DO you know Glanders? Let's have a bird's eye view on this imperative disease. It is a serious zoonotic bacterial disease of the respiratory tract and skin, affecting mainly equids. It dates back to relic, described in Graeco-Roman times, and has caused heavy losses of horses down the centuries.
Two forms of the disease caused by bacteria, Burkholderia mallei. The disease is called "Glanders" when the principal lesions are seen in the nostrils, submaxillary glands and lungs: "Farcy" when located on the surface of limbs or body. Horses, mules and donkeys are the species most often affected. Horses tend to be chronically affected, whereas donkeys and mules get the disease in the acute form.
Apparently recovered animals remain carriers.
Infection occurs by ingestion, leading to blood infection localised in the lungs, and also in the skin and the mucous membrane of the nasal passage. Humans can be infected from affected horses by inoculation through a wound. If untreated, the mortality rate in humans is as high as 95 percent.
Although rare and sporadic, human transmission of Glanders in its natural form occurs in individuals with close and frequent contact with infected animals, such as veterinarians, animal caretakers, and laboratory personnel. The low rate of human transmission is still not understood.
There are three routes of infection by the bacteria. In the localised form, bacteria enter through skin by way of a cut or abrasion.
The most likely bioweapon use of glanders would be an aerosolised form, causing pulmonary infection in those who inhaled the bacteria. glanders is deadly if it gets into the bloodstream.
Because of fatal and transmittable nature of the disease, B. mallei was considered as an ideal agent for bioterrorism.
What is bioterrorism? Terrorism using biologic agents. Biological diseases and the agents that might be used for terrorism have been listed by the US Centers for Disease Control and Prevention (CDC). The list includes a sizable number of "select agents" - potential weapons whose transfer in the scientific and medical communities is regulated to keep them out of unfriendly hands. These "select agents" are very varied.
They comprise viruses, bacteria, rickettsiae (micro-organisms that have traits common to both bacteria and viruses), fungi and biological toxins.
The CDC has classified all of these "select agents" according to the degree of danger each agent is felt to pose into one of three categories.
The glanders is placed in category "B". It is not surprising that it was used by Germany in World War first, Japanese in World War second, and Soviet Union employed it as biological weapon in Afghanistan against Mujaheddin and their horses, which served their main mode of transportation in remote areas. Russia (former USSR) has also grown 2000 tons of B. mallei but did not weaponize it.
This disastrous disease has been eradicated from the Great Britain by rigorous implementation of test and slaughter policy (Glanders and Farcy Act) in 1928, the United States in 1934, Canada in 1938, Western Europe in 1965 and from North Africa in 1996.
In addition, eradication campaign was also augmented by motorization which has decreased the utilisation of equines as transport animals. However, the disease is still endemic in developing countries like Pakistan, India, Iraq, China, Iran, United Arab Emirates.
The true incidence of the disease in these countries remains unknown. Of the 155 countries, which reported to OIE, the glanders was present only in Pakistan, Brazil and Mongolia. Because of lack of stern implementation of Glanders and Farcy Act 1899, glanders is of major concern in Pakistan, wherein it is considerably distributed, has high incidence in endemic areas and affects all ages and breeds of equines.
There are currently no vaccines available for glanders. In countries where glanders is common in animals, the only prevention methods available are identification and elimination of the infection in animal populations.
Recently an outbreak at Lahore Polo Club was reported. This situation compelled the scientists to develop an effective, rapid and sensitive method for identification of diseased animals.
Many diagnostic tests are available but mallein test is considered as a legitimately certified test.
Considering the critical situation, the scientists at the Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad have developed a modified sero-diagnostic test "Rose Bengal plate agglutination test (RBT)" for first time to diagnose equine glanders.
This test was found to be more efficient than the certified standard (mallein) test and successfully fulfilled all other standard evaluation parameters. Results can be observed within 3 minutes instead of the other test mallein which took 24-36 hours for result interpretation.
To this end, RBT proved to be economical, rapid, and can be a good test to replace other time taking and laborious test like mallein.
It would be a novel approach horizon concerning diagnosis of this deadly disease.
(Researchers are Dr Abeera Naureen (Ph.D Scholar) and Dr Ghulam Muhammad (Associate Professor) Department of Clinical Medicine and Surgery, University of Agriculture, Faisalabad.)
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