The tests used for detecting<unk>  vary considerably, as do the regulations in various jurisdictions for when, and which cattle, must be tested. For instance in the EU, the cattle tested are older (30 months or older), while many cattle are slaughtered younger than that. At the opposite end of the scale, Japan tests all cattle at the time of slaughter. Tests are also difficult, as the altered prion protein has very low levels in blood or urine, and no other signal has been found. Newer tests are faster, more sensitive, and cheaper, so future figures possibly may be more comprehensive. Even so, currently the only reliable test is examination of tissues during a necropsy. As for vCJD in humans, autopsy tests are not always done, so those figures, too, are likely to be too low, but probably by a lesser fraction. In the United Kingdom, anyone with possible vCJD symptoms must be reported to the Creutzfeldt–Jakob Disease Surveillance Unit. In the United States, the CDC has refused to impose a national requirement that physicians and hospitals report cases of the disease. Instead, the agency relies on other methods, including death certificates and urging physicians to send suspicious cases to the National Prion Disease Pathology Surveillance Center (NPDPSC) at Case Western Reserve University in Cleveland, which is funded by the CDC. To control potential transmission of vCJD within the United States, the FDA had established strict restrictions on individuals' eligibility to donate blood. Individuals who had spent a cumulative time of 3 months or more in the United Kingdom between 1980 and 1996, or a cumulative time of 5 years or more from 1980 to 2020 in any combination of countries in Europe, were prohibited from donating blood. Due to blood shortages associated with the 2020 COVID-19 outbreak, the FDA announced that these restrictions were rescinded effective immediately. They are expected to remain rescinded indefinitely. Similar rules also apply in Australia for any British expats. Anyone who lived in the UK between 1980 and 1996 for longer than 6 months is prohibited from giving blood. There are also prohibitions on donating breast milk and tissue. This is partly because there is no appropriate screening test that donation centres can use. However, there are no restrictions on organ donation. Some blood donation organisations considered relaxing the rules after the COVID-19 pandemic and some natural disasters that depleted the blood supply. North America The first reported case in North America was in December 1993 from Alberta, Canada. Another Canadian case was reported in May 2003. The first known U.S. occurrence came in December of the same year, but it was later confirmed to be a cow of Canadian origin imported to the U.S. The cow was slaughtered on a farm near Yakima, Washington. The cow was included in the United States Department of Agriculture's surveillance programme, specifically targeting cattle with<unk> . Canada announced two additional cases of<unk>  from Alberta in early 2005. In June 2005, John R. Clifford, chief veterinary officer for the United States Department of Agriculture Animal and Plant Health Inspection Service, confirmed a fully domestic case of<unk>  in Texas. United States Soybean meal is cheap and plentiful in the United States, and cottonseed meal (1.5 million tons of which are produced in the U.S. every year, none of which is suitable for humans or any other simple-stomach animals) is even cheaper than soybean meal. Historically, meat and bone meal, blood meal, and meat scraps have almost always commanded a higher price as a feed additive than oilseed meals in the U.S., so not much incentive existed to use animal products to feed ruminants. As a result, the use of animal byproduct feeds was never common, as it was in Europe. However, U.S. regulations only partially prohibited the use of animal byproducts in feed. In 1997, regulations prohibited the feeding of mammalian byproducts to ruminants such as cattle and goats. However, the byproducts of ruminants can still be legally fed to pets or other livestock, including pigs and poultry. In addition, it is legal for ruminants to be fed byproducts from some of these animals. Because of this, some authors have suggested that under certain conditions, it is still possible for<unk>  incidence to increase in U.S. cattle. In February 2001, the US Government Accountability Office reported the FDA, which is responsible for regulating feed, had not adequately enforced the various bans. Compliance with the regulations was shown to be extremely poor before the discovery of the cow in Washington infected with<unk>  in 2003, but industry representatives report that compliance is now total. Even so, critics call the partial prohibitions insufficient. US meat producer Creekstone Farms was forcibly prevented from conducting<unk>  testing by the USDA, which under an obscure 1913 law had the authority to restrict sales of<unk>  testing kits, allegedly to protect other producers from being forced to conduct the same tests to stay competitive. The USDA has issued recalls of beef supplies that involved introduction of downer cows into the food supply. Hallmark/Westland Meat Packing Company was found to have used electric shocks to prod downer cows into the slaughtering system in 2007. Possibly due to pressure from large agribusiness, the United States has drastically cut back on the number of cows inspected for<unk> . Effect on the US beef industry Japan was the top importer of US beef, buying $1.7 billion worth in 2003. After the discovery of the first case of<unk>  in the US on 23 December 2003, Japan halted US beef imports. In December 2005, Japan once again allowed imports of US beef, but reinstated its ban in January 2006 after a violation of the US-Japan beef import agreement: a vertebral column, which should have been removed prior to shipment, was included in a shipment of veal. Tokyo yielded to US pressure to resume imports, ignoring consumer worries about the safety of US beef, said Japanese consumer groups. Michiko Kamiyama from Food Safety Citizen Watch and Yoko Tomiyama from Consumers Union of Japan said about this: "The government has put priority on the political schedule between the two countries, not on food safety or human health." Sixty-five nations implemented full or partial restrictions on importing US beef products because of concerns that US testing lacked sufficient rigor. As a result, exports of US beef declined from 1,300,000 tonnes (t) in 2003, (before the first mad cow was detected in the US) to 322,000 t in 2004. This has increased since then to 771,000 t in 2007 and to 1,300,000 t by 2017. On 31 December 2006, Hematech Inc, a biotechnology company based in Sioux Falls, South Dakota, announced it had used genetic engineering and cloning technology to produce cattle that lacked a necessary gene for prion production – thus theoretically making them immune to<unk> . In April 2012, some South Korean retailers ceased importing beef from the United States after a case of<unk>  was reported. Indonesia also suspended imports of beef from the US after a dairy cow with mad cow disease was discovered in California. Japan With 36 confirmed cases, Japan experienced one of the largest number of cases of<unk>  outside Europe. It was the only country outside Europe and the Americas to report non-imported cases. Reformation of food safety in light of the<unk>  cases resulted in the establishment of a governmental Food Safety Commission in 2003. Europe Evolution of the<unk>  <unk>  epidemic in the UK. Cattle are naturally herbivores, eating grasses. In modern industrial cattle-farming, though, various commercial feeds are used, which may contain ingredients including antibiotics, hormones, pesticides, fertilizers, and protein supplements. The use of meat and bone meal, produced from the ground and cooked leftovers of the slaughtering process, as well as from the carcasses of sick and injured animals such as cattle or sheep, as a protein supplement in cattle feed was widespread in Europe prior to about 1987. Worldwide, soybean meal is the primary plant-based protein supplement fed to cattle. However, soybeans do not grow well in Europe, so cattle raisers throughout Europe turned to the cheaper animal byproduct feeds as an alternative. The British Inquiry dismissed suggestions that changes to processing might have increased the infectious agents in cattle feed, saying, "changes in process could not have been solely responsible for the emergence of<unk> , and changes in regulation were not a factor at all." (The prion causing<unk>  is not destroyed by food heat treatment.) The first confirmed instance in which an animal fell ill with the disease occurred in 1986 in the United Kingdom, and lab tests the following year indicated the presence of<unk> ; by November 1987, the British Ministry of Agriculture accepted it had a new disease on its hands. Subsequently, 177 people (as of June 2014) contracted and died of a disease with similar neurological symptoms subsequently called (new) variant Creutzfeldt–Jakob disease (vCJD). This is a separate disease from 'classical' Creutzfeldt–Jakob disease, which is not related to<unk>  and has been
Bovine spongiform encephalopathy
Variant Creutzfeldt–Jakob disease
Creutzfeldt–Jakob disease
Powassan encephalitis
Saint Louis encephalitis
Eastern equine encephalitis
Japanese encephalitis
Viliuisk encephalomyelitis