Dr. Arshed Iqbal Dar
Zoonoses constitutes an important part of the global public health programme of the world health organization. Zoonotic diseases or zoonoses are diseases shared between animals and humans or we can say, zoonoses are those diseases and infections which are naturally transmitted between vertebrate animals and humans. Zoonoses acts as a multipronged weapon, first by causing fatal diseases in human beings, the second by undermining animal health and productivity and producing a great economic loss to the livestock industry and the third is the most lethal agent and that is the development of zoonotic agents as the weapons of war. World Zoonoses day is observed on July 6 every year to commmemorate the scientific achievement of administrating first vaccination against a zoonotic disease / rabies / Viral Zoonoses by Louis pasteur on July 6, 1885. One of the most important scientific figures, a French Biologist born in 1822 was the Louis Pasteur, who is often regarded as one of the founders of microbiology and is chiefly famous for his discovery of the role that microorganisms play in health and diseases, he is also remembered for the studies on the nature of fermentation, and for refuting the theory of spontaneous generation. He studied fermentation, authenticating that it is a chemical process carried out by microscopic organisms and these findings proved to be a game changer and accord him the knowledge which rebute the myth of spontaneous generation and with the help of these findings he proposed the methodology for preventing the growth of bacteria in food items. While studying an epidemic in silkworm that was disrupting France’s Silk industry, he isolated the microorganisms causing the disruption in the normal structure of silk worms and from these findings he proposed the germ theory or the pathogenic theory of medicine, which simplistically states that many diseases are caused by microorganisms too small to see without magnification and is now a fundamental part of modern medicine and clinical microbiology, leading to such important innovations as antibiotics and hygienic practices. The first human vaccination against a zoonotic disease (rabies) attenuated by exposure to dry air started on July 6, 1885 and was reported in the session of the French Academy of Sciences on October 26, 1885. In his report, Louis Pasteur describes how he started the experiment by taking pieces of spinal cord from a rabid street dog and inoculating by trepanation (a surgical intervention in which a hole is drilled or scrapped into human skull) under the dura-mater into the cranium of a rabbit and then passing it from rabbit to rabbit 20 to 25 times until the virus was consistently virulent. Then he attenuated (weakened) the virus present in the affected pieces of spinal cord of rabbits by exposing them to dry air. Before first human trial, Pasteur experimented his vaccine (suspension of the dehydrated spinal cord) on dogs. In his animal trial, he innoculated approximately 50 dogs with a suspension of the dehydrated spinal cord and had observed that the dogs had become refractory to the innoculation with virulent rabid spinal material. Now, the Pasteur was ready to use his vaccine on humans and on July 6, 1985 three people arrived from Alsace, one of them was Joseph Meister, a nine year old boy, who had been bitten by a dog at 8:00 am on July 4. The boy had atleast 14 bites and his death from rabies seemed inevitable. Since, Pasteur was not a licensed physician and in order to avoid the prosecution, he consulted with Dr. Vulpian and Dr. Grancher (Professor at the faculty of Medicine, University of Paris) and together with them, on July 6, Pasteur innoculated the boy with material from a rabid rabbit spinal cord that had been dehydrated for 15 day. And the first human vaccination against a viral zoonoses (rabies) was accomplished and it opened new vistas in the field of innovations and discoveries.
In drawing things to a close, as we develop strategy to protect the human lives, livestock and crops from zoonotic diseases, we must not forget that we are part of this interconnected system and to develop a strong strategy in protecting our nation from biological warfare agent should be our prime concern.
World Health Organization (WHO) and the Centres for Disease Control and Prevention (CDC) deals with the following major zoonotic diseases: Zoonotic influenza, Salmonellosis, West Nile Virus, Plague, Rabies, Brucellosis, Lyme disease. Anthrax, Avian influenza, Botulism, Brucellosis, Campylobacter, Chagas disease, Chikengunya, Dengue, E.Coli, Echinococcosis, Encephalitis, Food borne trematode infections, Haemorrhagic fevers, Ebola virus disease, Lassa fever, Marburg virus disease, Rift valley fever, Japanese encephalitis, Leishmaniasis, Leptospiroris, Spongiform encephalopathies, Steptococcus suis, Taeniasis/cysticercosis, Variant Creutzfeldt-Jakob disease, Zika virus, Zoonotic Tuberculosis, Emerging Coronaviruses e.g SARS (Severe Acute Respiratory Syndrome), MERS (Middle East Respiratory Syndrome) and the third zoonotic virus after SARS and MERS is SARS-CoV-2 (nCOVID-19). If we talk about Rifat Valley Fever (RVF) which is a viral zoonotic disease mostly seen in domesticated animals such as cattle, buffalo, sheep, goat and camels. Humans get infection through the contact with infected animals and one of the most widely used vaccine (the Smithburn vaccine) is used for controlling RVF in Africa. However, this vaccine is know to cause birth defects and aborations in pregnant livestock and may provide cattle with limited protection from infection with RVF. Moreover, new vaccine candidates are in race and time will decide the efficacy and promising nature of the future vaccine candidates. You know, In India, a lot of zoonotic diseases have been neglected due to many unknown reasons and new zoonotic diseases like Cutaneous Leishmaniasis, Japanese Encephalitis, Leptospirosis and Scrub typhus are spreading to a much wider areas at an alarming rate, which have caused greater annual disease burden on large population of India. To avoid future pandemic like situations, India shouldn’t neglect these zoonotic diseases and dire need is to develop strong strategies and policies to fight against these zoonotic diseases. Since World War 1st , dispute amongst nations, accusations and counter accusations, and the strikes and surgical strikes is escalating the hostility and the interest to develop biological agents as weapons of war is mushrooming at an alarming rate. A majority of the biological agents that have been considered as weapons are zoonotic. The zoonoses often considered in the context of biological warfare include anthrax, brucellosis, various strains of encephalitis-causing viruses, ebola, marburg viruses, histoplasmosis, plague, Q fever, rabies, tularemia etc. Many of these zoonotic agents are well understood scientifically and some novel zoonotic agents are in the race of weapons of war and more importantly the animal species are available which can be used as an animal model to test and alter the virulence of the agent or to serve as a living bioreactor in which to grow zoonotic agents and in future with the advancement in science and technology these zoonotic agents may become the favored target for genetic manipulation or in other words we can say that the testing step of novel biological agents as the weapons of war is in the pipeline. In drawing things to a close, as we develop strategy to protect the human lives, livestock and crops from zoonotic diseases, we must not forget that we are part of this interconnected system and to develop a strong strategy in protecting our nation from biological warfare agent should be our prime concern.
(The author is an Assistant Professor at Govt. Degree College Sumbal Sonawari . Views are his own) [email protected]