Understanding Foot-and-Mouth Disease: History, Transmission, and Prevention Measures

Foot-and-mouth disease (FMD) is a highly contagious viral infection that primarily affects cloven-hoofed animals, including cattle, pigs, goats, sheep, and deer. While humans, dogs, and cats are not susceptible to the virus, it poses a significant threat to livestock, often resulting in the culling of infected animals. Historical outbreaks in Austria occurred in 1952 and 1981, with a notable crisis in 1973. Recently, all suspected cases in the country have returned negative results.

Potential Hosts of the Virus
FMD is known to infect various livestock species, including buffalo, elephants, camels, giraffes, and alpacas; however, horses are immune. Although the disease does not directly affect humans, contact with infected animals can occasionally lead to mild infections without severe health implications, according to the Austrian Agency for Health and Food Safety (AGES). Pets such as dogs and cats do not contract FMD but can carry the virus on their fur and contribute to its spread.

Discovery of the Virus
The FMD virus was first identified in 1898 by German bacteriologists Friedrich Loeffler and Paul Frosch, marking a significant milestone in virology. This virus, similar to SARS-CoV-2, contains RNA as its genetic material. It proliferates within host cells, ultimately destroying their membranes and releasing new virions. Remarkably, a single virion is sufficient for infection in susceptible animals.

Global Prevalence
FMD is considered endemic in regions of Africa, Asia, and parts of South America, where cases regularly occur. In Europe, sporadic outbreaks are reported, such as those in the UK in 2001 and 2007. Notably, New Zealand remains free from FMD despite having susceptible animal populations.

Transmission Pathways
The transmission of the FMD virus typically occurs through direct contact or contaminated surfaces, with infected animals capable of spreading the virus to others. The virus can also be transported by humans via contaminated clothing or footwear. Airborne transmission is possible over considerable distances, potentially up to 60 kilometers, as reported by AGES.

Clinical Signs of Infection
Infected animals exhibit clinical signs such as blisters in the mouth, udder, and on hooves, alongside high fever exceeding 40 degrees Celsius. Affected animals may become lethargic, lose their appetite, and experience pain, leading to decreased milk production in lactating females.

Vaccination and Prevention
Currently, preventative vaccination against FMD is prohibited within the European Union, a decision made by the European Commission in 1991 after the disease was successfully eradicated in the region. This policy aids in cost-saving and allows EU producers to export to countries that require imports exclusively from FMD-free zones without vaccination.

To prevent transmission, farmers are advised to wear designated clothing and boots when entering livestock facilities, practicing hand hygiene before and after interactions. Visits to farms during outbreaks should be minimized. No effective treatment exists for infected animals; if FMD is confirmed on a farm, all cloven-hoofed animals must be culled to contain the outbreak.

Diagnosis and Response
Due to the similarity of FMD symptoms to other diseases, expert diagnosis is often inconclusive without laboratory testing. Confirmation or exclusion of FMD relies on laboratory analyses, such as PCR tests or antigen assays. When FMD is suspected, veterinary authorities must enforce immediate quarantines and investigations of the affected farm.

In the event of a positive diagnosis, authorities will close the affected farm, cull all susceptible animals, and dispose of carcasses promptly. Disinfection procedures will be initiated, and a protection zone of at least three kilometers will be established around the outbreak, supplemented by a surveillance zone extending ten kilometers.

Historical Outbreaks in Austria
The last recorded outbreak of FMD in Austria occurred in 1981, affecting only a few animals in Lower Austria. The situation was swiftly contained. However, the crisis in 1973 saw extensive spread throughout Lower Austria, Vienna, and Burgenland, impacting over 1,600 farms and resulting in the culling of approximately 4,500 cattle and 75,000 pigs, among others. Desinfectant 'seuchenteppiche' were deployed around affected areas to mitigate further spread.

Regular surveillance is conducted by AGES to monitor potential outbreaks. In recent years, only a handful of animals have been tested for FMD, with no positive findings among livestock or zoo animals.