Large areas within the Indian capital of Delhi will likely be declared controlled areas after a further 32 horses were diagnosed with the much-feared disease glanders.
The movement of horses, donkeys and mules have been banned in the western part of the city since last December, after seven equines tested positive for the bacterial infection, which is capable of infecting humans.
The declaration of a “controlled area” across a major swathe of the city – covering 11 areas where infected equines were identified – will result in movement limits on all horses, donkeys and mules, including in and out of the city limits.
It is reported that the animals will be restricted to within a 5km radius of their homes.
Officials intend to advertise the restrictions in local media and will be urging people to take precautions around equines.
There are about 2700 equines in Delhi, 2012 animal census figures suggest. They are mostly used for light carriage work, especially for transporting married couples on their wedding day. Some are also used in riding schools. Most are believed to be of the native Marwari breed.
Around 2000 samples from horses in the city were sent to the National Research Centre on Equines for testing after the discovery of the first cases late last year. About half of the results have so far been received, with 32 animals recorded as positive for glanders.
The 11 areas where the infected animals were found will be subject to the planned restrictions.
It is expected that some conditions will be placed on the upcoming Republic Day parade, on January 26, with all participating horses to be screened for symptoms. Each animal will require a health certificate to take part, and no civilian horses will be allowed in the parade area.
To date, no army or police horses have tested positive for the disease, which is caused by the bacterium Burkholderia mallei.
The government is taking samples from people who had contact with affected animals to determine whether they have caught the infection.
Glanders cases have been reported in 12 Indian states in recent years, involving some 200 equines.
It is a life-threatening, notifiable zoonotic disease which can be fatal to both animals and humans.
The highly infectious disease was known from ancient times, and recognized as a horse disease by Hippocrates and Aristotle.
Signs include lung lesions and ulceration of mucous membranes in the respiratory tract. The acute form results in coughing and fever, followed by septicaemia and death within days. In chronic cases, nodules form on the skin and in the nasal passages, eventually ulcerating. Death can result within months, with those surviving acting as carriers.
The only known reservoirs of B. mallei are single-hooved animals, particularly horses. Chronically infected horses can be free of symptoms but may remain highly infectious.
Due to its high death rate and the small number of organisms needed to cause infection, it is considered a potential biological warfare or bioterrorism agent.
It can be transmitted by aerosol and is known to be resistant to multiple antibiotics.
Although glanders has been eradicated from many Western countries, it recently emerged in Asia, the Middle-East, Africa, and South America.
Due to its rareness, little is known about outbreak dynamics of the disease.