Of the seven serotypes of this virus, A, C, O, Asia 1, and SAT3 appear to be distinct lineages; SAT 1 and SAT 2 are unresolved clades. The mutation rate of the protein-encoding sequences of strains isolated between 1932 and 2007 has been estimated to be 1.46 × 10−3 substitutions/site/year, a rate similar to that of other RNA viruses. The most recent common ancestor appears to have evolved about 481 years ago (early 16th century). This ancestor then diverged into two clades which have given rise to the extant circulating Euro-Asiatic and<unk>  African. SAT 1 diverged first 397 years ago, followed by sequential divergence of serotype SAT 2 (396 years ago), A (147 years ago), O (121 years ago), Asia 1 (89 years ago), C (86 years ago), and SAT 3 (83 years ago). Bayesian skyline plot reveals a population expansion in the early 20th century that is followed by a rapid decline in population size from the late 20th century to the present day. Within each serotype, there was no apparent periodic, geographic, or host species influence on the evolution of global<unk>  viruses. At least seven genotypes of serotype Asia 1 are known. Transmission The<unk>  virus can be transmitted in a number of ways, including close-contact, animal-to-animal spread, long-distance aerosol spread and fomites, or inanimate objects, typically fodder and motor vehicles. The clothes and skin of animal handlers such as farmers, standing water, and uncooked food scraps and feed supplements containing infected animal products can harbor the virus, as well. Cows can also catch<unk>  from the semen of infected bulls. Control measures include quarantine and destruction of both infected and healthy (uninfected) livestock, and export bans for meat and other animal products to countries not infected with the disease. There is significant variation in both susceptibility to infection and ability to spread disease between different species, virus strains, and transmission routes. For example, cattle are far more vulnerable than pigs to infection with aerosolized virus, and infected pigs produce 30 times the amount of aerosolized virus compared to infected cattle and sheep. Also, pigs are particularly vulnerable to infection through the oral route. It has been demonstrated experimentally that<unk>  can be spread to pigs when they eat commercial feed products contaminated by the<unk>  virus. Also, the virus can remain active for extended periods of time in certain feed ingredients, especially soybean meal. Feed biosecurity practices have become an important area of study since a 2013 outbreak of Porcine Epidemic Diarrhea Virus (PEDV) in the US, thought to be introduced through contaminated feed. Just as humans may spread the disease by carrying the virus on their clothes and bodies, animals that are not susceptible to the disease may still aid in spreading it. This was the case in Canada in 1952, when an outbreak flared up again after dogs had carried off bones from dead animals. Wolves are thought to play a similar role in the former Soviet Union. Daniel Rossouw Kannemeyer (1843–1925) published a note in the Transactions of the<unk>  African Philosophical Society volume 8 part 1 in which he links saliva-covered locusts with the spread of the disease. Transmission of the<unk>  virus is possible before an animal has apparent signs of disease, a factor that increases the risk that significant spread of the virus has occurred before an outbreak is detected. A 2011 experiment measured transmission timing in cattle infected with serotype O virus by exposing susceptible cattle in 24-hour increments. It estimated the infectious period of the infected cattle to be 1.7 days, but showed the cattle were only infectious for a few hours before they developed fevers or classic<unk>  lesions. The authors also showed that the infectious period would have been estimated to be much higher (4.2 to 8.2 days) if detection of virus had been used as a substitute for infectiousness. A similar 2016 experiment using serotype A virus exposed susceptible pigs to infected pigs for 8 hour periods and found that pigs were able to spread disease for a full day before developing signs of disease. Analysis of this experimental data estimated the infectious period to be approximately 7 days. Again, the study showed that detection of virus was not an accurate substitution for infectiousness. An accurate understanding of the parameters of infectiousness is an important component of building epidemiological models which inform disease control strategies and policies. Infecting humans Humans can be infected with<unk>  through contact with infected animals, but this is extremely rare. Some cases were caused by laboratory accidents. Because the virus that causes<unk>  is sensitive to stomach acid, it cannot spread to humans via consumption of infected meat, except in the<unk>  before the meat is swallowed. In the UK, the last confirmed human case occurred in 1966, and only a few other cases have been recorded in countries of continental Europe, Africa, and<unk>  America. Symptoms of<unk>  in humans include malaise, fever, vomiting, red ulcerative lesions (surface-eroding damaged spots) of the oral tissues, and sometimes vesicular lesions (small blisters) of the skin. According to a newspaper report,<unk>  killed two children in England in 1884, supposedly due to infected milk. Another viral disease with similar symptoms, hand,<unk>  and<unk>  disease, occurs more frequently in humans, especially in young children; the cause, Coxsackie A virus, is different from the<unk>  virus. Coxsackie viruses belong to the Enteroviruses within the Picornaviridae. Because<unk>  rarely infects humans, but spreads rapidly among animals, it is a much greater threat to the agriculture industry than to human health. Farmers around the world can lose enormous amounts of money during a<unk> -and-mouth epizootic, when large numbers of animals are destroyed, and revenues from milk and meat production go down.
Foot-and-mouth disease
Tongue disease
Plague 
Chickenpox
Polymeal
Sealpox
Shingles
Mumps