known about the incubation period for variant CJD.

The third patient was born and raised in Saudi Arabia and has lived in the United States since late 2005. The patient occasionally stayed in the United States for up to 3 months at a time since 2001 and there was a shorter visit in 1989. The patient’s onset of symptoms occurred in Spring 2006. In late November 2006, the Clinical Prion Research Team at the University of California San Francisco Memory and Aging Center confirmed the vCJD clinical diagnosis by pathologic study of adenoid and brain biopsy tissues. The patient has no history of receipt of blood, a past neurosurgical procedure, or residing in or visiting countries of Europe. Based on the patient’s history, the occurrence of a previously reported Saudi case of vCJD attributed to likely consumption of BSE-contaminated cattle products in Saudi Arabia, and the expected greater than 7 year incubation period for food-related vCJD, this U.S. case-patient was most likely infected from contaminated cattle products consumed as a child when living in Saudi Arabia (1). The patient has no history of donating blood and the public health investigation has identified no known risk of transmission to U.S. residents from this patient.

The fourth patient was a US citizen born outside of the United States. The investigation by CDC and the Texas Department of State Health Services indicated that the patient’s exposure to the BSE/vCJD agent most likely occurred before he moved to the United States; the patient had resided in Kuwait, Russia and Lebanon. The completed investigation did not support the patient’s having had extended travel to European countries, including the United Kingdom, or travel to Saudi Arabia. The specific overseas country where this patient’s infection occurred is less clear than those for the 3 previously reported US cases largely because the investigation did not definitely link him to a country where other known vCJD cases likely had been infected. The patent’s illness first manifested in late 2012 and death occurred 18 months later. The vCJD diagnosis was confirmed on the basis of a biochemical analysis of a urine sample collected late in the patient’s illness and by histopathologic examination of brain tissue obtained at autopsy.